JP2002281202A - Electromagnetic interfering wave reducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means for improving the structure of a case body in which electronic equipment for transmitting an electromagnetic wave whose frequency is high is housed, and for reducing an electromagnetic wave leaking from the case body to the outside. SOLUTION: Electromagnetic equipment 2 such as a reader is arranged in a case body 1 of the scanner unit of a copying machine, and a slit 2 notched from the scanner upper part to side face is formed at the edge of the case body 1. Then, it is possible to prevent the oscillation of the case body itself by an electromagnetic wave, and to lock up the electromagnetic wave inside the case body by the slit 2 formed at the case body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, which prevents electromagnetic waves from leaking out of a housing from a member that generates electromagnetic waves such as a unit used for reading image information. To a device that

[0002]

2. Description of the Related Art In recent years, electromagnetic interference has become a problem as electronic devices become more sophisticated and clocked. Generally, in a scanner that is combined with an image copying apparatus such as a copying machine or a facsimile machine and is arranged in a reading unit of an image of a document, the number of clocks is increased in order to improve image quality.
Leaking electromagnetic noise has become a problem. In the scanner or the image signal processing unit, various protection means have been proposed in order to prevent high-frequency electromagnetic waves leaking from the electronic device from affecting other electronic devices and signal processing / transmission circuits. . For example, JP-A-5-19
In the image forming apparatus as shown in 9340, as shown in FIG. 20, the reading section (scanner) 13 and the signal processing section 35 of the image forming apparatus 10 are housed in a grounded conductive casing 36. In addition, there has been proposed a method of reducing leakage of electromagnetic waves from an electronic device such as the reading unit that emits a large amount of electromagnetic wave noise, and reducing the influence of noise due to the electromagnetic wave on other devices.

[0003]

However, when the frequency for signal processing becomes higher, there is a problem that the housing itself for housing the electronic device or the like oscillates. In particular, the housing of the scanner part of the copier has a reading device with a high clock rate and a signal processing unit inside the housing, and since the glass is structurally fitted on the top of the scanner, it is completely shielded. It is impossible to prevent leakage of electromagnetic waves.

[0004] It is an object of the present invention to improve the configuration of a housing for accommodating an electronic device as described above, and to provide means for reducing leaked electromagnetic waves.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a notch such as a slit is provided in a housing for accommodating a member, such as a scanner, which generates electromagnetic noise, so that the propagation of the electromagnetic wave is interrupted, and the electromagnetic wave noise is reduced. It is to reduce. For this reason, if electronic devices that emit a large amount of electromagnetic waves are placed at the center of the edge of the scanner or at any position on the housing, the case is prevented from resonating with the electromagnetic waves, and as leakage electromagnetic waves. However, electromagnetic interference is reduced.

By forming a slit or the like in the housing, it is possible to reduce electromagnetic noise, without reducing the mechanical strength of the housing, and to form a slit in the housing. Forming such as can be formed at an arbitrary position of a housing such as a scanner, and a housing for housing the electronic device can be easily manufactured.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the apparatus of the present invention will be described with reference to the illustrated example. Examples described below are:
An image forming apparatus equipped with a scanner, such as a copying machine or a facsimile machine, described in the above-described conventional example, in which an electronic device for generating a high-frequency electromagnetic wave is provided inside a metal case will be described. Note that the electronic device described below is not limited to a reading device, but is a device in which a signal processing circuit or other electronic component that generates a high-frequency electromagnetic wave, a circuit, or the like is provided inside a housing. The general can be applied.

FIG. 1 shows an embodiment of the present invention. In the figure, 1 is a housing of a scanner unit of a copying machine,
Reference numeral 2 denotes a slit cut into the edge of the scanner unit from the top to the side of the scanner. The electromagnetic field propagation behavior in the case where no slit is formed in the housing 1 and in the case where a slit is formed are evaluated by simulation using a calculation analysis method called a finite difference time domain method. This is a method of dividing the analysis space into a grid and solving the MAXWELL equation by the difference method. Generally, the behavior of an electromagnetic wave radiated from an object can be calculated if the current distribution in the dynamic time of the object is known. Further, since the near magnetic field generated by the surface current of a certain object is proportional to the intensity of the surface current, if the near magnetic field of a certain object is known, the electromagnetic wave behavior from the certain object can be calculated.

In FIG. 1, a monopole antenna is placed at the position where the reading device 3 is placed by modeling the shape of the housing 1 of the scanner when the slit 2 is not provided.
FIG. 2 shows a magnetic field component in the X direction on the upper surface of the scanner at a certain time when a 500 MHz sine wave is applied.
As shown in FIG. 2, the magnetic field strength is expressed in logarithmic representation, and the brighter the color, the stronger the magnetic field strength. It can be seen that the magnetic field is distributed vertically from the position where the reading device 3 is placed.

Next, in the state where the slit 2 is provided, the shape of the housing 1 of the scanner is modeled, and the reading device 3 is modeled.
Place a monopole antenna at the position where
FIG. 3 shows a magnetic field component in the X direction on the upper surface of the scanner at a certain time when the sine wave is applied. As shown in FIG. 3, it can be seen that the magnetic field component is distributed only below the position where the reading device 3 is placed. By providing the slit 2, when the electronic device 3 is located at the center of the edge of the scanner housing 1, the distribution of the nearby magnetic field is reduced and the radiated electromagnetic wave is reduced. it can.

FIG. 4 shows a second embodiment of the present invention. In the example shown in FIG. 4, the scanner unit of the copying machine is cut from the top to the side of the scanner unit 1 at the edge of the housing. The figure shows a case where a slit 2 is formed and an electronic device 3 such as a reading device is arranged. Is shown. 3
The electronic device such as the reading device is placed as close as possible to the corner of one scanner unit. In FIG. 4, the scanner shape without the slit 2 is modeled, a monopole antenna is placed at the position where the reading device 3 is placed, and a 500 MHz sine wave is applied. The magnetic field component in the direction is almost the same as the example shown in FIG. 2, and a magnetic field distribution with the corner of the scanner as a node is seen.

Next, with the slit 2 provided, the shape of the housing 1 of the scanner is modeled, and a monopole antenna is placed at a position where the reading device 3 is placed.
FIG. 6 shows a magnetic field component in the X direction on the scanner upper surface at a certain time when a sine wave of z is applied. In this case,
It can be seen from the figure that the slit 2 provided in the housing 1 blocks the propagation, and when there is an electronic device at the edge of the scanner, the distribution of the nearby magnetic field decreases and the radiated electromagnetic wave decreases. I understand.

FIG. 6 shows a third embodiment of the present invention, wherein a slit 2 cut from the top to the side of the scanner is formed in the housing 1 of the scanner unit of the copying machine. A case where a plate member 4 made of a plastic insulator is fixed so as to cover the slit 2 is shown. In the example of FIG. 6, an insulator 4 such as plastic is attached so as to cover the slit 2 as shown by an arrow in the figure, and an adhesive or a screw is used to obtain a structurally large strength of the housing. Be able to do it. With the configuration described above, the electrical properties of the housing 1 do not change, the mechanical strength of the housing 1 of the scanner unit increases, and the decrease in mechanical strength due to the slit 2 is reduced. be able to.

FIG. 7 shows a fourth embodiment of the present invention.
A slit group 5 in which a large number of slits are formed at arbitrary intervals is provided. The slit group 5 is formed as a slit cut halfway from the scanner upper and side surfaces at the edge of the housing of the scanner unit, and electronic devices such as the reading device 3 are disposed inside. In the example shown in FIG. 7, when there is no slit group 5 in the housing, FIG.
As in the case of (1), a magnetic field distribution with the corner of the scanner as a node is seen.

Next, with the slit group 5 formed in the housing, a monopole antenna is placed at the position where the reading device 3 is placed inside the housing 1 of the scanner, and a 500 MHz sine wave is applied. FIG. 8 shows a magnetic field component in the X direction on the upper surface of the scanner at a certain time, where it can be seen that the propagation of the electromagnetic wave is blocked by the slit group 5, the distribution of the nearby magnetic field is reduced, and the radiated electromagnetic wave is reduced. Further, the shape of the slit group is structurally stronger than that of the first embodiment shown in FIG. 1 and can be manufactured by punching, so that the productivity is high. It can be facilitated.

FIG. 9 shows a fourth embodiment of the present invention.
A large number of slits 5 are formed in the longitudinal direction and the lateral direction of the edge of the scanner unit. Electronic equipment is located. The electronic device such as the reading device 3 is placed as close as possible to the corner of the housing 1 of the scanner unit.

As shown in FIG. 9, a slit group 5 is formed on each side in the longitudinal direction and the lateral direction of the housing 1, and a monopole antenna is placed at the position where the reading device 3 is placed, and 500 MHz. FIG. 10 shows a magnetic field component in the X direction on the upper surface of the scanner at a certain time when the sine wave is applied. As can be seen from FIG. 10, the propagation of the electromagnetic wave is blocked by the slit group 5, the magnetic field distribution is concentrated at the corner of the scanner housing, and as a result, the distribution of the magnetic field is reduced and the radiated electromagnetic wave is reduced. However, by using the above-described configuration, it is possible to enhance the mechanical strength of the housing 1 and facilitate the manufacturing. When the slit group 5 is not provided in the housing, a magnetic field distribution with the corner of the housing as a node can be seen as in the case of FIG.

FIG. 11 shows a fifth embodiment of the present invention. A slit 6 formed by cutting only the side of the scanner unit is formed in the housing 1 of the scanner unit of the copying machine. The figure shows a case where an electronic device such as a reading device 3 is arranged inside a body. When the configuration of FIG. 11 is used, a monopole antenna is placed at a position corresponding to the reading device 3 inside the housing 1 in which the slit 6 is formed.
FIG. 12 shows a magnetic field component in the X direction on the scanner upper surface at a certain time when a 00 MHz sine wave is applied. As can be seen in this figure, it can be seen that the propagation of the electromagnetic wave is blocked by the slit 6, the magnetic field intensity at the position of the slit 6 is reduced, and the radiated electromagnetic wave is reduced. Can be reduced. On the other hand, when the slit 6 was not provided, the maximum of the magnetic field was found slightly inside the position corresponding to the reading device 3, although slightly different from the case of FIG.

FIG. 13 shows a sixth embodiment of the present invention, in which an electronic device 7 such as a reading device is vertically placed in a housing 1 of a scanner unit of a copying machine. ing. This is explained in response to the fact that a reading device or an image processing device is often placed at the bottom of the housing of a scanner unit in electronic devices in general. Therefore, the electric field component in the z-direction on the top surface of the scanner at a certain time when a 500 MHz sine wave is applied with a monopole antenna placed at the center or end of the scanner instead of the electronic device of FIG. 13 is shown. 14
FIG. 15 shows the electric field component on the scanner upper surface.
As a result, when the electronic device is placed at the bottom of the scanner, it can be understood that the radiation of electromagnetic waves is small when the electronic device is placed at the center of the scanner. This makes it possible to reduce the propagation of radiated electromagnetic noise from the electronic device at the bottom of the scanner.

FIG. 16 shows a seventh embodiment of the present invention. A slit group 8 cut from the top to the side of the scanner is provided in the housing 1 of the scanner unit of the copying machine.
Are attached to the end of the housing, and electronic devices such as the reading device 3 are arranged. There are two magnetic field distributions with the above-mentioned position 3 as a node. Therefore, as shown in FIG.
FIG. 17 shows a magnetic field component in the X direction on the upper surface of the scanner at a certain time when the monopole antenna is placed at the position where the reading device 3 is placed with the slit 8 provided, and a 300 MHz sine wave is applied. ing. As shown in FIG. 17, by providing the slit 8,
It can be seen that the length of the magnetic field distribution is reduced and the radiated electromagnetic wave is reduced, and that even if a slit cannot be formed in the center of the edge of the scanner housing, the electromagnetic wave noise can be reduced. On the other hand, in the case where the slit 8 is not provided, two magnetic field distributions are observed with the node corresponding to the position corresponding to the reading device 3 being slightly different from the case of FIG.

FIG. 18 shows an eighth embodiment of the present invention. In a housing 1 of a scanner unit of a copying machine, a slit group 8 cut from the top to the side of the scanner at the edge of the scanner unit is provided. Attach 4 to the edge of the scanner
An electronic device such as a reading device 3 is arranged inside the housing 1. In a state where the casing 1 has the slit 8, a monopole antenna is placed at a position where the reading device 3 is placed inside the casing, and when a sine wave of 500 MHz is applied, X on the scanner upper surface at a certain time is applied. The directional magnetic field component is shown in FIG. As can be seen from FIG. 19, it can be seen that the magnetic field distribution in the longitudinal direction is reduced and the radiated electromagnetic wave is reduced. Instead, the electromagnetic noise can be reduced from the longitudinal direction. On the other hand, when the slit 8 is not provided,
Although slightly different from the case of FIG. 2, a magnetic field distribution was observed at the longitudinal edge of the scanner.

FIG. 20 shows a copying machine 10 as an example of an image forming apparatus to which the electromagnetic wave reducing means can be applied. In the description of the conventional example, an electronic device 35 provided as a signal processing unit, When the housing 36 is housed in the housing 37, as shown in each of the above-described embodiments, a slit is formed in a part of the housing 37 to prevent leakage of electromagnetic waves. In the copying machine 10,
As in the case of a conventional copying machine or the like, an original placing table 11 made of a contact glass is provided at the upper part of the apparatus main body, the original 12 is placed, and the reading section 13 reads the image information of the original. .

The reading section 13 is provided with a light source 14, a mirror member 15 combining a plurality of mirrors, an imaging lens 16, and a photoelectric conversion scanning element 17. Then, the light source 14 and the mirror member are moved along the lower surface of the original to read the image of the original, and the optical information incident on the photoelectric conversion scanning element 17 is photoelectrically converted and output as an electric signal. . As the photoelectric conversion scanning element 17, for example, a CCD or an amorphous silicon element is used.

The photoelectrically converted image signal is sent to electronic devices 35 and 36, subjected to signal processing in accordance with data to be written on the photosensitive drum, and transmitted to the writing unit 20.
The writing unit 20 uses a laser diode that outputs a laser beam based on the transmitted image signal, and writes the laser beam on the photosensitive drum 23 while reflecting the laser beam on the rotating polygon mirror 21. The photosensitive drum 23
In the image forming unit 22 provided with the charging unit 24, a charging charger 24, a developing device 25, a transfer charger 26, a cleaner 27, and a discharging lamp 28 are arranged around a photosensitive drum 23. Then, in a state where the surface of the photosensitive drum 23 is charged to a uniform potential by the charging charger 24, a laser beam is irradiated to form an electrostatic latent image, and toner is applied to the electrostatic latent image from the developing device 25. The toner is supplied and visualized as a toner image. The toner image formed on the photosensitive drum 23 is transferred to a sheet by discharging from a transfer charger 26. After the image is transferred, the remaining toner is removed by a cleaner 27, and in a subsequent process, static elimination is performed. The lamp 28 gives a static elimination effect.

The paper 31 onto which the image from the photosensitive drum is transferred is taken out one by one by a paper feed roller 32 from a tray or the like disposed in a paper feed unit, and corresponds to the toner image formed on the photosensitive drum 23. Then, the sheet is conveyed toward the transfer position. Then, after the toner image is transferred, the toner image is fixed through the fixing device 33 and discharged outside the apparatus.

In the above-described example of the copying machine, the electronic devices 35 and 36 constituting the signal processing unit are provided with an image processing circuit required for making a copy in the copying machine. A facsimile function can also be incorporated into the machine. Then, in the case of a device that combines the facsimile function, the electronic device 3
Naturally, a progress processing circuit corresponding to the facsimile function is also provided at 5, 36. The electronic device 3
As described in the above-described embodiments, slits are provided at arbitrary positions of the housing 37 to reduce leakage of electromagnetic waves from the electronic device, and to reduce the distance between adjacent electronic devices in the device. Electronic circuits and devices can be protected from being affected by electromagnetic waves.

[0027]

As described above, by forming a slit or the like in the housing, electromagnetic wave noise can be reduced, and the mechanical strength of the housing does not decrease. Forming a slit or the like in the housing can be formed at any position of the housing such as a scanner,
It is possible to easily manufacture a housing for housing the electronic device.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a state of a magnetic field when there is no slit in FIG. 1;

FIG. 3 is an explanatory diagram of a state of a magnetic field when there is a slit in FIG. 1;

FIG. 4 is an explanatory diagram showing a configuration of a second example of the present invention.

FIG. 5 is an explanatory diagram of a state of a magnetic field when there is a slit in FIG. 4;

FIG. 6 is an explanatory diagram showing a configuration of a third example of the present invention.

FIG. 7 is an explanatory diagram showing a configuration of a fourth embodiment of the present invention.

FIG. 8 is an explanatory diagram of a state of a magnetic field when there is a slit in FIG. 7;

FIG. 9 is an explanatory diagram showing a configuration of a fifth example of the present invention.

FIG. 10 is an explanatory diagram of a state of a magnetic field when there is the slit of FIG. 9;

FIG. 11 is an explanatory diagram showing a configuration of a sixth example of the present invention.

FIG. 12 is an explanatory diagram of a state of a magnetic field when the slit of FIG. 11 is provided.

FIG. 13 is an explanatory diagram showing a configuration of a seventh embodiment of the present invention.

FIG. 14 is an explanatory diagram of a state of a magnetic field in the z direction when the slit of FIG. 13 is provided.

FIG. 15 is an explanatory diagram of a state of a magnetic field on the upper surface of the housing when the slit shown in FIG. 13 is provided.

FIG. 16 is an explanatory diagram showing a configuration of an eighth example of the present invention.

FIG. 17 is an explanatory diagram of a state of a magnetic field when there is the slit of FIG. 16;

FIG. 18 is an explanatory diagram showing a configuration of a ninth embodiment of the present invention.

FIG. 19 is an explanatory diagram of a state of a magnetic field when there is the slit of FIG. 18;

FIG. 20 is an explanatory diagram illustrating a configuration of an image forming apparatus to which the present invention can be applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 2 Slit 3 Electronic device 4 Reinforcement 5.8 Slit group 10 Copy machine 35/36 Electronic device 37 Case

Claims (9)

[Claims] In a scanner unit provided in an image forming apparatus, when an electronic device or the like is provided at the center of an edge of a housing of the scanner unit, a slit cut from an upper portion to a side surface of the scanner is provided at a center of the edge of the scanner unit. An electromagnetic interference wave reduction device characterized by the above-mentioned. 2. A scanner unit provided in an image forming apparatus, wherein when an electronic device or the like is provided at an edge of an edge of a scanner unit housing, a slit cut from an upper portion to a side surface of the scanner is provided at a central portion of the edge of the scanner unit. An electromagnetic interference wave reduction device characterized by the above-mentioned. 3. The electromagnetic interference wave reduction device according to claim 1, wherein a rectangular insulating material such as plastic is joined to the slit portion with an adhesive or a screw. 4. In a scanner unit provided in an image forming apparatus, when an electronic device or the like is located at the center of a short-side edge of a housing of the scanner unit, the scanner unit is evenly placed on the short-side edge of the scanner unit. An electromagnetic interference wave reduction device characterized in that there is a group of slits that are partially cut halfway around the fulcrum. 5. In a scanner unit provided in an image forming apparatus, when an electronic device or the like is provided at an end of a short-side edge of a housing of the scanner unit, a short-side edge and a long-side edge of the scanner unit are provided. An electromagnetic interference wave reduction device characterized in that there is a slit group cut halfway starting from the top and side surfaces of the scanner. 6. A scanner unit provided in an image forming apparatus, wherein, when an electronic device or the like is provided at a central portion of an edge of a housing of the scanner unit, a slit cut only on a side surface is provided at a central portion of the edge of the scanner unit. Characteristic electromagnetic interference reduction device. 7. An electromagnetic interference wave reducing apparatus, wherein an electronic device or the like is provided in a central portion of a bottom surface of a housing of the scanner unit in a scanner unit provided in the image forming apparatus. 8. A scanner unit provided in an image forming apparatus, wherein an electronic device or the like is provided at a center of an edge of a housing of the scanner unit. An electromagnetic interference wave reduction device, characterized in that there are two slits cut. 9. A scanner unit provided in an image forming apparatus, wherein an electronic device or the like is provided at a center of an edge of a housing of the scanner unit. Electromagnetic interference reduction device characterized by having two slits cut from the side to the side