JP2011227204A - Control device image and forming apparatus using the same - Google Patents

Abstract

A control device and an image forming apparatus using the same that can reduce electromagnetic wave noise at low cost even when a plurality of wiring openings are formed in a housing.
A control device main body having a conductive casing in which an opening for a first wiring is formed, and provided in the casing, partitioning a radiation portion and a non-radiation portion of electromagnetic noise, and a second An electrically conductive partition plate in which an opening for wiring is formed, and a waveguide provided on the partition plate so as to surround the edge of the second opening.
[Selection] Figure 1

Description

  The present invention relates to a control device that radiates electromagnetic noise and an image forming apparatus using the same.

  An image forming apparatus such as a copying machine is provided with a controller box (control box) on the back, takes an image signal from a scanner with a harness, performs signal processing on the image, and outputs a desired image to a fixing unit. For this reason, the controller box has an electronic device with a high clock (for example, several hundreds of MHz) for image processing, and an opening for turning around the harness, and electromagnetic noise from the electronic device is Leakage may occur from the opening to the outside of the device.

  For this reason, the technique regarding reduction of leakage electromagnetic waves is developed (for example, refer patent document 1, 2).

  The invention described in Patent Document 1 relates to an “electromagnetic shield casing”, and specifically, “an electromagnetic shield casing that is formed of a conductive plate and accommodates electrical components therein, and is provided on the conductive plate. And a strip-shaped conductive structure that is erected so as to surround the edge of the opening and that is in electrical contact with the conductive plate, and the height of the conductive structure is set to the opening. Is at least 0.11 times the maximum dimension of ".

  According to the invention described in Patent Document 1, the emission, leakage, and intrusion of electromagnetic waves from the opening of an electromagnetic shield housing can be reduced easily without increasing the number of components, and in an effective manner that does not require time and cost. It is possible to do that.

  The invention described in Patent Document 2 relates to an “electromagnetic interference wave reducing method”, specifically, “reducing electromagnetic interference waves generated in an electronic device installed inside a casing having a gap portion that communicates with the outside”. An electromagnetic interference wave reducing method for measuring information on the directivity and magnetic field strength of main magnetic field radiation for each frequency radiated from the electronic device, and a magnetic field that circulates at a plurality of resonance frequencies according to the dimensions of the casing The distribution vector is calculated, and the electronic device is installed at a position where the directivity of the magnetic field radiation radiated from the electronic device is orthogonal to the magnetic field distribution vector.

  According to the invention described in Patent Document 2, by installing the electronic device at a position where the directivity of the magnetic field radiation radiated from the electronic device is orthogonal to the vector of the magnetic field distribution in the housing, the electronic device Since the generated magnetic field radiation (electromagnetic wave noise) can be reduced, it is possible to reduce electromagnetic noise leaking to the outside without complicating the structure even in a case having a gap portion that leads to the outside. Become.

  However, in the invention described in Patent Document 1, a waveguide is provided in the opening for wiring, and leakage electromagnetic waves are reduced by this cutoff frequency. However, it is necessary to provide as many waveguides as the number of openings, which is expensive.

  Further, in the invention described in Patent Document 2, leakage electromagnetic noise is reduced by installing an electronic device at a resonance node in a housing having an opening, but the installation location of the electronic device is limited. is there.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a control device that can reduce electromagnetic wave noise at low cost even when a plurality of wiring openings are formed in a housing, and an image forming apparatus using the same.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a control device main body having a conductive casing in which an opening for a first wiring is formed, and is provided in the casing, so that electromagnetic noise is reduced. A conductive partition plate that divides the radiating portion from the non-radiating portion and has an opening for the second wiring formed therein, and a waveguide that is provided on the partition plate so as to surround an edge of the second opening. And a tube.

  According to a second aspect of the present invention, in the first aspect of the present invention, the opening for the second wiring is formed on the waveguide so that a cutoff frequency of the waveguide is lower than a frequency of the electromagnetic noise. A cross-sectional shape is set.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the casing is a rectangular parallelepiped, and the second wiring opening is rectangular.

  A fourth aspect of the present invention is an image forming apparatus using the control device according to any one of the first to third aspects.

  According to the present invention, it is possible to provide a control device capable of reducing electromagnetic wave noise at low cost and an image forming apparatus using the same even when a plurality of wiring openings are formed in the housing.

1 is an external perspective view showing an embodiment of an electronic apparatus according to the present invention. It is explanatory drawing for demonstrating the dimension of each part of the electronic device shown in FIG. It is an example of the cross-sectional view of the electronic device shown in FIG. It is an external appearance perspective view of the electronic device without a partition plate with a waveguide. It is a radiation electric field characteristic in the case of CASE1 shown in FIG. 1, and CASE2 (comparative example) shown in FIG. 1 is a configuration diagram showing an embodiment of an image forming apparatus according to the present invention.

Next, embodiments of the present invention will be described with reference to the drawings.
[Embodiment 1]
FIG. 1 is an external perspective view showing an embodiment of an electronic apparatus as a control device according to the present invention.
In the figure, 1 is a housing of an electronic device, 2 is a first wiring opening formed in the housing 1, and 3 is a monopole antenna (actually having an antenna) that looks like a circuit board of the electronic device body. 4 is a partition plate, and 5 is a conductive belt-like member (conducting member) erected on the edge of the second wiring opening 6 formed in the partition plate 4. Wave tube).
The first wiring opening 2 and the second wiring opening 6 are both rectangular and are suitable for flat cable wiring.

In the figure, the right side of the partition plate 4 is an electromagnetic wave radiation portion, and the left side of the partition plate 4 is an electromagnetic wave non-radiation portion. As an electromagnetic wave radiation | emission part, what has a function which generate | occur | produces the clock of high frequency (for example, several hundred MHz or more), such as CPU (Central Processing Unit), is mentioned, for example. Examples of the non-radiation part of the electromagnetic wave include a driver circuit that operates at a clock lower than that of the CPU.
Incidentally, there is a wiring between the radiation part and the non-radiation part through the second wiring opening 6 and between the non-radiation and the outside of the housing 1 through the first wiring opening 2. Yes, but omitted for explanation.

  The band-shaped member 5 constitutes a waveguide made of copper (or conductive metal) plated with gold or silver on the inside, and emits an electromagnetic noise emission part (right side in FIG. 1) and a non-radiation part ( The cross-sectional shape of the waveguide 5 is set so that the wiring between the left and the right side of FIG. 1 can pass and the cutoff frequency of the waveguide is lower than the frequency of electromagnetic noise.

  In the figure, the first wiring opening 2 is formed in two rectangular shapes (rectangular shapes), but is not limited, and may be three or more or one.

FIG. 2 is an explanatory diagram for explaining dimensions of each part of the electronic device shown in FIG.
In FIG. 2, the dimensions in the X, Y, and Z directions of the casing 1 of the electronic device are a1, b1, and c1, and the dimension in the Z direction of the monopole antenna 3 that is regarded as a circuit board of the electronic device is c3. The dimensions of the member 5 in the X and Y directions are a5 and b5.

FIG. 3 is an example of a cross-sectional view of the electronic device illustrated in FIG.
FIG. 3 shows a characteristic structure in which the conductive belt-like member 5 extends in the X direction.
This band-like member 5 is called a waveguide in microwave engineering, and has a property that electromagnetic waves hardly pass at a frequency lower than the cutoff frequency. This cut-off frequency can be obtained from the velocity of the electromagnetic wave and the cross-sectional dimension of the waveguide 5. If the velocity of the electromagnetic wave is c, it can be obtained by c / (2 × b5).

Next, the effect obtained by the conductive belt-like member having the above configuration will be verified by numerical simulation.
FIG. 4 is an external perspective view of an electronic device without a partition plate with a waveguide.
First, electromagnetic wave emission characteristics are calculated for the case where there is a partition plate with a waveguide shown in FIG. 1 (CASE 1) and the case where there is no partition plate with a waveguide as shown in FIG. 4 (CASE 2).

  1 is already shown in FIG. Here, for example, a1 = 400 mm, b1 = 300 mm, c1 = 25 mm, c3 = 18 mm, a5 = 30 mm, b5 = 100 mm.

  Next, the electromagnetic wave radiation characteristics are evaluated by simulation using a calculation analysis method called FDTD method (finite difference time domain method). In this analysis, the analysis space is divided into a grid, and the Maxwell equation is subtracted and solved in the time domain.

  Specifically, a Gaussian pulse including a wide range of frequency components is input to the input end of the monopole antenna 3 that is an input point, and a far electric field is calculated from an electromagnetic field in the vicinity of the casing 1 of the electronic device.

FIG. 5 shows the radiation electric field characteristics in the case of CASE 1 shown in FIG. 1 and CASE 2 (comparative example) shown in FIG.
In FIG. 5, the horizontal axis indicates the frequency, and the vertical axis indicates the electric field strength.
In CASE1 and CASE2, a peak occurs at 883 MHz, but CASE1 is considered to be a primary cavity resonance, and CASE2 is considered to be a secondary cavity resonance. In CASE2, a peak occurs at 617 MHz, which is considered to be a primary cavity resonance.

Electromagnetic radiation is strong at the peak frequency, but CASE 1 is 10 dB or more lower than CASE 2 at other frequencies, and the effect of reducing the partition plate with the waveguide appears. Further, the radiation intensity of CASE 1 and CASE 2 is reversed at 1471 MHz. This is considered because the cut-off frequency is 3 × 10 ⁸ / (2 × 100 × 10 ⁻³ ) and 1500 MHz, and the reduction effect is weakened in the vicinity of the cut-off frequency.

  As described above, according to the present embodiment, the wiring 1 is formed in the housing 1 by passing the wiring between the electromagnetic noise radiating portion and the non-radiating portion of the control device through one waveguide 5. Even if a plurality of the electrodes are formed, electromagnetic wave noise can be reduced at a low cost.

[Embodiment 2]
Next, an embodiment of an image forming apparatus using a control device according to the present invention will be described with reference to the drawings.

FIG. 6 is a block diagram showing an embodiment of the image forming apparatus according to the present invention.
The image reading apparatus shown in FIG. 1 includes a contact glass 101 on which a document 105 is mounted, a sheet-through reading contact glass 102, a reference white plate 103 for white level adjustment and shading correction data generation, a light source 107 that irradiates the document 105, A first carriage 109 on which one mirror 108 is mounted, a second mirror 110, a second carriage 112 on which a third mirror 111 is mounted, and a home position sensor (hereinafter referred to as HPS) provided for detecting the carriage position. 117, a lens unit 113 for reducing and forming an image on a CCD image sensor (hereinafter referred to as CCD) 114, an image reading circuit 115 on which a CCD 114 as a photoelectric conversion element is mounted, a control device 116 (electronic device in FIG. 1), a first Scanner for driving the carriage 109 and the second carriage 112 Moving motor, and a document sensor or the like (e.g., see JP 2005-77520).
The control device 116 includes an image processing function and is shown in the image forming apparatus in the figure, but may be provided on the back surface of the image forming apparatus.

  In the above configuration, when the document 105 is mounted on the contact glass 101, the light source 107 is turned on, and the first carriage 109 and the second carriage 112 are rotated by a control signal from a control unit (not shown). By moving the light source 107, the light source 107 is turned on while the first carriage 109 and the second carriage 112 are stopped. A method of reading the document image information by irradiating the other document 106 conveyed by the document conveying device 104 via 102 can be selected.

  When scanning the first carriage 109 and reading the document 105, the data of the reference white plate 103 is acquired and the shading correction data is generated and stored in the memory before reading the document 105, and the shading correction data is stored. Thus, by normalizing the image data of the document 105, the light distribution unevenness and the CCD sensitivity unevenness in the image reading device are corrected, and the image information of the document 105 is read with high quality.

The image data subjected to the shading correction process is output to an image processing unit (not shown).
In the case of sheet-through reading where the original 106 is conveyed and the original image data is read while the first carriage 109 is stopped, the first carriage 109 is first placed under the reference white plate 103 prior to reading the original 106. It is moved to generate shading correction data, and after returning to the sheet-through reading position, the conveyance of the document is started and the document reading operation is started.

  A neutralizing device L, a cleaning device 202, a charging device 203, and a developing device 205 are disposed on the outer periphery of the photosensitive member 201 that is rotatably supported and rotates in the direction of the arrow in FIG.

Between the charging device 203 and the developing device 205 on the outer periphery of the photoconductor 201, a space for allowing light information emitted from the exposure device 204 to enter is secured.
In the configuration shown in FIG. 6, there are four photoconductors 201 (201a, 201b, 201c, 201d), but only the color of the color material (toner) handled by the developing device 205 is different, and the images provided on the respective outer peripheral portions. The component configuration described above for forming is the same.

  The photoconductor 201 is configured by providing an organic semiconductor layer, which is a photoconductive substance, on the surface of an aluminum cylinder having a diameter of about 30 mm to 100 mm, and a part of the photoconductor 201 is an intermediate transfer belt (first visible image carrier) 210. Is in contact with

  The intermediate transfer belt 210 is supported by rotating rollers 211, 212, 213, and 214, and is stretched so as to be movable in the direction of the arrow in FIG. On the back side of the intermediate transfer belt 210 (inside the loop), a roller 212 as a first transfer unit is provided in the vicinity of the photoconductor 201 to transfer a visible image on the photoconductor 201 to the intermediate transfer belt 210.

  On the outside of the belt loop of the intermediate transfer belt 210, the intermediate transfer belt cleaning is performed downstream of the position at which the developed image is transferred from the intermediate transfer belt 210 to the recording medium or the intermediate transfer belt for the rear surface (second developed image carrying means) 200. A device 250 is provided. The brush of the cleaning device 250 wipes off unnecessary toner remaining on the surface of the belt after another visible image is transferred from the intermediate transfer belt 210.

FIG. 6 shows a state in which the brush roller is separated from the surface of the intermediate transfer belt 200 for the back surface. This brush roller is provided so as to be swingable about a fulcrum 250A, and is configured to be able to contact and separate from the surface of the intermediate transfer belt 200 for the back surface.
Before the toner image transferred from the intermediate transfer belt 210 is transferred to the recording medium P, that is, when the intermediate transfer belt for back surface 200 carries the toner image, the toner image is separated and transferred to the recording medium P. When cleaning becomes necessary, the brush roller is swung in the counterclockwise direction in FIG.
The removed unnecessary toner is collected in the toner storage unit 250B.

  The exposure device 204 uses a known laser system, and irradiates light information corresponding to full-color image formation on the surface of the uniformly charged photoreceptor 201 as a latent image. As the exposure device 204, an exposure device including an LED array and an image forming unit may be used.

  Thus, the above-described photoreceptor 201, cleaning device 202, charging device 203, exposure device 204, developing device 205, static eliminator L, and roller 212 are transferred to the intermediate transfer belt 210. It functions as an image forming means for generating (image with toner).

The intermediate transfer belt 210 is a belt based on a resin film or rubber having a base thickness of 50 μm to 600 μm, and has a resistance value that allows toner to be transferred from the photoreceptor 201.
A belt-like intermediate transfer belt for back surface 200 is disposed on the right side of FIG. 6 with respect to the intermediate transfer belt 210. The intermediate transfer belt for back surface 200 is supported by rotating rollers 216, 217, and 219, and is stretched so as to be movable in the direction of the arrow in FIG. 6. On the back side (inside the loop), the second transfer means 2 18 is provided. Is arranged. Outside the belt loop formed by the back surface intermediate transfer belt 200, the back surface intermediate transfer belt cleaning device 250, the charger CH, and the like are disposed.

  The intermediate transfer belt 210 and the back surface intermediate transfer belt 200 come into contact with each other by the second transfer means 218, the rotation rollers 216, 217, and 219, and the roller 214 that supports the intermediate transfer belt 210, and are determined in advance. A transfer nip is formed.

  The intermediate transfer belt for back surface 200 is a belt having a base of a resin film or rubber having a base thickness of 50 μm to 600 μm, and has a resistance value that enables transfer of toner from the intermediate transfer belt 210.

The recording medium (paper) P is stored in the lower paper feeders (paper cassettes) 226-1 and 226-2 in FIG. 6, and the uppermost paper is fed by a paper feed roller 227 one by one, and a plurality of guides. Then, the sheet is conveyed to the registration roller pair 228 via 229.
Further downstream of the recording medium P being conveyed, a fixing heating unit 230, a paper discharge guide pair 231, a paper discharge roller pair 232, and a paper discharge stack unit 240 are disposed.

  A storage unit TS that can store replenishment toner is provided above the intermediate transfer belt 210 and below the paper discharge stack unit 240 in FIG. There are four toner colors, magenta, cyan, yellow, and black, which are in the form of a cartridge TC. From the cartridge TC, the corresponding color developing device is appropriately supplied by a powder pump or the like.

  The frame 251 that is a part of the apparatus main body has a structure that can be rotated and opened around the opening / closing support shaft 251A. For this reason, the user can open the recording medium conveying path by opening the frame 251 to facilitate the processing of the recording medium (paper) when a jam occurs.

  Further, the image reading apparatus shown in FIG. 6 is connected to the upper portion of the apparatus main body for forming an image on the recording medium P described above via a support portion 266, and the image data read by the image reading apparatus is described above. The apparatus main body prints on the recording medium P so that a copying operation can be performed.

An operation / display unit (display means and input means) is provided on the outer periphery of the image reading apparatus. This operation / display unit includes various buttons such as a touch panel and numeric keys for notifying the user of various types of operation information by display and receiving operation inputs.
The user performs various operations such as one-side / double-side switching of a copy, start of a copy operation, setting of the number of copies, and switching between a copy function and a printer function by using the operation / input unit.

  As described above, according to the present embodiment, the wiring for the electromagnetic wave noise radiation portion and the non-radiation portion of the control device of the image forming apparatus is passed through one waveguide, thereby opening the wiring opening in the housing. Even if multiple are formed, electromagnetic noise can be reduced at low cost.

<Effect>
In the present embodiment, even if a plurality of wiring openings are formed in the casing, the partition plate with the waveguide can be obtained by passing the wiring of the electromagnetic wave noise radiation portion and the non-radiation portion through one waveguide. The electromagnetic wave noise can be effectively reduced at a low cost.

  The above-described embodiment shows an example of a preferred embodiment of the present invention, and the present invention is not limited thereto, and various modifications can be made without departing from the scope of the invention. is there.

  The present invention can be used for electronic devices such as a copying machine, a facsimile machine, and a multifunction machine having a radiation part that emits electromagnetic waves.

DESCRIPTION OF SYMBOLS 1 Case 2 Opening part for 1st wiring 3 Dipole antenna 4 Partition plate 5 Conductive strip | belt-shaped member (waveguide)
6 Opening for second wiring

JP-A-8-316679 JP 2003-115961 A

Claims (4)

A control device body having a conductive casing in which an opening for the first wiring is formed;
A conductive partition plate provided in the housing, which partitions the radiation part and non-radiation part of electromagnetic noise and has an opening for a second wiring;
And a waveguide provided on the partition plate so as to surround an edge of the second opening.   2. The cross-sectional shape of the waveguide is set so that the second wiring opening has a cutoff frequency of the waveguide lower than the frequency of the electromagnetic noise. Control device.   The control device according to claim 1, wherein the casing is a rectangular parallelepiped, and the second wiring opening has a rectangular shape.   An image forming apparatus using the control device according to claim 1.

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