JPH063877A - Wiring duct of electronic apparatus - Google Patents

Abstract

PURPOSE:To prevent the influence that the noise generated from harness connecting circuit boards exerts on other load without adopting the special remedy for the noise. CONSTITUTION:The harness 9 connecting the circuit boards (ICU circuit board 8 and LSU circuit board 6 as an example) of a system block constituting an electronic apparatus, for example, a digital copying machine 1 is housed in the duct of a conductive ferromagnetic material constituting the frame 3 of a housing 2 in such a manner that the distance between the respective circuit boards 6 and 8 is made shortest.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring duct for electronic equipment such as a copying machine, and more particularly to a digital duct for a furnace (wiring bundle) for connecting circuit blocks constituting a system of a digital copying machine. The present invention relates to a wiring duct used as a frame of a copying machine housing.

[0002]

2. Description of the Related Art In an electronic device such as a copying machine, the number of electric wires connecting each circuit is large because the circuit structure is diversified and complicated. Since these electric wires are integrated into a bundle-like furnace, noise is often superposed between the loads via the electric wires. Therefore, countermeasures against noise by wiring have been an important issue in terms of device configuration. Conventionally, shielded wires and noise filters have been generally used as measures against noise. Further, as another noise prevention measure, the present applicant has previously proposed a “wiring duct”.
This wiring duct accommodates a bundle of wiring and has a connector at a predetermined location, but the material of the duct is made of conductive plastic to have a shielding effect against static electricity and the like and to prevent noise introduced from the outside. Further, it has the effect of eliminating spurious emission to the outside and preventing malfunction of the electronic circuit of the device itself.

[0003]

However, in the above-mentioned measures using the shielded wire used as a countermeasure against noise, the shield process performed for wiring is troublesome and inefficient, and the wiring space for shielding is not sufficient. Was large, and it was effective as an electrostatic shield but not as an electromagnetic shield. Further, when the noise filter is used, the mounting space becomes large, which is disadvantageous to the trend toward miniaturization of electronic devices, resulting in high cost. The wiring duct proposed by the applicant requires a mold of a mold corresponding to the shape of the duct because a conductive resin or the like is molded by a mold or the like, which is expensive, and further, the conductive wiring duct is grounded. There was a problem that it took time to do.

[0004]

The present invention, in order to solve the above-mentioned problems, comprises a circuit block which constitutes a system,
In an electronic device such as a copying machine having a furnace for connecting the respective circuit blocks and transmitting a signal and a housing for housing the circuit blocks and the furnace, the frame of the housing is made of a conductive ferromagnetic duct. The duct for accommodating the furnace is the frame of the casing.

[0005]

The frame of the housing for accommodating electronic equipment such as a copying machine is made of a hollow pipe made of a conductive ferromagnetic material, and the furnace for connecting circuit blocks constituting the system of the electronic equipment constitutes a grounded frame of the housing. It is housed in a hollow pipe that shields the furnace from static electricity and electromagnetic waves, and also prevents spurious emission.

[0006]

2 is an overall configuration diagram for explaining a digital copying machine as an example of an electronic apparatus to which the present invention is applied. The digital copying machine 30 includes a scanner section 31, a laser printer section 32, A multi-stage paper feeding unit 33 and a sorter 34 are provided. The scanner unit 31 includes a document placing table 35 made of transparent glass and a double-sided automatic document feeder (R
DF) 36 and a scanner unit 40. The multi-stage paper feeding unit 33 includes a first cassette 51, a second cassette
It has a cassette 52, a third cassette 53, and a fifth cassette 55 which can be optionally added. In the multi-stage paper feeding unit 33, the papers are fed one by one out of the papers stored in the cassettes of the respective tiers and are conveyed toward the laser printer unit 32. The RDF 36 sets a plurality of originals at one time, automatically feeds the originals one by one to the scanner unit 40, and causes the scanner unit 40 to read one side or both sides of the original according to the operator's selection. . The scanner unit 40 forms a lamp reflector assembly 41 for exposing a document, a plurality of reflection mirrors 43 for guiding a reflected light image from the document to a photoelectric conversion element (CCD) 42, and a reflected light image from the document on the CCD 42. It includes a lens 44 for making it.

The scanner section 31 is constructed so that when scanning a document placed on the document table 35, the scanner unit 40 moves along the lower surface of the document table 35 to read the document image. When the RDF 36 is used, the document image is read while the document is being conveyed while the scanner unit 40 is stopped at a predetermined position below the RDF 36. The image data obtained by reading the original image with the scanner unit 40 is sent to the image processing unit and subjected to various processing, and then temporarily stored in the memory of the image processing unit, and the image in the memory is stored according to the output instruction. The data is given to the laser printer unit 32 to form an image on a sheet.

The laser printer unit 32 includes a manual document tray 45, a laser writing unit 46, and an electrophotographic process unit 47 for forming an image. The laser writing unit 46 is a semiconductor laser that emits a laser beam according to the image data from the above-mentioned memory, a polygon mirror that deflects the laser beam at a constant angular velocity, and a laser beam that is deflected at a constant angular velocity is exposed by the electrophotographic process section 47. Body drum 48
It has an f-θ lens and the like for performing correction so as to have a uniform velocity tendency. The electrophotographic process section 47 comprises a charging device, a developing device, a transfer device, a peeling device, a cleaning device, a static eliminator, and a fixing device 49, which are arranged around the photosensitive drum 48 according to a well-known mode. A transport path 50 is provided downstream of the fixing device 49 in the transport direction of the sheet on which the image is to be formed, and the transport path 50 communicates with the sorter 34.
And a conveyance path 58 leading to the multi-stage sheet feeding unit 33.

The multi-stage paper feeding unit 33 includes a common transport path 56, which is the first cassette 51 and the second cassette.
The sheets from the cassette 52 and the third cassette 53 are configured to be conveyed toward the electrophotographic process section 47. The common transport path 56 joins the transport path 59 from the fifth cassette 55 on the way to the electrophotographic process section 47, and communicates with the transport path 60. The transport path 60 is a double-sided transport path 50b.
And the confluence point 6 with the conveying path 61 from the manual document tray 45
The photoconductor drum 4 of the electrostatographic process unit 47 merges at 2
8 and the transfer device to communicate with the image forming position, and the confluence point 62 of these three conveying paths is provided at a position close to the image forming position. Therefore, in the laser writing unit 46 and the electrophotographic process unit 47, the image data read from the above-mentioned memory causes the laser writing unit 46 to scan the laser beam to form an electrostatic latent image on the surface of the photosensitive drum 48. The toner image visualized by the toner is electrostatically transferred and fixed on the surface of the sheet conveyed from the multi-stage sheet feeding unit 33. The sheet on which the image is thus formed is sent from the fixing device 49 to the sorter 34 via the transport paths 50 and 57, or is transported to the reverse transport path 50a via the transport paths 50 and 58.

Next, the structure and function of the image processing unit and each control system included in the digital copying machine 30 will be described. FIG. 3 is a block diagram of an image processing unit included in the digital copying machine 30 shown in FIG. The image processing unit included in the digital copying machine 30 includes an image data input unit 70, an image processing unit 71, an image data output unit 72,
A memory 73 including a RAM (random access memory) and an image processing central processing unit (CPU) 74
Is equipped with.

The image data input section 70 is a CCD section 70a,
It includes a histogram processing unit 70b and an error diffusion processing unit 70c. The image data input unit 70 is the CCD 42 of FIG.
Binary conversion of the image data of the original read from
While taking a histogram as a binary digital amount, the image data is processed by the error diffusion method and temporarily stored in the memory 73. That is, the CCD unit 70
In a, the analog electrical signal corresponding to each image density of the image data is A / D converted, and then MTF (Modulation Trans
fer function) correction, black-and-white correction, or gamma correction is performed, and is output to the histogram processing unit 70b as a digital signal of 256 gradations (8 bits). In the histogram processing unit 70b, the digital signal output from the CCD unit 70a is added for each pixel density of 256 gradations to obtain density information (histogram data), and if necessary, the obtained histogram data is subjected to image processing. CPU74
Error diffusion processing unit 70c which is sent to
Sent to. The error diffusion processing unit 70c uses the error diffusion method, which is a kind of pseudo-halftone processing unit, that is, the method of reflecting the binarization error in the binarization determination of the adjacent pixels.
8 bit / pixel digital signal output from 0a is 1
It is converted into bits (binary), and a redistribution operation is performed to faithfully reproduce the local area density in the original.

The image processing unit 71 includes multi-valued processing units 71a and 71b, a synthesis processing unit 71c, a density conversion processing unit 71d, a scaling processing unit 71e, an image processing unit 71f, an error diffusion processing unit 71g and a compression processing unit 71b. Contains. The image processing unit 71 is a processing unit that finally converts the input image data into image data that the operator desires, and this processing unit is used until the memory 73 stores the finally converted output image data. Are configured to process. However, each of the above-mentioned processing units included in the image processing unit 71 functions as necessary and may not function.

That is, in the multi-value quantization processing units 71a and 71b, the data binarized by the error diffusion processing unit 70c is converted again into 256 gradations. In the combination processing unit 71c, a logical operation for each pixel, that is, a logical sum, a logical product, or an exclusive logical sum is selectively performed. The data to be calculated is the image data stored in the memory 73 and the pit data from the pattern generator (PG). The density conversion processing unit 71d arbitrarily sets the relationship between the input density and the output density for the 256-tone digital signal based on a predetermined gradation conversion table. In the scaling processing unit 71e, pixel data (density value) for the target pixel after scaling is obtained by performing interpolation processing based on the input known data according to the instructed scaling ratio, and the sub-scanning is varied. After being multiplied, the main scanning is subjected to a scaling process. In the image processing unit 71f, various image processes may be performed on the input pixel data, and information collection such as feature extraction may be performed on the data string. In the error diffusion processing unit 71g,
Processing similar to that of the error diffusion processing unit 70c of the image data input unit 70 is performed. The compression processing unit 71h compresses the binary data by the encoding called run length. Regarding the compression of image data, the compression functions in the final processing loop when the final output image data is completed. The image data output unit 72 includes a restoration unit 72a, a multi-value quantization processing unit 72b, an error diffusion processing unit 72c, and a laser output unit 72.
d is included.

The image data output unit 72 restores the image data stored in the memory 73 in a compressed state, and restores the original 2
It is configured to convert again to 56 gradations, perform error diffusion of four-valued data that is a smoother halftone expression than binary data, and transfer the data to the laser output unit 72d. That is, the restoration unit 72a restores the image data compressed by the compression processing unit 71b. The multilevel halftoning processing unit 72b performs the same processing as the multilevel halftoning processing units 71a and 71b of the image processing unit 71. The error diffusion processing unit 72c performs the same processing as the error diffusion processing unit 70c of the image data input unit 70. In the laser output unit 72d, the digital image data is converted into a laser on / off signal based on a control signal from the print unit control CPU 79, and the laser is turned on / off. The data handled by the image data input unit 70 and the image data output unit 72 is basically stored in the memory 73 in the form of binary data in order to reduce the capacity of the memory 73. It is also possible to process in the form of four-valued data in consideration of deterioration.

FIG. 4 shows the digital copying machine 30 shown in FIG.
2 is a block diagram showing the signal flow of the entire copying machine included in the figure. In the figure, white arrows indicate the flow of image data, solid arrows indicate the flow of control signals, and broken line bidirectional arrows indicate the communication control lines. Show.

As shown in the figure, the digital copying machine 30 includes a control system for controlling the operation of the entire copying machine, and this control system has a central control unit (PCU) 81, which is a central control unit. The (PCU) 81 includes a central processing unit (CPU), and an image processing unit (ICU) 8
2, operation board unit (OPU) 83, sorter control unit (FCU) 84, input data preprocessing unit (CCU) 85, and laser control unit 86
Is equipped with.

FIG. 5 is a diagram showing each circuit board having a high-speed clock and a clock between the circuit boards which constitutes the control system of the digital copying machine 30. 1. The image data 1 between the CCD substrate and the ICU (image processing unit) substrate is 21.8 MHZ (megahertz). Image data 2 between ICU (image processing unit) substrate and LSU (laser control unit) is about 5.5M
HZ 3. The communication 1 between the ICU (image processing unit) board and the PCU (central control unit) board is 20 KHZ 4. Communication 2 between the PCU (central control unit) board and the OPE (operation board) unit is 20 KHZ 5. The serial data between the PCU (central control unit) board and the relay board is 250 KHZ, and since each circuit board has a high-speed clock, a lot of noise is generated from the harness connecting each circuit board.

FIG. 1 is a side perspective view for explaining an example of a wiring duct of an electronic device according to the present invention, and the electronic device shown is a digital copying machine. In the figure, 1 is a digital copying machine, 2 is a housing of the digital copying machine, 3 is a vertical frame of the housing 2, 4 is a horizontal frame of the housing 2, 5 is a scanner unit, 6 is an LSU (laser control). Unit) board,
7 is a paper output unit, 8 is an ICU (image processing unit) substrate, 9
Is a furnace, 10 and 11 are connectors, and 12 and 13 are holes.

The digital copying machine of FIG. 1 is an IC as an example.
The figure shows that the U board 8 and the LSU board 6 are connected by a furnace 9. In the figure, the digital copying machine 1 has a process element which is housed in a housing 2 and which constitutes the copying machine. Ferromagnetic elements, for example, process elements each having a frame composed of a vertical frame 3 and a horizontal frame 4 of a duct (a square pipe in the figure) made of a soft iron pipe, the outer peripheral surface of which is reinforced by side plates (not shown). A furnace 9 for connecting the circuit board is stored in the duct. In FIG. 1, as process elements, the scanner unit 5 and the LS are used.
Only the U substrate 6, the paper output unit 7, and the LCU substrate 8 are shown.

In FIG. 1, an LSU board 6 and an ICU board 8 have a furnace 9 having connectors 10 and 11 at both ends.
The furnace 9 is housed in the vertical frame 3. In addition, the furnace 9 is the LSU substrate 6
And the ICU board 8 are preferably housed in the vertical frame 3 so that they can be connected at the shortest distance. Therefore, the furnace 9 is inserted into the vertical frame 3 at a position close to the LSU board 6 and the ICU board 8. Holes 12 and 13 for drilling are formed. The size of the holes 12, 13 is the connector 10, 1
1 is the smallest size that can be inserted, and the furnace 9
This prevents noise generated from the holes 12 and 13 from leaking to the outside of the vertical frame 3. Furnace 9 is LSU
Since it enters the vertical frame 3 from a position close to the substrate 6 and the ICU substrate 8, it is housed in the vertical frame 3 to the extent that it cannot be seen from the outside. Thus, the furnace 9 has a short exposed portion and is housed in the pipe of the conductive ferromagnetic material, so that the influence of noise on other loads can be eliminated. Similarly, by passing the furnace of other high-speed clock parts through the pipe of the frame of the conductive ferromagnetic material, no special noise countermeasure parts are required, and the noise influence of the furnace on other loads can be prevented. it can. The furnace 9 can be housed in the horizontal frame 4 depending on the position of the circuit board.

[0021]

As is apparent from the above description, according to the present invention, since the furnace for connecting the circuit boards is housed in the grounded conductive ferromagnetic material pipe constituting the housing, a special case is provided. It is possible to inexpensively prevent the influence of noise on other loads without taking measures against noise. Moreover, grounding is also easy.

[Brief description of drawings]

FIG. 1 is a side perspective view for explaining an example of a wiring duct of an electronic device according to the present invention, in which the electronic device shown is a digital copying machine.

FIG. 2 is an overall configuration diagram for explaining a digital copying machine as an example of an electronic device to which the present invention is applied.

3 is a block configuration diagram of an image processing unit included in the digital copying machine 30 shown in FIG.

4 is a block diagram showing a signal flow of the entire copying machine included in the digital copying machine 30 shown in FIG.

5 is a diagram showing each circuit board having a high-speed clock and a clock between the circuit boards, which constitutes a control system of the digital copying machine 30. FIG.

[Explanation of symbols]

1 ... Digital copying machine, 2 ... Housing, 3 ... Duct (vertical frame), 4 ... Duct (horizontal frame), 5 ... Scanner section,
6 ... LSU (laser control unit) substrate, 7 ...
Paper output section, 8 ... ICU (image processing unit) substrate, 9 ... Furnace, 10, 11 ... Connector, 12, 13 ... Hole.

Claims (1)

[Claims] 1. An electronic device, such as a copying machine, having a circuit block that constitutes a system, a furnace that connects between the circuit blocks and transmits a signal, and an electronic device such as a copying machine having a housing for housing the circuit block. A wiring duct for electronic equipment, characterized in that the body frame is a duct of a conductive ferromagnetic material, and the furnace is housed in the duct.