KR100607963B1 - Facsimile for reducing EMI by controlling spread and method for reducing clock spread of the facsimile - Google Patents

Abstract

The present invention relates to a fax machine and a clock spread reduction method of a fax machine for reducing EMI through spread control.

Conventional fax machines are not enough to reduce EMI. In order to solve this problem, the clock spread reduction method of the fax machine of the present invention is a clock spread reduction method of a fax machine that communicates through a computer and a USB cable, the method comprising the steps of: (a) setting the clock spread amount of the fax machine to the maximum; ; (b) connecting the USB cable to the computer and the fax machine and performing communication with each other; (c) setting the spread amount to 0 to 3% if an abnormality is found in the communication; (d) calculating a reduction amount of the spread and transmitting it to the computer; (e) the amount of clock spread is reduced; And (f) repeating steps (b) to (e) until the computer and the fax machine are in good communication.

Description

Facsimile for reducing EMI by controlling spread and method for reducing clock spread of the facsimile}

BRIEF DESCRIPTION OF THE DRAWINGS In order to better understand the drawings cited in the detailed description of the invention, a brief description of each drawing is provided.

1 is a block diagram of a conventional fax machine.

2 is a block diagram of a fax machine according to the present invention.

3 is a flowchart illustrating a clock spread reduction method of a fax machine according to the present invention.

TECHNICAL FIELD The present invention relates to a fax machine, and more particularly, to a fax machine and a clock spread reduction method of a fax machine for reducing EMI through spread control.

The concept of spread spectrum was first used in World War II to eliminate intentional jamming and to exchange information confidentially. Spread spectrum systems must meet at least two criteria. First, the transmission bandwidth must be much larger than the information transmission bandwidth or transmission rate, and second, some functions other than information transmission are used to determine the modulated RF bandwidth. Thus, a prerequisite for spread spectrum communication is that the desired signal can be extended by extending the signal's bandwidth, transmitting the extended signal, and remapping the received spread spectrum to the original information bandwidth for transmitting error-free information in a noisy signal environment. It involves recovering. Many methods have been developed to meet these two conditions, but typically excessive interference, including interference from narrowband interferers, renders the above systems ineffective.

1 is a block diagram of a conventional fax machine. Referring to FIG. 1, the conventional fax machine 101 includes a central processing unit (CPU) 111, an OPE control unit 115, a ROM 121, a RAM 125, and a computer interface 131. Spread spectrum clock generator 135, oscillator 141, modem 145, line interface 151, handset 155, speaker driver 161, speaker 165, printing engine 171 and scan unit ( 175).

The CPU 111 controls all operations of the fax machine 101 in accordance with the program stored in the ROM 121.

The OPE control unit 115 has a plurality of operation keys for inputting data, and has an LED (Light Emitting Device) or LCD (Liquid Crystal Display) to indicate the operation state of the fax machine 101, and an error message. Can also be displayed.

The ROM 121 stores a program for performing an operation of the fax machine 101.

The RAM 125 temporarily stores various data generated while the operation of the fax machine 101 is performed, and stores the fax data.

The computer interface 131 is a connection portion between the fax machine 101 and a computer (not shown), and is generally connected to a parallel port, a USB1394, or the like of the computer. The fax machine 101 and an inkjet printer (not shown) can be connected through the port.

The spread spectrum clock generator (SSCG) 135 converts the clock into a spread spectrum to reduce electro-magnetic interference (EMI) noise.

The oscillator 141 generates a clock to be used by the fax machine 101.

The modem 145 codes / decodes the fax image data and detects a tone.

The line interface 151 interfaces between the switching network PSTN and the modem 145.

The handset 155 is a part that can exchange voice signals with the other party.

The speaker driver 161 transmits a dial tone and a voice to the speaker 165.

The printing engine 171 includes a device capable of printing an image on a thermal paper in the case of a thermal fax, and a structure and a device capable of fixing toner on plain paper in the case of a mono laser.

A paper feed motor (not shown) is a motor for moving a recording sheet for recording image data, and is composed of a motor, a motor control circuit, and the like.

The scanning unit 175 scans image data (originals).

As described above, the conventional fax machine 101 sets the spread as hardware in a system using the spread spectrum clock generator 135 as a countermeasure for EMI. Therefore, due to the initially set spread, there may be a problem in USB recognition, signal, and signal rate depending on the counterpart computer, and it may be ambiguous whether the problem is a computer or a corresponding product. You will receive a (Signal Certificate).

However, even if the spread is in the range of ± 0.25% to 5%, there is no problem in USB recognition and communication, but only ± 0.25% is allowed in the USB signal authentication, which means that the meaning to use as an EMI reduction measure is diluted.

It is an object of the present invention to provide a fax machine for reducing EMI through spread control.

Another technical problem to be solved by the present invention is to provide a spread reduction method of a fax machine for reducing EMI.

The present invention to achieve the above technical problem

A fax machine for communicating with a computer through a USB cable, comprising: a control unit for controlling all operations of the fax machine; An oscillator for generating a clock for synchronizing signals used by the controller to control the operation of the fax machine; A spread spectrum signal generator for converting a clock output from the oscillator into a spread spectrum signal and outputting the spread spectrum signal; And a spread control unit configured to reduce the EMI noise by controlling the spread amount of the spread spectrum signal output from the spread spectrum signal generating unit to 0 to 3% under the control of the control unit. Provides a reducing machine.

Preferably, the fax machine includes all the functions of the multifunction machine.

The present invention to achieve the above other technical problem

A method of reducing a clock spread of a fax machine that communicates with a computer via a USB cable, the method comprising: (a) setting a maximum clock spread amount of the fax machine; (b) connecting the USB cable to the computer and the fax machine and performing communication with each other; (c) setting an amount of clock spread of the fax machine to 0 to 3% when an abnormality is found in the communication; (d) calculating a reduction amount of the spread and transmitting it to the computer; (e) the amount of clock spread is reduced; And (f) repeating steps (b) to (e) until the computer and the fax machine have no problem in communication.

Preferably, if there is no abnormality in communication in the step (c) (c-1) performing a USB communication; And (c-2) restoring the spread amount to the maximum.

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EMI is minimized by the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

2 is a block diagram of a fax machine according to the present invention. Referring to FIG. 2, the fax machine 201 of the present invention includes a CPU 211, an OPE control unit 215, a ROM 221, a RAM 225, a computer interface 231, a spread control unit 233, and a spread spectrum clock. Generator 235, oscillator 241, modem 245, line interface 251, handset 255, speaker driver 261, speaker 265, printing engine 271, automatic alignment unit ( 273 and a scanning unit 275.

The CPU 211 controls all operations of the fax machine 201 in accordance with the program stored in the ROM 221.

The OPE control unit 215 is provided with a plurality of operation keys for inputting data, and has an LED (Light Emitting Device) or LCD (Liquid Crystal Display) to indicate the operation state of the fax machine 201 and an error message. Can also be displayed.

The ROM 221 stores a program for performing an operation of the fax machine 201.

The RAM 225 temporarily stores various data generated during the operation of the fax machine 201 and stores the fax data.

The computer interface 231 is a connection portion between the fax machine 201 and a computer (not shown), and is connected to a parallel port, a USB1394, or the like of the computer. The fax machine 201 and an inkjet printer (not shown) may be connected through the port.

The spread control unit 233 adjusts the spread amount of the fax machine 201 in the range of 0% to 3%.

The spread spectrum clock generator (SSCG) 235 converts the clock into a spread spectrum to reduce electro-magnetic interference (EMI) noise.

The oscillator 241 generates a clock to be used by the fax machine 201.

The modem 245 codes / decodes the fax image data and detects a tone.

The line interface 251 interfaces between the switching network PSTN and the modem 245.

The handset 255 is a part that can exchange voice signals with the other party.

The speaker driver 261 transmits a dial tone and a voice to the speaker 265.

The printing engine 271 includes a device capable of printing an image on a thermal paper in the case of a thermal fax, and a structure and a device capable of fixing toner on plain paper in the case of a mono laser. The printing engine 271 transmits the output data to the printer to print.

The automatic alignment unit 273 detects skew of the paper.

A paper feed motor (not shown) is a motor for moving a recording sheet for recording image data, and is composed of a motor, a motor control circuit, and the like.

The scanning unit 275 scans image data (originals).

In this way, the fax machine 201 includes a spread control unit 233 for controlling the spread amount, thereby maximizing the effect of the spread spectrum clock generator 235 without interrupting USB recognition and communication, and accordingly EMI Is minimized.

The fax machine 201 produces the same effect even if it is replaced with a multifunction printer including a printer and a copy machine.

3 is a flowchart illustrating a clock spread reduction method of a fax machine according to the present invention. The spread reduction method of the fax machine shown in FIG. 3 will be described with reference to FIG. 2.

In the first step 311, the clock spread amount of the fax machine (201 in Fig. 2) is set to the maximum.

As a second step, a USB cable is connected to a computer and a fax machine (201 of FIG. 2) (321), and communication between the two is performed (331).

As a third step, it is checked whether there is an abnormality in the communication (335), and if an abnormality occurs, the spread amount of the fax machine (201 of FIG. 2) is set to the minimum or 0% (341).

In a fourth step 351, the decrease amount of the spread is calculated and transmitted to the computer.

In a fifth step 361, the amount of clock spread is reduced.

As a sixth step, steps 2 to 5 are repeated until the computer and the fax machine (201 in FIG. 2) have no problem with communication.

Then, if no abnormality is found during communication, USB communication is performed in the current setting state (345), and then the spread amount is maximally restored (355).

As such, communication is performed with the spread amount set to the maximum at the beginning, and when an error occurs, the spread can be reduced to the minimum by setting the spread to 0% or the minimum to perform data communication and then resetting the spread amount to communicate. have.

The present invention can be equally applied to all systems using a clock besides USB.

The best embodiments have been disclosed in the drawings and the specification, and the terminology used herein is for the purpose of describing the invention only and is not intended to be limiting of the scope of the invention as defined in the appended claims or claims. Therefore, those skilled in the art will be capable of various modifications and other equivalent embodiments from this, and therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

As described above, the system development period is shortened by minimizing EMI noise by adjusting the spread amount in a fax machine (201 of FIG. 2) or a multifunction apparatus using USB according to the present invention.

In addition, it is possible to minimize the recognition failure and communication failure during communication between these models.

Claims (5)

In a fax machine that communicates with a computer via a USB cable, A control unit controlling all operations of the fax machine; An oscillator for generating a clock for synchronizing signals used by the controller to control the operation of the fax machine; A spread spectrum signal generator for converting a clock output from the oscillator into a spread spectrum signal and outputting the spread spectrum signal; And Spread control to reduce the EMI noise by controlling the spread amount of the spread spectrum signal output from the spread spectrum signal generation unit under the control of the control unit to 0 to 3% to reduce EMI through the spread control A fax machine. The fax machine of claim 1, wherein the fax machine includes all functions of the multifunction apparatus. In the method of reducing the clock spread of the fax machine to communicate with a computer via a USB cable, (a) setting a maximum amount of clock spread of the fax machine; (b) connecting the USB cable to the computer and the fax machine and performing communication with each other; (c) setting an amount of clock spread of the fax machine to 0 to 3% when an abnormality is found in the communication; (d) calculating a reduction amount of the spread and transmitting it to the computer; (e) the amount of clock spread is reduced; And (f) repeating steps (b) to (e) until the computer and the fax machine have no problem in communication. The method of claim 3, wherein if there is no error in communication in the step (c) (c-1) performing USB communication; And (c-2) further comprising restoring the spread amount to the maximum. delete

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