JP2007336644A - Circuit board and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent increase in power consumption due to the intervention of such an electric circuit as a filter circuit between electronic equipment and a commercial power supply. <P>SOLUTION: A filter circuit board 3 is placed between a power supply circuit board 4 and a commercial power supply. The filter circuit board includes: a filter circuit 31 for reducing electromagnetic noise; power supply-side terminals 32, 33 to which the commercial power supply is connected; power supply circuit-side terminals 34, 35 to which the power supply circuit board 4 is connected; and switch terminals 36, 37 the main switch 5 of which is connected between one terminal 32 constructing the power supply-side terminals 32, 33 and the filter circuit 31. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a circuit board and an image forming apparatus in which an electric circuit having a predetermined function is formed and interposed between an electronic device and a commercial power source. In particular, the present invention relates to a copying machine, a printer, a facsimile machine, an Internet facsimile machine, which is an apparatus for forming an image on recording paper, and a multifunction machine having any one of these functions.

  In order to prevent deterioration of the electromagnetic environment caused by electronic devices that handle digital signals, EMI (Electro Magnetic Interference) regulations have been implemented in each country. Various techniques have been disclosed in order to comply with EMI regulations for image forming apparatuses such as copying machines.

For example, in a digital copying machine including a printer device as a main device and other component devices (scanner device, printer device, multi-stage sheet feeding device, post-processing device, etc.), a noise filter is provided only in the printer device. A digital copier is disclosed. According to this digital copying machine, it is possible to avoid duplication of noise filters in a digital copying machine formed by combining a plurality of component devices.
JP 2002-258990 A

  On the other hand, if a standard (FCC standard or the like) that becomes a standard for EMI regulations is tightened after the digital copier is manufactured, the digital copier may not satisfy the standard for EMI regulations. Further, during the development of a digital copying machine, it may be necessary to dispose an external filter circuit in order to satisfy the standard that is the standard of EMI regulations. In such a case, it is necessary to replace the power supply circuit board on which the main switch of the digital copying machine is interposed, or to arrange the filter circuit board at a terminal to which the commercial power supply of the power supply circuit board is connected. .

  However, it is not preferable to replace the power supply circuit board on which the power switch of the digital copying machine is interposed because the manufacturing cost is greatly increased. Therefore, the filter circuit board is arranged at a pair of terminals to which the commercial power supply of the power circuit board is connected. In this case, even if the power switch is turned off, the filter circuit board consumes power. Therefore, the power consumption of the digital copying machine increases.

  The present invention has been made in view of the above problems, and is a circuit capable of preventing an increase in power consumption due to an electrical circuit such as a filter circuit interposed between an electronic device and a commercial power supply. It is an object to provide a substrate and an image forming apparatus.

  In order to achieve the above object, the circuit board according to claim 1 is a circuit board in which an electric circuit having a predetermined function is formed and interposed between an electronic device and a commercial power source. A pair of terminals connected to the equipment side terminal, a pair of terminals connected to the commercial power supply, a power supply side terminal, between one terminal constituting the power supply side terminal and the electric circuit, And a switch terminal that is a pair of terminals configured to be connectable to a power switch of the electronic device.

  A circuit board according to a second aspect is the circuit board according to the first aspect, wherein the electric circuit is a filter circuit that reduces electromagnetic noise.

  A circuit board according to a third aspect is the circuit board according to the second aspect, wherein the electronic device is an image forming apparatus that forms an image on a recording sheet.

  According to a fourth aspect of the present invention, there is provided an image forming apparatus including a fixing unit that fixes a toner image on a recording paper, and the circuit board according to any one of the first to third aspects is configured to be detachable. Yes.

  According to the circuit board according to claim 1, the power switch of the electronic device is provided between the one terminal constituting the power supply side terminal which is a pair of terminals connected to the commercial power supply and the electric circuit having a predetermined function. Since a switch terminal that is a pair of terminals configured to be connectable to each other is provided, an electric circuit is provided between the electronic device and the commercial power supply by moving the power switch of the electronic device to the switch terminal. An increase in power consumption can be prevented.

  According to the circuit board of the second aspect, since the electric circuit is a filter circuit that reduces electromagnetic noise, the electromagnetic noise can be reduced while preventing an increase in power consumption.

  According to the circuit board according to claim 3, since the electronic device is an image forming apparatus that forms an image on recording paper, the degree of freedom in selecting a control method for the heater of the fixing unit provided in the image forming apparatus. Can be increased.

  According to the image forming apparatus of the fourth aspect, since the circuit board according to any one of the first to third aspects is configured to be detachable, an electric circuit is interposed between the electronic device and the commercial power source. An image forming apparatus capable of preventing an increase in power consumption associated with the installation can be realized.

  Hereinafter, an example of an electronic apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram (side view) showing an example of a schematic configuration of an electronic apparatus according to the present invention. Here, the case where the electronic device is a monochrome printer will be described. However, the electronic device may be a color printer, or another image forming apparatus that forms an image on a recording sheet by transferring toner (for example, Facsimile, copier, etc.). Further, the electronic device may be an electronic device (for example, a personal computer) other than the image forming apparatus. As shown in FIG. 1, the printer 1 includes a display unit 11, an operation unit 12, a developing unit 13, a photosensitive unit 14, a laser scanning unit 15, and a fixing unit 16.

  The display unit 11 displays various information so as to be visible from the outside. Specifically, the display unit 11 includes, for example, an LCD (Liquid Crystal Display) and displays various operation information, setting information, guidance information, and the like. To do.

  The operation unit 12 receives an operation from the outside. Specifically, the operation unit 12 includes, for example, various operation buttons, a touch panel formed integrally with the LCD disposed in the display unit 11, and the like. The operation of is accepted.

  The developing unit 13 attaches toner to an electrostatic latent image formed on the surface of the photosensitive drum by a laser beam from the laser scanning unit 15 and corresponding to image data input from an external device (for example, a personal computer). Thus, a toner image is formed.

  The photosensitive unit 14 includes a photosensitive drum. The surface of the photosensitive drum is first charged substantially uniformly by a charging roller, and then toner is attached to the electrostatic latent image corresponding to the original image by the developing unit 13. Thus, a toner image is formed, and the toner image is further transferred onto a recording sheet by a transfer roller.

  The fixing unit 16 includes a heating roller (= fixing roller) 161, and fixes the toner image transferred onto the recording paper by the photosensitive unit 14 onto the recording paper. In addition, the fixing roller 161 is heated by a heater such as a halogen lamp (not shown), and the surface temperature of the fixing roller 161 is controlled to be 210 to 220 ° C., for example.

  In the fixing unit 16, the power supplied to the heater is accurately controlled to maintain the surface temperature of the fixing roller 161 at the fixing temperature (or standby temperature). Here, a phase control method and a half-wave control method are known as heater control methods.

  FIG. 2 is a waveform diagram of a voltage (or current) generated by the phase control method and the half-wave control method when the duty ratio is 50%. (A) is a waveform diagram of a voltage (or current) generated by the phase control method, and (b) is a waveform diagram of a voltage (or current) generated by the half-wave control method. When the phase control method or the half-wave control method is applied, the surface temperature of the fixing roller 161 can be controlled by controlling the duty ratio of the supplied power.

  In addition, when the phase control method is applied, since the waveform distortion becomes large, harmonic current is likely to be generated, and as a result, electromagnetic noise is likely to be generated. On the other hand, when the half-wave control method is applied, the ON / OFF fluctuation of the heater becomes large, so that an inrush current is generated and voltage fluctuation flicker (hereinafter simply referred to as “flicker”) is likely to occur. Therefore, when the phase control method is used to suppress the occurrence of flicker, electromagnetic noise is likely to be generated. Therefore, the filter circuit board described later with reference to FIGS. 3 and 4 is replaced with a power circuit board and a commercial power supply. It may be necessary to intervene between them.

  FIG. 3 is a circuit diagram showing an example of a power supply circuit 200 in which a conventional filter circuit board 300 is interposed. The power supply circuit 200 is disposed at an appropriate position of the printer 1 and supplies power to each unit such as the fixing unit 16 constituting the printer 1, and includes a filter circuit board 300, a power supply circuit board 4, and a main switch. 5 is provided. The main switch 5 (corresponding to a power switch) receives an operation from the user and supplies and shuts off power to each unit such as the fixing unit 16 constituting the printer 1.

  The power circuit board 4 includes power side terminals 41 and 42, switch terminals 43 and 44, and a power circuit 45. The power supply side terminals 41 and 42 are a pair of terminals to which the filter circuit board 300 is connected. The switch terminals 43 and 44 are a pair of terminals to which the main switch 5 is connected. The power supply circuit 45 generates power (for example, a constant voltage direct current power supply) suitable for each unit such as the fixing unit 16 constituting the printer 1 using power supplied from a commercial power supply.

  The filter circuit board 300 includes a filter circuit 31, power supply side terminals 32 and 33, and power supply circuit side terminals 34 and 35. The filter circuit 31 (corresponding to an electric circuit) includes an across-the-line capacitor, a common mode choke coil, a line bypass capacitor, and the like, and reduces electromagnetic noise. The power supply side terminals 32 and 33 are a pair of terminals to which a commercial power supply (for example, AC100V power supply) is connected. The power circuit side terminals 34 and 35 (corresponding to the device side terminals) are a pair of terminals to which the power circuit board 4 is connected.

  Thus, electromagnetic wave noise can be reduced by connecting the filter circuit board 300 to the power supply circuit board 4. However, in the power supply circuit 200, even when the main switch 5 is turned off, the filter circuit 31 is connected to the commercial power supply, so that power is consumed by the filter circuit board 300 (filter circuit 31). It will be. As a result, the power consumption of the printer 1 increases as compared with the case where the filter circuit board 300 is not connected.

  FIG. 4 is a circuit diagram showing an example of the power supply circuit 2 provided with the filter circuit board 3 according to the present invention. Here, the same reference numerals are assigned to the same components as those of the power supply circuit 200 provided with the conventional filter circuit board 300 shown in FIG. 3, and the description thereof is omitted. The power supply circuit 2 is different from the conventional power supply circuit 200 in that the conventional filter circuit board 300 is replaced with the filter circuit board 3 according to the present invention. The power supply circuit 2 is disposed at an appropriate position of the printer 1 and supplies power to each unit such as the fixing unit 16 constituting the printer 1, and includes a filter circuit board 3, a power supply circuit board 4, and a main switch. 5 is provided.

  The filter circuit board 3 includes a filter circuit 31, power supply side terminals 32 and 33, power supply circuit side terminals 34 and 35, and switch terminals 36 and 37. The filter circuit 31 includes an across-the-line capacitor, a common mode choke coil, a line bypass capacitor, and the like, and reduces electromagnetic noise. The power supply side terminals 32 and 33 are a pair of terminals to which a commercial power supply (for example, AC100V power supply) is connected. The power circuit side terminals 34 and 35 are a pair of terminals to which the power circuit board 4 is connected. The switch terminals 36 and 37 are a pair of terminals to which the main switch 5 is connected. However, the power supply circuit side terminals 34 and 35 of the filter circuit board 3 are connected to the switch terminal 44 and the power supply side terminal 41 of the power supply circuit board 4, respectively.

  Thus, electromagnetic wave noise can be reduced by connecting the filter circuit board 3 to the power supply circuit board 4. Further, in the power supply circuit 2, when the main switch 5 is turned off, the commercial power supply and the filter circuit 31 are interrupted by the main switch 5 so that the main switch 5 cannot be energized. No power is consumed.

  In this way, the main switch 5 of the printer 1 is connected between the one terminal 32 constituting the power supply side terminals 32 and 33 which are a pair of terminals connected to the commercial power supply and the filter circuit 31 having a predetermined function. Since the switch terminals 36 and 37 which are a pair of terminals configured to be connectable are provided, the filter circuit 31 is connected between the printer 1 and the commercial power supply by connecting the main switch 5 of the printer 1 to the switch terminals 36 and 37. It is possible to prevent an increase in power consumption that accompanies the interposition.

  Further, since the filter circuit 31 for reducing electromagnetic wave noise is interposed between the printer 1 and the commercial power supply, the electromagnetic wave noise can be reduced while preventing an increase in power consumption.

  Furthermore, since a filter circuit 31 for reducing electromagnetic noise is interposed between the printer 1 and the commercial power supply, the degree of freedom in selecting a control method for the heater of the fixing unit 16 disposed in the printer 1 can be increased. it can. That is, the phase control method can be used in addition to the half-wave control method.

The present invention can also be applied to the following forms.
(A) In this embodiment, the case where the electronic device is the printer 1 has been described. However, the electronic device may be another image forming apparatus, or the electronic device may be an electronic device other than the image forming apparatus ( For example, it may be a form such as a personal computer.

  (B) In the present embodiment, the case where the electric circuit having a predetermined function is a filter circuit that reduces electromagnetic noise has been described. However, the electric circuit having other functions may be used. For example, it may be a stabilization circuit that stabilizes the voltage when the power supply voltage of the commercial power supply is unstable, or it may be a low-pass filter circuit when high-frequency noise is superimposed on the commercial power supply. Good.

These are the schematic diagrams (side view) which show an example of schematic structure of the electronic device which concerns on this invention. These are waveform diagrams of the voltage (or current) generated by the phase control method and the half-wave control method when the duty ratio is 50%. These are circuit diagrams which show an example of the power supply circuit in which the conventional filter circuit board was interposed. These are circuit diagrams which show an example of the power supply circuit 2 in which the filter circuit board based on this invention was interposed.

Explanation of symbols

1 Printer (electronic equipment)
16 Fixing Unit 161 Fixing Roller 2 Power Supply Circuit 3 Filter Circuit Board (Circuit Board)
31 Filter circuit (electric circuit)
32, 33 Power supply side terminal 34, 35 Power supply circuit side terminal (equipment side terminal)
36, 37 Switch terminal 4 Power supply circuit board 41, 42 Power supply side terminal 43, 44 Switch terminal 45 Power supply circuit 5 Main switch (power switch)

Claims (4)

An electric circuit having a predetermined function is formed, and is a circuit board interposed between an electronic device and a commercial power source,
A device-side terminal that is a pair of terminals connected to the electronic device;
A power supply side terminal which is a pair of terminals connected to the commercial power supply;
A switch terminal which is a pair of terminals configured to be connectable to a power switch of the electronic device between one terminal constituting the power supply side terminal and the electric circuit;
A circuit board comprising:   The circuit board according to claim 1, wherein the electric circuit is a filter circuit that reduces electromagnetic noise.   The circuit board according to claim 1, wherein the electronic device is an image forming apparatus that forms an image on a recording sheet. A fixing unit for fixing the toner image on the recording paper;
An image forming apparatus comprising the circuit board according to claim 1 detachably.

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