JP2009193017A - Phase control device and fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce user's discomfort due to flicker phenomenon. <P>SOLUTION: The above problem is solved by providing a voltage regulation calculating part 71 for calculating a voltage regulation based on the detection results of a voltmeter 11, a pattern setting part 72 for setting a phase control pattern based on the calculation results, and a switch control part 73 for conducting the phase control by turning on and off a switch 12 according to setting of the pattern setting part 72. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a phase control device that performs phase control of a power supply voltage, and a fixing device including the phase control device.

  Some image forming apparatuses include a heating element such as a halogen heater in order to fix an image on a recording sheet by thermocompression bonding. Since the heating element consumes a large amount of power, a large inrush current flows when the heating element is turned on. As a result, flickering (flicker phenomenon) may occur in an illuminating device such as a fluorescent lamp connected to a power supply wiring that supplies an alternating current to the image forming apparatus.

  If the difference between the commercial power supply voltage when the heating element is not driven and the commercial power supply voltage when the heating element is driven is outside the specified value, the image forming apparatus disclosed in Patent Document 1 causes flickering. The user is notified on the operation panel that the situation is likely to occur.

Further, the image forming apparatus disclosed in Patent Document 2 attempts to reduce the flicker phenomenon by performing phase control for controlling the energization ratio in the half wave of the power supply waveform.
Japanese Patent Laid-Open No. 7-225536 (released on August 22, 1995) JP 10-20711 (published January 23, 1998)

  In the above conventional technique, it cannot be said that the user's discomfort due to the flicker phenomenon can be sufficiently reduced, and there is room for improvement.

  In view of the above-described conventional problems, an object of the present invention is to provide a technique capable of reducing user discomfort due to a flicker phenomenon.

  The phase control device according to claim 1 is a phase control device that performs phase control of electric power applied to a load from an AC power supply, a fluctuation rate acquisition unit that acquires a voltage fluctuation rate of the AC power supply, and the AC power supply. A phase control unit that performs phase control of power supply to the load, and a pattern setting unit that can change the phase control pattern according to the voltage variation rate.

  The voltage fluctuation rate affects the degree of flicker in the flicker phenomenon. Further, the pattern of the phase control operation (phase control pattern) also affects the degree of flicker. Therefore, according to the phase control device, by varying the phase control operation pattern according to the voltage fluctuation rate, even if the voltage fluctuation rate changes, the degree of flicker in the flicker phenomenon can be averaged. As a result, the phase control device can reduce user discomfort due to the flicker phenomenon.

  According to a second aspect of the present invention, in the phase control device according to the first aspect, the phase control unit is configured to reduce the voltage of the AC power source after a predetermined transition time has elapsed since the start of the phase control operation. The current is set between the load and the AC power supply over the entire wave, and the pattern setting unit increases the transition time as the voltage fluctuation rate increases. It is preferable.

  As the voltage fluctuation rate increases, the degree of flicker in the flicker phenomenon increases. On the other hand, as the transition time becomes longer, the degree of flickering is reduced. According to the second aspect of the present invention, the longer the voltage fluctuation rate, the longer the subsequent time. Therefore, even if the voltage fluctuation rate changes, the flicker phenomenon is averaged and the user's discomfort is reduced. The

  Moreover, as described in claim 3, in the phase control device according to claim 2, the phase control unit converts the power supplied to the load within one cycle of the voltage cycle of the AC power supply to the phase. It may be monotonously increased from the start of the control operation until the transition time elapses.

  According to a fourth aspect of the present invention, the phase control device described above is a fixing device connected to an AC power source, the heating unit for applying heat to the recording paper on which the image is placed, and the AC power source. A pattern of the phase control operation based on the voltage fluctuation rate, a phase control unit that performs phase control of power supply from the AC power source to the heating unit, and a voltage fluctuation rate. The present invention can be applied to a fixing device including a pattern setting unit to be changed.

  According to the present invention, by varying the phase control operation pattern according to the voltage fluctuation rate, it is possible to average the degree of flicker in the flicker phenomenon even if the voltage fluctuation rate changes. As a result, user discomfort due to the flicker phenomenon can be reduced.

[1] First Embodiment A copying machine 100 according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a main configuration of the copying machine 100, FIG. 2 is a block diagram showing a configuration relating to phase control of the power supply voltage of the copying machine 100, and FIG. 3 is a conceptual diagram of phase control. 4 is a diagram showing a table used for phase control in the present embodiment, and FIG. 5 is a flowchart showing a flow of phase control pattern determination processing.

  First, the outline of the copying machine 100 will be described with reference to FIG.

  As shown in FIG. 1, a copying machine 100 includes an operation panel 2 that receives an instruction from a user, an image reading unit 3 that acquires image data from a document, and an image forming unit that forms an image made of a developer based on the image data. 4. A transfer unit 5 that transfers the image formed by the image forming unit 4 onto the recording paper, a fixing unit 6 that fixes the image after transfer onto the recording paper by thermocompression, and each unit in the copying machine 100. A control device 7 and the like are provided.

  As the image forming unit 4, an apparatus for forming an image by an electrophotographic method can be suitably used.

  The control device 7 can be realized by a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and other storage media. In this case, each functional unit of the control device 7 is realized by the CPU reading and executing the program in the ROM. The RAM can function as a work area for the CPU.

  Next, the phase control of the power supply voltage will be described with reference to FIG.

  As shown in FIG. 2, the copying machine 100 is connected to an AC power source 200, and includes a power supply board 10, a voltmeter 11, a switch 12, and the like in addition to the above-described configuration. The fixing unit 6 includes a heater 61 for thermocompression bonding. The AC power source 200 is connected to a lighting device such as a fluorescent lamp.

  The power supply board 10 includes an electronic component such as a transformer that is connected to the AC power supply 200 and adjusts the voltage from the AC power supply 200 to a value suitable for the heater 61.

  The voltmeter 11 is provided on a power supply path from the power supply substrate 10 to the heater 61. When the voltmeter 11 detects the power supply voltage, it outputs a detection result to the control device 7.

  As the switch 12, a conventionally known switch element such as SSR (Solid State Relay) can be used.

  As shown in FIG. 2, the control device 7 includes a voltage fluctuation rate calculation unit (fluctuation rate acquisition unit) 71, a pattern setting unit 72, a switch control unit 73, a memory 74, and the like. The voltage fluctuation rate calculation unit 71 refers to the detection result of the voltmeter 11 and calculates the power supply voltage fluctuation rate. The pattern setting unit 72 refers to the calculation result of the voltage fluctuation rate calculation unit 71 and sets the phase control pattern. The switch control unit 73 executes phase control by controlling on / off of the switch 12. The memory 74 stores information such as the transition time table 741 in FIG.

The phase control by the switch control unit 73 will be described more specifically. The switch control unit 73 can switch the heater 61 between the energized state and the non-energized state by turning the switch 12 off / on within one half wave of the power supply voltage. Specifically, as shown in FIG. 3, the switch control unit 73 performs an operation of turning off the switch 12 at the voltage zero cross M ₀ and turning on the switch 12 at the timing M ₁ until the next zero cross M _0. repeat.

As shown in FIG. 3, the switch control unit 73, by changing the timing M ₁ to turn on the switch 12, the 1 Han'naminai voltage, changing the ratio of the duration of the heater 61 (energized / de-energized) Can be made.

Specifically, switch control unit 73, by advancing the timing M ₁ gradually can increase the ratio of the period of (energization / de-energized) at 1 within the half-wave voltage monotonically. In particular, in this embodiment, the ratio of the (energization / non-energization) period increases in proportion to the elapsed time from the start of phase control for each cycle (two half waves) of the voltage. That is, in the phase control start point (origin in FIG. 3) and the first half wave and the second half-wave, are identical to each other timing M ₁ to turn on the switch 12, and the third half wave and the fourth half-wave in the timing _{M 1} are identical to each other. Then, every other half-wave, by timing M ₁ is advanced, and is increased the ratio of period (energization / de-energized).

  As shown in FIG. 3, after the transition time T has elapsed from the start of phase control (in FIG. 3, from one cycle before the transition time T elapses), the switch 12 is turned on over the entire voltage wave. The As described above, in the present embodiment, the supply voltage from the AC power supply 200 to the heater 61 gradually increases until the transition time T elapses after the power is turned on, that is, after the phase control is started. It has become.

  The transition time T from the start of phase control to all waves is variable. The transition time T is set by processing according to the flowchart of FIG. The timing for performing this process is not particularly limited, and can be performed, for example, when the copying machine 100 is installed. Once the transition time T is set at the time of installation of the device, the switch control unit 73 can thereafter perform phase control based on this setting.

  As shown in FIG. 5, at the start of processing, the switch control unit 73 turns on the switch 12 over the full wave of the power supply voltage without performing phase control, so that the heater 61 is energized full wave (step S1). ). The voltage fluctuation rate calculation unit 71 calculates the power supply voltage fluctuation rate based on the detection result of the voltmeter 11 during full-wave energization (step S2). Based on this calculation result and the transition time table 741 of FIG. 4, the pattern setting unit 72 sets a phase control pattern (step S3).

  As shown in FIG. 4, in the transition time table 741, the transition time T (seconds) corresponding to the voltage fluctuation rate increases as the voltage fluctuation rate (%) increases. The greater the voltage fluctuation rate, the greater the flicker in the lighting equipment that shares the AC power supply 200. On the other hand, as the transition time T becomes longer, the flickering becomes smaller. Therefore, flickering of the lighting device can be prevented by changing the transition time T in accordance with the voltage fluctuation rate. Furthermore, since the transition time T is set to be larger as the voltage variation rate is larger, the variation in flickering of the lighting device caused by the variation in the electric variation rate is reduced. As a result, user discomfort can be further reduced.

  The transition time T corresponding to each voltage fluctuation rate is appropriately set depending on the capacity of the heater 61 and other configurations, and is not limited to a specific numerical value. The upper limit of the transition time T is preferably limited to such an extent that EMI (ElectroMagnetic Interference) or the like does not become a problem.

[2] Other Embodiments (a) In the first embodiment, the switch 12 and the control device 7 functioning as a phase control device are incorporated in the copying machine 100. However, the same mechanism can be applied to an image forming apparatus other than a copying machine or an electrical apparatus other than an image forming apparatus.

  (B) The load to be subjected to phase control is not limited to the heater 61, and may be another member such as each block shown in FIG. However, it is preferable that the load to be subjected to phase control has a large amount of power consumption such as a heater.

  (C) In the first embodiment, the energization period within one half wave of voltage is monotonously and linearly increased from the start of phase control to the elapse of transition time T, so that it is within one half wave. The amount of power supplied to the heater 61 was gradually increased. However, the mode of change in the ratio of the (energization / non-energization) period is not limited to the first embodiment, and can be appropriately changed according to the capacity of the load to be phase-controlled and other configurations. is there. For example, as another aspect, the ratio of the period of (energization / non-energization) may be monotonously increased so as to draw a concave or convex curve.

(D) In the first embodiment, turning off the power supply to the load by a factor of zero crossing M _0, to turn on the power supplied to the timing M ₁ until the next zero crossing M _0, switching off / on of, It was supposed to be repeated every half wave. However, on the contrary, the power supply to the load is turned on from the first zero cross M ₀ to the timing M ₁ , and the power supply is turned off from the timing M ₁ to the next zero cross M _0. It may be.

  (E) The transition time T is only an example of an element that determines the phase control pattern. That is, elements other than the transition time T may be changed in order to reduce flickering or variation in flickering conditions. For example, the phase control pattern can be changed by changing the ratio of the ratio of (energized / non-energized) period described in (c) above, or the final magnitude of the supplied power after the transition time T has elapsed. Can be changed. That is, even in the configuration other than that described in the first embodiment, the phase that can reduce flickering of lighting equipment or variation in flickering condition by changing the phase control pattern according to the voltage fluctuation rate. The control device is included in the technical scope of the present invention.

  As described above, embodiments obtained by appropriately combining the embodiments described in different columns are also included in the technical scope of the present invention.

1 is a block diagram showing a main configuration of a copying machine 100 according to an embodiment of the present invention. 2 is a block diagram showing a configuration relating to phase control of a power supply voltage of the copying machine 100. 3 is a conceptual diagram of phase control in the copying machine 100. FIG. The figure which shows the table matched with the voltage fluctuation rate and the transition time T. FIG. The flowchart which shows the flow of a process of phase control pattern determination.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Copier 200 AC power supply 11 Voltmeter 12 Switch 6 Fixing part 61 Heater 7 Control apparatus 71 Voltage fluctuation rate calculation part 72 Pattern setting part 73 Switch control part 74 Memory 741 Transition time table

Claims (4)

A phase control device that performs phase control of power applied from an AC power supply to a load,
A fluctuation rate acquisition unit for acquiring a voltage fluctuation rate of the AC power supply;
A phase control unit that performs phase control of power supply from the AC power supply to the load;
A pattern setting unit capable of varying the phase control pattern according to the voltage fluctuation rate;
A phase control device comprising: The phase control unit is configured to energize the load and the AC power supply over the entire wave of the AC power supply voltage after a predetermined transition time has elapsed since the start of the phase control operation. And
The phase control apparatus according to claim 1, wherein the pattern setting unit increases the transition time as the voltage fluctuation rate increases.   The phase control unit is configured to monotonously increase the power supplied to the load within one cycle of the voltage cycle of the AC power supply from the start of the phase control operation until the transition time has elapsed. The phase control apparatus according to claim 2. A fixing device connected to an AC power source,
A heating unit for applying heat to the recording paper on which the image is placed;
A fluctuation rate acquisition unit for acquiring the voltage fluctuation rate of the AC power supply;
A phase control unit that performs phase control of power supply from the AC power source to the heating unit;
A pattern setting unit that changes the pattern of the phase control operation based on the voltage fluctuation rate;
A fixing device.

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