JP5375477B2 - HEATER CONTROL DEVICE, IMAGE FORMING DEVICE, HEATER CONTROL METHOD, AND HEATER CONTROL PROGRAM - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heater controller capable of maintaining stable quality against flickering. <P>SOLUTION: The heater controller includes: a temperature detecting means for detecting the temperature of an object to be heated by a heater; an AC power source 101 for applying an AC voltage to the heater; an ON-duty determination part 114 for determining the on-ratio of the heater based on the temperature of the object to be heated and the target temperature; and a turn-on control part 117 for controlling the heater to turn on based on an energizing pattern formed by, in the half-wavelength of the AC voltage, allocating partial turn-on in a half-wavelength just before a half wavelength having turn-on full first, and allocating turn-on full or turn-off full based on the on-ratio for the half-wavelength after the half-wavelength having turn-on full first. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a heater control device that controls lighting of a heater, an image forming apparatus, a heater control method, and a heater control program.

  Conventionally, in an image forming apparatus such as a copying machine, a printer device, or a multifunction device, various techniques are known as lighting control of a heater of a fixing device or the like. The human eye has the characteristic that the flicker is most sensitive to flickering of a frequency around 10Hx centered on 8.8Hx. In recent image forming apparatuses, flicker countermeasures have been taken by controlling the heater lighting timing so as to avoid frequency bands that are sensitive to flickering of human eyes or to shift frequency bands to reduce flickering as much as possible. Is going.

  For example, the control cycle for changing the lighting cycle of the heater is set to 10 half wavelengths close to 10 Hz, which is easy for human eyes to feel flicker, and is set in advance to avoid a frequency band around 10 Hz. A technique for maintaining stable quality against flicker by controlling lighting of a heater with a high-frequency lighting pattern is known (see, for example, Patent Document 1).

  In addition, for the purpose of suppressing inrush current, a technology has been proposed that introduces phase control (soft start) that turns on the heater only for a part of the half wavelength immediately before the above-described high-frequency lighting pattern and gradually increases the on-time. (For example, refer to Patent Document 2).

  However, even when the soft start is performed, the inrush current is still large depending on the heater power amount, the environmental temperature, the heater configuration, and the like, and the flicker value may not satisfy the standard value. As a result, there is a problem that stable quality cannot be maintained against flicker.

  SUMMARY An advantage of some aspects of the invention is that it provides a heater control device, an image forming apparatus, a heater control method, and a heater control program capable of maintaining stable quality against flicker. To do.

In order to solve the above-mentioned problems and achieve the object, the present invention is a heater control device, which is a temperature detecting means for detecting the temperature of a heating object heated by the heater, and an AC voltage is applied to the heater. An AC power source, a lighting ratio determining means for determining a lighting ratio of the heater based on the temperature and target temperature of the heating object, and a pattern used when the AC power source is turned on , wherein the first control cycle is Phase control pattern storage means for storing a phase control pattern in which partial lighting is assigned to a half wavelength of the AC voltage within the first control period in order to change the phase of the AC voltage as a unit; and second control A half-wave control pattern in which full lighting or full lighting is assigned to a half wavelength of the AC voltage in the second control cycle so as to avoid flicker, in order to avoid flicker. Half-wave control pattern storage means for storing in association with the lighting ratio, and a half-wave control pattern associated with the lighting ratio determined by the lighting ratio determination means in the half-wave control pattern storage means Half-wave control pattern extracting means, and when the half-wave control pattern extracted by the half-wave control pattern extracting means is used immediately after the phase control pattern, the first half-wave of the half-wave control pattern is turned off. In this case, start position changing means for changing the start position of the half-wave control pattern so that the first half wavelength of the half-wave control pattern is fully lit, and the half wave whose start position has been changed. And a lighting control means for controlling lighting of the heater based on a control pattern .
Moreover, this invention is a heater control apparatus, Comprising: The temperature detection means which detects the temperature of the heating target object heated by a heater, the alternating current power supply which applies an alternating voltage to the said heater, The temperature of the said heating target object, A lighting ratio determining means for determining a lighting ratio of the heater based on a target temperature, and a pattern used when the AC power supply is turned off, in order to change the phase of the AC voltage in units of a first control cycle. A phase control pattern storage means for storing a phase control pattern in which partial lighting is assigned to a half wavelength of the AC voltage within the first control cycle, and a pattern with a second control cycle as a unit, wherein flicker is A half-wave that stores a half-wave control pattern in which full lighting or full lighting is assigned to a half wavelength of the AC voltage within the second control period in association with the lighting ratio so as to avoid Control pattern storage means, half-wave control pattern extraction means for extracting a half-wave control pattern associated with the lighting ratio determined by the lighting ratio determination means in the half-wave control pattern storage means, and the half-wave control pattern storage means When the half wave control pattern extracted by the wave control pattern extraction unit is used immediately before the phase control pattern, the half wave control pattern is used when the last half wavelength of the half wave control pattern is all extinguished. Based on the start position changing means for changing the start position of the half-wave control pattern so that the last half-wave is fully turned on and the half-wave control pattern whose start position has been changed, the heater is turned on And a lighting control means for controlling the lighting.

According to another aspect of the present invention, there is provided an image forming apparatus including a temperature detecting unit that detects a temperature of an object to be heated by a heater, an AC power source that applies an AC voltage to the heater, and the heating object. A lighting ratio determining means for determining a lighting ratio of the heater based on an object temperature and a target temperature; and a pattern used when the AC power supply is turned on, wherein the phase of the AC voltage is in units of a first control period. Phase control pattern storage means for storing a phase control pattern in which partial lighting is assigned to a half wavelength of the AC voltage within the first control period, and a pattern with a second control period as a unit. In order to avoid flicker, a half-wave control pattern in which full lighting or full lighting is assigned to the half wavelength of the AC voltage within the second control period is stored in association with the lighting ratio. Half-wave control pattern storage means, and in the half-wave control pattern storage means, a half-wave control pattern extraction means for extracting a half-wave control pattern associated with the lighting ratio determined by the lighting ratio determination means; When the half-wave control pattern extracted by the half-wave control pattern extracting means is used immediately after the phase control pattern, the half-wave is turned off when the first half-wave of the half-wave control pattern is off. Based on the start position changing means for changing the start position of the half wave control pattern so that the first half wavelength of the control pattern is fully lit, the heater based on the half wave control pattern whose start position has been changed characterized by comprising a lighting control means for controlling the lighting, the.
According to another aspect of the present invention, there is provided an image forming apparatus including a temperature detecting unit that detects a temperature of an object to be heated by a heater, an AC power source that applies an AC voltage to the heater, and the heating object. A lighting ratio determining means for determining a lighting ratio of the heater based on an object temperature and a target temperature; and a pattern used when the AC power supply is turned off, wherein the phase of the AC voltage is in units of a first control period. Phase control pattern storage means for storing a phase control pattern in which partial lighting is assigned to a half wavelength of the AC voltage within the first control period, and a pattern with a second control period as a unit. In order to avoid flicker, a half-wave control pattern in which full lighting or full lighting is assigned to the half wavelength of the AC voltage within the second control period is stored in association with the lighting ratio. Half-wave control pattern storage means, and in the half-wave control pattern storage means, a half-wave control pattern extraction means for extracting a half-wave control pattern associated with the lighting ratio determined by the lighting ratio determination means; When the half-wave control pattern extracted by the half-wave control pattern extraction means is used immediately before the phase control pattern, when the last half-wave of the half-wave control pattern is all extinguished, the half-wave control pattern is extracted. Based on the start position changing means for changing the start position of the half wave control pattern so that the last half wavelength of the wave control pattern is fully lit, and the half wave control pattern in which the start position is changed, And a lighting control means for controlling lighting of the heater.

According to another aspect of the present invention, there is provided a heater control method in a heater control device, the temperature detecting step for detecting the temperature of an object to be heated heated by the heater, and the temperature and target temperature of the object to be heated. A lighting ratio determining step for determining a lighting ratio of the heater, and a pattern used when the AC power supply of the heater is turned on, in order to change the phase of the AC voltage in units of a first control cycle. A phase control pattern storing step for storing a phase control pattern in which partial lighting is assigned to half the wavelength of the AC voltage in the first control cycle, and a pattern in units of the second control cycle, and avoids flicker. As described above, a half-wave control pattern in which full lighting or full lighting is assigned to the half wavelength of the AC voltage within the second control period is described in association with the lighting ratio. A half-wave control pattern storage step, and a half-wave control pattern extraction step of extracting a half-wave control pattern associated with the lighting ratio determined in the lighting ratio determination step in the half-wave control pattern storage step; When the half-wave control pattern extracted in the half-wave control pattern extraction step is used immediately after the phase control pattern, when the first half-wave of the half-wave control pattern is off, the half-wave Based on the start position changing step of changing the start position of the half wave control pattern so that the first half wavelength of the control pattern is fully lit, and the half wave control pattern in which the start position is changed, the heater It characterized by having a a lighting control step of controlling the lighting of.
According to another aspect of the present invention, there is provided a heater control method in a heater control device, the temperature detecting step for detecting the temperature of an object to be heated heated by the heater, and the temperature and target temperature of the object to be heated. A lighting ratio determining step for determining a lighting ratio of the heater, and a pattern used when the AC power of the heater is turned off, in order to change the phase of the AC voltage in units of a first control cycle. A phase control pattern storing step for storing a phase control pattern in which partial lighting is assigned to half the wavelength of the AC voltage in the first control cycle, and a pattern in units of the second control cycle, and avoids flicker. As described above, a half-wave control pattern in which full lighting or full lighting is assigned to the half wavelength of the AC voltage within the second control period is described in association with the lighting ratio. A half-wave control pattern storage step, and a half-wave control pattern extraction step of extracting a half-wave control pattern associated with the lighting ratio determined in the lighting ratio determination step in the half-wave control pattern storage step; When the half-wave control pattern extracted in the half-wave control pattern extraction step is used immediately before the phase control pattern, when the last half-wave of the half-wave control pattern is all extinguished, Based on the start position change step of changing the start position of the half-wave control pattern so that the last half wavelength of the wave control pattern is fully lit, and the half-wave control pattern in which the start position is changed, A lighting control step for controlling lighting of the heater.

According to another aspect of the present invention, there is provided a heater control program, comprising: a temperature detection step for detecting a temperature of a heating object heated by the heater; and the heater based on the temperature and the target temperature of the heating object. A lighting ratio determining step for determining the lighting ratio of the heater, and a pattern used when the AC power of the heater is turned on, wherein the first control period is used to change the phase of the AC voltage in units of the first control period. A phase control pattern storing step for storing a phase control pattern in which partial lighting is assigned to a half wavelength of the AC voltage, and a pattern having a second control period as a unit, so as to avoid flicker, A half-wave control pattern for storing a half-wave control pattern in which full lighting or full lighting is assigned to the half wavelength of the AC voltage within the second control period in association with the lighting ratio. A half-wave control pattern extracting step for extracting a half-wave control pattern associated with the lighting ratio determined in the lighting ratio determining step in the half-wave control pattern storing step; In the case where the half wave control pattern extracted in the wave control pattern extraction step is used immediately after the phase control pattern, when the first half wavelength of the half wave control pattern is off, the half wave control pattern Based on the start position changing step for changing the start position of the half-wave control pattern so that the first half-wave is fully turned on, and the heater is turned on based on the half-wave control pattern whose start position has been changed. is a program for executing a lighting control step of controlling, to a computer.
According to another aspect of the present invention, there is provided a heater control program, comprising: a temperature detection step for detecting a temperature of a heating object heated by the heater; and the heater based on the temperature and the target temperature of the heating object. A lighting ratio determining step for determining a lighting ratio of the heater, and a pattern used when the AC power of the heater is turned off, wherein the first control period is used to change the phase of the AC voltage in units of the first control period. A phase control pattern storing step for storing a phase control pattern in which partial lighting is assigned to a half wavelength of the AC voltage, and a pattern having a second control period as a unit, so as to avoid flicker, A half-wave control pattern for storing a half-wave control pattern in which full lighting or full lighting is assigned to the half wavelength of the AC voltage within the second control period in association with the lighting ratio. A half-wave control pattern extracting step for extracting a half-wave control pattern associated with the lighting ratio determined in the lighting ratio determining step in the half-wave control pattern storing step; When the half-wave control pattern extracted in the wave control pattern extraction step is used immediately before the phase control pattern, the half-wave control pattern is used when the last half-wave of the half-wave control pattern is all extinguished. The heater is turned on based on the start position changing step for changing the start position of the half-wave control pattern so that the last half-wave is fully turned on, and the half-wave control pattern whose start position is changed And a lighting control step for controlling the computer.

  According to the present invention, it is possible to maintain stable quality against flicker.

FIG. 1 is a block diagram showing the overall configuration of an image forming apparatus 10 according to the first embodiment of the present invention. FIG. 2 is a diagram schematically showing the phase control pattern. FIG. 3 is a diagram schematically showing a half-wave control pattern. FIG. 4 is a flowchart showing heater control processing by the image forming apparatus 10 when the halogen heater 121 is turned on. FIG. 5 is a diagram for explaining the start position changing process (step S110) when the soft start is executed. FIG. 6 is a flowchart showing heater control processing by the image forming apparatus 10 when the halogen heater 121 is turned off. FIG. 7 is a diagram for explaining the start position changing process (step S210) when the soft stop is executed. FIG. 8 is a diagram for explaining a second modification.

  Exemplary embodiments of a heater control device, an image forming apparatus, a heater control method, and a heater control program according to the present invention will be explained below in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a block diagram showing the overall configuration of an image forming apparatus 10 according to the first embodiment of the present invention. The image forming apparatus 10 includes a heater control device that controls a heater such as a fixing unit provided in the image forming apparatus 10. Specifically, the image forming apparatus 10 mainly includes a main power supply 100 and a control board 110. Further, the image forming apparatus 10 further includes a fixing unit 120, a power source SW 141, a door SW 142, and a triac (TRI) 143.

  The control board 110 controls the entire image forming apparatus 10. The control board 110 is implemented as a computer (not shown) having a CPU, RAM, ROM, NVRAM, ASIC (Application Specific Integrated Circuit), and an input / output interface connected via a bus.

  The control board 110 controls the ON / OFF of the TRI 143 and the electromagnetic relay 106 provided between the main power supply 100 and the fixing unit 120, thereby controlling the temperature of the halogen heater 121 of the fixing unit 120 and the ON / OFF control. I do. Instead of the halogen heater 121, another heater such as a ceramic heater may be used.

  A thermistor 122 disposed in the vicinity of the halogen heater 121 of the fixing unit 120 detects the surface temperature of the halogen heater 121. The control board 110 detects the surface temperature of the halogen heater 121 by A / D converting the surface temperature detected by the thermistor 122. The control board 110 controls on / off of the TRI 143 and the electromagnetic relay 106 so that the surface temperature is stabilized.

  When the power supply SW 141 of the image forming apparatus 10 is turned on, the current supplied from the AC power supply 101 is subjected to noise removal by the filter 102, smoothed by the rectifier diode 103 and the smoothing capacitor 104, and then supplied to a DDC (Digital Down Converter) 105. Supplied. The DDC 105 is a switching type DC-DC converter, and supplies a constant voltage Vcc to the control board 110 and 24 V to the electromagnetic relay 106.

  The electromagnetic relay 106 can turn on the switch 107 and turn off the fixing unit 120 via the control board 110 when the door SW 142 of the image forming apparatus 10 is turned on. That is, it becomes a safety device of the fixing unit 120.

  The zero cross detection circuit 108 detects a zero cross point of the AC power supply 101. The control board 110 turns on / off the TRI 143 according to this zero cross point. When the switch 107 is on, the voltage of the alternating current supplied to the zero-cross detection circuit 108 becomes close to zero every half wavelength. For this reason, the transistor of the zero cross detection circuit 108 cannot hold the on-voltage. The zero cross detection circuit 108 detects the state of the transistor and outputs a zero cross signal to the control board 110.

  The control board 110 includes a phase control pattern storage unit 111, a half-wave control pattern storage unit 112, and a control unit 113. The control unit 113 performs half-wave control for controlling on / off of energization to the halogen heater 121 with a half wavelength of the AC voltage as one unit. The control unit 113 also performs phase control to appropriately turn on only a part of the half wavelength in order to suppress the occurrence of inrush current when the halogen heater 121 is turned on and off. Specifically, the control unit 113 controls lighting of the halogen heater 121 according to the phase control pattern or the half wave control pattern stored in the phase control pattern storage unit 111 or the half wave control pattern storage unit 112.

  The phase control pattern storage unit 111 stores a phase control pattern. FIG. 2 is a diagram schematically showing the phase control pattern. The phase control pattern storage unit 111 stores a phase control pattern used at the time of soft start and a phase control pattern used at the time of soft stop. In FIG. 2, a hatched area is an area corresponding to lighting of the halogen heater 121.

  The phase control pattern is a lighting pattern of the halogen heater 121 determined in units of control cycles. The control cycle is a voltage cycle of the AC power supply 101 controlled by the control board 110, and is a cycle having a predetermined length. In the present embodiment, the control period is 10 half wavelengths. Corresponding to this, the phase control pattern stored in the phase control pattern storage unit 111 is set in units of 10 half wavelengths.

  Soft start is a process at the start of lighting of the halogen heater 121, and is a process of performing phase control immediately after the start of lighting of the halogen heater 121 and before half-wave control in order to suppress the occurrence of inrush power. Here, the half-wave control is control for turning on or off all the half wavelengths. Soft stop is processing when the halogen heater 121 is turned off, and is processing for turning off the halogen heater 121 after performing phase control after half-wave control in order to suppress the occurrence of inrush power.

  In the phase control pattern at the time of soft start, the lighting time within a half wavelength is set so as to become gradually longer within the control period. Further, in the phase control pattern at the time of soft stop, the lighting time within a half wavelength is set to be gradually shortened within the control period.

  The presence or absence of execution of soft start and soft stop is determined by the control unit 113 based on, for example, the length of turn-off time.

  The half wave control pattern storage unit 112 stores a half wave control pattern. The half-wave control pattern is a lighting pattern of the halogen heater 121 determined in units of control cycles, that is, 10 half wavelengths.

  FIG. 3 is a diagram schematically showing a half-wave control pattern. The half-wave control pattern storage unit 112 stores a plurality of half-wave control patterns associated with the lighting duty. Here, the lighting duty is the ratio of the lighting time (lighting ratio) to the total time of turning on and off the halogen heater 121. In the present embodiment, 10 half-wave control patterns are stored at intervals of lighting duty of 10%. In FIG. 3, the half wavelength indicated by diagonal lines is a region corresponding to lighting of the halogen heater 121. For example, at a lighting duty of 30%, lighting of the halogen heater 121 is set at a predetermined three half wavelength out of ten half wavelengths. The half-wave control patterns stored in the half-wave control pattern storage unit 112 according to the present embodiment are all lighting patterns that avoid a frequency band around 10 Hz. That is, it is a lighting pattern in which all lighting or all lighting is assigned so as to avoid flicker. In the present embodiment, a half-wave control pattern having a control period of 20 half wavelengths is stored for a lighting duty of 10%.

  The control unit 113 in FIG. 1 includes a lighting duty determination unit 114, a pattern extraction unit 115, a start position change unit 116, and a lighting control unit 117. The lighting duty determining unit 114 determines the lighting duty based on the surface temperature of the halogen heater 121 detected by the thermistor 122 and the target temperature. The pattern extraction unit 115 extracts the control pattern used by the lighting control unit 117 from the phase control pattern storage unit 111 or the half-wave control pattern storage unit 112 based on the lighting duty. For example, when the lighting duty determining unit 114 determines that the lighting duty is 70%, the half-wave control pattern associated with the lighting duty 70% is extracted in the half-wave control pattern storage unit 112. Further, the pattern extraction unit 115 extracts the phase control pattern at the time of soft start or the phase control pattern at the time of soft stop stored in the phase control pattern storage unit 111 at the time of executing soft start or soft stop.

  When the half wave control pattern specified by the pattern extraction unit 115 is used immediately after the soft start, the start position changing unit 116, when the first half wavelength of the half wave control pattern is completely turned off, The start position of the half-wave control pattern is shifted so that all the half wavelengths at the head of the half-wave control pattern are fully lit. In addition, when the half wave control pattern specified by the pattern extraction unit 115 is used immediately before the soft stop, when the last half wavelength of the half wave control pattern is all off, the half wave control pattern The start position of the half wave control pattern is shifted so that the last full half wavelength is full lighting.

  The lighting control unit 117 controls the lighting of the halogen heater 121 according to the phase control pattern, the half wave control pattern specified by the pattern extraction unit 115, or the half wave control pattern whose start position is shifted by the start position changing unit 116. .

  FIG. 4 is a flowchart showing heater control processing by the image forming apparatus 10 when the halogen heater 121 is turned on. When the control unit 113 receives an instruction to turn on the halogen heater 121 (step S100), the lighting duty determination unit 114 acquires the surface temperature of the halogen heater 121 from the thermistor 122, and turns on the lighting duty based on the acquired surface temperature and target temperature. Is determined (step S102). Next, the pattern extraction unit 115 extracts a half-wave control pattern from the half-wave control pattern storage unit 112 based on the lighting duty (step S104). Furthermore, when it is determined by the control unit 113 to perform soft start (Yes in step S106), the start position changing unit 116 determines that the first half wavelength of the half-wave control pattern extracted by the pattern extraction unit 115 is the first half wavelength. Check if all lights are off. If the first half wavelength is all extinguished (step S108, Yes), the start position of the half wave control pattern is changed (step S110).

  Here, the start position changing process (step S110) will be described. FIG. 5 is a diagram for explaining the start position changing process (step S110) when the lighting duty is determined by the lighting duty determining unit 114 when the soft start is executed. In the start position changing process, the start position changing unit 116 searches for the half wavelength that is fully lit from the half wave control pattern, determines the half wavelength that is fully lit as the start position, and is 1 or 2 before the start position. The above half wavelength is moved to the end of the original half wave control pattern.

  In the example shown in FIG. 5, the start position is shifted backward by two half wavelengths from the beginning of the half-wave control pattern, and the two half wavelengths before the start position are moved to the end of the original half-wave control pattern.

  As another example, in the half-wave control pattern of the 70% lighting duty shown in FIG. 5, only the first half wavelength may be moved to the end. Thus, the half wavelength of full lighting only needs to be the head of the half wave control pattern, and the shift amount (change amount) to the start position is not limited to the embodiment.

  When the start position is changed by the start position changing unit 116, the lighting control unit 117 first performs phase control as a soft start according to the phase control pattern at the time of soft start extracted from the phase control pattern storage unit 111 ( Then, half-wave control is performed according to the half-wave control pattern in which the start position is changed (step S114). This completes the heater control process when the halogen heater 121 is turned on.

  Soft start is performed in order to suppress the occurrence of an inrush current during lighting. However, if the half wavelength immediately after the soft start is fully turned off, the inrush current increases at the time of full lighting of the half wavelength following the full turn-off. On the other hand, in the image forming apparatus 10 according to the present embodiment, the start position of the half-wave control pattern is shifted so that the half wavelength immediately after the soft start is fully lit. As a result, the half wavelength immediately after the soft start can always be fully lit, so an increase in inrush current can be avoided.

  Furthermore, since the image forming apparatus 10 can perform half-wave control according to the half-wave control pattern only by shifting the start position of the half-wave control pattern, flicker can be reduced.

  When the halogen heater 121 is continuously turned on after the halogen heater 121 is turned on, the lighting duty determination unit 114 periodically determines the lighting duty based on the surface temperature and the target temperature obtained by the thermistor 122 and turns on the lighting. The control unit 117 performs half-wave control according to the half-wave control pattern specified based on the lighting duty. Note that the start position may or may not be changed in the half-wave control pattern used for half-wave control after half-wave control in step S114.

  When the control is performed with the same lighting duty following the half-wave control in step S114, the half-wave control pattern in which the start position is shifted in the control after half-wave control in step S114 as shown in FIG. It is desirable to use Thereby, it can avoid that the half wavelength of lighting or light extinction continues excessively.

  On the other hand, when the lighting duty is changed while the halogen heater 121 is lit, the used half-wave control pattern itself is changed. Therefore, it is not necessary to change the start position of the changed half-wave control pattern. .

  FIG. 6 is a flowchart showing heater control processing by the image forming apparatus 10 when the halogen heater 121 is turned off. When the control unit 113 receives an instruction to turn off the halogen heater 121 (step S200), the lighting duty determination unit 114 determines the lighting duty based on the surface temperature and the target temperature of the halogen heater 121 (step S202). Next, the pattern extraction unit 115 extracts a half-wave control pattern from the half-wave control pattern storage unit 112 based on the lighting duty (step S204). Further, when it is determined by the control unit 113 to perform soft stop (Yes in step S206), the start position changing unit 116 determines that the last half wavelength of the half-wave control pattern extracted by the pattern extraction unit 115 is Check if all lights are off. When the last half wavelength is all off (step S208, Yes), the start position of the half wave control pattern is changed (step S210).

  Here, the start position changing process (step S210) will be described. FIG. 7 is a diagram for explaining the start position changing process (step S210) when the lighting duty determination unit 114 determines the lighting duty 30% when the soft stop is executed. In the start position changing process, the start position changing unit 116 searches for the half wavelength that is fully lit from the half wave control pattern, determines the half wavelength that is fully lit as the end of the end half wave control pattern, and One or two or more half wavelengths behind are moved to the head of the original half wave control pattern. In the example shown in FIG. 7, the start position is shifted from the head of the original half-wave control pattern to six half wavelengths later by the above processing.

  The soft stop is performed for the purpose of reducing voltage fluctuation when the light is turned off immediately after half-wave control. However, when the half wavelength immediately before the soft stop is all extinguished, the soft stop is not performed immediately after the last half wavelength of the last full lighting in the half wave control, and thus flicker cannot be reduced sufficiently.

  In contrast, in the image forming apparatus 10 according to the present embodiment, the start position of the half-wave control pattern is shifted so that the half wavelength immediately before the soft stop is fully lit. Thereby, since the half wavelength immediately before the soft stop can be always turned on, flicker can be sufficiently reduced.

  Furthermore, even in this case, flicker can be reduced because half-wave control according to the half-wave control pattern can be performed only by shifting the start position of the half-wave control pattern.

  When the start position is changed by the start position changing unit 116, the lighting control unit 117 first performs half-wave control according to the half-wave control pattern in which the start position is changed (step S212), and then as a soft stop, After performing phase control according to the phase control pattern during soft stop extracted from the phase control pattern storage unit 111 (step S214), the halogen heater 121 is turned off (step S216). On the other hand, when the soft stop is not performed (No at Step S206), the lighting control unit 117 performs half-wave control according to the half-wave control pattern (Step S220), and then turns off the halogen heater 121 (Step S216). . This completes the heater control process when the halogen heater 121 is turned off.

  A first modification of the image forming apparatus 10 according to the first embodiment will be described. The image forming apparatus 10 according to the embodiment stores the half-wave control pattern of each lighting duty in advance, and extracts the half-wave control pattern associated with the determined lighting duty. A half-wave control pattern that avoids flicker may be created that is used in the set lighting duty. Even in this case, when the half-wave control pattern to be created is used immediately after the soft start, the half-wave control pattern is created so that the first half wavelength is fully lit. Further, when the half-wave control pattern to be created is used immediately before the soft stop, a half-wave control pattern is created so that the last half wavelength is fully lit.

  As described above, the image forming apparatus 10 uses the energization pattern used when the halogen heater 121 is lit as the half wave just before the first half wavelength that is fully lit as in the half wave control. A pattern to which partial lighting is assigned may be used, and the energization pattern used when the halogen heater 121 is turned on is not limited to the embodiment. Further, as the energization pattern used when the halogen heater 121 is turned off, a pattern in which partial lighting is assigned as in phase control to the half wavelength immediately after the last half wavelength in which full lighting is performed as in half wave control. The energization pattern used when the halogen heater 121 is turned off is not limited to the embodiment.

  Further, as a second modification example, in the case of performing soft start and soft stop, the start position changing unit 116 searches for a half wavelength that is continuously turned on for two half wavelengths, and the half wave control pattern The start position may be shifted to the second half wavelength among the half wavelengths that are continuously lit for two half wavelengths. FIG. 8 is a diagram for explaining a second modification. In this way, when the second half wavelength of the half wavelengths that are continuously lit for two half wavelengths is shifted to the start position of the half wave control pattern, the last half wave control pattern The half wavelength is also fully lit. Therefore, by repeating the half-wave control pattern after changing the start position, both the half wavelength immediately after the soft start and immediately before the soft stop can be turned on.

  In the above embodiment, the image forming apparatus according to the present invention is described by taking an example in which the image forming apparatus is applied to a multifunction machine having at least two functions among a copy function, a printer function, a scanner function, and a facsimile function. The present invention can be applied to any image forming apparatus such as a printer, a scanner apparatus, and a facsimile apparatus.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 100 Main power supply 101 AC power supply 102 Filter 103 Rectifier diode 104 Smoothing capacitor 106 Electromagnetic relay 107 Switch 108 Zero cross detection circuit 110 Control board 111 Phase control pattern memory | storage part 112 Half wave control pattern memory | storage part 113 Control part 114 Lighting duty determination Section 115 Pattern extraction section 116 Start position changing section 117 Lighting control section 120 Fixing unit 121 Halogen heater 122 Thermistor 141 Power supply SW
142 Door SW
143 TRI

Japanese Patent No. 3316170 JP 2004-212510 A

Claims (11)

Temperature detecting means for detecting the temperature of the heating object heated by the heater;
An AC power supply for applying an AC voltage to the heater;
A lighting ratio determining means for determining a lighting ratio of the heater based on the temperature of the heating object and a target temperature;
A pattern used when the AC power is turned on, in which the first control cycle is used as a unit, and partial lighting is assigned to a half wavelength of the AC voltage within the first control cycle in order to change the phase of the AC voltage Phase control pattern storage means for storing the obtained phase control pattern;
A pattern having a second control cycle as a unit, and a half-wave control pattern in which full lighting or full lighting is assigned to a half wavelength of the AC voltage in the second control cycle so as to avoid flicker, Half-wave control pattern storage means for storing in association with the lighting ratio;
In the half wave control pattern storage means, half wave control pattern extraction means for extracting a half wave control pattern associated with the lighting ratio determined by the lighting ratio determination means;
When the half-wave control pattern extracted by the half-wave control pattern extraction unit is used immediately after the phase control pattern, the half-wave control is performed when the first half-wave of the half-wave control pattern is off. Start position changing means for changing the start position of the half-wave control pattern so that the first half wavelength of the pattern is fully lit ;
Based on the half-wave control pattern start position is changed, the lighting control means for controlling the lighting of said heater,
Features and to Ruhi over motor controller further comprising a. Temperature detecting means for detecting the temperature of the heating object heated by the heater;
An AC power supply for applying an AC voltage to the heater;
A lighting ratio determining means for determining a lighting ratio of the heater based on the temperature of the heating object and a target temperature;
A pattern used when the AC power supply is turned off, in which the first control period is a unit, and partial lighting is assigned to a half wavelength of the AC voltage within the first control period in order to change the phase of the AC voltage Phase control pattern storage means for storing the obtained phase control pattern;
A pattern having a second control cycle as a unit, and a half-wave control pattern in which full lighting or full lighting is assigned to a half wavelength of the AC voltage in the second control cycle so as to avoid flicker, Half-wave control pattern storage means for storing in association with the lighting ratio;
In the half wave control pattern storage means, half wave control pattern extraction means for extracting a half wave control pattern associated with the lighting ratio determined by the lighting ratio determination means;
In the case where the half-wave control pattern extracted by the half-wave control pattern extraction unit is used immediately before the phase control pattern, the half-wave when the last half wavelength of the half-wave control pattern is all extinguished. Start position changing means for changing the start position of the half-wave control pattern so that the last half wavelength of the control pattern is fully lit ;
Based on the half-wave control pattern start position is changed, the lighting control means for controlling the lighting of said heater,
Features and to Ruhi over motor controller further comprising a. The phase control pattern storage means assigns partial lighting to a half wavelength of the AC voltage in the first control cycle in order to change the phase of the AC voltage in units of a first control cycle, and the AC power source In order to change the phase of the AC voltage in units of the first phase control pattern and the first control cycle used at the time of turning on, partial lighting is assigned to the half wavelength of the AC voltage within the first control cycle. is, stores a second phase control pattern to be used when the AC power-off,
The half-wave control pattern storage means is a pattern having a second control cycle as a unit, and all lighting or non-lighting is assigned to a half wavelength of the AC voltage in the second control cycle so as to avoid flicker. The half-wave control pattern is stored in association with the lighting ratio,
The half-wave control pattern extraction means, in the half-wave control pattern storing means, extracts a half-wave control pattern that is associated with the lighting ratio determined by the lighting ratio determining means,
The start position changing means is extracted by the half-wave control pattern extracting means when the first phase control pattern is used when the AC power is on and the second phase control pattern is used when the AC power is off. The start position of the half-wave control pattern is changed to the second half wavelength among the half wavelengths that are fully lit for two half wavelengths,
The heater control device according to claim 1, wherein the lighting control unit controls lighting of the heater based on the half-wave control pattern in which a start position is changed. The heater control device according to any one of claims 1 to 3 , wherein the first control cycle is an integral multiple of the second control cycle. Temperature detecting means for detecting the temperature of the heating object heated by the heater;
An AC power supply for applying an AC voltage to the heater;
A lighting ratio determining means for determining a lighting ratio of the heater based on the temperature of the heating object and a target temperature;
A pattern used when the AC power is turned on, in which the first control cycle is used as a unit, and partial lighting is assigned to a half wavelength of the AC voltage within the first control cycle in order to change the phase of the AC voltage Phase control pattern storage means for storing the obtained phase control pattern;
A pattern having a second control cycle as a unit, and a half-wave control pattern in which full lighting or full lighting is assigned to a half wavelength of the AC voltage in the second control cycle so as to avoid flicker, Half-wave control pattern storage means for storing in association with the lighting ratio;
In the half wave control pattern storage means, half wave control pattern extraction means for extracting a half wave control pattern associated with the lighting ratio determined by the lighting ratio determination means;
When the half-wave control pattern extracted by the half-wave control pattern extraction unit is used immediately after the phase control pattern, the half-wave control is performed when the first half-wave of the half-wave control pattern is off. Start position changing means for changing the start position of the half-wave control pattern so that the first half wavelength of the pattern is fully lit;
Based on the half-wave control pattern whose start position has been changed, lighting control means for controlling lighting of the heater ,
An image forming apparatus comprising: Temperature detecting means for detecting the temperature of the heating object heated by the heater;
An AC power supply for applying an AC voltage to the heater;
A lighting ratio determining means for determining a lighting ratio of the heater based on the temperature of the heating object and a target temperature;
A pattern used when the AC power supply is turned off, in which the first control period is a unit, and partial lighting is assigned to a half wavelength of the AC voltage within the first control period in order to change the phase of the AC voltage Phase control pattern storage means for storing the obtained phase control pattern;
A pattern having a second control cycle as a unit, and a half-wave control pattern in which full lighting or full lighting is assigned to a half wavelength of the AC voltage in the second control cycle so as to avoid flicker, Half-wave control pattern storage means for storing in association with the lighting ratio;
In the half wave control pattern storage means, half wave control pattern extraction means for extracting a half wave control pattern associated with the lighting ratio determined by the lighting ratio determination means;
In the case where the half-wave control pattern extracted by the half-wave control pattern extraction unit is used immediately before the phase control pattern, the half-wave when the last half wavelength of the half-wave control pattern is all extinguished. Start position changing means for changing the start position of the half-wave control pattern so that the last half wavelength of the control pattern is fully lit;
Based on the half-wave control pattern whose start position has been changed, lighting control means for controlling lighting of the heater,
An image forming apparatus comprising: A heater control method in a heater control device,
A temperature detection step for detecting the temperature of the heating object heated by the heater;
A lighting ratio determination step for determining a lighting ratio of the heater based on the temperature of the heating object and a target temperature;
A pattern to be utilized when AC power is turned on before Symbol heater, a first control period as a unit, part half wave of the AC voltage of the first control cycle to change the phase of the AC voltage A phase control pattern storage step for storing a phase control pattern to which lighting is assigned;
A pattern having a second control cycle as a unit, and a half-wave control pattern in which full lighting or full lighting is assigned to a half wavelength of the AC voltage in the second control cycle so as to avoid flicker, A half-wave control pattern storing step for storing in association with the lighting ratio;
In the half-wave control pattern storage step , a half-wave control pattern extraction step for extracting a half-wave control pattern associated with the lighting ratio determined in the lighting ratio determination step;
When the half-wave control pattern extracted in the half-wave control pattern extraction step is used immediately after the phase control pattern, the half-wave control is performed when the first half-wave of the half-wave control pattern is off. A start position changing step for changing the start position of the half-wave control pattern so that the first half wavelength of the pattern is fully lit ;
Based on the half-wave control pattern start position is changed, the lighting control step of controlling the lighting of said heater,
Heater control method characterized by having a. A heater control method in a heater control device,
A temperature detection step for detecting the temperature of the heating object heated by the heater;
A lighting ratio determination step for determining a lighting ratio of the heater based on the temperature of the heating object and a target temperature;
A pattern to be utilized when AC power is off before Symbol heater, a first control period as a unit, part half wave of the AC voltage of the first control cycle to change the phase of the AC voltage A phase control pattern storage step for storing a phase control pattern to which lighting is assigned;
A pattern having a second control cycle as a unit, and a half-wave control pattern in which full lighting or full lighting is assigned to a half wavelength of the AC voltage in the second control cycle so as to avoid flicker, A half-wave control pattern storing step for storing in association with the lighting ratio;
In the half-wave control pattern storage step , a half-wave control pattern extraction step for extracting a half-wave control pattern associated with the lighting ratio determined in the lighting ratio determination step;
When the half-wave control pattern extracted in the half-wave control pattern extraction step is used immediately before the phase control pattern, when the last half-wave of the half-wave control pattern is all extinguished, the half-wave A start position changing step for changing the start position of the half-wave control pattern so that the last half wavelength of the control pattern is fully lit ;
Based on the half-wave control pattern start position is changed, the lighting control step of controlling the lighting of said heater,
Heater control method characterized by having a. In the phase control pattern storing step, in order to change the phase of the AC voltage in units of the first control cycle, partial lighting is assigned to half-waves of the AC voltage within the first control cycle, In order to change the phase of the AC voltage in units of the first phase control pattern used when the AC power is turned on and the first control cycle, a part of the AC voltage is lit in half wavelength. It is assigned, and stores a second phase control pattern to be used when the AC power-off,
The half-wave control pattern storing step is a pattern having a second control cycle as a unit, and all lighting or all-off is assigned to a half wavelength of the AC voltage in the second control cycle so as to avoid flicker. The half-wave control pattern is stored in association with the lighting ratio ,
The half-wave control pattern extraction step, in the half-wave control pattern storing step, extracts a half-wave control pattern that is associated with the lighting ratio determined by the lighting ratio determining step,
The start position changing step is extracted in the half-wave control pattern extraction step when the first phase control pattern is used when the AC power is on and the second phase control pattern is used when the AC power is off. It is the start position of the half-wave control pattern, 2 half the wavelength continuously full lighting variations in the second half-wave of the half wavelength puff,
In the lighting control step, immediately after the lighting control based on the first phase control pattern and immediately before the lighting control based on the second phase control pattern, based on the half-wave control pattern in which the start position is changed. The heater control method according to claim 7 , wherein lighting of the heater is controlled. The heater control method according to any one of claims 7 to 9 , wherein the first control cycle is an integral multiple of the second control cycle. A heater control program for causing a computer to execute the heater control method according to any one of claims 7 to 10 .

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