JP2008003469A - Heating device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating device and an image forming apparatus, constituted so that common product can be supplied throughout the world, regardless of 100 V system commercial power supply regions or 200 V system commercial power supply regions, will not cause failures such as errors and troubles, can appropriately switch the operating mode, and can obtain proper image fixing. <P>SOLUTION: The heating device includes a ceramic heater 109c, an ON/OFF-control switch 202, a thermistor 109d and an engine controller 126. The ceramic heater 109c has a series connection mode, corresponding to the 200 V system commercial power supply and a parallel connection mode, corresponding to the 100 V system commercial power supply. The duty value of the ON/OFF-control switch 202 is monitored by the engine controller 126, and the ceramic heater 109 is switched between the serial connection mode and the parallel connection mode, based on the monitored duty value. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heating device and an image forming apparatus, and more particularly to a heat fixing device as a heating device, and an image forming device such as a copying machine, a facsimile, and a printer including the heat fixing device. Further, the present invention relates to a universal heat fixing device that can be used in common in both 100V / 200V AC power supply voltages. The present invention also relates to a universal image forming apparatus that includes these heat fixing devices and can be used in common in both AC power supply voltage 100 V system / 200 V system regions.

  In recent years, various products have traveled between countries, and it is not uncommon for a single product to be widely distributed around the world. Under such circumstances, there are cases where differences in commercial power supply voltage or the like become a problem depending on the region of the world, and there is a situation in which specifications must be distinguished and shipped to each region.

  In an image forming apparatus such as a copying machine or a printer that forms an image by heating and fixing toner on a recording medium, it is necessary to generate an appropriate amount of heat when supplying power to a heating member such as a heater serving as a heat source. Which does not depend on the commercial power supply voltage input to the image forming apparatus. Therefore, conventionally, the optimum amount of heat for each commercial power supply voltage is generated for commercial power supply voltages in each region, for example, 100V power supply areas mainly in Japan and North America, and 200V power supply areas such as China, Europe and South America. The heat fixing device to be made was separately manufactured and provided. Two types of image forming apparatuses corresponding to the voltages of the 100V system / 200V system must be manufactured, managed, and provided. As a result, individual parts corresponding to each commercial power supply voltage have to be developed, manufactured, and managed, resulting in an increase in cost due to an increase in the number of parts.

As a method for solving this problem, for example, an invention as disclosed in Patent Document 1 is disclosed, and a common component can be used by appropriately switching the connection direction of an electric board or the like regardless of the commercial power supply voltage. Therefore, even if the commercial power supply voltage is 100V system or 200V system, a heat fixing device included in an operable image forming apparatus is manufactured by switching a simple method, that is, by switching the connection. A method of manufacturing, managing, and providing an image forming apparatus has been used.
JP 2004-86096 A

  However, in the above conventional example, it is necessary to set and manufacture a product for each commercial power supply voltage region at the factory, and in order to perform appropriate control corresponding to each region, in the case of a 100V commercial power supply and a 200V commercial power supply. In the case of a power supply, it is necessary to switch the setting of the thermal fixing device at the time of manufacture. Therefore, the same product cannot be produced as an image forming apparatus, and it is necessary to separately manufacture, manage, and provide products for each region. Therefore, there is a risk of causing an increase in cost due to these.

  In some areas, 100V commercial power supply and 200V commercial power supply coexist, making it difficult to provide products. In some cases, human error causes connection to the wrong commercial power supply voltage. Fear cannot be denied.

  Furthermore, there are areas and environments where the commercial power supply voltage is unstable, and in some cases, a high voltage is supplied while being in the 100V commercial power supply area, or vice versa. In some cases, only a low voltage is supplied.

  In such a case, the image forming apparatus itself is compatible with a 100V / 200V commercial power supply, but the product is not set appropriately, so that it is difficult to obtain a good fixability of the image, In some cases, it may cause a failure. For example, if a product compatible with a 200V commercial power supply is to be operated with a 100V commercial power supply, sufficient voltage cannot be supplied to the thermal fixing device because the voltage is low. Therefore, the heat capacity necessary for heat fixing cannot be obtained, and an unfixed image is output, or an error occurs because the temperature does not rise. Conversely, if a product corresponding to a 100V commercial power supply is to be operated with a 200V commercial power supply, excessive power is supplied to the thermal fixing device because the voltage is high. For this reason, the temperature rises rapidly, so that the control is impossible, the fine temperature control cannot be performed, an error is caused, and the fixing unevenness occurs in the output image. Moreover, even if it operates barely, there is a possibility that the noise level such as the terminal noise voltage may be deteriorated, for example, the phase angle of the phase angle control becomes very small in the power control.

  The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to provide a common product regardless of whether it is a 100 V system commercial power source region or a 200 V system commercial power source region. The present invention provides a heating apparatus and an image forming apparatus that can be supplied to the world. In addition, the present invention provides a heating apparatus and an image forming apparatus capable of appropriately switching the operation mode and obtaining a good image fixing property without causing a problem such as an error or a failure without distinguishing between products. A region where 100V commercial power supply and 200V commercial power supply coexist, a case where a high voltage is supplied while being in a 100V system commercial power supply region, or a case where only a low voltage is supplied while being in a 200V system commercial power supply region However, the heating apparatus and the image forming apparatus are provided.

  In order to solve the above problems, a heating device and an image forming apparatus of the present invention have the following configurations.

  (1) In a heating apparatus that includes a heat generating means and operates corresponding to at least two types of input voltages, a high input voltage and a low input voltage, and that heats the heat generating means, at least the high input voltage and the low input voltage A power supply means that operates in response to two types of input voltages and supplies power to the heat generating means; a temperature detection means that is provided near the heat generating means and detects the temperature of the heat generating means; and Control means for controlling the power supply means based on the output, and adjusting the power input ratio of the power supply means to the power that can be supplied to the heat generation means to control the temperature of the heat generation means. The means has at least two kinds of operation modes corresponding to at least two kinds of input voltages of the high input voltage and the low input voltage, and the control means is a power of the power supply means. It monitors the incoming ratio, heating device and switches the operation mode of the heating means based on a result of the monitoring.

  (2) The control means operates when the heating means operates in an operation mode corresponding to the low input voltage and the power supply ratio of the power supply means is lower than a reference power input ratio d1. The heating apparatus according to (1), wherein the operation mode is switched to an operation mode corresponding to the high input voltage.

  (3) The control means operates when the heat generating means operates in an operation mode corresponding to the high input voltage and the power supply ratio of the power supply means is higher than a reference power input ratio d2. The heating apparatus according to (1), wherein the operation mode is switched to an operation mode corresponding to the low input voltage.

  (4) In a heating apparatus that includes a heat generating means and operates corresponding to at least two types of input voltages, a high input voltage and a low input voltage, and that heats the heat generating means, at least the high input voltage and the low input voltage A power supply means that operates in response to two types of input voltages and supplies power to the heat generating means; a temperature detection means that is provided near the heat generating means and detects the temperature of the heat generating means; and Control means for controlling the power supply means based on the output, and adjusting the power input ratio of the power supply means to the power that can be supplied to the heat generation means to control the temperature of the heat generation means. The means has at least two kinds of operation modes corresponding to at least two kinds of input voltages of the high input voltage and the low input voltage, and the control means is an operation mode of the heating means. Is set to the operation mode corresponding to the high input voltage, the power input ratio of the power supply means is set to a predetermined value, power supply to the heat generating means is started, and the output of the temperature detection means is monitored. As a result of the monitoring, when the temperature increase rate is smaller than the reference temperature increase rate s1, the heating device switches the operation mode of the heating means to an operation mode corresponding to the low input voltage.

  (5) In a heating apparatus that includes a heat generating unit and operates in accordance with at least two types of input voltages, a high input voltage and a low input voltage, and heats the heat generating unit, at least the high input voltage and the low input voltage A power supply means that operates in response to two types of input voltages and supplies power to the heat generating means; a temperature detection means that is provided near the heat generating means and detects the temperature of the heat generating means; and Control means for controlling the power supply means based on the output, and adjusting the power input ratio of the power supply means to the power that can be supplied to the heat generation means to control the temperature of the heat generation means. The means has at least two kinds of operation modes corresponding to at least two kinds of input voltages of the high input voltage and the low input voltage, and the control means is an operation mode of the heating means. Is set to an operation mode corresponding to the high input voltage, the detection result of the temperature detection means is controlled to become a determined temperature rise rate, the power input ratio of the power supply means is monitored, and the result of the monitoring When the power input ratio is higher than the reference power input ratio d3, the heating device switches the operation mode of the heat generating means to an operation mode corresponding to the low input voltage.

  (6) The control means stores and holds the operation mode of the heat generating means that was set at the end of the operation of the heating device, and the operation that is stored and held when the heat generating means is next heated. The heating device according to any one of (1) to (5), wherein the heating device is operated in a mode.

  (7) The heat generating means has at least two heat generating elements that generate heat by applying a voltage to both ends and have substantially the same resistance characteristics, and the power supply means is an electrode that supplies power to the heat generating means. A and an electrode B, the two heating elements are connected in series, and have an electrode C and an electrode D, and an electrode E between the two heating elements, and the electrode A is the electrode C The electrode D can be selectively connected to the electrode A or the electrode B via the first switching means, and the electrode E can be connected to the electrode B via the second switching means The heating apparatus according to any one of (1) to (5), wherein:

  (8) The heating device according to any one of (1) to (7), further comprising a universal power supply that operates in response to at least two types of input voltages, the high input voltage and the low input voltage. .

  (9) An image forming apparatus comprising the heating device according to any one of (1) to (8).

  According to the present invention, even when the input voltage is switched from a high voltage to a low voltage for some reason while the heating device is in operation, an appropriate operation mode is obtained without causing a malfunction such as an error or a failure. And stable operation can be performed.

  Whether the input voltage is low or the input voltage is high, the operation mode can be switched appropriately without any distinction between input voltages and without causing errors or malfunctions. , Can operate stably.

  Furthermore, by storing and holding the operation mode, it is possible to operate smoothly at each startup.

  Switching corresponding to these input voltages can be realized with a minimum component configuration.

  It is possible to provide an image forming apparatus having these characteristics and capable of obtaining good image fixing properties.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

  Hereinafter, a first embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic cross-sectional view of an image forming apparatus using an electrophotographic process, and shows, for example, a laser beam printer.

  A laser beam printer main body 101 (hereinafter referred to as printer 101) has a paper feed cassette 102 in which recording paper S is stored. Also, a cassette presence / absence sensor 103 that detects whether or not the recording paper S is in the paper feed cassette 102, and a cassette size sensor 104 (consisting of a plurality of microswitches) that detect the size of the recording paper S in the paper feed cassette 102. Have). Further, a paper feed roller 105a for feeding the recording paper S from the paper feed cassette 102, a pair of transport rollers 105b, 105c, 105d, and the like are provided. A registration roller pair 106 that synchronously conveys the recording paper S is provided downstream of the paper feed roller 105a and the conveyance roller pairs 105b, 105c, and 105d. Further, a paper feed sensor 124 for detecting the leading edge and the trailing edge of the recording paper S and taking an image writing timing is provided downstream of the registration roller pair 106. A process cartridge 108 for forming a toner image on the recording paper S based on the laser beam 118 from the laser scanner unit 107 is provided.

  Further, a fixing device 109 (corresponding to a heating device) for thermally fixing the toner image formed on the recording paper S is provided downstream of the process cartridge 108. Downstream of the heat fixing unit in the fixing device 109, a paper discharge sensor 110 that detects the conveyance state of the paper discharge unit, a pair of conveyance rollers 111 that convey the recording paper S, and a pair of face-up paper discharge rollers that discharge the recording paper S are provided. 140, a stacking tray 112 for stacking recording sheets S on which recording has been completed is provided. The conveyance reference of the recording paper S is set so as to be centered with respect to the length of the recording paper S in the direction orthogonal to the conveyance direction of the image forming apparatus, that is, the width of the recording paper S.

  The paper discharge sensor 110 is provided inside the fixing device 109 and detects the timing at which the recording paper S has passed through the thermal fixing unit. The recording paper S passes through the conveyance roller pair 111 and is then discharged to the stacking tray 112 via the face-up paper discharge roller pair 140. The full load detection sensor 142 provided in the paper discharge unit is a sensor that detects whether the recording paper S on the stacking tray 112 is full and detects the movement of the recording paper S in the paper discharge unit.

  The laser scanner 107 includes a laser unit 113 that emits a laser beam modulated based on an image signal (image signal / VDO) transmitted from an external device 131 described later. The laser unit 113 includes a polygon motor 114, an imaging lens 115, a folding mirror 116, and the like for scanning a later-described photosensitive drum 117 with laser light.

  The process cartridge 108 includes a photosensitive drum 117, a primary charging roller 119, a developing device 120, a transfer charging roller 121, a cleaner 122, and the like necessary for a known electrophotographic process. The fixing device 109 includes a fixing film 109a, a pressure roller 109b, a ceramic heater 109c (corresponding to a heat generating means) provided in the fixing film, and a thermistor 109d (corresponding to a temperature detecting means) for detecting the surface temperature of the ceramic heater. It is configured.

  The main motor 123 applies driving force to the paper feed roller 105a via the paper feed roller clutch 125, and to the transport roller pairs 105b, 105c, 105d and to the registration roller pair 106 via the registration roller clutch 129. Yes. Further, a driving force is applied to each unit of the process cartridge 108 including the photosensitive drum 117, the fixing device 109, the discharge roller pair 111, and the face-up discharge roller pair 140.

  Reference numeral 126 denotes an engine controller (corresponding to a control means), which controls the electrophotographic process by the laser scanner unit 107, the process cartridge 108, and the fixing device 109, and controls the conveyance of the recording paper S in the printer 101.

  Reference numeral 127 denotes a video controller, which is connected to an external device 131 such as a personal computer via a general-purpose interface 130 (Centronics, RS232C, USB, etc.). Then, the image information sent from the general-purpose interface 130 is developed into bit data, and the bit data is sent to the engine controller 126 as a / VDO signal.

  A line 128 connecting the engine controller 126 and the video controller 127 includes a command / status signal line, a clock signal line, a / VDO signal line, a synchronization signal line, and the like between the controllers.

  Next, the configuration of the fixing unit will be described. The fixing unit is configured as shown in FIG. 2, and power is supplied to the fixing device 109 from a commercial power source 201 (corresponding to an input voltage). The ceramic heater (hereinafter simply referred to as a heater) 109c is composed of two heating elements having a resistance value R as shown in the figure. The selector switch 203 (corresponding to the second switching means) and the selector switch 204 (corresponding to the first switching means) are switched. One of the two heating elements (corresponding to the electrode C) is connected to the terminal A side (corresponding to the electrode A), and the changeover switch 204 is connected to the other (corresponding to the electrode D). The changeover switch 203 is provided so that a terminal C (corresponding to the electrode B) and a terminal D (corresponding to the electrode E) from between the two heating elements can be connected.

  This switches to the serial connection mode (FIG. 3A) (corresponding to an operation mode corresponding to a high input voltage) set mainly when the commercial power supply 201 is a 200V system (corresponding to a high input voltage). It is like that. Alternatively, the mode is switched to the parallel connection mode (FIG. 3B) (corresponding to an operation mode corresponding to a low input voltage) set mainly when the commercial power supply 201 is a 100V system (corresponding to a low input voltage). It has become. Instructions to these changeover switches 203 and 204 are given by the engine controller 126. For example, the resistance value of the heater 109c is set to R = 20Ω. At this time, for an input voltage of 120 V, the changeover switch 203 is turned on and the changeover switch 204 is switched to the terminal A side as shown in FIG. 3B to enter the parallel connection mode, and the heater 109c generates heat of up to 1440 W. Is possible. On the other hand, for an input voltage of 240 V, the selector switch 203 is turned off and the selector switch 204 is switched to the terminal side (corresponding to the electrode B) as shown in FIG. In addition, the heater 109c can generate a maximum of 1440W. Therefore, the maximum power that can be supplied to the heater 109c can be 1440W and the same power for both the 120V and 240V systems.

  Next, the startup operation of the heater 109c (hereinafter also referred to as a fixing heater) will be described with reference to the flowchart shown in FIG. 5 and FIGS. First, when the main power of the printer 101 is turned on (step S101), the engine controller 126 starts a pre-multiple rotation for warm-up (step S102). At this time, by driving the main motor 123, each unit of the process cartridge 108 including the photosensitive drum 117, the fixing device 109, the paper discharge roller pair 111, and the face-up paper discharge roller pair 140 are rotationally driven. At the same time, the driving of the heater 109c in the fixing device 109 is started, and a preparatory operation for a predetermined process device is executed.

  In this heater drive, as shown in the flowchart of FIG. 5, the engine controller 126 controls as follows. First, the selector switches 203 and 204 are switched to the serial connection mode that is also for the 200V region as shown in FIG. 3A (step S103). Then, the ON / OFF control switch 202 (corresponding to the power supply means) is driven with a predetermined duty value (corresponding to the power input ratio) (step S104).

  The engine controller 126 controls the duty value by controlling the ON / OFF control switch 202, for example, an ON / OFF control switch including a switching element such as a triac, to change the phase angle or the wave number to which power is applied.

  The heater 109c starts to be heated by the electric power supplied by the ON / OFF control switch 202, and the temperature gradually rises. At this time, the engine controller 126 monitors the rising curve when the temperature rises with the thermistor 109d. Then, the temperature increase rate ΔT ′ / Δt is compared with a predetermined temperature increase rate ΔT / Δt (corresponding to the reference temperature increase rate s1) stored and held in the engine controller 126 (step S105, FIG. 4).

  When the engine controller 126 determines that the temperature increase rate ΔT ′ / Δt of the heater 109c is lower than the predetermined temperature increase rate ΔT / Δt (FIG. 4A) (step S105), the voltage of the commercial power supply 201 is 100V. Judge that there is. Then, the selector switches 203 and 204 are switched to the parallel connection mode as shown in FIG. 3B (step S106). Thereafter, while the printer 101 is energized, the fixing device 109 is controlled while the changeover switches 203 and 204 are always switched to the parallel connection mode.

  On the other hand, when the engine controller 126 determines that the temperature increase rate ΔT ′ / Δt of the heater 109c is higher than the predetermined temperature increase rate ΔT / Δt (FIG. 4B) (step S105), the voltage of the commercial power supply 201 Is determined to be a 200V system. Then, as shown in FIG. 3A, the changeover switches 203 and 204 are held in the serial connection mode, and thereafter, during energization, the fixing device 109 is controlled while the changeover switches 203 and 204 are always switched to the serial connection mode. Do.

  At this time, the temperature increase rate ΔT / Δt is set in consideration of the following points. That is, the maximum voltage of the 100V commercial power supply, for example, a voltage with a margin of + 10% with respect to 127V in the Mexican region or the like, and the margin of -15% with respect to the minimum voltage of the 200V commercial power supply, for example, 220V 187V, which is a voltage with This is set in consideration of the variation of the heater 109c and the variation of the ON / OFF control switch 202.

  The engine controller 126 then causes the heater 109c to reach a predetermined temperature (step S107) and finishes the preparation operation of each process device (step S108), and enters a standby state (step S109).

  Next, the printing operation will be described.

  When the engine controller 126 receives a print operation start command from the video controller 127, the engine controller 126 starts the print operation. Driving of the main motor 123, starting of the ceramic heater 109c (details will be described later), and driving of the polygon motor 114 are started. By driving the main motor 123, the photosensitive drum 117 and the transfer charging roller 121, the fixing film 109a and the pressure roller 109b of the fixing device 109, the conveyance roller pair 111, and the face-up discharge roller pair 140 start to rotate. Thereafter, the engine controller 126 starts the light amount control of the laser unit 113 and sequentially drives the primary charging roller 119, the developing device 120, and the transfer charging roller 121 to a high voltage.

  The engine controller 126 detects that the rotation of the polygon motor 114 is in a steady state from the pulse interval of the / BD signal sent from the laser light detection sensor by a CPU (not shown). Then, the paper feed roller clutch 125 is turned on to drive the paper feed roller 105a, and the recording paper S in the paper feed cassette 102 is fed out one by one. The paper feed roller clutch 125 is immediately turned off when one sheet of recording paper S is fed from the cassette. The fed recording sheet S is conveyed toward the registration roller pair 106 by the conveyance roller pairs 105b, 105c, and 105d rotated by the registration roller clutch 129 that is turned on together with the paper supply roller clutch 125. Then, the CPU detects that the recording paper S has reached the paper feed sensor 124 and starts outputting a synchronization signal to the video controller 127. In addition, the paper feeding registration roller clutch 129 is turned off to temporarily stop the driving of the conveyance roller pairs 105b, 105c, 105d and the registration roller pair 106.

  At that time, the video controller 127 has started developing the image information into a dot image, and has completed preparations for starting the output of the / VDO signal. The video controller 127 receives the synchronization signal from the engine controller 126 and starts outputting the / VDO signal as image data for one page.

  On the other hand, the engine controller 126 turns on the registration roller clutch 129 again at the start of the output of the synchronization signal, and resumes driving of the conveying roller pairs 105b, 105c, 105d and the registration roller pair 106. The conveyance roller pairs 105 b, 105 c, 105 d and the registration roller pair 106 are driven until the trailing edge of the recording paper S passes the registration roller pair 106. During this time, the engine controller 126 drives the laser unit 113 according to the / VDO signal from the video controller 127. The laser beam 118 emitted from the laser unit 113 is converted into a linear scan by the rotation of the polygon mirror 114 of the laser scanner unit 107, and is irradiated onto the photosensitive drum 117 by the imaging lens 115 and the folding mirror 116.

  The photosensitive drum 117 is rotationally driven in the clockwise direction in FIG. 1 at a predetermined peripheral speed (process speed). The photosensitive drum 117 is uniformly charged to a predetermined polarity and potential by a primary charging roller 119 as a charging means during the rotation process. Scanning exposure using a laser beam modulated and controlled (ON / OFF control) with respect to a time-series electric digital pixel signal of target image information output from the laser scanner unit 107 to the uniformly charged surface of the photosensitive drum 117. Is made. Then, an electrostatic latent image of target image information is formed on the surface of the photosensitive drum 117. The electrostatic latent image formed on the photosensitive drum 117 is developed with a developer (toner) and visualized by a developing device 120 as a developing unit.

  On the other hand, the recording sheet S fed out one by one is transferred to a transfer nip portion, which is a pressure contact portion between the photosensitive drum 117 and the transfer charging roller 121 as a transfer means, by a pair of conveying rollers 105b, 105c, 105d and a pair of registration rollers 106. It is fed at the control timing. Then, the toner image on the surface of the photosensitive drum 117 is sequentially transferred onto the surface of the recording paper S. The recording sheet S exiting the transfer nip is sequentially separated from the surface of the photosensitive drum 117 during the rotation process, and is introduced into the fixing device 109 for fixing the toner image. Toner on the recording paper S is applied to the recording paper S passing between the fixing film 109a and the pressure roller 109b by applying heat from the ceramic heater 109c through the fixing film 109a and applying pressure by the pressure roller 109b. The image is heat-fixed. The recording sheet S exiting the fixing device 109 is printed out on the stacking tray 112 by the pair of conveyance rollers 111 and the pair of face-up discharge rollers 140.

  The photosensitive drum 117 after the recording paper S is separated is cleaned by a cleaner 122 as a cleaning unit to remove adhered contaminants such as transfer residual toner, and the electrophotographic image is started repeatedly by charging. Served for formation.

  Next, the fixing control of this embodiment will be described including the flowchart shown in FIG. The engine controller 126 stores the operation modes of the changeover switches 203 and 204 set at the time of multiple front rotation. That is, it stores either the serial connection mode (FIG. 3A) or the parallel connection mode (FIG. 3B), and the heater 109c is started up in the stored operation mode (step S202). . In that case, in order to achieve a predetermined temperature rise curve, the duty value may be controlled, or the control may be performed with a predetermined duty value to increase the temperature to a predetermined temperature.

  Thereafter, the engine controller 126 controls the duty value by controlling the ON / OFF control switch 202 to change the phase angle and the wave number to which power is applied in order to maintain the temperature of the heater 109c at a desired temperature. The electric power supplied to the heater 109c is controlled by increasing / decreasing the duty value, and the heater 109c is held at a desired temperature (step S203).

  When the temperature control of the heater 109c is performed at a desired temperature, the engine controller 126 monitors the duty value supplied to the heater 109c. For example, during the operation in the parallel connection mode (FIG. 3B) that is also for the 100V region, the duty value D falls below a predetermined value D1 (corresponding to the reference power input ratio d1) for a predetermined time t1 or more. (D <D1) (step S204, step S208). In this case, it is determined that it is preferable to perform control in the serial connection mode (FIG. 3A) in which the voltage of the commercial power supply 201 is also for a higher 200V region, and the changeover switches 203 and 204 are set in the serial connection mode ( Switching to FIG. 3A) (step S209). Therefore, even if the voltage of the commercial power supply 201 does not change at the same voltage as when the printer is started up, the parallel connection mode (FIG. 3B) may be switched to the serial connection mode (FIG. 3A). is there. That is, even when the periphery of the fixing device 109 is sufficiently warmed due to continuous printing for a long time and so on, so much power is not required, the parallel connection mode (FIG. 3B) is changed to the serial connection mode (FIG. 3A). It may change. Here, the predetermined time t1 may be a continuous time, or may be a total time that falls below the duty value D1 during a certain fixed time.

  As described above, even if the voltage of the commercial power supply 201 is 100 V, harmonic noise, terminal noise voltage, flicker, power factor, and the like are improved by appropriately switching to the serial connection mode (FIG. 3A). Can do.

  Further, during the operation in the series connection mode (FIG. 3A) also for the 200V region (step S205), the duty value D exceeds a predetermined value D2 (corresponding to the reference voltage input rate d2) for a predetermined time t1 or more. Consider the case of exceeding (D> D2). In this case, it is determined that it is preferable to perform control in the parallel connection mode (FIG. 3B) in which the voltage of the commercial power supply 201 is also for a lower 100V region (step S210). Then, the changeover switches 203 and 204 are switched to the parallel connection mode (FIG. 3B) (step S211).

  If printing is completed (step S206), the process ends normally in step S207. If printing is not completed (step S206), the process returns to step S203.

  In the present embodiment, the system is always started in the serial connection mode at the time of multiple rotations before the power is turned on, after returning from sleep, or after some processing to the printer 101 such as jam processing. And after that, it describes in the example which memorize | stores and hold | maintains the operation mode judged at the time of previous multi-rotation in either serial connection mode or parallel connection mode. However, as a matter of course, after that, every time printing is performed, it may be determined again whether the input is a 100V power supply or a 200V power supply.

  When switching between the serial connection mode (FIG. 3A) and the parallel connection mode (FIG. 3B), the ON / OFF control switch 202 is turned off. At this time, the printing operation is once stopped and the energization to the heater is stopped, and the switch is switched from the parallel connection mode to the series connection mode or from the series connection mode to the parallel connection mode. In the subsequent control, the fixing unit is controlled in the changed operation mode. The switching may be performed during printing or between prints (the rotation control of the main motor 123 or the like is not stopped), or may be completely stopped once and performed during standby. Usually, it is preferable to perform it during a paper interval or in a standby state where the image is not affected.

  In the above-described embodiment, a printer as an image forming apparatus is described. However, the present invention can be applied to all devices including a heating device.

  As described above, by realizing the present embodiment, the same printer can be supplied to each region in the world without being divided between the 100V power supply voltage region and the 200V power supply voltage region. In addition, for example, even when the power supply voltage is low enough to cause an abnormality in driving of the fixing device in the 200V power supply voltage region, the printing operation can be performed correctly without causing an error. On the other hand, even if the power supply voltage is high enough to cause abnormality in driving the fixing device, the printing operation can be performed correctly and without causing an error even though the power supply voltage region is 100V. Furthermore, it is possible to cope with regions where power supply voltage fluctuation is severe. In addition, since the changeover switches 203 and 204 are configured, even if a failure such as contact welding occurs in these changeover switches, a failure due to a short circuit between both poles of the AC power source does not occur.

  Further, as described above, even when the voltage of the commercial power supply 201 is 100 V, when it is necessary to reduce the input power because the fixing device is sufficiently warmed, the series connection mode (FIG. 3 ( a)). Thereby, harmonic noise, terminal noise voltage, flicker, power factor, and the like can be improved.

  Next, a second embodiment of the present invention will be described with reference to the drawings. Since the main configuration and operation are the same as those described in the first embodiment of the present invention, they are omitted.

  In the present embodiment, when the heater 109c at the time of warm-up is started, the heater 109c is started at a predetermined temperature rise rate, and the duty value to be input to the heater 109c is set in accordance with the rise rate. Adjustments are made as appropriate. The duty value at that time is monitored, and the input voltage is determined based on the duty value.

  Next, the operation will be described including the flowchart shown in FIG. 7 and FIGS. First, when the main power of the printer 101 is turned on (step S301), the engine controller 126 starts a pre-multiple rotation for warm-up (step S302). At this time, by driving the main motor 123, each unit of the process cartridge 108 including the photosensitive drum 117, the fixing device 109, the paper discharge roller pair 111, and the face-up paper discharge roller pair 140 are rotationally driven. At the same time, the driving of the heater 109c in the fixing device 109 is started, and a preparatory operation for a predetermined process device is executed.

  In this heater drive, as shown in the flowchart of FIG. 7, the engine controller 126 first switches the changeover switches 203 and 204 to the serial connection mode that is also for the 200V region as shown in FIG. 3A (step S303). Then, the ON / OFF control switch 202 is controlled to increase the temperature of the heater 109c at a predetermined temperature increase rate (step S304).

  The engine controller 126 controls the duty value by controlling the ON / OFF control switch 202, for example, an ON / OFF control switch including a switching element such as a triac, to change the phase angle or the wave number to which power is applied. The electric power supplied to the heater 109c is controlled by increasing / decreasing the duty value, and the temperature of the heater 109c is increased at a desired temperature increase rate.

  The heater 109c starts to be heated by the electric power supplied by the ON / OFF control switch 202, and the temperature gradually rises. At this time, the engine controller 126 monitors the duty value D when the temperature rises, and compares it with a predetermined duty value D3 (corresponding to the reference power input ratio d3) stored and held in the engine controller 126 (step S3). S305). If the duty value D exceeds the predetermined value D3 by a predetermined time t2 or more (D> D3) (step S305), it is determined that the voltage of the commercial power supply 201 is 100V. Then, the selector switches 203 and 204 are switched to the parallel connection mode as shown in FIG. 3B (step S306). Thereafter, while the printer 101 is energized, the fixing device 109 is controlled while the changeover switches 203 and 204 are always switched to the parallel connection mode (step S307).

  Here, the predetermined time t2 may be a continuous time, or may be a total of time exceeding the duty value D3 during a certain fixed time. In addition, the predetermined temperature rise rate mentioned here means driving at a minimum voltage value of a 200V system power supply input, for example, 187V which is -15% of 220V. In addition, in consideration of variations due to the heater 109c, the ON / OFF control switch 202, etc., even if all of them are swung in the worst direction, it is necessary that the temperature rise rate does not reach 100%.

  On the other hand, when the engine controller 126 determines that the duty value when the power is supplied to the heater 109c is equal to or less than the predetermined value D3 (D <D3) (step S305), it is determined that the voltage of the commercial power supply 201 is 200V. To do. Then, as shown in FIG. 3A, the changeover switches 203 and 204 are held in the serial connection mode, and thereafter, during energization, the changeover switches 203 and 204 are always switched to the serial connection mode to control the fixing device 109. This is performed (step S307).

  The engine controller 126 then causes the heater 109c to reach a predetermined temperature (step S307), finishes the preparation operation of each process device (step S308), and enters a standby state (step S309).

  Since the printing operation is the same as that described in the first embodiment of the present invention, the description thereof will be omitted.

  As described above, by realizing the present embodiment, the same printer can be supplied to each region in the world without being divided between the 100V power supply voltage region and the 200V power supply voltage region. In addition, for example, even when the power supply voltage is low enough to cause a malfunction in the fixing device drive even in the 200V power supply voltage region, the printing operation can be performed correctly without causing an error. On the other hand, even when the power supply voltage is high enough to cause an abnormality in the fixing device drive even in the 100 V power supply voltage region, the printing operation can be performed correctly without causing an error. Furthermore, it is possible to cope with regions where power supply voltage fluctuation is severe. In addition, since the changeover switches 203 and 204 are configured, even if a failure such as contact welding occurs in these changeover switches, a failure due to a short circuit between both poles of the AC power source does not occur.

  Further, as described above, even when the voltage of the commercial power supply 201 is 100 V, when it is necessary to reduce the input power because the fixing device is sufficiently warmed, harmonic noise, terminal noise voltage, Flicker, power factor, etc. can be improved. This is based on a configuration in which the mode is appropriately switched to the serial connection mode (FIG. 3A).

1 is a schematic sectional view showing an image forming apparatus according to the present invention. 1 is a block diagram showing a circuit configuration of a fixing device in a first embodiment. It is a block diagram which shows the circuit connection of the heater in 1st Example, (a) is a block diagram which shows the circuit connection of series connection mode, (b) is a block diagram which shows the circuit connection of parallel connection mode 6 is a graph showing a relationship between time and temperature indicating heater start-up control in the first embodiment, where (a) is a graph when ΔT> ΔT ′, and (b) is a graph when ΔT <ΔT ′. Flowchart showing fixing heater start-up control in the first embodiment Flowchart showing fixing heater control in the first embodiment. Flowchart showing fixing heater start-up control in the second embodiment

Explanation of symbols

101 Image forming apparatus 109 Fixing device (equivalent to heating device)
109c Ceramic heater (equivalent to heat generating means)
109d thermistor (equivalent to temperature detection means)
126 Engine controller (equivalent to control means)
201 Commercial power supply (equivalent to input voltage)
202 ON / OFF control switch (equivalent to power supply means)
203 changeover switch (equivalent to the second switching means)
204 changeover switch (equivalent to the first switching means)

Claims (9)

In a heating apparatus that includes a heating means, operates corresponding to at least two types of input voltages, a high input voltage and a low input voltage, and heats the heating means.
Power supply means that operates corresponding to at least two types of input voltages, the high input voltage and the low input voltage, and supplies power to the heat generating means;
A temperature detecting means provided in the vicinity of the heat generating means for detecting the temperature of the heat generating means;
Control means for controlling the power supply means based on the output of the temperature detection means and adjusting the power input ratio of the power supply means to the power that can be supplied to the heat generation means to control the temperature of the heat generation means; With
The heating means has at least two types of operation modes corresponding to at least two types of input voltages, the high input voltage and the low input voltage,
The heating device characterized in that the control means monitors the power input ratio of the power supply means and switches the operation mode of the heat generating means based on the monitoring result.   The control means sets the operation mode of the heat generating means when the heat generating means operates in an operation mode corresponding to the low input voltage and the power supply ratio of the power supply means is lower than a reference power input ratio d1. The heating apparatus according to claim 1, wherein the operation mode is switched to an operation mode corresponding to the high input voltage.   The control means sets the operation mode of the heat generating means when the heat generating means operates in an operation mode corresponding to the high input voltage and the power supply ratio of the power supply means is higher than a reference power input ratio d2. The heating apparatus according to claim 1, wherein the operation mode is switched to an operation mode corresponding to the low input voltage. In a heating apparatus that includes a heating means, operates corresponding to at least two types of input voltages, a high input voltage and a low input voltage, and heats the heating means.
Power supply means that operates corresponding to at least two types of input voltages, the high input voltage and the low input voltage, and supplies power to the heat generating means;
A temperature detecting means provided in the vicinity of the heat generating means for detecting the temperature of the heat generating means;
Control means for controlling the power supply means based on the output of the temperature detection means and adjusting the power input ratio of the power supply means to the power that can be supplied to the heat generation means to control the temperature of the heat generation means; With
The heating means has at least two types of operation modes corresponding to at least two types of input voltages, the high input voltage and the low input voltage,
The control means sets the operation mode of the heat generation means to an operation mode corresponding to the high input voltage, sets the power input ratio of the power supply means to a predetermined value, and supplies power to the heat generation means. Start,
The output of the temperature detecting means is monitored, and when the temperature rise rate is smaller than the reference temperature rise rate s1 as a result of the monitoring, the operation mode of the heat generating means is switched to an operation mode corresponding to the low input voltage. A heating device. In a heating apparatus that includes a heating means, operates corresponding to at least two types of input voltages, a high input voltage and a low input voltage, and heats the heating means.
Power supply means that operates corresponding to at least two types of input voltages, the high input voltage and the low input voltage, and supplies power to the heat generating means;
A temperature detecting means provided in the vicinity of the heat generating means for detecting the temperature of the heat generating means;
Control means for controlling the power supply means based on the output of the temperature detection means and adjusting the power input ratio of the power supply means to the power that can be supplied to the heat generation means to control the temperature of the heat generation means; With
The heating means has at least two types of operation modes corresponding to at least two types of input voltages, the high input voltage and the low input voltage,
The control means sets the operation mode of the heat generating means to an operation mode corresponding to the high input voltage, and controls the detection result of the temperature detection means to be a determined temperature rise rate,
The power input ratio of the power supply means is monitored. As a result of the monitoring, when the power input ratio is higher than the reference power input ratio d3, the operation mode of the heat generating means is switched to an operation mode corresponding to the low input voltage. A heating device characterized by that. The control means stores and holds the operation mode of the heat generating means set at the end of the operation of the heating device,
6. The heating apparatus according to claim 1, wherein the heating unit is operated in the operation mode stored and held when the heating unit is next heated. The heating means generates heat by applying a voltage to both ends, and has at least two heating elements having substantially the same resistance characteristics,
The power supply means includes an electrode A and an electrode B for supplying power to the heat generating means,
The two heating elements are connected in series, and have an electrode C and an electrode D, and an electrode E between the two heating elements,
The electrode A is connected to the electrode C;
The electrode D can be selectively connected to the electrode A or the electrode B through first switching means,
The heating apparatus according to any one of claims 1 to 5, wherein the electrode E is connectable to the electrode B through a second switching means.   The heating apparatus according to any one of claims 1 to 7, further comprising a universal power supply that operates in response to at least two types of input voltages, the high input voltage and the low input voltage.   An image forming apparatus comprising the heating device according to claim 1.

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