JP2022147504A - Image forming apparatus - Google Patents

Abstract

To heat a sub heater at an appropriate timing to allow use in a shorter time depending on the power circumstances.SOLUTION: An image forming apparatus comprises: a heating unit and a pressure unit that heat and fix toner; a voltage detection unit that detects input voltage; a storage unit that stores first specified voltage necessary to maintain the operation of units; and a control unit that controls an image forming unit, the voltage detection unit, and the storage unit. The heating unit includes a first heater and a second heater that heat a heating roller. The storage unit stores power consumption information on the heaters. The control unit defines the input voltage after the execution of an initial operation of the image forming unit as a first voltage and the input voltage after the start of the drive of the first heater as a second voltage, predicts the amount of reduction of the input voltage due to the drive of the heaters based on the first and second voltages, causes the voltage detection unit to update the second voltage every prescribed time, defines a voltage reflecting, from the second voltage, the amount of reduction of the input voltage due to the drive of the second heater as a third voltage, and when the third voltage becomes equal to or more than a first prescribed voltage, starts the drive of the second heater.SELECTED DRAWING: Figure 6

Description

The present invention relates to an image forming apparatus, and more particularly to a fixing/heating type image forming apparatus.

2. Description of the Related Art Conventionally, in an image forming apparatus using a fixing heating method, a formed image is fixed by heating with a heater in order to fix toner on the surface of a medium made of paper.
In such an image forming apparatus, when the power of the fixing device is turned on, a rush current is generated by the heater, and the current may reach a peak.

Therefore, in order to prevent the occurrence of rush current, a proposal has been made to alleviate the rush current caused by the main heater and sub-heater by starting heating of the sub-heater after a predetermined time T1 has elapsed after the start of heating of the main heater.

Conventionally, as an invention for preventing a rush current when a fixing device is powered on, on standby, or during printing, heating of either the center lamp or the side lamp is stopped when the lamp is heating. An invention of a heater control device for a fixing device that waits until the other lamp starts heating and maintains the heat roller 10 within a predetermined control temperature range has been disclosed (see, for example, Patent Document 1).

JP-A-2005-070628

However, in the heating sequence of the conventional fixing device, in which the heating of the sub-heater is started after a predetermined time T1 has elapsed after the heating of the main heater is started, the delay time T1 for the start of heating of the sub-heater is set regardless of the circumstances of the power supply at that time. often

Therefore, if the power supply conditions are good (for example, in the case of a 100V, 15A outlet), no particular problem occurs even if the above heating sequence is performed. If the above heating sequence is performed in case ), the voltage drops due to the inrush current, so that sufficient power cannot be obtained, which may hinder the start-up of the image forming apparatus.

Also, if the heating sequence is set according to an environment with poor power supply conditions, the heater start-up time will be longer in an environment with good power supply conditions, and it will take longer for the image forming apparatus to reach a temperature at which it can be used. It takes a long time and it becomes inconvenient to use.

Furthermore, in the actual power supply environment, not just in the region, various problems may occur due to wiring in buildings, etc., so it is difficult to set the heating sequence of the fuser heater in advance according to each power supply environment. is.

The present invention has been made in consideration of the above circumstances, and by determining the heating timing of the sub-heater at a more appropriate timing than the conventional one, it can be used in a shorter time according to the power supply situation. To provide an image forming apparatus that enables

(1) An image forming apparatus according to the present invention comprises: an image forming section for forming an image by means of a heating section for heating and fixing toner onto a printing sheet, a heating roller and a pressure section; a voltage detecting section for detecting an input voltage; a storage unit storing a predetermined first specified voltage required to maintain operation; and a control unit controlling the image forming unit, the voltage detection unit, and the storage unit. A first heater and a second heater for heating the heating roller are provided, the storage unit stores information about the power consumption of the first heater and the second heater, and the control unit stores information in advance in the image forming unit. After executing a predetermined initial operation, the voltage detection unit is caused to detect the input voltage to obtain the first voltage, and then the first heater is started to be driven, and then the voltage detection unit is caused to detect the input voltage. is the second voltage, and based on the first voltage and the second voltage, the amount of decrease in the input voltage due to the driving of the first heater is calculated, and the amount of change in the input voltage due to the driving of the first heater is Based on the information about the power consumption of the first heater and the second heater, the amount of decrease in the input voltage due to the driving of the second heater is predicted, and the second voltage is detected by the voltage detection unit every predetermined detection time. The second voltage is updated to reflect the amount of decrease in the input voltage due to the driving of the second heater as a third voltage, and when the third voltage becomes equal to or higher than the first specified voltage, the image is displayed. It is characterized by causing the formation unit to start driving the second heater.

In the present invention, the "image forming apparatus" means a copier or multifunction machine having a copying function, such as a printer that uses an electrophotographic method for image formation with toner, or an MFP (Multifunctional Peripheral: A device that forms and outputs an image, such as a multi-function peripheral device.
"Information on power consumption" is not limited to information directly indicating power consumption such as wattage. For example, the power consumption of the second heater may be 50% of that of the first heater. .

According to the present invention, by determining the heating timing of the sub-heater at an appropriate timing, it is possible to realize an image forming apparatus that can be used in a shorter period of time according to power supply conditions.

Furthermore, preferred embodiments of the present invention will be described.

(2) Power consumption of the first heater is preferably larger than power consumption of the second heater.

In this way, the amount of decrease in input voltage due to driving of the second heater is predicted based on the amount of change in input voltage due to driving of the first heater and the power consumption of the first heater and the second heater. Therefore, by determining the heating timing of the sub-heater at an appropriate timing, it is possible to realize an image forming apparatus that can be used in a shorter time according to the power supply situation.

(3) The storage unit stores a predetermined second specified voltage necessary to maintain the operation of each unit, and the control unit stores the amount of change in the input voltage due to the driving of the first heater and the Based on the information about the power consumption of the first heater and the second heater, the input voltage due to the driving of the second heater is predicted, and the voltage detection unit is caused to update the second voltage every predetermined detection time. and calculating a voltage difference obtained by subtracting the predicted voltage of the input voltage due to the driving of the second heater from the second voltage. It may start driving the second heater.

In this way, the process is facilitated by comparing the voltage difference with the specified voltage. Therefore, by determining the heating timing of the sub-heater at an appropriate timing, it can be used in a shorter time according to the power supply situation. An image forming apparatus that enables

1 is a perspective view showing the appearance of a digital multi-function peripheral according to Embodiment 1 of the image forming apparatus of the present invention; FIG. 2 is a cross-sectional view showing the mechanical configuration of the main body of the digital multi-function peripheral shown in FIG. 1; FIG. 2 is a block diagram showing an electrical configuration of the digital multi-function peripheral shown in FIG. 1; FIG. 2 is a block diagram showing an electrical configuration of a power monitor unit of the digital multi-function peripheral shown in FIG. 1; FIG. FIG. 10 is an explanatory diagram showing a problem of heater heating in a conventional digital multi-function peripheral; (A) shows an example of voltage change when the power environment is good, and (B) shows an example of voltage change when the power environment is bad. 4 is a flow chart showing the flow of a heater heating procedure of the digital MFP according to Embodiment 1 of the present invention; 9 is a flow chart showing the flow of heater heating procedures of the digital multi-function peripheral according to Embodiment 2 of the present invention; 9 is a flow chart showing the flow of heater heating procedures of the digital multi-function peripheral according to Embodiment 2 of the present invention; 13 is a flow chart showing the flow of a heater heating procedure of the digital multi-function peripheral according to Embodiment 3 of the present invention; FIG. 14 is a flow chart showing the flow of a heater heating procedure of the digital multi-function peripheral according to Embodiment 4 of the present invention; FIG. FIG. 11 is a flow chart showing the flow of a heater heating procedure of the digital multi-function peripheral according to Embodiment 5 of the present invention; FIG.

The present invention will be described in further detail below with reference to the drawings. It should be noted that the following description is illustrative in all respects and should not be construed as limiting the present invention.

[Embodiment 1]
A digital multi-function peripheral 1, which is an embodiment of the image forming apparatus of the present invention, will be described with reference to FIGS. 1 to 6. FIG.
FIG. 1 is a perspective view showing the appearance of a digital multifunction peripheral 1 according to Embodiment 1 of the image forming apparatus of the present invention.
FIG. 2 is a cross-sectional view showing the mechanical configuration of the main body of the digital multifunction machine 1 shown in FIG.

The digital multifunction peripheral 1 is a device such as a multifunction peripheral or MFP (Multifunctional Peripheral) that digitally processes image data and has a copying function, a scanning function, and a facsimile function.

As shown in FIG. 2, the digital multi-function peripheral 1 includes a transport section 112 that transports a document to a reading section, a reading section 111 that reads the document, and an image forming section 102 that forms an image.

The digital multifunction peripheral 1 executes scanning, printing, and copying jobs based on user instructions received via the operation unit 103 and communication unit 55 .

<Configuration of Digital MFP 1>
Here, the internal configuration of the digital multi-function peripheral 1 shown in FIG. 2 will be briefly described.

The digital multi-function peripheral 1 prints a color image using black (K), cyan (C), magenta (M), and yellow (Y) on a print sheet. Alternatively, a monochrome image using a single color (for example, black) is printed on the print sheet.

Therefore, four developing devices 12, photosensitive drums 13, drum cleaning devices 14, chargers 15, etc. are provided.
Four image stations Pa, Pb, Pc, and Pd are configured corresponding to black, cyan, magenta, and yellow, respectively, in order to form four types of toner images corresponding to respective colors.

A toner image is formed in each of the image stations Pa, Pb, Pc, and Pd as follows.
A drum cleaning device 14 removes and collects residual toner on the surface of the photosensitive drum 13 .
After that, the charger 15 uniformly charges the surface of the photosensitive drum 13 to a predetermined potential.
Then, the optical scanning device 11 exposes the uniformly charged surface to form an electrostatic latent image on the surface.
After that, the developing device 12 develops the electrostatic latent image.
As a result, a toner image of each color is formed on the surface of each photosensitive drum 13 .

In addition, the intermediate transfer belt 21 rotates in the arrow direction C. As shown in FIG.
The belt cleaning device 22 removes and collects residual toner from the intermediate transfer belt 21 that rotates.
The toner images of the respective colors on the surfaces of the photosensitive drums 13 are sequentially transferred onto the intermediate transfer belt 21 and superimposed to form a color toner image on the intermediate transfer belt 21 .

The print sheet is pulled out from any one of the four feed trays 18 by the pickup roller 33 and fed to the secondary transfer device 23 via the sheet transport path R1.
Alternatively, the sheet is fed from the manual feed tray 19 by a pick-up roller (not shown) and fed to the secondary transfer device 23 via the sheet transport path R1.

A registration roller 34 that temporarily stops the print sheet and aligns the leading edge of the print sheet is arranged in the sheet transport path R1.
In addition, a conveying roller 35 and the like are arranged to prompt the conveying of the print sheet.
After temporarily stopping the print sheet, the registration roller 34 conveys the print sheet to the nip area between the intermediate transfer belt 21 and the transfer roller 23a in synchronization with the transfer timing of the toner image.

A nip area is formed between the transfer roller 23 a of the secondary transfer device 23 and the intermediate transfer belt 21 .
When the print sheet passes through the nip, the color toner image formed on the surface of the intermediate transfer belt 21 is transferred to the print sheet.
After passing through the nip area, the print sheet is sandwiched between the heating roller 24 and the pressure roller 25 of the fixing device 17 and is heated and pressed.
This heat and pressure fixes the color toner image onto the print sheet.

The print sheet that has passed through the fixing device 17 is discharged to a discharge tray 39a or 39b via a discharge roller 36a or 36b.
The output destination of the print sheet is controlled by a control unit 100, which will be described later, and the transport path is switched by a switching mechanism (not shown) so that the print sheet is guided to either one of the output trays 39a and 39b.
A mechanism for switching the transport path of the print sheet is well known in the technical field of image forming apparatuses, and detailed illustration thereof is omitted.

Next, based on FIG. 3, the electrical configuration of the digital multifunction peripheral 1 will be briefly described.
FIG. 3 is a block diagram showing an electrical configuration of the digital multi-function peripheral 1 shown in FIG. 1. As shown in FIG.
As shown in FIG. 3, the digital multifunction peripheral 1 includes a communication section 55, a control section 100, a timer 101, an image forming section 102, an operation section 103, a memory 104, a reading section 111 and a transport section 112. FIG.

Each electrical component of the digital multifunction peripheral 1 will be described below.

The communication unit 55 is a circuit and firmware of a communication interface that transmits and receives communication data to and from an external device and receives, for example, a print job execution request from an external computer.

The control unit 100 integrally controls the digital multifunction peripheral 1, and includes a CPU, a RAM, a ROM, various interface circuits, and the like.
In order to control the overall operation of the digital multi-function peripheral 1, the control unit 100 detects each sensor, monitors and controls all loads such as a motor, a clutch, and a fixing lamp.

A timer 101 is a part that measures and counts time, and obtains the time through, for example, an internal clock or a network.

The image forming unit 102 prints a print image on a print sheet by electrophotography.
As shown in FIG. 2, the image forming section 102 includes electrical components such as an optical scanning device 11, a developing device 12, a photosensitive drum 13, a drum cleaning device 14, and a charger 15. As shown in FIG.
The image forming section 102 further includes electrical components related to the intermediate transfer belt 21, the fixing device 17, the sheet conveying path R1, the feed tray 18, and the discharge trays 39a and 39b.

In addition to the components shown in FIG. 2, the image forming unit 102 includes a heating unit 120 for heating the heating roller 24 of the fixing device 17 and a voltage monitor unit 130 for monitoring the input voltage, as shown in FIG. composed of

An operation unit 103 is composed of a liquid crystal display (Liquid Crystal Display) and a touch panel, displays information on the liquid crystal display, and receives instructions from a user through the touch panel.
The control unit 100 displays the operation and status of the digital multifunction peripheral 1 through the operation unit 103 .

The memory 104 includes a RAM 104a and a ROM 104b, and is non-volatile storage means such as a hard disk drive (HDD) or flash memory, and stores various data and programs.

The RAM 104a is a memory (random access memory) that can be accessed by the control unit 100, and provides a work memory for temporarily storing data.
The RAM 104a records, for example, the voltages of the main heater and the sub-heater, the amount of voltage change, the predicted value, and the like.

The ROM 104b is a read only memory that can be accessed by the control unit 100, and stores data necessary for program control of the control unit 100. FIG.
The ROM 104b stores, for example, various types of data that serve as the basis for setting the image forming function and the power saving mode transition function, as well as a predetermined specified voltage required to maintain the operation of the digital multi-function peripheral. .

The RAM 104a and the ROM 104b are bus-connected to the control unit 100, and store programs for operating the control unit 100 and develop memory.
Note that these are only examples of the configuration, and a system configured with a plurality of CPUs and substrates may also be used.

For example, the control unit 100 controls the reading unit 111 and the transport unit 112 so that the transport unit 112 transports the document.
Then, the image of the original is read by the reading unit 111 , and the image data representing the image of the original is stored in the memory 104 .
Further, the image forming unit 102 is controlled to print the original image indicated by the image data in the memory 104 on a print sheet.

The above is the outline of the configuration of the digital multifunction peripheral 1 .

<Electrical Configuration of Voltage Monitor Unit 130>
Next, based on FIG. 4, the electrical configuration of the voltage monitor section 130 will be described.
FIG. 4 is a block diagram showing electrical configurations of the heating section 120 and the voltage monitor section 130 of the digital multifunction peripheral 1 shown in FIG.

As shown in FIG. 4, the heating unit 120 includes a main halogen lamp 121, a sub halogen lamp 122, a switch element 123, a switch element 124, and a power generation circuit 125.

The voltage monitor section 130 also includes a voltage sense circuit 131 and a voltage (power) arithmetic circuit 132 .

Each component of heating unit 120 and voltage monitor unit 130 will be described below.

The heating unit 120 includes a main halogen lamp 121, a sub halogen lamp 122, and switch elements 123 and 124, and heats the heating roller 24 of the fixing device 17 by receiving power from the power generation circuit 125 and generating heat. part.

It is assumed that the wattage (power consumption) of the halogen lamp 121 is greater than the wattage (power consumption) of the halogen lamp 122 .

The switch elements 123 and 124 are contacts (portions for opening and closing switches) that connect the main halogen lamp 121 and the sub halogen lamp 122 to the power generation circuit 125, respectively.

The power generation circuit 125 is a circuit that supplies AC power of a predetermined voltage and frequency to the main halogen lamp 121 and the sub halogen lamp 122 .

The voltage sense circuit 131 is a circuit that measures the voltage of the external power supply.

The voltage (power) arithmetic circuit 132 is a circuit that calculates voltage (power) based on the voltage of the external power supply measured by the voltage sense circuit 131 .

Based on the voltage (power) calculated by the voltage (power) arithmetic circuit 132, the control unit 100 controls ON/OFF of the outputs of the switch elements 123 and 124, thereby controlling the main halogen lamp 121 and the sub halogen lamp. 122 to control the heating of the heating roller 24 appropriately.

In Embodiment 1, the "heating section" of the present invention is implemented by at least the main halogen lamp 121 and the sub halogen lamp 122 . Also, the “pressure unit” of the present invention is implemented by the pressure roller 25 . Also, the “voltage detection unit” of the present invention is implemented by the voltage monitor unit 130 . Also, the "first heater" and the "second heater" of the present invention are realized by the halogen lamp 121 and the halogen lamp 122, respectively.

(Problem of Heater Heating of Conventional Digital MFP 1)
Next, based on FIG. 5, the problem of heater heating in the conventional digital multifunction peripheral 1 will be described.

FIG. 5 is an explanatory diagram showing the problem of heater heating in the conventional digital multifunction peripheral 1. As shown in FIG.

In FIG. 5, the horizontal axis represents time, and the vertical axis represents changes in voltage when the main heater and sub-heater are driven.

In the example of FIG. 5, it is assumed that the main heater is turned on at time T1, and the sub-heater is turned on again at time T2 after 200 ms from time T1.

FIG. 5A shows an example of voltage changes when the power supply environment is good (for example, when a commercial power supply voltage of 100 V and 15 A is used).

As shown in FIG. 5A, when the main heater is turned on at time T1, the voltage temporarily drops due to the rush current, but recovers to the original voltage of 100 Vrms again.

Next, when the sub-heater is turned on at time T2, 200 ms after time T1, the voltage drops temporarily but recovers to 90 Vrms, so that the operation of the digital multi-function peripheral 1 does not suffer much.

On the other hand, FIG. 5B shows an example of voltage changes when the power supply environment is bad (for example, when a commercial power supply voltage of less than 100 V and 15 A is used).

As shown in FIG. 5(B), when the main heater is turned on at time T1, the voltage drops significantly due to the inrush current, and even after recovery, the voltage remains much smaller than 100 Vrms.

Next, when the sub-heater is turned on at time T2, which is 200 ms after time T1, the voltage drops further, but at this time it falls below the minimum voltage required to maintain the operation of the digital multifunction peripheral 1. FIG.
As a result, the power required for startup cannot be obtained, and the operation of the digital multi-function peripheral 1 is hindered.

It is also conceivable to perform the heating sequence when the power supply environment is bad, but in that case, the heater start-up time becomes long when the power supply environment is good.
As a result, it takes a long time for the digital multifunction peripheral 1 to reach a usable temperature, resulting in poor usability.

Furthermore, in the actual power supply environment, various failures may occur not only due to the amount of power supplied to the area, but also due to the wiring in buildings, etc. Therefore, the heating sequence of the fuser heater should be adjusted according to the individual power supply environment. Setting in advance is difficult.

(Flow of Heater Heating Procedure of Digital MFP 1 of Embodiment 1 of the Invention)
Next, based on FIG. 6, the flow of the heater heating procedure of the digital multifunction peripheral 1 according to the first embodiment of the present invention will be described.

FIG. 6 is a flow chart showing the flow of the heater heating procedure of the digital multi-function peripheral 1 of Embodiment 1 of the present invention.

In step S1 of FIG. 6, when the user turns on the main power of the digital multifunction peripheral 1 to start it up (if the determination in step S1 is Yes), in step S2, the control unit 100 initializes each load other than the heater. are performed in a predetermined order (step S2).

At this time, the control unit 100 causes the voltage sensing circuit 131 of the voltage monitor unit 130 to acquire the primary voltage signal of the commercial power source, and causes the voltage (power) arithmetic circuit 132 to perform calculation processing based on the primary voltage signal. to obtain the effective voltage value for each half cycle.

Control unit 100 causes memory 104 to store the detected voltage effective value as the first voltage.

Next, the control section 100 causes the image forming section 102 to start the operation of the fixing device 17 to enter the warm-up mode.

In step S3, the controller 100 turns on the switch element 123 of the halogen lamp 121, which is the main heater, to light the halogen lamp 121 (step S3).

When the halogen lamp 121 is turned on, the control unit 100 detects the voltage effective value for each half cycle and stores it in the memory 104 as the second voltage in the same manner as in step S2.

Next, in step S4, the control unit 100 turns on the halogen lamp 121 based on the first voltage detected when the initial operation is performed in step S2 and the second voltage detected when the halogen lamp 121 is on in step S3. The amount of change in voltage due to the inrush current is calculated (step S4).

Next, in step S5, the control unit 100 predicts the amount of voltage drop during driving of the halogen lamp 122 based on the wattages of the halogen lamp 121, which is the main heater, and the halogen lamp 122, which is the sub heater (step S5). .

Next, in step S6, the control unit 100 detects the voltage effective value (second voltage) when the halogen lamp 121 is turned on every half cycle, in the same manner as in step S2 (step S6).

Next, in step S7, based on the second voltage detected in step S6 and the amount of voltage drop during driving of the halogen lamp 122 predicted in step S5, the control unit 100 determines the voltage when the halogen lamp 122, which is the sub-heater, is driven. (step S7).

Next, in step S8, the control unit 100 determines whether or not the third voltage is equal to or higher than a predetermined specified voltage required to maintain the operation of the digital multifunction peripheral 1 (step S8).

When the third voltage is less than the specified voltage (when the determination in step S8 is No), the control unit 100 returns the process to step S6, and continues the processes of steps S6 to S8 until the third voltage becomes equal to or higher than the specified voltage. repeat.

On the other hand, when the third voltage becomes equal to or higher than the specified voltage (when the determination in step S8 is Yes), in step S9, the control unit 100 determines that the halogen lamp 122, which is the sub-heater, can be turned on, and switches The element 124 is turned ON to light the halogen lamp 122 (step S9).

After that, the image forming section 102 enters a warm-up mode, and turns on the main/sub halogen lamps 121 and 122 until a predetermined target temperature of the fixing device 17 is reached.

In this way, by determining the heating timing of the sub-heater at more appropriate timing than in the conventional art, it is possible to realize the digital multi-function peripheral 1 that can be used in a shorter time according to the power supply situation.

[Embodiment 2]
Next, based on FIGS. 7 and 8, the flow of the heater heating procedure of the digital multifunction peripheral 1 of Embodiment 2 of the present invention will be described.

In Embodiment 1, the heating procedure using two heaters, the main heater and the sub-heater, has been described.
In Embodiment 2, a heating procedure using three heaters, a main heater, a first sub-heater and a second sub-heater, will be described.

In Embodiment 2, the configuration of the digital multifunction peripheral 1 is the same as that of Embodiment 1, except that the image forming unit 102 has two sub-heaters, a first sub-heater and a second sub-heater, in addition to the main heater. is.

7 and 8 are flow charts showing the flow of the heater heating procedure of the digital multi-function peripheral 1 according to Embodiment 2 of the present invention.

7 correspond to the case where the sub-heater is replaced with the first sub-heater in the processing of steps S1-S8 in FIG. 6 (Embodiment 1), so description thereof will be omitted. .

Here, processing of step S19 in FIG. 7 and steps S20 to S25 in FIG. 8, which are not included in the first embodiment, will be described.

In the following description, it is assumed that the first sub-heater is composed of the halogen lamp 122A and the switch element 124A, and the second sub-heater is composed of the halogen lamp 122B and the switch element 124B.

In step S18, when the third voltage becomes equal to or higher than the specified voltage (when the determination in step S18 is Yes), the control unit 100 determines that the halogen lamp 122A, which is the first sub-heater, can be turned on, and switches The element 124A is turned ON to light the halogen lamp 122A.

When the halogen lamp 122A is turned on, the control unit 100 detects the voltage effective value for each half cycle and stores it in the memory 104 as the third voltage.

Next, in step S20 of FIG. 8, the control unit 100 controls the voltage change due to the inrush current when the halogen lamp 122A is ON, based on the second voltage detected in step S16 and the third voltage detected in step S19. Calculate the amount (step S20).

Next, in step S21, the control unit 100 drives the halogen lamp 122B based on the wattage of the halogen lamp 121 as the main heater, the halogen lamp 122A as the first sub-heater, and the halogen lamp 122B as the second sub-heater. The amount of voltage drop at this time is predicted (step S21).

Next, in step S22, control unit 100 detects the voltage effective value (third voltage) when halogen lamp 121 and halogen lamp 122A are ON every half cycle (step S22).

Next, in step S23, the controller 100, based on the third voltage detected in step S22 and the amount of voltage drop predicted in step S21, drops due to the inrush current when the halogen lamp 122B, which is the sub-heater, is driven. A voltage (fourth voltage) is calculated (step S23).

Next, in step S24, the control unit 100 determines whether or not the fourth voltage is equal to or higher than a predetermined specified voltage necessary for maintaining the operation of the digital multifunction peripheral 1 (step S24).

When the fourth voltage is less than the specified voltage (when the determination in step S24 is No), the control unit 100 returns the process to step S22, and continues the processes of steps S22 to S24 until the fourth voltage becomes equal to or higher than the specified voltage. repeat.

On the other hand, when the fourth voltage is equal to or higher than the specified voltage (when the determination in step S24 is Yes), the control unit 100 determines that the halogen lamp 122B, which is the second sub-heater, can be turned on, and switches the switch element 124B. is turned on to turn on the halogen lamp 122B.

After that, the image forming section 102 enters a warm-up mode, and turns on the main/first and second sub halogen lamps 121/122A and 122B until a predetermined target temperature of the fixing device 17 is achieved.

Also, even if there are three sub-heaters, the same processing as steps S21 to S24 for the second sub-heater is performed on the third sub-heater, thereby determining the heating timing of the third sub-heater at an appropriate timing. can do.
The same applies to the case of having four or more sub-heaters.

In this way, even if you have two or more sub-heaters, by determining the heating timing of the sub-heaters at a more appropriate timing than before, you can use it in a shorter time according to the power supply situation. The MFP 1 can be realized.

[Embodiment 3]
Next, based on FIG. 9, the flow of the heater heating procedure of the digital multifunction peripheral 1 according to Embodiment 3 of the present invention will be described.

Since the configuration of the digital multi-function peripheral 1 of Embodiment 3 is the same as that of Embodiment 1 (FIGS. 2 to 4), description thereof will be omitted.

FIG. 9 is a flow chart showing the flow of the heater heating procedure of the digital multi-function peripheral 1 according to Embodiment 3 of the present invention.

9 correspond to steps S1 to S4 and S9 of FIG. 6 (embodiment 1), respectively, and thus description thereof is omitted.

Here, the processes of steps S35 to S38 in FIG. 9, which are not included in the first embodiment, will be described.

In step S34 of FIG. 9, after calculating the amount of change in voltage due to the inrush current when the halogen lamp 121, which is the main heater, is turned on (step S34), in step S35, the controller 100 calculates the wattage of each heater. , the voltage during driving of the halogen lamp 122, which is a sub-heater, is predicted (step S35).

Next, in step S36, the control unit 100 detects the voltage effective value (second voltage) when the halogen lamp 121 is ON every half cycle (step S36).

Next, in step S37, the control unit 100 calculates a voltage difference by subtracting the predicted voltage predicted in step S35 from the safe voltage during driving of the main/sub heater (step S37).

Next, in step S38, the control unit 100 determines whether or not the voltage difference is equal to or greater than a predetermined specified voltage required to maintain the operation of the digital multifunction peripheral 1 (step S38).

When the voltage difference is less than the specified voltage (when the determination in step S38 is No), the control unit 100 returns the process to step S36, and repeats the processes of steps S36 to S38 until the voltage difference becomes equal to or greater than the specified voltage. .

On the other hand, when the voltage difference is equal to or higher than the specified voltage (when the determination in step S38 is Yes), in step S39, the control unit 100 determines that the halogen lamp 122, which is the sub-heater, can be turned on, and switches the switch element. 124 is turned on to turn on the halogen lamp 122 (step S39).

In this way, by comparing the voltage difference with the specified voltage, the process becomes easier. Therefore, by determining the heating timing of the sub-heater at a more appropriate timing than before, it can be done in a shorter time according to the power supply situation. It is possible to realize a digital multi-function peripheral 1 that enables the use of

[Embodiment 4]
Next, based on FIG. 10, the flow of the heater heating procedure of the digital multifunction peripheral 1 according to Embodiment 4 of the present invention will be described.

The configuration of the digital multi-function peripheral 1 of Embodiment 4 is the same as that of Embodiment 1 (FIGS. 2 to 4), so description thereof will be omitted.

FIG. 10 is a flow chart showing the flow of the heater heating procedure of the digital multi-function peripheral 1 according to Embodiment 4 of the present invention.

In step S41 of FIG. 10, when the user turns on the main power of the digital multifunction peripheral 1 to start it up (if the determination in step S41 is Yes), in step S42, the control unit 100 turns on the halogen lamp 121, which is the main heater. The switch element 123 is turned on to turn on the halogen lamp 121 (step S42).

When the halogen lamp 121 is turned on, the control unit 100 detects the voltage effective value for each half cycle and stores it in the memory 104 as the first voltage.

Next, in step S43, the control unit 100 turns on the switch element 124 of the halogen lamp 122, which is a sub-heater, to turn on the halogen lamp 122, and measures the amount of change in voltage due to the inrush current when the halogen lamp 122 is turned on. Calculate and store in memory 104 (step S43).

Next, in step S44, the control unit 100 acquires power other than the heater power from the memory 104, and calculates the second voltage when driving the entire device (step S44).

Next, in step S45, the control unit 100 determines whether or not the second voltage is equal to or higher than a predetermined specified voltage required to maintain the operation of the digital multifunction peripheral 1 (step S45).

If the second voltage is less than the specified voltage (No in step S45), in step S46, the control section 100 turns off the switch element 124 to extinguish the halogen lamp 122 (step S46).

Thereafter, in step S47, similarly to step S42, the voltage effective value (first voltage) when the halogen lamp 121 is ON is detected every half cycle (step S47).

Next, in step S48, the control unit 100 calculates a third voltage by adding the amount of change in voltage due to the inrush current when the halogen lamp 122 is ON calculated in step S43 to the first voltage (step S48).

Next, in step S49, the control unit 100 determines whether or not the third voltage is equal to or higher than a predetermined specified voltage necessary for maintaining the operation of the digital multifunction peripheral 1 (step S49).

When the third voltage is less than the specified voltage (when the determination in step S49 is No), the control unit 100 returns the process to step S47, and continues the processes of steps S47 to S49 until the third voltage becomes equal to or higher than the specified voltage. repeat.

On the other hand, when the third voltage becomes equal to or higher than the specified voltage (when the determination in step S49 is Yes), in step S50, the control unit 100 determines that the halogen lamp 122, which is the sub-heater, can be turned on, and switches The element 124 is turned ON to light the halogen lamp 122 (step S50).

Thereafter, in step S51, initial operations of the loads other than the heater are performed in a predetermined order (step S51).

On the other hand, in step S45, when the second voltage becomes equal to or higher than the specified voltage (when the determination in step S45 is Yes), in step S51, the control unit 100 causes the initial operation of each load other than the heater to be set in advance. This is done in order (step S51).

In this way, even when the main/sub-heater is heated first and then the initial operation is performed, the heating timing of the sub-heater is determined at a more appropriate timing than in the past, so that the heating time can be shortened according to the power supply situation. It is possible to realize a digital multi-function peripheral 1 that can be used at any time.

[Embodiment 5]
Next, based on FIG. 11, the flow of the heater heating procedure of the digital multifunction peripheral 1 according to the fifth embodiment of the present invention will be described.

The configuration of the digital multi-function peripheral 1 of Embodiment 5 is the same as that of Embodiment 1 (FIGS. 2 to 4), so description thereof will be omitted.

FIG. 11 is a flowchart showing the flow of the heater heating procedure of the digital multi-function peripheral 1 according to Embodiment 5 of the present invention.

11 correspond to steps S1 to S6 and S9 in FIG. 6 (embodiment 1), respectively, and thus description thereof is omitted.

Here, processing of steps S66 and S68 in FIG. 11, which are not included in the first embodiment, will be described.

In the first embodiment, the control unit 100 calculates the voltage when driving both the main heater and the sub heater each time, and determines whether or not the voltage is equal to or higher than the specified voltage.

On the other hand, in the fifth embodiment, the control unit 100 calculates an assumed voltage by adding the voltage when the sub-heater is driven to the specified voltage.

After predicting the amount of voltage drop during driving of the halogen lamp 122 (step S65) in step S65 of FIG. An assumed voltage is calculated by adding the predicted voltage when the sub-heater is driven to the determined specified voltage (step S66).

Next, in step S67, after detecting the current second voltage by driving the main heater (step S67), in step S68, the control unit 100 determines whether or not the second voltage is equal to or higher than the assumed voltage ( step S68).

When the second voltage is less than the assumed voltage (when the determination in step S68 is No), the control unit 100 returns the process to step S67, and repeats the processes of steps S67 to S68 until the second voltage becomes equal to or higher than the assumed voltage. repeat.

On the other hand, when the second voltage is equal to or higher than the assumed voltage (when the determination in step S68 is Yes), in step S69, the control unit 100 determines that the halogen lamp 122, which is the sub-heater, can be turned on, and switches The element 124 is turned ON to light the halogen lamp 122 (step S69).

After that, the image forming section 102 enters a warm-up mode, and turns on the main/sub halogen lamps 121 and 122 until a predetermined target temperature of the fixing device 17 is reached.

In this way, without having to calculate the voltage when driving both the main and sub-heaters each time, by determining the heating timing of the sub-heaters at a more appropriate timing than before, the heating can be completed in a short time according to the power supply situation. It is possible to realize a digital multi-function peripheral 1 that can be used.

Preferred aspects of the present invention include combinations of any of the aspects described above.
Various modifications of the present invention are possible in addition to the above-described embodiments. Those modifications should not be construed as not belonging to the scope of the present invention. The present invention should include all modifications within the scope of the claims, the meaning of equivalents, and the scope.

1: Digital MFP 11: Optical Scanning Device 12: Developing Device 13: Photosensitive Drum 14: Drum Cleaning Device 15: Charger 17: Fixing Device 18: Feeding Tray 19: Manual Feed Tray 21: intermediate transfer belt 22: belt cleaning device 23: secondary transfer device 23a: transfer roller 24: heating roller 25: pressure roller 33: pickup roller 34: registration roller 35: transport roller 36a, 36b: discharge rollers 39a, 39b: discharge tray 55: communication unit 100: control unit 101: timer 102: image forming unit 103: operation unit 104: memory 104a: RAM 104b: ROM 111: reading unit 112: conveying unit 120: heating unit 121, 122, 122A, 122B: halogen lamps 123, 124, 124A, 124B: switch elements 125: power generation circuit 130: voltage monitor unit 131: voltage sensing circuit 132: voltage (power) arithmetic circuit C: arrow direction Pa, Pb, Pc, Pd: image station R1: sheet conveying path T1, T2: time

Claims (3)

an image forming unit that forms an image by a heating unit that heats and fixes toner onto a print sheet, a heating roller, and a pressure unit;
a voltage detection unit that detects an input voltage;
a storage unit that stores a predetermined first specified voltage necessary to maintain the operation of each unit;
a control unit that controls the image forming unit, the voltage detection unit, and the storage unit;
The heating unit includes a first heater and a second heater that heat the heating roller,
The storage unit stores information about power consumption of the first heater and the second heater,
After causing the image forming unit to perform a predetermined initial operation, the control unit causes the voltage detection unit to detect an input voltage to set it as a first voltage, and then after starting to drive the first heater. causing the voltage detection unit to detect the input voltage as a second voltage, and calculating an amount of decrease in the input voltage due to the driving of the first heater based on the first voltage and the second voltage;
predicting the amount of input voltage drop due to driving of the second heater based on the amount of change in the input voltage due to driving of the first heater and information about the power consumption of the first heater and the second heater;
The voltage detection unit is caused to update the second voltage every predetermined detection time, and the voltage reflecting the amount of decrease in the input voltage due to the driving of the second heater from the second voltage is set as the third voltage. An image forming apparatus, wherein the image forming unit starts driving the second heater when the third voltage becomes equal to or higher than the first specified voltage. 2. The image forming apparatus according to claim 1, wherein power consumption of said first heater is greater than power consumption of said second heater. The storage unit stores a predetermined second specified voltage necessary to maintain the operation of each unit,
The control unit predicts the input voltage by driving the second heater based on the amount of change in the input voltage by driving the first heater and information on the power consumption of the first heater and the second heater,
causing the voltage detection unit to update the second voltage every predetermined detection time, calculating a voltage difference obtained by subtracting the predicted voltage of the input voltage due to the driving of the second heater from the second voltage, and calculating the voltage 3. The image forming apparatus according to claim 1, wherein the image forming section starts driving the second heater when the difference is equal to or greater than the second specified voltage.

Images