Image forming apparatus and method for controlling image forming apparatus

Abstract

To provide an image forming apparatus that can prevent an increase in the temperature of a stepping motor provided at a portion affected by ambient heat.SOLUTION: An image forming apparatus comprises: a fixing unit (210) that applies heat to fix a toner image formed on a recording sheet by an electrophotographic system; stepping motors for recording sheet conveyance (230m1), (230m2) that are installed around the fixing unit; and a control unit (100) that controls current attenuation settings of the stepping motors according to the type of the recording sheet.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an image forming apparatus and the like. [Background technology]

[0002] Conventionally, in image forming devices in which printing-related components are driven by a stepping motor, multiple damping modes have been provided, and an appropriate current damping mode is set in response to changes in the rotational speed, such as acceleration and deceleration, of the stepping motor, thereby reducing vibration and loss (see, for example, Patent Document 1).

[0003] Furthermore, a recording device has been proposed that has a constant current motor driver that can change multiple current decay modes depending on the rate of increase or decrease of the current, which is suitable for finding the optimal driving method (see, for example, Patent Document 2).

[0004] It is believed that Patent Documents 1 and 2 switch the current decay setting as needed depending on the rate of increase or decrease in current according to changes in rotation speed during acceleration or deceleration. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-127630 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-125593 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the case of stepping motors, if the driver IC (Integrated Circuit) or motor is installed in a location that is subject to heat, such as around the fixing unit, problems may occur due to temperature rise caused by heat in addition to heat generated by the motor itself.

[0007] The present disclosure aims to provide an image forming apparatus and the like that can suppress a temperature rise in a stepping motor that is provided in a location that is affected by the surrounding heat. [Means for solving the problem]

[0008] The present disclosure relates to an image forming apparatus characterized by comprising a fixing unit that applies heat to a toner image formed on recording paper by an electrophotographic method to fix the toner image, a stepping motor for transporting the recording paper that is installed around the fixing unit, and a control unit that controls the current attenuation setting of the stepping motor depending on the type of the recording paper.

[0009] The present disclosure also provides a control method for an image forming apparatus, characterized by including a fixing step of applying heat to a toner image formed on recording paper by an electrophotographic method to fix the toner image, a step of driving a stepping motor for transporting recording paper that is installed in the vicinity of the fixing unit, and a control step of controlling the current attenuation setting of the stepping motor depending on the type of recording paper. [Effects of the Invention]

[0010] The image forming apparatus of the present disclosure can achieve the excellent effect of suppressing the temperature rise of the stepping motor provided in a portion that is subject to the influence of heat. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an explanatory diagram illustrating an overall configuration of an image forming apparatus according to an embodiment; [Figure 2] FIG. 1 is a block diagram showing a configuration of an image forming apparatus. [Figure 3] 2 is an explanatory diagram of the structure of a printing unit including an image forming unit and the arrangement of stepping motors. FIG. [Figure 4] FIG. 2 is a control block diagram of a stepping motor. [Figure 5] 1A and 1B are explanatory diagrams of waveforms at each part of the stepping motor from the driver IC, where (a) is an explanatory diagram of measurement points, (b) is an explanatory diagram of 2-2 phase control, and (c) is an explanatory diagram of the waveform of 1-2 phase control. [Figure 6] FIG. 10 is an explanatory diagram of the difference between chopping frequency and drive frequency. [Figure 7] FIG. 10 is an explanatory diagram of conditions for changing the current attenuation setting. [Figure 8] 10 is a flowchart of current decay setting. [Figure 9] 1A and 1B are explanatory diagrams of current decay settings (Decay), where FIG. 1A shows the relationship between pulse voltage and current, and FIG. 1B shows the current decay. [Figure 10] An example of an H-bridge circuit is shown, where (a) shows when the motor is driven, (b) shows when the current decays quickly, and (c) shows when the current decays slowly. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment for carrying out the present disclosure will be described below with reference to the drawings.

[0013] The premise of this disclosure is that in a stepping motor, if the fixed setting current of the driver IC is set to the maximum and the current decay setting (decay setting) is set to slow decay, problems may occur due to temperature rise in the driver IC and motor depending on the rotation conditions and fixing temperature. In particular, if the motor is installed in a location that is affected by heat, such as around the fixing unit, problems may occur due to temperature rise caused by the radiant heat of the fixing unit in addition to heat generated by the motor itself.

[0014] To solve this problem, it was necessary to sacrifice torque by changing the set current, or to change the driver IC or motor. Therefore, in an embodiment of the present disclosure, in a stepping motor for transporting recording paper mounted in an image forming device such as a multifunction printer, the current decay setting is switched depending on the rotation speed / fixing temperature corresponding to the thickness of the recording paper, thereby enabling control to suppress the temperature of the driver IC and motor while achieving high torque output in the high-speed rotation range without requiring additional circuit components or fans.

[0015] It should be noted that the following embodiment is an example for explaining the present disclosure, and the technical scope of the disclosure described in the claims is not limited to the following description.

[0016] [1. Embodiment] [1.1 Overall structure] First, the configuration of an image forming apparatus 10 according to the embodiment will be described. As shown in FIG. 1, the image forming apparatus 10 is a multifunction printer (MFP: Multifunction Peripheral) that includes an original reading unit 112 on top of the image forming apparatus 10, reads an image of an original, and outputs the image by electrophotography.

[0017] [1.2 Image forming device] 2, image forming apparatus 10 mainly includes control unit 100, image input unit 110, document reading unit 112, image processing unit 120, image forming unit 130, operation unit 140, display unit 150, storage unit 160, and communication unit 170. Image forming apparatus 10 also includes printing unit 180, which includes image forming unit 130 and prints a toner image on recording paper.

[0018] The control unit 100 is a functional unit for controlling the entire image forming apparatus 10.

[0019] The control unit 100 realizes various functions by reading and executing various programs, and is configured by, for example, one or more arithmetic units (for example, CPUs (Central Processing Units)).

[0020] The image input unit 110 is a functional unit for inputting image data to be input to the image forming apparatus 10. The image input unit 110 is connected to an original reading unit 112, which is a functional unit for reading an image of an original, and inputs image data output from the original reading unit 112.

[0021] The image input unit 110 may also input image data from a storage medium such as a USB memory or an SD card. Also, image data may be input from another terminal device via the communication unit 170 that connects to the other terminal device.

[0022] The document reading unit 112 has a function of optically reading a document placed on a contact glass (not shown) or the like, and transferring the read data to the image processing unit 120 .

[0023] Image forming unit 130 is a functional unit for forming output data based on image data onto a recording medium (e.g., recording paper). For example, as shown in FIG. 1, recording paper is fed from paper feed cassette 122, and after an image is formed on the surface of the recording paper in image forming unit 130, the paper is discharged to paper discharge tray 124 (124a). Image forming unit 130 is configured, for example, with a laser printer or the like that uses an electrophotographic method. A series of printing processes from paper feeding to paper discharge is performed by printing unit 180, as shown in FIG. 3, which will be described later.

[0024] The image processing unit 120 has an image processing function for converting image data read by the document reading unit 112 into a set file format (TIFF, GIF, JPEG, etc.), and then forms an output image based on the image data that has been subjected to image processing.

[0025] The operation unit 140 is a functional unit for receiving operation instructions from the user, and is composed of various key switches, devices for detecting input by touch, etc. The user inputs the functions and output conditions to be used via the operation unit 140.

[0026] The display unit 150 is a functional unit for displaying various information to the user, and is configured by, for example, an LCD (Liquid Crystal Display) or the like.

[0027] That is, the operation unit 140 provides a user interface for operating the image forming apparatus 10, and the display unit 150 displays various setting menu screens and messages for the image forming apparatus.

[0028] 1, the image forming apparatus 10 may include a touch panel as part of the configuration of the operation unit 140, in which the operation panel 141 and the display unit 150 are integrally formed. In this case, the method for detecting input to the touch panel may be any common detection method, such as a resistive film method, an infrared method, an electromagnetic induction method, or a capacitance method.

[0029] The storage unit 160 is a functional unit that stores various programs including a control program required for the operation of the image forming apparatus 10, various data including read data, and user information. The storage unit 160 is configured, for example, with one or more non-volatile read only memories (ROMs), one or more random access memories (RAMs), one or more hard disk drives (HDDs), etc. The storage unit 160 may also include one or more solid state drives (SSDs), which are semiconductor memories.

[0030] The communication unit 170 establishes a communication connection with an external device. A communication interface (communication I / F) used for transmitting and receiving data is provided as the communication unit 170. The communication I / F allows data stored in a storage unit of the image forming apparatus 10 to be transmitted and received to and from another computer device connected via a network in response to a user operation on the image forming apparatus 10.

[0031] [1.3 Printing section 180] As shown in FIG. 3, the printing section 180 of the image forming apparatus 10 includes a paper feed section 190, an image forming section 130, a fixing section 210, a conveying section 200, a double-sided conveying section 220, and a paper ejection section 230.

[0032] The printing unit 180 inside the image forming apparatus 10 is provided with a paper feed unit 190 that feeds recording paper, a transport unit 200 that transports recording paper to the fixing unit 210, and a duplex transport unit 220 that transports recording paper that has been printed on one side in the case of duplex printing. The paper feed unit 190 is provided with paper feed rollers 190a that feed paper from the paper feed cassette 122 (see FIG. 1) (FIG. 3 shows only a portion of the paper feed rollers 190a, and paper feed rollers corresponding to the paper feed structure of the paper feed cassette 122, manual feed tray, etc. are provided).

[0033] During paper feeding, one of the paper feed rollers 190a rotates to deliver the fed recording paper to the conveying section 200, and the pair of conveying rollers 200a in this conveying section 200 conveys the recording paper toward the image forming section 130. The conveying section 200 also has a pair of registration rollers 200b provided in front of the image forming section 130, and the registration rollers 200b cause the recording paper conveyed by the conveying roller 200a to wait in front of the image forming section 130 and send the paper toward the image forming section 130 in time with the formation of the toner image.

[0034] Image forming unit 130 forms a toner image on photosensitive drum 130a based on image data processed by image processing unit 120. The formed toner image is transferred to intermediate transfer belt 130b, and secondary transfer member 130c presses recording paper against intermediate transfer belt 130b, thereby transferring the toner image on the surface of intermediate transfer belt 130b to the recording paper. Photosensitive drum 130a forms a black toner image, but in the case of color images, photosensitive drums that form toner images of each color (yellow, cyan, magenta, etc.) are installed in contact with intermediate transfer belt 130b, although not shown. In addition, intermediate transfer belt 130b is driven in a circular motion by a drive roller (not shown) and a driven roller 130b1.

[0035] Fixing unit 210 fixes the toner image onto the recording paper by sandwiching the recording paper, onto which the toner image has been transferred, between heated fixing rollers 210a and feeding the recording paper while applying heat and pressure. After the toner image has been fixed by fixing unit 210, the recording paper is transported by a pair of discharge rollers (upper discharge roller 230u, lower discharge roller 230d) of discharge unit 230 located above fixing unit 210, and is discharged onto discharge tray 124 (discharge tray 124a below operation panel 141), upper discharge tray 124u, or lower discharge tray 124d).

[0036] When double-sided printing is performed, the paper that has been printed on one side and discharged from the fixing unit 210 is sent downward through the conveying rollers 220a, 220a of the double-sided conveying unit 220 as the discharge roller 230u rotates in the reverse direction from the path toward the upper discharge tray 124u, and then sent again upstream of the registration roller 200b via the conveying rollers 200a, 200a of the conveying unit 200, where a toner image is formed on the other side (back side) of the recording paper by the image forming unit 130, and after being fixed by the fixing unit 210, the paper is conveyed by the discharge rollers (upper discharge roller 230u, lower discharge roller 230d) of the discharge unit 230 and discharged to the discharge tray 124 (upper discharge tray 124u, lower discharge tray 124d).

[0037] The rollers of the paper discharge unit 230, the conveying unit 200, and the double-sided conveying unit 220 are driven by the driving force of a stepping motor via a driving mechanism such as a gear.

[0038] In the embodiment, the stepping motors 230m1 and 230m2 for driving the discharge rollers (upper discharge roller 230u, lower discharge roller 230d) of the discharge section 230 are installed around and above the fixing section 210, in a location where the heat generated in the fixing section 210 is transmitted through space.

[0039] [Stepping motor control block diagram] Fig. 4 is a control block diagram of stepping motors 230m1 and 230m2. As shown in Fig. 4, a control signal from control unit 100 is input to a motor control microcomputer (a chip computer such as a microcomputer or microcontroller) 300, which controls driver ICs 310 for driving stepping motors 230m1 and 230m2.

[0040] The microcomputer 300 generates an operation pulse signal CLK, a current decay setting signal Decay, and a clockwise / counterclockwise rotation direction signal CW / CCW in response to the control / drive signals output from the control unit 100, and outputs them to the driver IC 310.

[0041] The stepping motors 230m1 and 230m2 each have a stator with phases A, A / , B, and B / . Based on the drive voltage output from the driver IC 310, the stepping motors 230m1 and 230m2 are driven with a fixed set current.

[0042] [Waveforms of each part] 5A is an explanatory diagram of the waveforms of each part. As shown in FIG. 5A, the transmission path of the operation pulse signal CLK from the microcomputer 300 to the driver IC 310 is used as a measurement point [P1] to measure the operation pulse, and the drive voltage path between the driver IC 310 and the stepping motors 230m1 and 230m2 is used as a measurement point [P2] to measure the waveforms of the voltage [V] and current [A].

[0043] As a result of the measurement, Figure 5(b) shows the waveforms of the step operation voltage and current in the case of 2-2 phase control (also called 2-2 phase excitation), and Figure 5(c) shows the waveforms of the step operation voltage and current in the case of 1-2 phase control (also called 1-2 phase excitation, which alternates between 1-1 phase excitation and 2-2 phase excitation).

[0044] [Chopping frequency, driving frequency] FIG. 6 is a diagram illustrating the difference between the chopping frequency and the drive frequency. As shown in Figure 6, the drive frequency [Hz] is the step frequency that determines the rotation speed of the stepping motor. Also, the chopping frequency, as shown in enlarged area A, is the frequency of the chopping operation to maintain the current value at the set current in constant current drive.

[0045] As shown in Figure 6, the drive voltage applied to the motor coil is a voltage V that is chopped so that a set current (VREF) is obtained for current i. In this case, a constant voltage V is initially applied, and then a chopped voltage V is applied so that the set current (VREF) is obtained. At this time, at the falling edge of voltage V, an attenuated current begins to flow from the motor coil.

[0046] [Explanation of operation of the embodiment] Next, in the image forming apparatus, as shown in Fig. 7, the tolerance for temperature rise caused by motor drive in the stepping motor located above the fixing unit 210 changes, so the current attenuation setting is changed depending on the type of recording paper (thick paper, plain paper, thin paper, etc.). The type of recording paper (paper type) is set by the user through input from the operation panel 141 (corresponding to the "setting unit"). However, instead of being set by the user, the thickness of the recording paper can also be detected and set.

[0047] That is, in the case of constant current stepping motors for paper discharge (stepping motors 230m1 and 230m2 for paper discharge rollers 230u and 230d) that are attached to the top of an image forming device such as a multifunction printer and are heavily affected by fan heat, by switching the current decay setting (decay setting) according to the rotation speed / fixing temperature corresponding to the type of recording paper, it is possible to control the motor so that both torque and temperature are achieved through decay control by microcomputer 300, without the need for additional circuit components or fans.

[0048] In the high-speed rotation range, there are concerns about the output torque relative to the load, so the slow setting (Slow Decay) is used, which prioritizes output torque.The high-speed rotation range is expected to be used for passing plain paper, and since the fixing temperature is low, the impact of fan heat is small. On the other hand, in the low-speed rotation range, thick paper is expected to be fed, the fixing temperature is high, and the temperature of the motor affected by the fan heat becomes high. Also, the driver IC 310 is subject to high temperatures, so the Fast setting (Fast Decay) is used to suppress this temperature rise. Because of the low rotation speed, there is ample output torque for the load.

[0049] From the above, when the thickness of the recording paper is thick, the temperature of the recording paper does not rise easily, so the fixing temperature becomes higher and the paper transport speed becomes slower, so the allowable temperature rise of the stepping motors 230m1 and 230m2 of the paper discharge rollers 230u and 230d becomes more severely affected by the rise in ambient temperature. Therefore, in the image forming device of the embodiment, when thick paper is passed through, the control unit 100 controls the current decay setting to a fast current decay setting (Fast Decay) based on the table stored in the memory unit 160, as shown in Figure 7.

[0050] On the other hand, when the recording paper is thin paper such as plain paper, the temperature of the recording paper rises easily, so the fixing temperature is lower and the paper conveyance speed is increased, so the allowable range for the temperature rise of the stepping motor is wider than for thick paper. Therefore, as shown in Fig. 7, the current decay setting is controlled to a slow current decay setting (slow decay) based on the table stored in memory unit 160.

[0051] Fig. 8 is a flowchart of the current decay setting executed by the control unit 100. As shown in Fig. 8, information on the set paper type of recording paper is acquired (step S100), and it is determined whether the thickness of the recording paper is thicker than regular paper (step S110). If the thickness is thicker than regular paper (step S110: Yes), the paper discharge speed is set to the low rotation speed range (step S120) and a high current decay setting (fast decay) is used (step S130). On the other hand, if the thickness of the recording paper is the same as or thinner than regular paper (step S110: No), the paper discharge speed is set to the high rotation speed range (step S140) and a low current decay setting (slow decay) is used (step S150).

[0052] Specific settings will be explained. Setting to feed plain paper Paper thickness: ~80g / m 2 We are assuming a certain level. Print speed: 80 cpm (= 80 sheets per minute) Motor rotation frequency: 12000 pps (high speed rotation is assumed to be around 9000 pps) Fixing temperature: (Example) 120℃ Load torque: (Example) 40mNm (30~50mNm)

[0053] Thick paper feed settings Paper thickness: ~220g / m 2 Expected to be about ~ Print speed: 80 cpm (= 80 sheets per minute) Motor rotation frequency: 6000 pps (low speed rotation is assumed to be around 7000 pps) Fixing temperature: (Example) 165℃ Load torque: (Example) 20mNm (5~30mNm)

[0054] Current decay setting (Decay) is a control technology that controls current decay and reduces the energy supplied to the coil by changing the current path, such as by stopping the power supply to the motor coil of a stepping motor.

[0055] Figure 9 is an explanatory diagram comparing current decay settings (Decay). As shown in Figure 9, the slow current decay (Slow Decay) has a gentler decay slope than the fast current decay (Fast Decay). The degree of current decay is different.

[0056] FIG. 10 is an explanatory diagram of an example of an H-bridge circuit that performs current decay setting, and is configured in a driver IC 310 that applies voltage to the motor coils M of stepping motors 230m1 and 230m2 (see FIG. 3). This H-bridge circuit is configured by connecting four transistors (FET1 to FET4) in an H shape so that a power supply voltage VDD is applied to the motor coils M. Note that GND is ground, and D1 to D4 schematically represent body diodes or parasitic diodes formed between the source and drain of the FETs (field effect transistors). Also, FETs are an example of switching elements, and various switching elements (power transistors, MOSFETs) can also be used.

[0057] Figure 10(a) shows the motor in operation, (b) shows high-speed current decay, and (c) shows low-speed current decay. In the operation state shown in Figure 10(a), the transistors FET1 and FET4 of the H-bridge circuit are turned on, and the transistors FET2 and FET3 are turned off. This causes current to flow as shown by the symbol I-1, supplying energy to the inductor of the motor coil M from the power supply VDD and ground GND.

[0058] During fast current decay (Fast Decay) shown in Figure 10(b), the H-bridge circuit is in the reverse state, meaning that transistors FET2 and FET3 are turned on and transistors FET1 and FET4 are turned off. This causes current to flow as shown by symbol I-2, and the energy of the inductor of motor coil M is regenerated via the power supply VDD and ground GND.

[0059] During the slow current decay (Fast Decay) shown in Figure 10(c), the transistors FET3 and FET4 are turned ON and the transistors FET1 and FET2 are turned OFF to enter a braking state. This causes current to flow as indicated by symbol I-3, and the current I-3 consumes energy in the inductor of the motor coil M itself.

[0060] As described above, in the image forming apparatus of the embodiment, the stepping motor for transporting the recording paper is equipped with a current decay setting that can be switched depending on the rotation speed / fixing temperature corresponding to the type of recording paper thickness, etc., thereby achieving high torque output in the high-speed rotation range while suppressing the temperature of the driver IC and motor without requiring additional circuit components or fans.

[0061] Although the embodiments have been described above, the specific configurations are not limited to the embodiments, and designs that do not deviate from the gist of the present disclosure are also included in the scope of the claims.

[0062] In the embodiments, the programs that run on each device are programs that control the CPU, etc. (programs that make a computer function) so as to realize the functions of the above-described embodiments. Information handled by these devices is temporarily stored in a temporary storage device (e.g., RAM) during processing, and then stored in various ROMs and HDDs, and is read, modified, and written by the CPU as needed.

[0063] Here, the recording medium for storing the program may be any non-transitory recording medium such as a semiconductor medium (e.g., a ROM or a non-volatile memory card), an optical recording medium or a magneto-optical recording medium (e.g., a DVD (Digital Versatile Disc), an MO (Magneto Optical Disc), an MD (Mini Disc), a CD (Compact Disc), or a BD (Blu-ray (registered trademark) Disc)), or a magnetic recording medium (e.g., a magnetic tape, a flexible disk, etc.).

[0064] In addition, not only are the functions of the above-described embodiments realized by executing the loaded program, but the functions of the present disclosure may also be realized by processing in cooperation with an operating system or other application programs, etc., based on the instructions of the program.

[0065] Furthermore, when distributing the program on the market, the program can be stored in a portable storage device and distributed, or transferred to a server computer connected via a network such as the Internet. In this case, the storage device of the server computer is of course also included in the present disclosure.

[0066] Furthermore, some or all of the devices in the above-described embodiments may be realized as LSI (Large Scale Integration), which is typically an integrated circuit. Each functional block of each device may be individually formed into a chip, or some or all of them may be integrated into a chip. Furthermore, the integrated circuit method is not limited to LSI, and may be realized using a dedicated circuit or a general-purpose processor. Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology, it is of course possible to use an integrated circuit based on that technology. [Industrial Applicability]

[0067] The image forming apparatus of the present disclosure can be used in various image forming apparatuses such as multifunction peripherals. [Explanation of symbols]

[0068] 10 Image forming device 100 control section 110 Image input unit 112 Document reading unit 120 Image processing unit 120 Paper cassette 124 Paper output tray 124d Upper Output Tray 124u Lower Output Tray 130 Image forming unit 160 Storage section 180 Printing Department 190 Paper feed section 200 Conveyor 210 Fixing unit 220 Double-sided conveying section 230 Paper output section 230u Upper paper ejection roller 230m1 stepping motor 230d Lower paper ejection roller 230m2 stepping motor 300 microcomputers FET1 to FET4 FET transistors VDD power supply GND Ground

Claims

1. a fixing unit that applies heat to a toner image formed on recording paper by an electrophotographic method to fix the toner image; a stepping motor for conveying recording paper, the stepping motor being disposed in the vicinity of the fixing unit; a control unit that controls a current attenuation setting of the stepping motor in accordance with the type of the recording paper; An image forming apparatus comprising:

2. 2. The image forming apparatus according to claim 1, wherein the stepping motor is installed above the fixing unit at a location that is subject to the heat of the fixing unit.

3. a setting unit for allowing a user to set the type of recording paper, such as thick paper, plain paper, thin paper, etc.; The image forming apparatus according to claim 1 or 2, characterized in that the control unit sets the current decay speed to a high speed when a paper type thicker than regular paper is set for the recording paper, and switches to a low speed when a paper type thinner than regular paper is set for the recording paper.

4. a setting unit for allowing a user to set the type of recording paper, such as thick paper, plain paper, thin paper, etc.; The image forming apparatus according to claim 1 or 2, characterized in that, when a paper type thicker than regular paper is set for the recording paper, the control unit sets the paper discharge speed to a low rotation range and a high current decay setting, and, on the other hand, when a paper type thicker than regular paper or regular paper is set for the recording paper, the control unit sets the paper discharge speed to a high rotation range and a low current decay setting.

5. a fixing step in which the toner image formed on the recording paper by the electrophotographic method is fixed by applying heat to the toner image by a fixing unit; a step of driving a stepping motor for conveying recording paper, the stepping motor being disposed in the vicinity of the fixing unit; a control step of controlling a current decay setting of the stepping motor in accordance with the type of the recording paper; 10. A method for controlling an image forming apparatus, comprising:

Images