JP6900145B2 - Motor control device and image forming device - Google Patents

Description

The present invention relates to a technique for estimating motor temperature.

Image forming devices such as copiers, multifunction devices, and printers print, that is, form images on the recorded material to be conveyed. In such an image forming apparatus, a motor is used as a driving source for transporting a recording material and a driving source for rotating each member for image forming. Since the motor generates heat when driven, it is necessary to control the motor temperature so that it does not exceed the permissible value. However, providing a temperature sensor for measuring the motor temperature leads to an increase in cost. Therefore, Patent Document 1 discloses a configuration in which the motor temperature is estimated based on a parameter value that correlates with the motor temperature. Specifically, the coil resistance value of the motor is estimated by the sequential least squares method, and the motor temperature is estimated based on the estimated coil resistance value.

Japanese Unexamined Patent Publication No. 2012-130162

In the configuration described in Patent Document 1, it is necessary to use a current sensor to estimate the coil resistance value, which increases the cost.

The present invention provides a motor control device and an image forming device that estimate a motor temperature without using a temperature sensor and a current sensor that measure the temperature of the motor.

According to one aspect of the present invention, the motor control device includes a detection means for detecting the rotation speed of the motor and a control means for controlling the rotation speed of the motor based on the rotation speed of the motor detected by the detection means. a temperature detection means for detecting the ambient temperature of the control device comprises information indicating a first temperature, holding means for holding the previous SL information indicating a first torque constant at the first temperature, wherein the The control means rotates the motor at two different rotation speeds when the power of the control device is turned on or when the control device returns from the energy saving mode, and the average of each output to the motor. The first countercurrent power constant is obtained from the voltage, the first torque constant is obtained based on the first countercurrent power constant, the temperature detected by the temperature detecting means is defined as the first temperature, and the first torque constant is defined as the first temperature. And when the holding means holds the first temperature and estimates the temperature of the motor, the motor is rotated at two different rotation speeds, and the second back torque is obtained from the average voltage of each output to the motor. A constant is obtained, and a second torque constant is obtained based on the obtained second backlash power constant, and the first temperature, the first torque constant , the second torque constant, and the magnet possessed by the motor are obtained. It is characterized in that the temperature of the motor is estimated only from the temperature coefficient.

According to the present invention, the motor temperature can be estimated without using a temperature sensor and a current sensor for measuring the temperature of the motor.

The block diagram of the image forming apparatus by one Embodiment. The figure which shows the control structure of the image forming apparatus by one Embodiment. The block diagram of the drive circuit of the DC brush motor according to one Embodiment. The flowchart of the back electromotive force constant estimation processing by one Embodiment. The flowchart of the temperature estimation process by one Embodiment. The flowchart of the motor control process by one Embodiment.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. The following embodiments are examples, and the present invention is not limited to the contents of the embodiments. Further, in each of the following figures, components that are not necessary for the description of the embodiment will be omitted from the drawings.

<First Embodiment>
Hereinafter, the present embodiment will be described assuming that the device provided with the motor control device according to the present embodiment is an image forming device. FIG. 1 is a configuration diagram of an image forming apparatus 100 according to the present embodiment. The photoconductor 5 is an image carrier and is rotationally driven during image formation. The charging unit 6 charges the surface of the photoconductor 5 to a predetermined potential. The exposure unit 14 exposes the charged photoconductor 5 with light 13 to form an electrostatic latent image. The developing unit 7 attaches toner to the electrostatic latent image of the photoconductor 5 to obtain a toner image. On the other hand, the recording material 1 fed from the storage portion to the transport path by the pickup roller 2 is transported to the opposite position of the photoconductor 5 by the rollers 3 and 4. The transfer roller 10 transfers the toner image of the photoconductor 5 to the recording material 1. The fixing roller 11 and the pressurizing roller 12 heat and pressurize the recording material 1 to which the toner image is transferred, and fix the toner image on the recording material 1. After fixing the toner image, the recording material 1 is discharged to the paper ejection tray 19. In the image forming apparatus 100 of the present embodiment, the photoconductor 5, the charging unit 6, and the developing unit 7 are configured in a cartridge 9 that can be attached to and detached from the image forming apparatus 100. The DC brush motor 18 (hereinafter, simply referred to as a motor 18) is a drive source for a rotating member of the image forming apparatus 100, and rotates, for example, a photoconductor 5, rollers 3 and 4, and the like. The number of members rotated by the motor 18 may be one or a plurality. The encoder 21 is provided to detect the rotation speed of the motor 18. The controller 20 controls the image forming apparatus 100.

FIG. 2 is a diagram showing a control configuration of the motor 18. The controller 20 is a control unit that collectively controls the image forming apparatus, and includes a CPU 26, a ROM 27, a RAM 28, and an EEPROM 29. The CPU 26 executes each process for controlling the image forming apparatus by executing the program held by the ROM 27. At that time, the CPU 26 uses the RAM 28 as a work area. Further, the CPU 26 stores various data to be retained in the EEPROM 29 even when the power of the image forming apparatus is turned off. The controller 20 outputs a PWM signal to the drive circuit 23, and the drive circuit 23 outputs a voltage for rotating the motor 18 to the motor 18 based on the PWM signal.

The encoder 21 is a detection unit that detects the rotation speed of the motor 18, and includes a photo sensor 31 including a light emitting unit 32 and a light receiving unit 33, and a slit unit 34 that rotates together with the motor 18 and is provided with one or more slits. , Is equipped. When the slit of the slit portion 34 comes on the optical path from the light emitting unit 32 to the light receiving unit 33, the light receiving unit 33 receives the light from the light emitting unit 32 and outputs a high level signal. On the other hand, when the position where the slit of the slit portion 34 is not formed comes from the light emitting unit 32 on the optical path of the light receiving unit 33, the light receiving unit 33 does not receive the light from the light emitting unit 32 and outputs a low level signal. To do. Therefore, when the slit portion 34 rotates together with the motor 18, the light receiving portion 33 alternately outputs high-level and low-level signals due to the rotation of the slit. Therefore, the controller 20 can obtain the rotation speed of the motor 18 from, for example, the high-level timing output by the light receiving unit 33. The controller 20 obtains the rotation speed of the motor 18 from the output of the encoder 21 and controls the PWM signal output to the drive circuit 23 so that the motor 18 reaches the target rotation speed. The temperature sensor 30 is a temperature detection unit that detects the atmospheric temperature in which the image forming apparatus 100 is installed. The components other than the motor 18 in FIG. 2 constitute a control device for the motor 18.

FIG. 3 is a configuration diagram of the drive circuit 23. The FET 24 of the drive circuit 23 is turned ON / OFF based on the PWM signal from the controller 20. When the PWM signal is high, the FET 24 is turned on and the voltage Va is output to the DC brush motor 18. The controller 20 increases the high level time per cycle of the PWM signal when the rotation speed of the motor 18 is increased. That is, the On duty ratio of the PWM signal is increased. The On-duty ratio is the ratio of high-level time to one cycle of the PWM signal. On the contrary, when the rotation speed of the motor 18 is slowed down, the controller 20 reduces the On duty ratio of the PWM signal. The controller 20 detects the rotation speed of the motor 18 based on the output of the encoder 21 and controls the On duty ratio of the PWM signal so as to reach the target rotation speed.

Generally, the average voltage V output to the motor 18, the resistance R between the terminals of the motor, the motor current I, the counter electromotive force constant Ke of the motor, and the angular speed ω of the motor have a relationship of the equation (1). However, the frequency component of the angular velocity ω of the motor shall be sufficiently lower than the electrical response characteristics of the motor.
V = (RI + Ke ・ ω) (1)
When the inter-terminal resistance R and the motor current I are fixed values, the counter electromotive force constant Ke of the motor 18 can be calculated from the equation (1). However, not only the counter electromotive force constant Ke but also the inter-terminal resistance R and the motor current I change depending on the temperature. Therefore, in the present embodiment, it is a parameter that changes depending on the temperature by driving the motor 18 at two rotation speeds in a short time in which the temperature changes of the counter electromotive force constant Ke, the inter-terminal resistance R, and the motor current I are almost negligible. The counter electromotive force constant Ke is estimated. A detailed description of the present embodiment is shown below.

FIG. 4 is a flowchart of a process for calculating the counter electromotive force constant Ke0 when the temperature of the motor is equivalent to the atmospheric temperature. Therefore, the process of FIG. 4 may be performed when the power is turned on after the image forming apparatus has not been operated for a predetermined period of time, such as when the image forming apparatus 100 is installed, or when returning from the energy saving mode. it can. In S10, the controller 20 rotates the motor 18 at the first target speed. As an example, the first target speed is 400 rpm. In S11, the controller 20 acquires the average voltage V1 and the average angular velocity ω1 output to the motor 18 during a predetermined period in which the motor 18 is rotating at the first target speed. The average voltage V1 is determined by assuming that the On duty ratio of the PWM signal during the predetermined period is O1.
V1 = Va · O1 (2)
Is. Also, from equation (1),
ω1 = (V1-RI) / Ke0 (3)
It becomes.

Next, the controller 20 rotates the motor 18 at the second target speed in S12. As an example, the second target speed is the target rotation speed of the motor 18 at the time of image formation, and can be, for example, 2000 rpm. In S13, the controller 20 acquires the average voltage V2 and the average angular velocity ω2 output to the motor 18 during a predetermined period in which the motor 18 is rotating at the second target speed. The average voltage V2 is determined by assuming that the On duty ratio of the PWM signal during the predetermined period is O2.
V2 = Va · O2 (4)
Is. Also, from equation (1),
ω2 = (V2-RI) / Ke0 (5)
Is.

The time required for the processing from S11 to S13 is usually about several hundred msec, and the inter-terminal resistance R, the motor current I, and the counter electromotive force constant Ke0 in the equations (3) and (5) are temperature changes. It can be regarded as the same value without being affected by. Therefore, the controller 20 obtains the counter electromotive force constant Ke0 at the atmospheric temperature in S14 from the equations (2) to (5) by the following equation.
Ke0 = (V2-V1) / (ω2-ω1) (6)

The controller 20 stores the calculated back electromotive force constant Ke0 and the information indicating the atmospheric temperature T0 when the Ke0 is calculated in the EEPROM 29 in S15. The atmospheric temperature T0 is detected by the temperature sensor 30.

Subsequently, the estimation of the temperature of the motor 18 will be described. Generally, the output torque T of the DC brush motor 18 can be obtained from the torque constant Kt and the motor current I by the following equation.
T = Kt ・ I (7)
Further, the torque constant Kt is expressed by the following equation, where N is the number of turns of the winding of the motor 18 and φ is the generated magnetic flux.
Kt = N · φ / π (8)

Further, in the present embodiment, the motor 18 is driven by the PWM signal. That is, it is a square wave drive. The following relationship holds between the torque constant Kt and the counter electromotive force constant Ke in the case of square wave drive.
Kt = Ke (9)
From the formulas (8) and (9), the following formulas can be obtained.
Ke = N · φ / π (10)

From the equation (10), the counter electromotive force constant Ke is proportional to the magnetic flux φ. Here, the magnetic flux generated by the magnet used in the motor 18 is temperature-dependent. For example, if the magnet is a ferrite magnet, its temperature coefficient is −0.19% / ° C. Therefore, in the present embodiment, the winding temperature of the motor 18 is estimated from the amount of change in the counter electromotive force constant Ke0 at the ambient temperature estimated in the process of FIG. 4 and the counter electromotive force constant Kez calculated at a predetermined timing. This is estimated to be the temperature of the motor 18.

FIG. 5 is a flowchart of a process of estimating the temperature of the motor 18 by obtaining the counter electromotive force constant Kez at a predetermined timing. The resistance between terminals and the motor current at the temperature at this predetermined timing are Rz and Iz, respectively. The controller 20 starts printing in S20. In the image forming apparatus of the present embodiment, as described above, the target value of the rotation speed of the motor 18 in the printing process is the second target speed. That is, the controller 20 rotates the motor 18 at the second target speed in S21. In S22, the controller 20 acquires the average voltage V3 and the average angular velocity ω3 output to the motor 18 during a predetermined period of the motor 18 rotating at the second target speed. Assuming that the On-duty ratio of the PWM signal during the predetermined period is O3, the average voltage V3 is
V3 = Va · O3 (11)
Is. Also, from equation (1),
ω3 = (V3-Rz · Iz) / Kez (12)
Is.

The controller 20 repeats the process from S21 until the print process is completed in S23. That is, during the printing process, the average voltage V3 and the average angular velocity ω3 are repeatedly acquired. The controller 20 uses the last acquired average voltage V3 and average angular velocity ω3 in the process of S26 described later. When the printing process is completed, the controller 20 rotates the motor 18 at the first target speed in S24. In S25, the controller 20 acquires the average voltage V4 and the average angular velocity ω4 output to the motor 18 during a predetermined period of the motor 18 rotating at the first target speed. Assuming that the On-duty ratio of the PWM signal during the predetermined period is O4, the average voltage V4 is
V4 = Va · O4 (13)
Is. Also, from equation (1),
ω4 = (V4-Rz · Iz) / Kez (14)
Is.

The time required from the final processing of S22 to the processing of S25 is usually about several hundred msec, and the inter-terminal resistance Rz, motor current Iz, and counter electromotive force constant Kez in the equations (12) and (14) are It is not affected by temperature changes and can be regarded as the same value. Therefore, the controller 20 obtains the counter electromotive force constant Kez in S26 from the equations (11) to (14) by the following equation.
Kez = (V4-V3) / (ω4-ω3) (15)

The magnetic force of the ferrite magnet of the motor 18 changes with temperature, and the rate of change is −0.19% / ° C. as described above. Further, the magnet and the winding of the motor 18 are very close to each other, and the temperature of the magnet and the temperature of the winding are almost the same. Therefore, the counter electromotive force constant Kez obtained by the equation (15), the counter electromotive force constant Ke0 at the atmospheric temperature T0 stored in the EEPROM 29, and the winding temperature Tz to be estimated have the following relationship.
Kez = Ke0 · (1-0.0019 · (Tz-T0)) (16)
From the equation (16), the controller 20 obtains the winding temperature Tz in S27 by the following equation.
Tz = T0 + (1-Kez / Ke0) /0.0019 (17)
The winding temperature Tz can be regarded as the temperature of the motor 18, whereby the controller 20 estimates the winding temperature Tz as the motor temperature Tz.

For example, from equations (6) and (15),
Kez / Ke0 = ((V4-V3) · (ω2-ω1)) / ((V2-V1) · (ω4-ω3)) (18)
Is. Here, assuming that ω2 = ω3 = 2000 rpm and ω1 = ω4 = 400 rpm, the equation (18) is
Kez / Ke0 = (V3-V4) / (V2-V1) (19).
For example, if (V3-V4) / (V2-V1) = 0.9905, the equation (17) is
Tz = T0 + 0.0095 / 0.0019
= T0 + 5
If T0 is 25 degrees, the motor temperature Tz is 30 degrees.

In this embodiment, it is assumed that the motor 18 uses a ferrite magnet, and the rate of change of the magnetic flux depending on the temperature is −0.19% / ° C. However, the value of this rate of change is an example, and the value determined by the magnet used is used as the rate of change of the magnetic flux. Further, in S23, the process waits until the end of printing, and the process of S24 or less is performed after the end of printing. However, for example, the process of S24 or less may be performed by starting the cleaning process performed by interrupting the print process.

Further, in the process of FIG. 5, after the start of printing, the winding temperature Tz may be estimated by first rotating at the first target speed and then rotating at the second target speed. Further, the winding temperature Tz may be repeatedly estimated by temporarily rotating at the first target speed and then rotating at the second target speed even in the middle of printing. When the motor temperature Tz is likely to exceed the specified temperature, the controller 20 can control the motor temperature to the specified temperature or lower by slowing down the image forming speed or temporarily interrupting the image forming process. it can. With the above configuration, it is possible to estimate the temperature of the motor 18 without adding a sensor, and it is possible to prevent deterioration of the motor characteristics due to the motor temperature exceeding the usable temperature. Further, in the present embodiment, the motor 18 is rotated at the same target speed in both the process of FIG. 4 and the process of FIG. 5, but the two rotation speeds in the process of FIG. 4 and the process of FIG. 5 are used. The two rotation speeds may be different.

As described above, in the present embodiment, the parameters of the motor 18 that change depending on the temperature are acquired by rotating the motor 18 at two different rotation speeds. The process of acquiring the parameters by rotating at two different rotation speeds is performed within a predetermined time so that the temperature change of the parameter and other temperature-changing parameters does not occur. At the timing when the temperature of the motor 18 can be estimated, the controller 20 acquires the value of the parameter and holds it in the EEPROM 29 together with the temperature. Then, the controller 20 acquires the value of the parameter at the timing of acquiring the temperature of the motor 18, and the motor 18 is based on the acquired parameter value, the parameter value and temperature held in the EEPROM 29, and the temperature change rate of the parameter. Estimate the temperature of. In this configuration, the motor temperature can be estimated without using a sensor that detects the temperature of the motor 18 or a current sensor. The temperature sensor 30 for detecting the atmospheric temperature is usually possessed by the image forming apparatus, and the cost increase by the temperature sensor 30 does not occur.

<Second embodiment>
Subsequently, the second embodiment will be described focusing on the differences from the first embodiment. In the present embodiment, as in the first embodiment, the counter electromotive force constant Kez at a predetermined timing is estimated, and the motor temperature Tz is estimated accordingly. After that, the time ta until the motor temperature reaches the threshold temperature Tth is calculated, and the motor temperature is controlled so as not to exceed the threshold temperature Tth based on the time ta. Therefore, in the present embodiment, the temperature rise profile of the winding temperature and the threshold temperature Tth are stored in the EEPROM 29 in advance. The temperature rise profile is information indicating the temperature rise rate of the winding temperature when the motor 18 is rotated at a certain rotation speed.

For example, suppose it takes 120 minutes for the winding temperature of the motor to change from 25 ° C to 150 ° C at a predetermined speed. In this case, the time t until the winding temperature rises from 25 ° C. to the threshold temperature Tth is expressed by the following equation.
t = -120 · LOG (1- (Tth-25) / (150-25)) (20)
From the equation (20), the time ta from the winding temperature Tz to the threshold temperature Tth is expressed by the following equation.
ta = -120 · LOG (1- (Tth-Tz) / (150-Tz)) (21)

FIG. 6 is a flowchart of the process according to the present embodiment. Also in this embodiment, the counter electromotive force constant Ke0 at the atmospheric temperature is estimated in advance by the process of FIG. 4, and the atmospheric temperature T0 at that time is stored in the EEPROM 29. The process of FIG. 4 is performed after the power-off state or the power-saving state of the image forming apparatus 100 continues for a long time. This is because the characteristics of the motor 18 change over time, and therefore the counter electromotive force constant Ke0 at the atmospheric temperature also changes over time.

When the controller 20 starts the printing operation in S30, the controller 20 rotates the motor 18 at the first target speed in S31. In S32, the controller 20 acquires the average voltage V5 and the average angular velocity ω5 during a predetermined period in which the motor 18 is rotating at the first target speed. The average voltage V5 is determined by assuming that the On duty ratio of the PWM signal during the predetermined period is O5.
V5 = Va · O5 (22)
Is. Also, from equation (1),
ω5 = (V5-Rz · Iz) / Kez (23)
It becomes. Rz, Iz, and Kez are the inter-terminal resistance, the motor current, and the counter electromotive force constant of the motor 18 during the processing of S32, respectively.

Next, the controller 20 rotates the motor 18 at the second target speed in S33. In S34, the controller 20 acquires the average voltage V6 and the average angular velocity ω6 during a predetermined period in which the motor 18 is rotating at the second target speed. The average voltage V6 is determined by assuming that the On duty ratio of the PWM signal during the predetermined period is O6.
V6 = Va · O6 (24)
Is. Also, from equation (1),
ω6 = (V6-Rz · Iz) / Kez (25)
Is.

The time required for the processing from S32 to S34 is usually about several hundred msec, and the inter-terminal resistance Rz, the motor current Iz, and the counter electromotive force constant Kez during this period are not affected by the temperature change and have the same values. Can be regarded as. Therefore, the controller 20 obtains the counter electromotive force constant Kez at the current temperature in S35 from the equations (22) to (25) by the following equation.
Kez = (V6-V5) / (ω6-ω5) (26)

In S36, the controller 20 determines the printable time ta by the equation (21). The printable time ta is the time from the present until the temperature of the motor 18 reaches the threshold temperature Tth when the motor 18 is continuously rotated at the second target speed. The controller 20 determines in S37 whether printing is completed, and if printing is completed, ends the process. On the other hand, if the printing is not completed, it is determined in S38 whether the time ta has elapsed, and if the time ta has not elapsed, the process from S37 is repeated. On the other hand, when the time ta elapses before the printing is completed, the controller 20 controls the motor 18 so as to lower the temperature of the motor 18 in S39, and then repeats the process from S31. The control for lowering the temperature of the motor 18 means a process of changing the rotation speed of the motor 18 to a speed slower than the second target speed, or a process of temporarily stopping the rotation of the motor 18.

As described above, in the present embodiment, by estimating the time until the motor temperature reaches the threshold temperature, it is possible to suppress the motor temperature from reaching the threshold temperature, thereby suppressing the wear of the brush and extending the life of the motor 18. Can be made to.

[Other Embodiments]
The present invention supplies a program that realizes one or more functions of the above-described embodiment to a system or device via a network or storage medium, and one or more processors in the computer of the system or device reads and executes the program. It can also be realized by the processing to be performed. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

21: Encoder, 20: Controller, 29: EEPROM

Claims (10)

It is a motor control device
A detection means for detecting the rotation speed of the motor and
A control means that controls the rotation speed of the motor based on the rotation speed of the motor detected by the detection means, and
A temperature detecting means for detecting the atmospheric temperature of the control device, and
Holding means for holding information indicating the first temperature, the information indicating the first torque constant before Symbol first temperature,
Is equipped with
The control means rotates the motor at two different rotation speeds when the power of the control device is turned on or when the control device returns from the energy saving mode , and outputs the motor to the motor. The first countercurrent power constant is obtained from the average voltage, the first torque constant is obtained based on the first countercurrent power constant, the temperature detected by the temperature detecting means is set as the first temperature, and the first torque is set. When the holding means holds a constant value and the first temperature and estimates the temperature of the motor, the motor is rotated at two different rotation speeds, and a second backlash is generated from the average voltage of each output to the motor. The power constant is obtained, and the second torque constant is obtained based on the obtained second countercurrent power constant, and the first temperature, the first torque constant , the second torque constant, and the magnet possessed by the motor are obtained. A control device characterized in that the temperature of the motor is estimated only from the temperature coefficient of. The control according to claim 1, wherein the control means rotates the motor at the two different rotation speeds within a predetermined time when obtaining the first torque constant and the second torque constant. apparatus. It is a motor control device
A detection means for detecting the rotation speed of the motor and
A control means that controls the rotation speed of the motor based on the rotation speed of the motor detected by the detection means, and
A temperature detecting means for detecting the atmospheric temperature of the control device, and
Is equipped with
The control means rotates the motor at two different rotation speeds at a first timing in which the temperature of the motor can be determined by the atmospheric temperature detected by the temperature detecting means, and from the average voltage of each output to the motor. The first countercurrent power constant is obtained, the first torque constant is obtained based on the first countercurrent power constant, and the motor is rotated at two different rotation speeds at the second timing for estimating the temperature of the motor. , The second countercurrent power constant is obtained from each average voltage output to the motor, the second torque constant is obtained based on the second countercurrent power constant, and the temperature of the motor determined by the atmospheric temperature, the first A control device characterized in that the temperature of the motor at the second timing is estimated only from the torque constant of 1, the second torque constant, and the temperature coefficient of the magnet of the motor. The control device according to claim 3, wherein the first timing is a timing at which the temperature of the motor is considered to be equal to the atmospheric temperature. The control means is characterized in that a torque constant is obtained based on the difference between two different rotation speeds and the difference in the average voltage output to the motor while rotating at the two different rotation speeds. Item 2. The control device according to any one of Items 1 to 4. The control device according to any one of claims 1 to 5 , wherein the control means controls the rotation speed of the motor so that the estimated temperature of the motor does not exceed the threshold temperature. Further, it is provided with a storage means for storing information indicating the rate of temperature rise with respect to the rotation speed of the motor.
The control means controls the motor to rotate at a target speed, and when the temperature of the motor is estimated, the temperature of the motor is the threshold temperature from the estimated temperature based on the temperature rise rate at the target speed. The control device according to claim 6 , wherein the time required to reach the temperature is estimated. When the time from when the temperature of the motor is estimated to when the temperature reaches the estimated threshold temperature elapses, the control means stops the motor or sets the rotation speed of the motor to a speed slower than the target speed. The control device according to claim 7 , wherein the control device is changed. It is an image forming device
Rotating members related to image formation and
A motor for rotating the rotating member and
A detection means for detecting the rotation speed of the motor and
A control means that controls the rotation speed of the motor based on the rotation speed of the motor detected by the detection means, and
A temperature detecting means for detecting the atmospheric temperature of the image forming apparatus, and
Holding means for holding information indicating the first temperature, the information indicating the first torque constant before Symbol first temperature,
Is equipped with
The control means rotates the motor at two different rotation speeds and outputs the motor to the motor when the power of the image forming apparatus is turned on or when the image forming apparatus returns from the energy saving mode. The first countercurrent power constant is obtained from each average voltage, the first torque constant is obtained based on the first countercurrent power constant, the temperature detected by the temperature detecting means is defined as the first temperature, and the first temperature is defined as the first temperature. When the holding means holds the torque constant and the first temperature of the motor and estimates the temperature of the motor, the motor is rotated at two different rotation speeds, and the second is obtained from the average voltage of each output to the motor. obtains counter electromotive force constant, it obtains a second torque constant based on the second back electromotive force constant obtained, the first temperature, the first torque constant, pre Symbol second torque constant, and the motor An image forming apparatus characterized in that the temperature of the motor is estimated only from the temperature coefficient of the magnet possessed by the motor. It is an image forming device
Rotating members related to image formation and
A motor for rotating the rotating member and
A detection means for detecting the rotation speed of the motor and
A control means that controls the rotation speed of the motor based on the rotation speed of the motor detected by the detection means, and
A temperature detecting means for detecting the atmospheric temperature of the image forming apparatus, and
Is equipped with
The control means rotates the motor at two different rotation speeds at a first timing in which the temperature of the motor can be determined by the atmospheric temperature detected by the temperature detecting means, and the first is from the average voltage of each output to the motor. 1 The counter electromotive force constant is obtained, the first torque constant is obtained based on the first counter electromotive force constant, and the motor is rotated at two different rotation speeds at the second timing for estimating the temperature of the motor. The second countercurrent power constant is obtained from each average voltage output to the motor, the second torque constant is obtained based on the second countercurrent power constant, and the temperature of the motor determined by the atmospheric temperature, the first An image forming apparatus, characterized in that the temperature of the motor at the second timing is estimated only from the torque constant of the above, the second torque constant, and the temperature coefficient of the magnet of the motor.

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