JP2009229629A - Fixing device, image forming apparatus, method of controlling fixing device, and control program for fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device capable of controlling the increase of ripple due to a response delay when detecting temperature. <P>SOLUTION: The fixing device includes a thermistor 55 directly detecting heat from a heating roller 31, and a thermopile 56 detecting temperature according to an amount of infrared radiation radiated from the heating roller 31. The detection temperature by the thermistor 55 is corrected based on at least either variation of the detection temperature by the thermopile 56 or that of the variation. The heating source of the heating roller 31 is controlled by entering the corrected detection temperature. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fixing device, an image forming apparatus, a fixing device control method, and a fixing device control program, and in particular, a fixing device having a function of suppressing a ripple increase due to a response delay at the time of temperature detection, an image forming apparatus, The present invention relates to a fixing device control method and a fixing device control program.

  2. Description of the Related Art An electrophotographic image forming apparatus (MFP (Multi Function Peripheral), facsimile machine, copier, printer, etc.) is provided with a fixing device that fixes a toner image onto a sheet by heat. In order to control the temperature of the roller and belt of the fixing device, the surface temperature of the roller and belt is detected.

  Non-contact temperature detection devices include a method of directly detecting heat from a measured object using a thermistor, a method of detecting temperature according to the amount of infrared rays emitted from the measured object using a thermopile, and the like. is there.

  Compared with the method of detecting the temperature according to the amount of infrared rays emitted from the measured object, the method of directly detecting the heat from the measured object is less affected by dirt and ambient temperature, but the thermal response performance is poor. There is a feature.

  On the other hand, the method of detecting the temperature according to the amount of infrared rays radiated from the object to be measured has better thermal response performance than the method of directly detecting the heat from the object to be measured, but the influence of dirt and ambient temperature There are features such as being easy to receive.

  Patent Document 1 below discloses a fixing device that corrects a thermopile detection temperature based on a direct measurement thermistor detection temperature. This suppresses the reduction in measurement accuracy due to variations in thermopile elements.

  Patent Document 2 below discloses a fixing device that suppresses the influence of an ambient temperature on a thermopile by generating an air flow. By preventing the dirt around the thermopile by airflow, the temperature detection accuracy of the thermopile is improved and temperature deviation is suppressed. Moreover, it is suppressed that the temperature of a thermopile exceeds heat-resistant temperature.

  Patent Document 3 below discloses an image forming apparatus that corrects the non-contact sensor detection temperature based on the contact sensor detection temperature when the heating roller is stopped, and controls energization to the heat source at the non-contact sensor corrected temperature. The image forming apparatus includes a fixing device having a contact temperature sensor made of a thermistor and a non-contact temperature sensor made of a non-contact thermistor or an infrared sensor. By taking measures against contamination of the infrared sensor, accurate temperature detection is possible.

The following Patent Document 4 discloses a temperature detection device that corrects the detection temperature of the infrared sensor based on the detection temperature of the non-contact sensor in a state where the airflow is stopped or controlled. A non-contact thermistor that directly detects the heat from the measured object is used as a countermeasure against contamination of the thermopile infrared sensor that detects the temperature in accordance with the amount of infrared radiation emitted from the measured object. Based on the temperature detected by the thermistor, the temperature detected by the infrared sensor is corrected.
JP 2004-93651 A JP 2005-24330 A JP 2006-47410 A JP 2006-184071 A

  When temperature adjustment is performed using a sensor (such as a thermistor) that directly detects heat from the measurement object and has poor thermal response performance, there is a problem that the temperature ripple increases due to response delay. When the temperature ripple increases, the fixed image performance is not stable.

  The present invention has been made to solve such a problem, and can fix an increase in ripple due to a response delay at the time of temperature detection, a fixing device, an image forming apparatus, a fixing device control method, and a fixing device. The purpose is to provide a control program.

  In order to achieve the above object, according to one aspect of the present invention, the fixing device is installed in a non-contact manner with respect to the measured object, and first temperature detecting means for directly detecting the heat from the measured object, and the measured object A second temperature detecting means which is installed in a non-contact manner with respect to the body and detects the temperature according to the amount of infrared rays emitted from the measured object; a heating source which heats the measured object; and a second temperature detecting means Based on at least one of the change amount of the detected temperature and the change amount of the change amount, the correction means for correcting the detection temperature of the first temperature detection means, and the detection temperature corrected by the correction means as input Control means for controlling the source.

  Preferably, at least one of the first detection unit and the second detection unit is installed outside the fixing device main body, and the control unit controls the amount of power supplied to the heating source.

  Preferably, the first detection means and the second detection means are integrated temperature detection means.

  Preferably, the first temperature detection means is a thermistor, and the second temperature detection means is a thermopile.

  According to another aspect of the present invention, an image forming apparatus includes a fixing device.

  According to still another aspect of the present invention, a fixing device control method is provided in a non-contact manner with respect to a measurement object, and includes a first temperature detection unit that directly detects heat from the measurement object, and a measurement object. A control method for a fixing device, which is installed in a non-contact manner and includes a second temperature detecting means for detecting the temperature according to the amount of infrared rays emitted from the measured object and a heating source for heating the measured object. A correction step for correcting the detected temperature of the first temperature detection means based on at least one of the change amount of the detection temperature of the second temperature detection means and the change amount of the change amount, and correction by the correction step And a control step for controlling the heating source using the detected temperature as an input.

  According to still another aspect of the present invention, a control program for a fixing device is installed in a non-contact manner with respect to a measured object, and includes first temperature detecting means for directly detecting heat from the measured object, and a measured object. A control program for a fixing device that is installed in a non-contact manner and includes a second temperature detecting means for detecting the temperature according to the amount of infrared rays emitted from the measured object and a heating source for heating the measured object. A correction step for correcting the detected temperature of the first temperature detection means based on at least one of the change amount of the detection temperature of the second temperature detection means and the change amount of the change amount, and correction by the correction step The computer is caused to execute a control step for controlling the heating source, using the detected temperature as an input.

  According to these inventions, it is possible to provide a fixing device, an image forming apparatus, a fixing device control method, and a fixing device control program capable of suppressing an increase in ripple due to a response delay during temperature detection.

  Hereinafter, an image forming apparatus including a fixing device according to an embodiment of the present invention will be described.

  [First Embodiment]

  FIG. 1 is a diagram illustrating a configuration of an image forming apparatus including a fixing device according to a first embodiment of the present invention.

  Here, the image forming apparatus is assumed to be a color printer, and is shown in a cross-sectional view illustrating a schematic configuration thereof. The following description is based on the image forming apparatus of FIG. 1, but the image forming apparatus to which the present invention is applied is not limited to this.

  In the image forming apparatus, each color image forming unit 1 for forming a black (BK), yellow (Y), magenta (M), and cyan (C) toner image circulates in the direction indicated by a large white arrow. The intermediate transfer belt 11 is arranged in the order of BK → Y → M → C from the upstream.

  The image forming unit 1 includes a charging unit 3 for uniformly charging the photosensitive drum 2, an exposure unit 9 for performing image exposure on the charged photosensitive drum 2, and an electrostatic latent image formed by the exposure. And a developing section 4 for developing with toner of each color.

  The control device 18 controls the entire image forming apparatus (in this case, a color printer). A signal corresponding to the image is sent from the control device 18 to the exposure control device 19. The exposure control device 19 drives each of the exposure units 9 according to each color.

  The toner image developed on the photosensitive drum 2 in the image forming unit 1 is transferred onto the intermediate transfer belt 11 by the primary transfer unit 12 at a contact position with the intermediate transfer belt 11. After the primary transfer, the toner remaining on the photosensitive drum 2 is removed by the cleaning unit 5 disposed downstream and collected from the lower side of the cleaning unit 5.

  Each time the toner image transferred onto the intermediate transfer belt 11 passes through each of the image forming units 1, each color is superimposed thereon. Finally, a full color toner image is formed on the intermediate transfer belt 11.

  Thereafter, the full-color toner image is further collectively transferred onto a recording sheet (recording paper) 14 such as paper by a so-called secondary transfer unit 13 further downstream. The recording sheet 14 passes through the upper fixing device 30 to fix the toner image, and is discharged onto the paper discharge tray 16.

  The recording sheets 14 are stored in the lowermost recording sheet cassette 17 and are conveyed one by one to the secondary transfer unit 13.

  The fixing device 30 includes a heating roller 31 and a pressure roller 32. A specific operation of the fixing device 30 will be described with reference to FIG.

  The toner remaining on the intermediate transfer belt 11 after the secondary transfer is removed from the intermediate transfer belt 11 by the cleaning blade 15, transported by a transport screw (not shown), and collected in a waste toner container (not shown).

  The arrangement of each element may be changed as appropriate according to the apparatus.

  FIG. 2 is a side view showing the configuration of the fixing device 30, and FIG. 3 is a plan view showing the configuration around the heating roller.

  The fixing device 30 includes a heating roller 31, a pressure roller 32, a thermistor 55, and a thermopile 56.

  A heating heater 53 is included in the heating roller 31. A pressure heater 54 is included in the pressure roller 32.

  The heating roller 31 has an outer diameter of 25 mm and a length of about 330 mm in the nip longitudinal direction. The heating roller 31 has a laminated structure of iron hollow core metal 0.8 mm, Si rubber 0.2 mm, and PTFE tube 30 μm.

  The pressure roller 52 has an outer diameter of 30 mm. The pressure roller 52 has a laminated structure of iron hollow core metal 2.5 mm, rubber 2.5 mm, and PFA 30 μm.

  The heater 53 is a 1180 W halogen lamp heater, and its light emission length is 290 mm.

  The pressure heater 54 is a 230 W halogen lamp heater, and its light emission length is 290 mm.

  The thermistor 55 directly detects heat from the heated object to be measured.

  The thermopile 56 detects the temperature according to the amount of infrared rays emitted from the heated object to be measured.

  The operation of bringing the surfaces of the heating roller 31 and the pressure roller 32 to a printable temperature after the power of the image forming apparatus is turned on is called warming up. The time required for this operation is called warm-up time. The warm-up operation is performed when the power is turned on again, when the jam processing is restored, when the cover is closed, and when the sleep mode is restored.

  In the warm-up operation, in order to raise the temperature of the heating roller 31 and the pressure roller 32 to the printable temperature, the heater 53 and the pressure heater 54 are turned on. By transmitting a driving force to a driving gear (not shown), the pressure roller 32 is rotated and the heating roller 31 is driven to rotate. Thereby, the heat of the heating roller 31 and the pressure roller 32 is transmitted to the surfaces of the heating roller 31 and the pressure roller 32.

  The linear velocity of the fixing device at this time is, for example, 90 mm / s. The surface of the heating roller 31 and the pressure roller 32 is raised to a printable temperature by turning on the heater and rotating the roller.

  At this time, the temperature of the heating roller 31 is detected, and if the temperature reaches a predetermined printable temperature, a ready indicating that printing is possible is made. The detected temperature of the heating roller 31 is determined to be in a printable state in any of the following cases.

  (1) When the temperature detected by the thermistor 55 is corrected by the amount of non-contact and further corrected by the temperature change amount of the thermopile 56, the corrected temperature is the printable temperature.

  (2) The corrected temperature obtained by correcting the temperature detected by the thermopile 56 by the amount of dirt is the printable temperature.

  When the fixing device 30 is ready for printing, if there is a print signal, the image forming apparatus starts a print operation.

  If there is no print signal, the image forming apparatus enters a print standby state. In the standby state, the heating roller 31 and the pressure roller 32 normally stop rotating, and the heater 53 is controlled to be turned on and off so as to reach a predetermined set temperature.

  The printable temperature of the heating roller 31 is 185 ° C., for example. The heating roller 31 and the pressure roller 32 are warmed by the heating by the heater 53 and the pressure heater 54 and the rotation operation. The temperature of the heating roller 31 detected by the thermistor 55 is corrected by the amount of non-contact, and further corrected by the temperature change amount of the thermopile 56, or the temperature of the heating roller 31 detected by the thermopile 56 On and off of the heater 53 is controlled using the corrected temperature obtained by correcting the amount of contamination as the input. Thereby, the temperature of the heating roller 31 is controlled.

  Thereafter, when the printing process is performed, the recording sheet 14 to which the toner image is transferred is conveyed to the fixing device 30. The fixing device 30 fixes the toner image on the recording sheet 14 with the heated heating roller 31 and the pressure roller 32, and discharges the recording sheet 14 to the discharge tray 16.

  Referring to FIG. 2, the thermistor 55 is disposed at a position 40 mm in front of the center sheet passing reference and at a position 2 mm away from the heating roller 31. The thermistor 55 is disposed in a non-contact state with the heating roller 31 that is the object to be measured.

  The thermopile 56 is disposed at a position 40 mm deep from the center sheet passing reference and at a position 30 mm away from the heating roller 31. The thermopile 56 is disposed in a non-contact state with the heating roller 31 that is a measurement object.

  At least one of the thermistor 55 and the thermopile 56 may be installed outside the fixing device 30 main body, or at least one of them may be installed inside the fixing device 30 main body.

  In the present embodiment, the correction amount of the thermistor 55 is determined based on the detected temperature of the thermopile 56, and the measured temperature of the thermistor 55 is corrected.

  FIG. 4 is a flowchart showing a process for adjusting the temperature of the heater 53 based on the corrected temperature of the thermistor 55.

  The heater 53 is controlled at a predetermined control cycle, and here, the control shown in the flowchart of FIG. 4 is repeated every 66 ms (0.066 seconds).

  When the control process is started, the temperature of the heating roller 31 is detected by the thermistor 55 and the thermopile 56 in step S1. The temperature detected by the thermistor 55 is Th1, and the temperature detected by the thermopile 56 is Th2.

  Next, in step S <b> 2, the detection temperature Th <b> 1 by the thermistor 55 is corrected using the detection temperature Th <b> 2 by the thermopile 56 as an input. This specific correction process will be described with reference to FIG. A value obtained by correcting the detection temperature Th1 detected by the thermistor 55 using the detection temperature Th2 detected by the thermopile 56 as an input is defined as Tr1.

  Thereafter, in step S <b> 3, the power supply to the heater 53 is adjusted by using the corrected temperature Tr <b> 1 of the thermistor 55 or the detected temperature Th <b> 2 of the thermopile 56, and the heater 53 is controlled. This specific control process will be described with reference to FIG.

  In the following description, a process for correcting the temperature detected by the thermistor and determining whether or not printing is possible will be described.

  FIG. 5 is a flowchart showing details of the process of determining the correction amount of the detected temperature by the thermistor 55 from the temperature detected by the thermopile 56 (process at S2 in FIG. 4).

  First, in step S2-1, the temperature gradient of the detected temperature Th2 of the heating roller 31 by the thermopile 56 is calculated. Since the flowchart of FIG. 4 is executed every 66 ms, the temperature gradient is also calculated every 66 ms here. The calculated temperature gradient is defined as Tg2.

  Here, the “temperature gradient” indicates a change amount (temperature change amount) of the detected temperature Th2 of the thermopile 56 during a predetermined period.

  Assuming that the current detected temperature is T (i) and the detected temperature 66 ms before is T (i-1), the difference between the detected temperatures is obtained by T (i) -T (i-1). The difference between this difference and the elapsed time is the temperature gradient. Therefore, the temperature gradient is

  Temperature gradient = {T (i) -T (i-1)} / 66 ms

  Is calculated as

  Next, in step S2-2, for example, the temperature change amount is calculated based on the difference between the average value of the thermopile detection temperature Th2 from 2 s to 1 s ago and the average value of the thermopile detection temperature Th2 from 1 s to this time. Desired. The obtained value is set as Thg2.

  In step S2-3, from the difference between the average value of the temperature gradient Tg2 from 2 s to 1 s and the average value of the temperature gradient Tg2 from 1 s to this time, the “temperature change amount” (temperature change amount Change amount, that is, the change amount of the detected temperature change amount). Let the value calculated | required here be Tgg2.

  In step S2-4, a correction amount is determined using a predetermined correction amount A due to the thermistor 55 being in non-contact with the heating roller 31, and the values of Thg2 and Tgg2. For example, the correction amount R is

  R = A + a × Thg2 + b × Tgg2

  Can be determined as Here, the variables a and b are adjustment values.

  In step S2-5, the temperature detected by the thermistor 55 is corrected. Here, the correction amount R obtained in step S2-3 is used. For example, the correction is performed by multiplying the detection temperature Th1 detected by the thermistor 55 by the correction amount R. This value becomes Tr1 and is used to control the heater 53.

  FIG. 6 is a flowchart showing details of the control process of the heater 53 (S3 in FIG. 4).

  First, in step S3-1, the temperature after the correction of the thermistor 55 obtained in step S2 in FIG. 4 or the detected temperature Th2 of the thermopile 56 obtained in step S1 is input, and the temperature of the heating roller 31 and a predetermined heater ON Compare temperature.

  If the temperature of the heating roller 31 is equal to or higher than the predetermined heater ON temperature, the heater 53 is turned off in step S3-2.

  When the temperature of the heating roller 31 is lower than the predetermined heater on temperature, the heater 53 is turned on in step S3-3.

  FIG. 7 is a graph showing a temperature change when the heater 53 is controlled with the thermopile 56 detected temperature Th2 as an input.

  The horizontal axis represents the elapsed time, and the vertical axis represents the measured temperature of the thermopile and the thermistor. Further, the thick line in the figure indicates the detected temperature of the thermopile 56, and the thin line indicates the detected temperature of the thermistor (before correction).

  In this case, the temperature of the heater rapidly increases in the vicinity of 78s to 79s. This is a temperature ripple, and in the case of FIG. 7, the ripple is relatively large.

  FIG. 8 is a graph showing a temperature change when the heater 53 is controlled using a value obtained by correcting the detected temperature Th1 of the thermistor 55 with the temperature gradient of the thermistor 55.

  In FIG. 8, the same processing as that in the flowchart of FIG. 5 is performed, but in order to obtain the correction amount of the thermistor 55, the detected temperature of the heating roller 31 by the thermistor 55 is used.

  That is, in the example of FIG. 8, in step S2-1 of FIG. 5, the detection temperature Th2 of the thermopile 56 is not input, but the detection temperature Th1 of the thermistor 55 is input. Thereby, the temperature gradient Tg1 of the detection temperature Th1 of the thermistor 55 is calculated.

  In step S2-2 of FIG. 5, a change amount Thg1 of the detection temperature Th1 of the thermistor 55 is obtained.

  In step S2-3 of FIG. 5, a change amount Tgg1 of the temperature gradient Tg1 of the thermistor 55 is obtained.

  In Step S2-4 of FIG. 5, a value of a predetermined correction amount A due to the contact of the thermistor 55, a change amount Thg1 of the detected temperature Th1 of the thermistor 55, and a change amount Tgg1 of the temperature gradient Tg1 of the thermistor 55. Is used to obtain the correction amount R. The correction amount R is

  R = A + a × Thg1 + b × Tgg1

  It is calculated by the following formula.

  In step S2-5 in FIG. 5, the temperature detected by the thermistor 55 is corrected. Here, Tr1 is a value obtained by multiplying the detected temperature Th1 of the thermistor 55 by the correction amount R. The heater is controlled using this value.

  As described above, when control is performed based on the temperature change amount measured by the thermistor, it can be seen that relatively large ripples are generated in 85 s to 87 s as shown in FIG. 8.

  FIG. 9 is a graph showing a temperature change when the heater 53 is controlled with the thermistor 55 corrected temperature Tr1 as an input, which is obtained in the flowchart of FIG.

  Again, ripples occur between 85 s and 86 s, but the magnitude is relatively small.

  Comparing the temperature behavior of the graphs of FIGS. 7 to 9, it can be seen that the temperature ripple in the graph of FIG. 9 is small. That is, it can be seen that when the detected temperature of the thermopile 56 is used as an input and the correction amount of the detected temperature of the thermistor 55 is determined, the thermal response performance is complemented and the ripple is reduced.

  [Second Embodiment]

  FIG. 10 is a side view showing the configuration of the fixing device 30 in the second embodiment, and FIG. 11 is a plan view showing the configuration around the heating roller.

  In this embodiment, a temperature detection device 57 in which a thermistor 57b and a thermopile 57a are integrated is used.

  The fixing device includes a heating roller 31 and a pressure roller 32. A heating heater 53 is included in the heating roller 31. A pressure heater 54 is included in the pressure roller 32.

  The temperature detection device 57 is disposed in the vicinity of the heating roller 31 in a non-contact state. The temperature detection device 57 may be disposed in the fixing device or may be disposed outside the fixing device.

  The temperature detection device 57 is a unit in which a thermopile 57a that detects a temperature in accordance with the amount of infrared rays radiated from a measurement object and a thermistor 57b that directly detects heat from the measurement object. The temperature detection device 57 detects and controls the temperature of the heating roller 31 that is the object to be measured.

  As described above, the control shown in FIGS. 4 to 6 can also be executed by the fixing device using the temperature detecting device 57 in which the thermistor 57b and the thermopile 57a are integrated.

  In the present embodiment, the control unit for correcting the detected temperature may be integrated with the temperature detection device 57.

  [Effects of the embodiment]

  As described above, in the image forming apparatus including the fixing device according to the embodiment of the present invention, the detected temperature of the thermistor is corrected using the detected temperature of the thermopile as an input. The heat source is controlled at the corrected detected temperature of the thermistor. By performing correction with the detected value of the thermopile that has good responsiveness to temperature changes, it is possible to suppress an increase in ripple due to a response delay of a non-contact thermistor.

  As described above, the corrected image performance can be stabilized by adjusting the power supply amount to the heating source using the corrected temperature of the thermistor as an input.

  [Others]

  In the above-described embodiment, the method for controlling power supply to the heater has been described. The power supply control to the heater is control for setting the temperature of the fixing device within a predetermined temperature range, and includes control for maintaining the temperature at a predetermined temperature during printing and in a standby state. Also included is control for turning off the energization when the temperature of the fixing device exceeds a predetermined temperature range at the time of abnormality.

  In the above-described embodiment, the detected temperature of the thermistor is corrected by the detected temperature of the thermopile, but the detected temperature of the thermopile may be corrected by the detected temperature of the thermistor. That is, the detected temperature of the thermopile is corrected according to the temperature change amount of the detected temperature of the thermistor and the change amount of the temperature change amount.

  Various conditions and settings of the fixing device are not limited to the above-described embodiment. For example, in the above-described embodiment, the member that directly detects heat is a thermistor, but a thermocouple may be used.

  Further, the heating source for heating the roller or the like is not limited to the heater. A resistance heating element and an induction heating device may be used. Further, the fixing device may be configured to perform belt fixing.

  In the above-described embodiment, the example of detecting the temperature of the heating roller of the fixing device of the image forming apparatus has been described, but the detection target is not limited to this. The present invention can be used for temperature measurement of various members in the image forming apparatus, and can also be used for temperature measurement of members of apparatuses other than the image forming apparatus.

  The image forming apparatus may be any one of a monochrome / color copying machine, a printer, a facsimile machine, and a complex machine (MFP) thereof.

  Furthermore, the processing in the above-described embodiment may be performed by software or by using a hardware circuit.

  In addition, a program for executing the processing in the above-described embodiment can be provided, and the program is recorded on a recording medium such as a CD-ROM, a flexible disk, a hard disk, a ROM, a RAM, and a memory card and provided to the user. You may decide to do it. The program may be downloaded to the apparatus via a communication line such as the Internet.

  In addition, it should be thought that the said embodiment is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a diagram illustrating a configuration of an image forming apparatus including a fixing device according to a first embodiment. 2 is a side view showing a configuration of a fixing device 30. FIG. It is a top view which shows the structure around a heating roller. 7 is a flowchart showing a process for adjusting the temperature of the heater 53 based on the corrected temperature of the thermistor 55. 5 is a flowchart showing details of a process of determining a correction amount of the detected temperature by the thermistor 55 from the temperature detected by the thermopile 56 (process in S2 of FIG. 4). It is a flowchart which shows the detail of the control process (S3 of FIG. 4) of the heater 53. FIG. It is a graph which shows the temperature change at the time of controlling the heater 53 by using the thermopile 56 detection temperature Th2. 6 is a graph showing a temperature change when the heater 53 is controlled using a value obtained by correcting the detected temperature Th1 of the thermistor 55 with the temperature gradient of the thermistor 55. It is a graph which shows the temperature change at the time of controlling the heater 53 by inputting the temperature Tr1 after the thermistor 55 correction | amendment calculated | required with the flowchart of FIG. FIG. 6 is a side view illustrating a configuration of a fixing device 30 according to a second embodiment. It is a top view which shows the structure around a heating roller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming unit 2 Photosensitive drum 3 Charging part 4 Developing part 5 Cleaning part 9 Exposure part 11 Intermediate transfer belt 12 Primary transfer part 13 Secondary transfer part 14 Recording sheet 15 Cleaning blade 16 Paper discharge tray 17 Recording sheet cassette 18 Control Device 19 Exposure control device 30 Fixing device 31 Heating roller 32 Pressure roller 53 Heating heater 54 Pressure heater 55, 57b Thermistor 56, 57a Thermopile 57 Temperature detection device

Claims (7)

A first temperature detecting means which is installed in a non-contact manner with respect to the measurement object and directly detects heat from the measurement object;
A second temperature detecting means that is installed in a non-contact manner with respect to the measured object and detects a temperature according to an amount of infrared rays emitted from the measured object;
A heating source for heating the object to be measured;
Correction means for correcting the detected temperature of the first temperature detection means based on at least one of the change amount of the detection temperature of the second temperature detection means and the change amount of the change amount;
And a control unit that controls the heating source with the detected temperature corrected by the correction unit as an input. At least one of the first detection means and the second detection means is installed outside the fixing device main body,
The fixing device according to claim 1, wherein the control unit controls a power supply amount to the heating source.   The fixing device according to claim 1, wherein the first detection unit and the second detection unit are an integrated temperature detection unit. The first temperature detecting means is a thermistor;
The fixing device according to claim 1, wherein the second temperature detection unit is a thermopile.   An image forming apparatus comprising the fixing device according to claim 1. A first temperature detecting means which is installed in a non-contact manner with respect to the measurement object and directly detects heat from the measurement object;
A second temperature detecting means that is installed in a non-contact manner with respect to the measured object and detects a temperature according to an amount of infrared rays emitted from the measured object;
A control method of a fixing device comprising a heating source for heating the object to be measured,
A correction step of correcting the detected temperature of the first temperature detection means based on at least one of the change amount of the detection temperature of the second temperature detection means and the change amount of the change amount;
And a control step of controlling the heating source using the detected temperature corrected in the correction step as an input. A first temperature detecting means which is installed in a non-contact manner with respect to the measurement object and directly detects heat from the measurement object;
A second temperature detecting means that is installed in a non-contact manner with respect to the measured object and detects a temperature according to an amount of infrared rays emitted from the measured object;
A control program for a fixing device comprising a heating source for heating the object to be measured,
A correction step of correcting the detected temperature of the first temperature detection means based on at least one of the change amount of the detection temperature of the second temperature detection means and the change amount of the change amount;
A control program for a fixing device, which causes a computer to execute a control step for controlling the heating source, using the detected temperature corrected in the correction step as an input.

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