JP2009098364A - Fixing device, image forming apparatus, and control method for fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device capable of appropriately controlling temperature. <P>SOLUTION: The fixing device includes: a non-contact thermistor for measuring the temperature of a body to be measured, which is disposed in the fixing device; an infrared sensor (thermopile) installed outside the fixing device. The fixing device detects the temperature by using both the sensors. If the fixing device of the image forming apparatus is fresh (YES in S301), it is determined whether an amount of correction of the infrared sensor has backup or not (S305). If YES, the amount of correction of the temperature of a non-contact thermistor is determined from the detected temperature of the infrared sensor subjected to the correction and the detection temperature of the non-contact thermistor (S307). After the amount of correction is determined, temperature after the correction to the non-contact thermistor is used for soil correction to the thermopile (S303). The non-contact thermistor and the thermopile are used to correct each other, and thereby accuracy in the detection of the temperatures of the non-contact thermistor and thermopile can be improved at the same time. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fixing device, an image forming apparatus, and a fixing device control method, and more particularly to a fixing device, an image forming apparatus, and a fixing device control method having a function of detecting the temperature of a measured object.

  2. Description of the Related Art An electrophotographic image forming apparatus (MFP (Multi Function Peripheral), facsimile machine, copying machine, printer, etc.) is provided with a fixing device that fixes a toner image onto a sheet by heat. As the fixing device, a temperature detection device for detecting the fixing temperature is used.

  The following Patent Document 1 discloses a temperature measuring device that takes measures against contamination of an infrared sensor (non-contact sensor) for detecting the surface temperature of a heat roller. When the heat roller is stopped, an error between the detection value of the infrared sensor and the detection value of the contact sensor is obtained and stored, and the detection value of the infrared sensor is corrected with the error when the heat roller rotates. When the corrected measured temperature is out of the allowable range, the temperature control is changed to the detection value of the contact sensor.

  Patent Document 2 below discloses an image forming apparatus that takes measures against contamination of an infrared sensor (non-contact sensor) for temperature detection. When the heating roller is stopped, the non-contact sensor detected temperature is corrected based on the detected temperature of the contact sensor, and the power supply to the heat source is controlled based on the corrected temperature of the non-contact sensor.

Patent Document 3 listed below discloses a temperature detection device that takes measures against contamination of an infrared sensor. The apparatus includes an infrared sensor and a non-contact sensor, and corrects the infrared sensor detection temperature based on the detection temperature of the non-contact sensor. When this temperature is detected, the airflow is stopped or suppressed.
JP-A-5-149790 JP 2006-47410 A JP 2006-184071 A

  When detecting the temperature of the fixing device with a non-contact thermistor (a sensor that detects the temperature of an object without contact) and an infrared sensor (a sensor that detects the temperature of an object without contact, such as a thermopile), Thus, it is conceivable to correct the detection value of the infrared sensor with the detection value of the non-contact thermistor. This correction is performed assuming that the infrared sensor is dirty.

  However, if the temperature detection accuracy of the non-contact thermistor is not stable, there is a problem that the correction accuracy of the detection temperature of the infrared sensor is not stable. In this case, the temperature control of the fixing device cannot be performed as intended.

  The present invention has been made to solve such a problem, and an object thereof is to provide a fixing device, an image forming apparatus, and a fixing device control method capable of appropriately controlling temperature. .

  In order to achieve the above object, according to one aspect of the present invention, a first temperature detecting means for directly detecting heat from the measured object and a second temperature for detecting the temperature according to the amount of infrared rays emitted from the measured object. The fixing device for detecting the temperature using the temperature detecting means includes a storage means for storing a correction amount for correcting the temperature detected by the second temperature detecting means, and a first detection by the first temperature detecting means. A first amount for determining a correction amount of the first detected temperature by the first temperature detecting unit is determined based on the temperature and the second detected temperature by the second temperature detecting unit corrected by the stored correction amount. Based on the correction amount determined by the correction amount determination unit and the first correction amount determination unit, the first correction unit corrects the temperature detected by the first temperature detection unit, and the first correction unit corrects the detected temperature. Corrected temperature and second temperature detection Based on the temperature detected by the stage, based on the second correction amount determining means for determining the correction amount of the detected temperature by the second temperature detecting means, and the correction amount determined by the second correction amount determining means, Second correction means for correcting the temperature detected by the second temperature detection means.

  Preferably, the fixing device backs up the correction amount determined by the second correction amount determination unit in the storage unit.

  Preferably, the fixing device includes a heating source that heats the measurement target, and the first temperature detection unit and the second temperature detection unit are installed in a non-contact manner with respect to the measurement target.

  Preferably, the first correction amount determining means determines the correction amount at least when the fixing device is new.

  Preferably, when the second temperature detection unit is not new, the first correction amount determination unit determines the correction amount.

  Preferably, the first temperature detection unit is installed in the fixing device, and the second temperature detection unit is installed outside the fixing device.

  Preferably, the fixing device includes a filter that transmits infrared light between the second temperature detection unit and the measurement target.

  Preferably, the filter can be clean.

  Preferably, the filter is configured to be replaceable.

  Preferably, the first temperature detecting means includes a thermistor, and the second temperature detecting means includes a thermopile.

  According to another aspect of the present invention, an image forming apparatus includes any of the fixing devices described above.

  According to still another aspect of the present invention, first temperature detection means for directly detecting heat from the measurement object, and second temperature detection means for detecting temperature according to the amount of infrared rays emitted from the measurement object. The method of controlling the fixing device that detects the temperature using the first and second temperature detection means stores a correction amount for correcting the temperature detected by the second temperature detecting means, and the first detected temperature by the first temperature detecting means. And a first correction for determining a correction amount of the first detected temperature by the first temperature detecting means based on the second detected temperature by the second temperature detecting means corrected by the stored correction amount. Based on the correction amount determined in the amount determination step, the first correction amount determination step, the first correction step for correcting the temperature detected by the first temperature detecting means, and the first correction step. The corrected temperature, A second correction amount determination step for determining a correction amount of the detected temperature by the second temperature detection unit based on the temperature detected by the second temperature detection unit, and a correction amount determined by the second correction amount determination step And a second correction step for correcting the temperature detected by the second temperature detecting means.

  According to these inventions, it is possible to provide a fixing device, an image forming apparatus, and a fixing device control method capable of appropriately controlling the temperature.

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

  The image forming apparatus includes a fixing device. The fixing device includes a heating source for heating the fixing device, a non-contact thermistor, and an infrared sensor (thermopile), and both sensors detect the temperature of the heating body of the fixing device. When the image forming apparatus is started up from when it is cold, the temperature correction amount of the non-contact thermistor is determined from the thermopile detection temperature and the detection temperature of the non-contact thermistor. After the correction amount is determined, the corrected temperature of the non-contact thermistor is used for correcting the dirt on the thermopile. By correcting each other with the non-contact thermistor and the thermopile, the temperature detection accuracy of the non-contact thermistor and the thermopile is improved at the same time.

  As described above, the fixing device includes at least the first temperature detection unit (non-contact thermistor) and the second temperature detection unit (infrared sensor (thermopile)). The first temperature detection unit and the second temperature detection unit are both installed in a non-contact manner with respect to the part to be measured and perform temperature detection.

  The first temperature detection unit directly detects heat from the measurement object. A 2nd temperature detection part detects temperature according to the amount of infrared rays radiated | emitted from a to-be-measured body.

  The fixing device adjusts the amount of power supplied to the heating source by using at least the temperature detected by either the first temperature detection unit or the second temperature detection unit or the corrected temperature as an input.

  The fixing device performs first and second correction amount determination controls, and the first and second correction controls are executed based on the correction amounts determined in each.

  By the first correction amount determination control, the first temperature detection unit performs the first detection by the first temperature detection unit based on the relationship between the first detection temperature by the first temperature detection unit and the second detection temperature by the second temperature detection unit. A correction amount of the detected temperature is determined.

  By the first correction control, the first detected temperature by the first temperature detection unit is corrected based on the correction amount by the first correction amount determination control (first corrected temperature).

  The power supply amount to the heating source is adjusted with at least the first corrected temperature by the first correction control or the detected temperature by the second temperature detection unit as an input.

  Since the first temperature detection unit directly detects the heat from the measurement object, the detection temperature varies depending on the installation distance tolerance or the like. Since the second temperature detection unit detects the temperature according to the amount of infrared rays emitted from the measurement object, there is almost no change in the detection temperature due to the installation distance tolerance.

  Therefore, the first temperature detection unit is installed in the fixing device, and the first correction amount determination control is performed when the fixing device is new, thereby improving the accuracy of the first corrected temperature.

  On the other hand, due to the durability of the fixing device, the first temperature detection unit and the second temperature detection unit become dirty due to the influence of paper dust, toner, and the like. Since the first temperature detection unit directly detects the heat from the measurement object, there is little change in the detection temperature due to the influence of paper dust or toner.

  A 2nd temperature detection part detects temperature according to the amount of infrared rays radiated | emitted from a to-be-measured body. For this reason, when the lens and filter of the second temperature detection unit become dirty, the temperature of the dirty lens and filter is mixed, and the detection temperature changes greatly.

  Therefore, by the second correction amount determination control, the second detected temperature is corrected by the second temperature detection unit based on the relationship between the first corrected temperature and the second detected temperature by the second temperature detection unit. Determine the amount.

  With the second correction control, the second detected temperature by the second temperature detection unit is corrected based on the correction amount by the second correction amount determination control (second corrected temperature).

  After the first correction amount determination control at the time of a new product, the correction amount by the second correction amount determination control also changes in accordance with the change in the degree of dirt. By performing the second correction amount determination control periodically, the accuracy of the second corrected temperature in the second correction control can be increased.

  FIG. 1 is a diagram illustrating a configuration of an image forming apparatus including a fixing device according to one 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 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. 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 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 from there to the transfer unit 13.

  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 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 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 developed toner image is primarily transferred to the intermediate transfer belt 11 by the primary transfer unit 12. 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.

  The fixing device 30 includes a heating roller 51 and a pressure roller 52 that press the recording sheet.

  2 and 3 are diagrams showing the configuration of the fixing device 30. FIG.

  FIG. 2 is a diagram illustrating a state in which the heating roller 51 and the pressure roller 52 are in a cross section, and FIG. 3 is a diagram for illustrating a temperature detection mechanism of the heating roller 51.

  The heating roller 51 is composed of a member having an outer diameter of 25 mm, a thickness of iron hollow core metal 0.8 mm + Si rubber 0.2 mm + PTFE tube 30 μm, and a length in the nip longitudinal direction of about 330 mm.

  The pressure roller 52 has an outer diameter of 30 mm and is composed of a member having a thickness of 2.5 mm of iron hollow core metal + 2.5 mm of rubber + 30 μm of PFA.

  The heater 53 in the heating roller 51 is a 1180 W halogen lamp heater, and the light emission length is 290 mm.

  The pressure heater 54 in the pressure roller 52 is a 230 W halogen lamp heater, and the light emission length is 290 mm.

  A non-contact thermistor 55 and a thermopile 56 are installed for the heating roller 51, and the surface temperature of the heating roller is detected by these. The non-contact thermistor 55 is installed at a position 40 mm in front of the center paper passing reference and a position 2 mm away from the heating roller 51. The thermopile 56 is installed at a position 40 mm behind the center sheet passing reference and a position 30 mm away from the heating roller 51. The thermopile 56 detects the temperature through a filter 57 that transmits infrared rays.

  Preferably, the non-contact thermistor 55 is installed in the fixing device, and the thermopile 56 is installed outside the fixing device. The thermopile 56 and the filter 57 may be installed in the fixing device. The filter 57 is preferably provided between the fixing device and the thermopile 56.

  Further, the filter can be made clean by cleaning. The first correction amount determination control is performed when the fixing device is new or when the filter is not contaminated by cleaning.

  It is also desirable that the filter be configured to be replaceable in order to keep the filter clean.

  The operation to bring the surface of the heating roller 51 and the pressure roller 52 to the printable temperature after the machine power is turned on is called warm-up, and the time taken 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, or when the sleep mode is restored.

  In the warm-up operation, the heater 53 and the pressure heater 54 are turned on to raise the temperature to the printable temperature. By transmitting a driving force to a driving gear (not shown), the pressure roller 52 is rotated and the heating roller 51 is driven to rotate, so that the heat of the heating roller 51 and the pressure roller 52 is heated. Tell the surface of the.

  At this time, the linear velocity of the roller rotation of the fixing device is, for example, 90 mm / s. The surface of the heating roller 51 and the pressure roller 52 is raised to a printable temperature by turning on and rotating the heater.

  The corrected temperature obtained by correcting the temperature detected by the thermistor 55 by the amount of non-contact or the corrected temperature obtained by correcting the temperature detected by the thermopile 56 by the amount of dirt is a predetermined printable temperature. If it becomes, the ready which shows that it can print is made. For example, when the corrected temperature obtained by correcting the temperature detected by the thermistor 55 by the amount of non-contact, or the corrected temperature corrected by the amount of dirt by the thermopile 56 becomes 185 ° C., ready. Shall be established.

  If there is no print signal, the print standby state is entered, and if there is a print signal, the print operation is started. In the standby state, usually, the rotation of the roller is stopped and the heater is controlled so as to reach a certain set temperature.

  The set temperature is, for example, 185 ° C. on the heating side. The corrected temperature obtained by correcting the temperature detected by the thermistor 55 by a non-contact amount, or the corrected temperature obtained by correcting the temperature detected by the thermopile 56 by the amount of dirt is input, and the heater 53 Perform on / off control.

  As described above, the correction amount of the thermistor 55 is determined from the relationship between the detected temperature of the thermopile 56 and the detected temperature of the thermistor 55.

  For example, the thermopile 56 and the thermistor 55 are set 30 mm apart and 2 mm away from the heating roller 51 as the object to be measured. Since the thermistor 55 detects temperature mainly by heat conduction and convection, it is easily affected by distance tolerance. As the distance changes, the detected temperature also changes greatly.

  FIG. 4 is a diagram illustrating a specific example of the measurement result of the detected temperature of the non-contact thermistor and the thermopile when the heating roller 51 is heated when the image forming apparatus is started up from when it is cold.

  The horizontal axis represents time, and the vertical axis represents the measured temperature of each sensor. As the non-contact thermistor, detection results in three different cases A to C are shown as (1) to (3). The detection result of the thermopile is represented as (4). In the thermistor, as shown in A to C, the detected temperature changes greatly due to a distance tolerance or the like.

  In this embodiment, when the image forming apparatus is started up from when it is cold, the measurement temperature of the non-contact thermistor is corrected based on the temperature detected by the thermopile.

  FIG. 5 is a flowchart showing a correction process when the fixing device is started up from when it is cold.

  The detection of a new fixing device is determined by, for example, the cutting state of a fuse installed in the fixing device. When it is determined that the fixing device is new, the processing in the flowchart of FIG. 5 is executed. This is to execute a sequence for determining the correction amount of the thermistor 55.

  First, the temperature of the heating roller 51 is raised (S101). At this time, the amount of power supplied to the heater 53 is adjusted according to the temperature detected by the thermopile 56. Here, electric power is supplied until the detection temperature of the thermopile reaches 170 ° C. (S103). You may adjust the electric power supply of a heating source with the temperature after correction | amendment which carried out the predetermined | prescribed correction | amendment preset to the temperature detected by the thermistor 55. FIG. However, in this case, since the correction amount is adjusted immediately, the correction amount to be used is a temporary correction amount.

  The detected temperature of the thermistor 55 when the detected temperature of the thermopile 56 is 170 ° C. is acquired (S105). The thermistor correction amount is determined from the deviation of the detected temperature of the thermistor 55 from the thermopile measurement temperature of 170 ° C. (S107). Thereafter, the detected temperature of the thermistor is corrected using the correction amount, and the temperature is detected (S109).

  FIG. 6 is a diagram showing the relationship between the detected temperature T1 of the thermistor 55 in step S105 of FIG. 5 and the correction amount determined in step S107.

  As shown in the figure, with respect to the detected temperature T1 of the thermistor, if T1 <84 ° C., the correction amount 1 is adopted. If 84 ° C. ≦ T1 <89 ° C., the correction amount 2 is adopted. If 89 ° C. ≦ T1 <94 ° C., the correction amount 3 is adopted. If 94 ° C. ≦ T1 <99 ° C., the correction amount 4 is adopted. If 99 ° C. ≦ T1, a correction amount of 5 is adopted.

  Instead of determining the correction amount using the table in this way, the correction amount may be determined as a numerical value from the thermistor detection temperature T1 based on a mathematical formula or the like.

  FIG. 7 is a diagram showing a specific example of the measurement result of the detected temperature of the non-contact thermistor and the thermopile when the image forming apparatus is started up from the cold time at a predetermined use time.

  The horizontal axis represents time, and the vertical axis represents the measured temperature of each sensor. As the non-contact thermistor, the corrected measured temperature determined in the process of FIG. 5 is shown as (4). The detection results in three different cases of the thermopile are shown as (1) to (3). As shown in (1) to (3), the detection temperature of the thermopile changes depending on the lens surface of the thermopile due to durability, dirt on the toner of the film 57, paper dust, and the like.

  In this embodiment, when the image forming apparatus is started up from a cold state at a predetermined use time, the thermopile detection temperature is corrected based on the measured temperature after correction of the non-contact thermistor.

  The thermopile 56 detects infrared rays radiated from the heating roller 51, and thus is easily affected by dirt on the lens surface and the film 57. If the lens surface or film becomes dirty, the temperature of the dirt will be mixed with the detected temperature. This means that a temperature lower than that of the heating roller is mixed, and the detected temperature is lowered.

  Therefore, in the present embodiment, after the correction amount determination control of FIG. 5 is performed, the corrected temperature of the thermistor 55 and the detected temperature of the thermopile 56 are compared as needed. The correction amount of the thermopile is determined from the detected temperature of the thermopile 56 when the temperature after correction of the thermistor 55 is 170 ° C.

  FIG. 8 is a flowchart showing a thermopile correction amount determination process executed at a predetermined timing.

  Referring to the figure, at the time of warm-up (S201), it is measured whether the detected temperature after the thermistor correction is 170 ° C. (S203). If the temperature reaches 170 ° C., the detection temperature of the thermopile is acquired (S205). Note that the temperature acquired at this time may be a temperature before correction of the thermopile, or may be a temperature after correction based on the previously obtained correction amount. Further, the temperature of the thermistor used in step S203 may be a corrected temperature or a detected temperature.

  Based on 170 ° C., which is the corrected temperature of the thermistor, and the measured temperature of the thermopile, a correction amount for setting the measured temperature of the thermopile to 170 ° C. is obtained (S207). Thereafter, the detected temperature of the thermopile is corrected using the correction amount to detect the temperature (S209).

  The thermopile correction amount is backed up to a recording medium such as an EEPROM in the control device 18 (S211).

  FIG. 9 is a diagram showing the relationship between the detected temperature T2 of the thermopile 56 in step S205 of FIG. 8 and the correction amount determined in step S207.

  As shown in the figure, regarding the thermopile detection temperature T2, if T2 <147 ° C., it is determined that the temperature deviation is large. In this case, since the contamination is severe and the response performance is affected, the use of the apparatus is stopped. Specifically, a warning is given to the user, prompting the user to clean the thermopile.

  If 145 ° C. ≦ T2 <150 ° C., the correction amount 1 is adopted. If 150 ° C. ≦ T2 <155 ° C., the correction amount 2 is adopted. If 155 ° C. ≦ T2 <160 ° C., the correction amount 3 is adopted. If 160 ° C. ≦ T2 <165 ° C., the correction amount 4 is adopted. If 165 ° C. ≦ T2 <170 ° C., a correction amount of 5 is adopted. If 170 ° C. ≦ T2, no correction is made.

  Here, as in the case of FIG. 6, the correction amount may be determined as a numerical value instead of a table.

  [Effects of the embodiment]

  As described above, according to the present embodiment, the correction amount of the non-contact thermistor is determined from the thermopile detection temperature and the detection temperature of the non-contact thermistor at the start-up from a new product or cold. After the correction amount is determined, the corrected temperature of the non-contact thermistor is used for correcting the dirt on the thermopile. By correcting each other with the non-contact thermistor and the thermopile, the temperature detection accuracy of the non-contact thermistor and the thermopile can be improved at the same time.

  [Processing for fixing device replacement]

  As described above, in step S211 of FIG. 8, the thermopile contamination correction amount is always backed up to a recording medium such as an EEPROM in the control device 18.

  As a result, when the thermopile is a durable product when the fixing device is replaced with a new one and the thermopile is durable, the thermopile detection temperature is corrected based on the backed-up correction amount (thermopile contamination correction). Can be performed.

  The correction amount of the non-contact thermistor is determined from the temperature at which the thermopile detection temperature is corrected for dirt and the detected temperature of the non-contact thermistor (new) provided in the fixing device. After the correction amount is determined, the corrected temperature of the non-contact thermistor is used for correcting the dirt on the thermopile.

  FIG. 10 is a flowchart illustrating a sensor correction amount determination control process performed by the image forming apparatus.

  In step S301, whether or not the fixing device is new is determined based on, for example, the cut state of a fuse installed in the fixing device. If it is determined that the fixing device is new (YES in step S301), a sequence for determining the correction amount of the thermistor 55 is executed in step S305 and subsequent steps.

  It is determined whether the dirt correction amount of the thermopile is backed up on the recording medium (S305). If there is no backup (NO in S305), the image forming apparatus itself is new or the thermopile 56 or the filter 57 is dirty. Indicates no state. In this case, as in FIG. 5, the correction amount of the thermistor 55 is determined from the relationship between the detected temperature of the thermopile 56 and the detected temperature of the thermistor 55 (S307).

  It is determined whether the dirt correction amount of the thermopile is backed up on the recording medium (S305). If there is a backup (YES in S305), the non-contact thermistor is installed in the fixing device, and the thermopile is installed in the copying machine main body. Indicates that only the device has been replaced. That is, the thermopile is a durable product and the non-contact thermistor is a new product.

  In this case, since the thermopile 56 (or the filter 57) is dirty, the thermistor is calculated based on the relationship between the corrected temperature obtained by correcting the detected temperature of the thermopile 56 with the correction amount backed up and the detected temperature of the thermistor 55. A correction amount 55 is determined (S309).

  In the processing in step S309, first, the temperature of the heating roller 51 is raised, and the power supply amount to the heater 53 is adjusted by the corrected temperature obtained by performing the correction with the correction amount backed up for the thermopile 56. You may adjust the electric power supply of a heating source with the temperature after correction | amendment which carried out the predetermined | prescribed correction | amendment preset to the temperature detected by the thermistor 55. FIG. However, in this case, the correction amount is adjusted immediately, so that it is a temporary correction amount. The correction amount is obtained in the same manner as in FIG.

  FIG. 11 is a diagram illustrating a specific example of the measurement result of the detected temperature of the non-contact thermistor and the thermopile (after correction) when the heating roller 51 is heated, when the fixing device is started up from when it is cold. .

  By the processing in step S309 in FIG. 10, the temperature measurement error of the thermistor when the fixing device is new can be corrected based on the measured temperature of the thermopile after the stain correction.

  If the fixing device is not new (NO in S301), or after the processing in step S307 or S309, the processing for correcting the dirt on the thermopile is executed at a predetermined timing from the corrected thermistor temperature in step S303. To do.

  It should be noted that when the thermopile lens or filter is cleaned or replaced, it is desirable to configure the apparatus so that the backed up content is cleared and NO is determined in step S305. For example, when the user performs cleaning, the user backs up the content that is backed up, or clears the backed up content when cleaning is automatically performed by the cleaning member.

  [Effect when processing corresponding to replacement of fixing device]

  As described above, when the fixing device is new and the thermopile or filter is a durable product by performing processing corresponding to replacement of the fixing device, the temperature after the thermopile is corrected when starting up from the cold state. And the detected temperature of the non-contact thermistor, the correction amount of the non-contact thermistor can be determined. After the correction amount is determined, the corrected temperature of the non-contact thermistor can be used for correcting the dirt on the thermopile. By correcting each other with the non-contact thermistor and the thermopile, the temperature detection accuracy of the non-contact thermistor and the thermopile can be improved at the same time.

  [Others]

  Various conditions and settings of the fixing device are not limited to the above-described embodiment. Although the thermistor has been described as an example in the above, not only the thermistor but also a thermocouple may be used. The heat source is not limited to a heater, and a resistance heating element or an induction heating device may be used. The present invention can also be applied to a fixing device that performs belt fixing.

  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.

  In the above-described embodiment, the temperature measurement of the heating roller of the fixing device of the image forming apparatus is taken as an example. However, the detection target is not limited to this, and may be another component of the image forming apparatus. An object other than the components of the image forming apparatus may be used.

  Further, 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 one embodiment of the present invention. 2 is a diagram illustrating a configuration of a fixing device 30. FIG. 2 is a diagram illustrating a configuration of a fixing device 30. FIG. FIG. 6 is a diagram illustrating a specific example of a measurement result of a detected temperature of a non-contact thermistor and a thermopile when a heating roller 51 is heated when the image forming apparatus is started up from when it is cold. 6 is a flowchart illustrating a correction process when the fixing device is started up from when it is cold. It is a figure which shows the relationship between the detection temperature T1 of the thermistor 55 in FIG.5 S105, and the correction amount determined by step S107. FIG. 6 is a diagram illustrating a specific example of measurement results of detected temperatures of a non-contact thermistor and a thermopile when the image forming apparatus is started up from a cold time at a predetermined use time. It is a flowchart which shows the thermopile correction amount determination process performed at a predetermined timing. It is a figure which shows the relationship between the detection temperature T2 of the thermopile 56 in step S205 of FIG. 8, and the correction amount determined in step S207. 5 is a flowchart illustrating sensor correction amount determination control processing performed by the image forming apparatus. FIG. 10 is a diagram illustrating a specific example of measurement results of detected temperatures of a non-contact thermistor and a thermopile (after correction) when the heating roller 51 is heated, when the fixing device is started up from when it is cold.

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, 51 Heating roller, 52 Pressure roller, 53 Heating heater, 54 Pressure heater, 55 Thermistor, 56 Thermopile, 57 Filter .

Claims (12)

First temperature detecting means for directly detecting heat from the measurement object;
A fixing device that performs temperature detection using second temperature detection means that detects temperature according to the amount of infrared rays emitted from the object to be measured;
Storage means for storing a correction amount for correcting the temperature detected by the second temperature detection means;
Based on the first detected temperature by the first temperature detecting means and the second detected temperature by the second temperature detecting means corrected by the stored correction amount, the first temperature detecting means. First correction amount determining means for determining a correction amount of the first detected temperature by
First correction means for correcting the temperature detected by the first temperature detection means based on the correction amount determined by the first correction amount determination means;
Second correction for determining a correction amount of the detected temperature by the second temperature detecting means based on the corrected temperature corrected by the first correcting means and the detected temperature by the second temperature detecting means. A quantity determining means;
And a second correction unit that corrects a temperature detected by the second temperature detection unit based on the correction amount determined by the second correction amount determination unit.   The fixing device according to claim 1, wherein the correction amount determined by the second correction amount determination unit is backed up in the storage unit. A heating source for heating the object to be measured;
The fixing device according to claim 1, wherein the first temperature detection unit and the second temperature detection unit are installed in a non-contact manner with respect to the measurement target.   The fixing device according to claim 1, wherein the first correction amount determination unit determines a correction amount at least when the fixing device is new.   5. The fixing device according to claim 1, wherein when the second temperature detection unit is not new, the first correction amount determination unit determines a correction amount. 6.   The fixing device according to claim 1, wherein the first temperature detection unit is installed in a fixing device, and the second temperature detection unit is installed outside the fixing device.   The fixing device according to claim 1, further comprising a filter that transmits infrared light between the second temperature detection unit and the measurement target.   The fixing device according to claim 7, wherein the filter can be in a clean state.   The fixing device according to claim 7, wherein the filter is configured to be replaceable. The first temperature detecting means includes a thermistor,
The fixing device according to claim 1, wherein the second temperature detection unit includes a thermopile.   An image forming apparatus comprising the fixing device according to claim 1. First temperature detecting means for directly detecting heat from the measurement object;
A fixing device control method for detecting temperature using a second temperature detecting means for detecting temperature according to the amount of infrared rays radiated from the measured object,
A storage step of storing a correction amount for correcting the temperature detected by the second temperature detection means;
Based on the first detected temperature by the first temperature detecting means and the second detected temperature by the second temperature detecting means corrected by the stored correction amount, the first temperature detecting means. A first correction amount determination step of determining a correction amount of the first detected temperature by
A first correction step for correcting the temperature detected by the first temperature detection means based on the correction amount determined in the first correction amount determination step;
Second correction for determining the correction amount of the detected temperature by the second temperature detecting means based on the corrected temperature corrected by the first correcting step and the temperature detected by the second temperature detecting means. A quantity determination step;
A fixing device control method comprising: a second correction step of correcting a temperature detected by the second temperature detection means based on the correction amount determined in the second correction amount determination step.

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