JP2003247892A - Temperature detector and fixer using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow accurate temperature detection by making thermal resistance of the base members of a non-contact temperature sensor and a correcting temperature sensor substantially equivalent to suppress drift from occurring. <P>SOLUTION: A temperature detector 8 comprises a sensor unit 5 provided with a non-contact temperature sensor 3 opposed to an object 1, which is to be heated, and a correcting sensor 4 which corrects temperature information, and detects, in non-contact manner, the surface temperature of the object 1 which is heated by a heater source 2. The sensor unit 5 comprises a base member 6a and a can case 6b which is attached to cover the base member 6a. The base member 6a is provided with the non-contact temperature 3 and the correcting sensor 4, with the non-contact temperature 3 and the correcting sensor 4 mounted on the base member 6a through a base material 3a having equivalent thermal conductivity. A fixer uses the temperature detector 8. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature detecting device for non-contact detection of a surface temperature of an object to be heated which is heated by a heating source and an improvement of a fixing device using the temperature detecting device.

[0002]

2. Description of the Related Art Generally, in image forming apparatuses such as copiers, printers, and facsimiles, a fixing device for fixing an unfixed toner image held on a recording sheet by an electrophotographic process is widely used. . Conventionally, this type of fixing device includes, for example, a pair of fixing members (a pair of fixing rolls, a combination of a fixing roll and a fixing belt, etc.) arranged in pressure contact with each other and rolling in contact, and at least one of the fixing members Is heated by a heater as a heating source, and the recording sheet is passed through the nip region between these fixing members, and the unfixed toner image on the recording sheet is fixed by the action of heat and pressure at that time to form a permanent image. Are known to form. In such a fixing device, it is necessary to perform fixing at an appropriate temperature so as to prevent hot offset, cold offset, etc. Therefore, the surface temperature of the fixing member is detected, and the fixing member is detected based on the detection result. The heating is controlled.

One condition for properly controlling the temperature of the fixing member is to accurately detect the surface temperature of the fixing member. More specifically, since how much heat is applied to the toner image on the recording sheet when passing through the nip area becomes a problem, an area where the toner image on the surface of the fixing member contacts (hereinafter referred to as “image area”). To accurately detect the surface temperature of. As a conventional temperature detecting device, in order to accurately detect the surface temperature of the fixing member,
As a contact-type temperature sensor, for example, a method in which a thermistor is brought into contact with the surface of the fixing member and the temperature thereof is detected is often adopted. Further, this method includes a method of bringing the thermistor into contact with the image area of the fixing member and a method of bringing it into contact with a non-image area (corresponding to a sheet non-passing area through which the recording sheet does not pass).

In such a contact type temperature detection system,
The method of contacting the thermistor with the image area of the fixing member is
The contact damages the image area on the surface of the fixing member, resulting in poor fixing at the scratched portion, which may result in image defects. Further, if the offset toner adheres to and accumulates on the thermistor, the temperature detection accuracy deteriorates. Further, when the deposited offset toner image comes off the thermistor, the offset toner lumps are fixed on the recording sheet, resulting in an image defect. Therefore, in the case of color fixing that requires high image quality and oilless, it is necessary to arrange the thermistor in the non-image area.

However, the method of bringing the thermistor into contact with the non-image area of the fixing member is the image defect due to these contact scratches,
Although problems such as deterioration in detection accuracy and image defects due to toner adhesion do not occur, this is not necessarily a preferable method from the viewpoint of accurate temperature detection. Further, in recent years, there has been a strong demand for energy saving worldwide, but in an electrophotographic image forming apparatus, since it is necessary to permanently fix powder toner to a recording sheet by heat, a large amount of power consumption is used by a fixing member. Therefore, it is necessary to promote the reduction of the heat capacity of the fixing member. In order to achieve this low heat capacity, it is necessary to make the thickness of the fixing member as thin as possible, but if the thickness is made thin, heat flow in the fixing member will be obstructed, and the low heat capacity for energy saving requirements This is contrary to the temperature uniformity performance of the fixing member. Further, in a color image forming apparatus, it is necessary to provide a predetermined elastic layer on the fixing member in order to obtain an image having a uniform gloss. However, since an elastic body generally has poor heat conduction as compared with metal, heat distribution is poor. Becomes even worse. Further, in order to ensure the heat resistance of the elastic body, it is necessary to accurately control the upper limit temperature. That is, although ideally the temperature of the image area on the fixing member should be detected, since the surface temperature of the non-image area is actually measured, a discrepancy occurs between these temperatures. I will end up. Therefore, in the temperature control in the non-image area, when a color fixing device that meets the energy saving requirement is pursued, there is a problem that the temperature control is not substantially established.

Therefore, instead of such a contact-type temperature detection method, a method (a non-contact-type temperature detection method) for detecting a temperature without contacting the fixing member by using a non-contact temperature sensor has already been proposed. Further, in order to improve the temperature detection accuracy, a device having a thermistor for temperature correction has been proposed (see Japanese Patent Laid-Open No. 5-126647).

In this type of temperature detecting device, for example,
A thermopile type temperature sensor is often used as the non-contact type temperature sensor for the fixing temperature of about 200 ° C.
This thermopile type temperature sensor is, for example, a temperature measuring element equipped with a thermopile in which a large number of thermocouples in which two kinds of different metals or semiconductors are joined are connected in series, and its hot junction has a small heat capacity such as an insulating thin film. In addition to being arranged above, the cold junction is arranged on a member having a large heat capacity such as a heat sink, and the hot junction is covered with an infrared absorber. Then, in this type of thermopile type temperature sensor, when infrared rays emitted (radiated) from the fixing member are absorbed by the infrared absorber formed on the hot junction and converted into heat, the cold junction and the hot junction are separated. The surface temperature of the fixing member is measured by generating a temperature difference between the electrodes and an electromotive force corresponding to the temperature difference between the electrodes formed at both ends of the thermopile.

However, since the thermopile type temperature sensor having such a principle can detect only the temperature difference between the hot junction and the cold junction, the reference cold temperature is used to determine the temperature of the hot junction. It is necessary to accurately measure the temperature of the contact and compensate the output. Therefore, in the temperature detection device, a method of mounting a thermistor near the thermopile on the base to which the thermopile is attached and using the temperature measured by this thermistor as the cold junction temperature to correct the temperature measured by the thermopile is adopted. There is.

[0009]

In such a method, if there is a difference between the actual cold junction temperature and the measured temperature of the cold junction, a measurement error occurs, and in particular, a transient temperature is detected in the temperature detecting device. There is a technical problem that a large error occurs when a variation occurs and the temperature of the entire temperature detection device has a gradient. This phenomenon is called temperature drift, but in order to eliminate this temperature drift, for example, a member with a large heat capacity is attached to at least the sensor that has a better followability to heat, and the thermal time constant of the two sensors is increased. There is a method of preventing the occurrence of temperature drift by apparently eliminating the difference between the two and making the two sensors follow the temperature change substantially equal to each other. However, even if the temperature difference between the thermopile and the thermistor is actually increased by several degrees even if it is attempted to prevent the temperature difference from being generated by attaching it to a member having a large heat capacity.
Occurs, the temperature drift reaches an unacceptable level, and the above technical problem still remains. In fact, there is a concern that a temperature drift of 5 ° C. or more may occur when the temperature of the fixing device rises.

The present invention has been made to solve the above technical problems, and makes the thermal resistances of the base members of the non-contact temperature sensor and the correction temperature sensor substantially equivalent. The present invention provides a temperature detection device capable of performing more accurate temperature detection by suppressing the occurrence of temperature drift, and a fixing device using the same.

[0011]

The inventors of the present invention analyzed the above-mentioned technical problem (occurrence of measurement error due to temperature drift) and found that the difference between the substrate materials of the thermopile (temperature sensor) and the thermistor (correction sensor). It was found that is caused by. In other words, the inventors of the present invention mounted the thermopile and thermistor on a member having a large heat capacity because the thermal conductivity of the substrate material of the thermopile and the member used for the substrate material of the thermistor are different even if the thermopile and thermistor are attached The present invention has been devised by discovering that the difference in heat transfer from the base member caused by the temperature difference is caused. That is, according to the present invention, as shown in FIG. 1, a non-contact type temperature sensor 3 arranged to face the heated body 1 and measuring infrared rays emitted from the heated body 1, and a non-contact type temperature sensor 3 are provided.
A sensor unit 5 having a correction sensor 4 for correcting the temperature information of the temperature sensor 8 and detecting the surface temperature of the object 1 to be heated by the heating source 2 in a non-contact manner. The unit 5 has a unit case 6 composed of a base member 6a and a can-like housing 6b attached so as to cover the base member 6a, and the base member 6a has a non-contact temperature sensor 3 and a correction unit. With the sensor 4
The non-contact temperature sensor 3 and the correction sensor 4 are mounted on the base member 6a via the substrate material 3a having the same thermal conductivity.

In such a technical means, the object to be heated 1 which is a temperature detection target is any object as long as it is heated, but the main one is a fixing device. Here, the fixing device may be a roll-shaped one or an endless belt-shaped one stretched by a plurality of rolls.
The heating source 2 heats the object to be heated 1,
When the heating source 2 is provided inside the heated body 1, the base material of the heated body 1 is preferably made of a material having high thermal conductivity, such as aluminum.

As the temperature sensor 3, the object to be heated 1
Various types of surface temperature can be selected as long as the surface temperature can be detected in a non-contact manner, but an inexpensive thermopile type temperature sensor having characteristics of high sensitivity and high speed response can be used. preferable. Here, the infrared detector (thermopile chip) of the thermopile type temperature sensor has a substrate material 3a, and the thin film thermoelectric material is formed on this substrate material 3a. Further, as for the correction sensor 4, the detection method may be appropriately selected as long as it is provided for correcting the temperature information of the temperature sensor 3, but from the viewpoint of the simplification of the configuration, it is possible to detect a change in temperature. It is preferable to use a sensor whose electric resistance value changes accordingly. As a concrete aspect of this,
For example, a thermistor or the like can be used. Here, the number of the correction sensors 4 may be one or plural. Further, even when a plurality of correction sensors 4 are used, those having the same characteristics (resistance value, etc.) or those having different characteristics may be used.

Further, the sensor unit 5 may have a mode in which the temperature sensor 3 is covered with the unit case 6. Further, the configuration of the unit case 6 includes a wide range of units including the temperature sensor 3, but normally, the base member 6a on which the temperature sensor 3 and the like are installed and an infrared transmission type optical filter are fitted in a can-shaped casing. It is composed of the body 6b. The base member 6a is provided with the temperature sensor 3 and the correction sensor 4, and is attached so as to cover the can-shaped housing 6b.

In such a technical means, the temperature sensor 3 and the correction sensor 4 have the substrate material 3a having the same thermal conductivity.
It is preferably mounted on the base member 6a via.
The term “equivalent in thermal conductivity” as used herein means that the thermal conductivity is the same and that the range is substantially equivalent (depending on the temperature control range of the heated object, for example, of the heated object of the fixing device). Since the accuracy required for temperature control is generally ± 4 ° C, for example, when the control temperature is 150 ° C, ±
2.5% range). By disposing the temperature sensor 3 and the correction sensor 4 on the substrate material 3a having the same thermal conductivity, the thermal resistance of the base member 6a of the temperature sensor 3 and the correction sensor 4 becomes substantially equivalent, and the base member 6a becomes substantially equivalent. The heat transfer from 6a becomes equal, and it is possible to prevent the measurement error of the cold junction due to the temperature difference between the two. Further, regarding the disposition aspect of the temperature sensor 3 and the correction sensor 4 on the substrate material 3a, the substrate material 3a of the temperature sensor 3 is
It is also possible to arrange the correction sensor 4 in a part of the above and mount the temperature sensor 3 and the correction sensor 4 on the base member 6a via the common substrate material 3a. Alternatively, the temperature sensor 3 and the correction sensor 4 may be mounted.
It is also possible to provide the respective substrate materials 3a having the same thermal conductivity, and mount the temperature sensor 3 and the correction sensor 4 on the base member 6a via the respective substrate materials 3a. Here, the substrate material 3a is preferably made of silicon. Silicon is an optimal material in that the thermopile chip is manufactured by photoetching or vapor deposition, and the emissivity is low when the thermopile chip is placed in the sensor unit.

Further, the temperature sensor 3 and the correction sensor 4 may be mounted on the base member 6a so that the amounts of heat transferred from the side peripheral wall of the can-shaped housing 6b to the temperature sensor 3 and the correction sensor 4 are substantially equal. preferable. Here, in order to make the heat transfer amounts from the side peripheral wall of the can-shaped housing 6b to the temperature sensor 3 and the correction sensor 4 approximately equal, for example, the temperature sensor 3 and the correction sensor 4 are provided near the side peripheral wall. In the case of arranging them, both of them may be mounted on the base member 6a so that the distances from the side peripheral wall to the respective arranging positions are substantially equal. If the distances from the side peripheral walls are substantially equal, it is possible to suppress variations in the heat effect from the side peripheral walls and prevent a temperature difference between the two. Further, as another arrangement mode, the temperature sensor 3 and the correction sensor 4 are provided in the base member 6a.
It should be implemented near the center of. According to this aspect, since the distance from the side peripheral wall of the can-shaped housing 6b is increased, the heat influence from the side peripheral wall becomes extremely small, and the heat transfer amount from the side peripheral wall to each of the temperature sensor 3 and the correction sensor 4 is also increased. It is almost the same.

Further, as another aspect of the present invention, a non-contact type temperature sensor 3 which is arranged to face the heated body 1 and measures infrared rays emitted from the heated body 1, and a non-contact type temperature sensor 3. A sensor unit 5 having a correction sensor 4 for correcting the temperature information of the temperature sensor 8 and detecting the surface temperature of the object 1 to be heated by the heating source 2 in a non-contact manner. The unit 5 includes a base member 6a
And a can-shaped housing 6b attached to cover the base member 6a
And a non-contact temperature sensor 3 is mounted on the base member 6a via the board member 3a, and the non-contact temperature sensor 3 is mounted on the board member 3
An example is one in which the correction sensor 4 is mounted on the inner peripheral wall of the can-shaped housing 6b via a substrate material having the same thermal conductivity as a. Here, the correction sensor 4 is mounted on the inner peripheral wall of the can-shaped housing 6b, but is mounted via a board material having the same thermal conductivity as the board material 3a on which the non-contact temperature sensor 3 is mounted. Therefore, the influence of heat from the can-shaped housing 6b is the same as that in the case where the correction sensor 4 is mounted on the base member 6a.

Further, it is preferable to dispose the correction sensor 4 close to the cold junction of the temperature sensor 3. By bringing the temperature closer to the cold junction, it becomes possible to measure the temperature at a position where the temperature distribution is equal, and the measurement error can be suppressed.

Further, it is preferable that at least the side peripheral wall of the can-like housing 6b and the base member 6a are integrally molded of the same material, and generally, a metal having good thermal conductivity is used. Here, when the transient state until the object 1 to be heated is heated by the heating source 2 and reaches the steady state is measured, the radiant heat from the object 1 to be heated first causes the can-shaped housing 6
The temperature of b rises, and subsequently the temperature of the base member 6a rises. At this time, since both the base member 6a and the can-shaped housing 6b are metallic, the thermal conductivity is good and the temperature distribution of the base member 6a is uniform. However, in the case where the base member 6a and the can-shaped housing 6b are joined, a temperature difference occurs due to the thermal resistance of the joint portion between the two. Since this temperature difference changes due to external heating or thermal resistance, the correction sensor 4 cannot compensate the temperature output error due to the infrared radiation emitted from the can-shaped housing 6b. Therefore, at least the side peripheral wall of the can-shaped housing 6b and the base member 6a are integrally molded,
The temperature difference between the two can be suppressed, and the can-shaped casing 6b is heated by the external heating element, and the heated can-shaped casing 6b is heated.
Even if the radiated infrared rays from b enter the infrared detection section of the temperature sensor 3 and an error occurs in the temperature output, the temperature of the can-shaped housing 6b is estimated by the correction sensor 4 and the radiation amount corresponding to the temperature is calculated. Accurate temperature measurement is possible by compensating for the error.

In such technical means, it is preferable that the sensor unit 5 is housed in the outer shell case 7 for keeping the ambient temperature of the sensor unit 5 uniform. It is preferable that the outer shell case 7 accommodates the sensor unit 5 in a sealed state. In addition, the sensor unit 5 may be appropriately selected as long as it has a function of maintaining the ambient temperature uniformly, but from the viewpoint of simplification of the configuration, the thermal conductivity of the outer shell case 7 may be reduced. It is preferable to adjust, for example, the outer shell case 7 is composed of a first outer shell case 7a on the side closer to the heated body 1 and a second outer shell case 7b on the side farther from the heated body 1, It is preferable to set the thermal conductivity of the second outer shell case 7b higher than that of the case 7a, or to configure the outer shell case 7 as a whole with good thermal conductivity.

Further, the present invention is not limited to the temperature detecting device, but also a fixing device using the same.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail based on the embodiments shown in the accompanying drawings. First Embodiment FIG. 2 is an explanatory diagram showing the overall configuration of the first embodiment of the fixing device to which the present invention is applied, which is used in the image forming apparatus.
In the figure, the fixing device has a pair of fixing rolls 11 and 12 that are arranged in pressure contact with each other and roll in contact with each other. In this example, both fixing rolls 11 and 12 have lamp heaters 13 and 14 built-in, respectively. The fixing rolls 11 and 12 may be appropriately selected. For example, a coating layer made of heat-resistant urethane resin is provided on a metal roll shaft to secure a predetermined fixing nip area between the fixing rolls 11 and 12. It is something that is done.

Further, in this embodiment, a pair of temperature detecting devices 15 (specifically, 15a and 15b) for non-contact detecting the surface temperature of each fixing roll 11 and 12 are provided. In the present example, the temperature detection device 15 is arranged at a position corresponding to a sheet passage area through which the recording sheet P passes, of the axial positions of the fixing rolls 11 and 12, for example.

Further, in the present embodiment, the detection data from the temperature detection device 15 (15a, 15b) is taken in by the temperature control device (calculating means) 16, and this temperature control device 16 is provided for each of the fixing rolls 11, 12. The surface temperature is calculated, and a control signal is sent to the power supply circuit 17 based on the calculation result to control ON / OFF of the lamp heaters 13 and 14.

FIG. 3 is a detailed view of the temperature detecting device 15 (15a). In the present embodiment, the temperature detection device 15a includes an outer shell case 21 having a box shape.
And a thermopile type temperature sensor unit 23 mounted inside the outer shell case 21, and a substrate 231 on which the sensor unit 23 is installed. here,
The outer shell case 21 includes a first outer shell case 211 provided on the side facing the fixing roll 11 and a second outer shell case 212 provided on the opposite side. Then, in the first outer shell case 211, the fixing roll 11 and the sensor unit 2
A silicon filter 22 capable of transmitting infrared rays is arranged at a position corresponding to a portion facing 3). The first outer shell case 211 and the second outer shell case 212 are fitted into each other to form the outer shell case 21. In the present embodiment, the first outer shell case 21
1 is made of a material having a low thermal conductivity, such as ceramic, polyethylene resin, polycarbonate resin, ABS resin, PBT resin, etc., and the second outer shell case 212 has a higher thermal conductivity than the first outer shell case 211. It is made of a good metal such as aluminum. The temperature detection device 15b also has the same structure as the temperature detection device 15a.

FIG. 4 is a perspective sectional view of the thermopile type temperature sensor unit 23. In the present embodiment, the sensor unit 23 includes the fixing rolls 11 and 12
A thermopile chip (non-contact temperature sensor) 31 that receives infrared rays emitted from the thermopile chip, and a thermistor (correction sensor) 32 mounted on the thermopile chip 31.
And a convex-shaped base member 25 on which is mounted, and a can-shaped housing 24 that covers the base member 25 to shield the thermopile chip 31 and the thermistor 32 from the outside air. A silicon lens 221 is attached to the upper wall surface of the can-shaped housing 24. Here, an inert gas such as nitrogen gas or Ar gas is sealed inside the can-shaped housing 24. Further, reference numerals 33 and 34 are thermistor output terminals to which the voltage of the thermistor 32 is output via the lead wires, and reference numerals 35 and 36 are thermopile output terminals to which the thermoelectromotive force generated in the thermopile chip 31 is output via the lead wires. (The thermoelectromotive force is generated at both ends of a large number of thermocouple groups that connect hot junctions and cold junctions in series, and in this example, reference numeral 35 is one end side terminal of the thermocouple, and reference numeral 36 is the other end side terminal of the thermocouple. ). Each of these terminals is connected to the temperature control device 16
(See FIG. 2).

Further, as shown in FIG. 5, the thermopile chip 31 has a thermopile 41 in which a large number of thermocouples in which polysilicon and aluminum are bonded are connected in series.
A temperature measuring element having a hot junction (not shown) arranged on an insulating thin film 40 having a small heat capacity, and a cold junction 4
2 is arranged on a heat sink 43 which is a substrate material made of silicon, and the hot junction is covered with an infrared absorbing film 44. Further, in the present embodiment, the thermistor 32.
Is a part of the heat sink 43 on which the thermopile 41 is placed, and is arranged close to the cold contact 42.
The thermistor 32 does not necessarily need to be directly arranged on the heat sink 43, and as shown in FIG. 6, the mounting piece 45 formed of a material having a thermal conductivity equal to that of the heat sink 43 is used as a substrate material. You may arrange | position on the heat sink 43 via this attachment piece 45. The entire surface of the mounting piece 45 may be adhered onto the heat sink 43, but it may be provided so as to project from the end of the heat sink 43. The mounting piece 45 is the heat sink 43.
If it is made of the same material as the thermal conductivity of
Even in a mode in which the thermistor 32 is arranged via 5,
The same effect as in the case of directly disposing the heat sink 43 can be expected.

Next, the operation of the temperature detecting device of the fixing device according to the present embodiment will be described. 2, 3 and 4
As shown in (4), when the heating of the fixing roll 11 (12) is started, the temperature detecting device 15 displays the fixing roll 11 (12).
The infrared rays emitted from (12) are irradiated. At this time, the infrared rays reaching the portion facing the silicon lens 221 are condensed by the silicon lens 221.
The infrared absorption film 44 provided on the thermopile 41 of the thermopile chip 31 is irradiated. Then, the hot junction of the thermopile 41 is heated, a thermoelectromotive force due to the Seebeck effect is generated between the hot junction and the cold junction 42, and the thermoelectromotive force is input to the temperature control device 16 via the thermopile output terminals 35 and 36. On the other hand, in the thermistor 32, the electric resistance value changes according to the temperature of the heat sink 43, and the output voltage of the thermistor 32 is also output via the thermistor output terminals 33 and 34.
6 is input.

Next, the surface temperature of the fixing roll 11 (12) is calculated based on the thermopile output voltage and the thermistor output voltage. Specifically, the temperature determined based on the thermistor output voltage is used as the cold junction 4 of the thermopile 41.
2, the temperature obtained based on the thermopile output voltage is corrected, and the fixing roll 11
The surface temperature of (12) is specified. Then, the temperature control device 16 sends a temperature control signal to the power supply circuit 17 based on the obtained surface temperature of the fixing roll 11 (12).
In such a temperature detecting process, the cold junction 42 of the thermopile 41 and the thermistor 32 are mounted on the base member 25 (see FIG. 4) via the same heat sink 43, so that the thermopile 41 and the base member of the thermistor 32 are mounted. The thermal resistance of 25 becomes substantially equivalent,
The heat transfer from the base member 25 becomes equal. For this reason,
It is possible to effectively prevent a measurement error of the cold junction 42 due to a temperature difference between the two. Also, thermopile 4
Since 1 and the thermistor 32 are arranged on the same heat sink 43, mounting on the base member 25 becomes easy. Further, by arranging the cold junction 42 close to the cold junction 42, it becomes possible to measure the temperature at a position where the temperature distribution is the same, and the measurement error can be suppressed.

Second Embodiment FIG. 7 shows a second embodiment of the thermopile type temperature sensor unit to which the present invention is applied. The basic configuration of the thermopile type temperature sensor unit 23 according to the present embodiment is
Although substantially the same as that of the first embodiment, a substrate is provided on each of the thermopile 41 and the thermistor 32, that is, a heat sink 43 and a substrate material 50, and each is mounted on the base member 25 via these substrates. Different from the form 1. The same components as those of the first embodiment are designated by the same reference numerals as those of the first embodiment, and detailed description thereof will be omitted here.

In this embodiment, as shown in FIG. 7, a substrate material 50 is provided, and the thermistor 32 is mounted at a position different from the thermopile chip 31 of the base member 25 via this substrate material 50. Here, the substrate material 50 may be a member made of the same material as the heat sink 43 in which the thermopile 41 is disposed, or may be appropriately selected as needed as long as it is a material having a thermal conductivity equal to that of the heat sink 43. Absent. The thermistor 32 is a thermopile chip 31.
Of the thermopile chip 31 and the thermistor 32 are mounted near the center of the base member 25. According to the present embodiment, since the distances from the side peripheral wall 26 to each other are increased, the heat influence from the side peripheral wall 26 becomes extremely small, and the amount of heat transferred from the side peripheral wall 26 to each is substantially equal. Therefore, the side wall 26
It is possible to prevent the occurrence of a temperature difference between the temperature sensor 3 and the correction sensor 4 due to the heat effect from the. In addition, the infrared absorbing film 44 of the thermopile chip 31 has the base member 2
In the case of a mode in which it is arranged at a position deviated from the center of 5, the infrared ray can be condensed on the infrared absorbing film 44,
As the silicon lens 221, it is preferable to use one having a shape that deviates and condenses infrared rays, or it is preferable to arrange the silicon lens 221 in the can-shaped housing 24 in an inclined manner.

In the present embodiment, the thermopile 41 and the thermistor 32 are arranged on different substrates (heat sink 43, substrate material 50).
By forming 0 and a material having the same thermal conductivity, the thermal resistances of the thermopile 41 and the base member 25 of the thermistor 32 become substantially equivalent, and the thermopile 4
1 and the thermistor 32 have equal heat transfer from the base member 25. For this reason, the first embodiment of preventing the measurement error of the cold junction 42 due to the temperature difference between the two is performed.
The same effect as is expected.

Third Embodiment FIG. 8 shows a third embodiment of the unit case in the thermopile type temperature sensor unit to which the present invention is applied. The basic configuration of the thermopile type temperature sensor unit 23 according to the present embodiment is substantially the same as that of the first embodiment, but the unit case 60 includes the base member 25 and the side peripheral walls of the can-like housing 24 in the first embodiment. A can-shaped housing 61 in which a hollow portion corresponding to 26 is integrally molded, and this can-shaped housing 6
The first embodiment is different from the first embodiment in that it is configured with a lid member 62 that fits in 1. That is, in the present embodiment, the unit case 60 includes a can-shaped housing 61 in which the base portion 70 on which the thermopile chip 31 and the thermistor 32 are mounted and the side peripheral wall portion 71 are integrally molded of the same metal, and a can-shaped body. A housing member 61 and a lid member 62 to which a silicon lens 221 that collects infrared rays is attached.
By fitting the can-shaped housing 61 and the lid member 62, the thermopile chip 31 and the thermistor 32 are shielded from the outside air. Here, in the present embodiment, the can-shaped housing 61 and the lid member 62 formed of the same metal are separately provided and fitted together, but at least the base portion 70 and the side are provided. If the peripheral wall portion 71 is integrally molded, the can-shaped housing 61 and the lid member 62 may be integrally molded. Also, the unit case 60
Need only be formed of the same material, but as in the present embodiment, a metal having good thermal conductivity is generally used. Incidentally, regarding the same components as in the first embodiment,
The same reference numerals as in Embodiment 1 are given and detailed description thereof is omitted here.

According to the present embodiment, at least the base portion 70 and the side peripheral wall portion 71 of the can-shaped housing 61 are integrally formed of metal, so that the base portion 70 and the side peripheral wall portion 71 are joined together. It is possible to prevent the adverse effect that a temperature difference occurs between the two due to the thermal resistance of the joint. Further, even if the can-shaped housing 61 is heated by the external heating element and the radiant infrared rays from the heated can-shaped housing 61 enter the infrared absorption film 44 of the thermopile chip 31, an error occurs in the temperature output. ,
Accurate temperature measurement can be performed by estimating the temperature of the can-shaped housing 61 by the thermistor 32 and compensating the error of the radiation amount corresponding to the temperature.

Fourth Embodiment FIG. 9 shows a fourth embodiment of a thermopile type temperature sensor unit to which the present invention is applied. In the figure, the basic configuration of the thermopile type temperature sensor unit 23 is substantially the same as that of the second embodiment, but unlike the second embodiment, the unit case 60 of the third embodiment is used and the substrate material 50 is interposed. The thermistor 32 is mounted inside the side peripheral wall portion 71 of the can-shaped housing 61. The same components as those in the second and third embodiments are designated by the same reference numerals as those in the second and third embodiments, and detailed description thereof will be omitted here.

In the present embodiment, the thermistor 32
Is mounted inside the side peripheral wall portion 71 of the can-like housing 61 via the substrate material 50, but is mounted via the substrate material 50 having the same thermal conductivity as the heat sink 43 of the thermopile chip 31. Therefore, the influence of heat from the can-like housing 61 is the same as in the case of mounting on the base portion 70, and it is possible to suppress the measurement error of the cold junction 42 as in the first and second embodiments. In particular, in the present embodiment, the can-shaped housing 61 is
Since the base portion 70 and the side peripheral wall portion 71 are integrally molded of metal, a more accurate temperature measurement can be performed in that the temperature difference caused by the thermal resistance of the joint can be ignored.

[0037]

As described above, according to the present invention, the non-contact type temperature sensor and the correction sensor for correcting the temperature information of the non-contact type temperature sensor are provided via the substrate material having the same thermal conductivity. Since it is mounted on the base member, a cold junction temperature measurement error caused by a temperature difference between the non-contact temperature sensor and the correction sensor can be prevented, and accurate temperature detection can be performed. Further, since it is possible to effectively avoid the temperature drift due to the temperature rise of the fixing device, it is possible to provide the fixing device that enables good temperature control.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an outline of a temperature detection device according to the present invention.

FIG. 2 is an explanatory diagram showing an overall configuration of a fixing device according to Embodiment 1 to which the present invention is applied.

FIG. 3 is an explanatory diagram showing an outline of the temperature detection device according to the first embodiment.

FIG. 4 is a perspective sectional view of a thermopile type temperature sensor unit according to the first embodiment.

FIG. 5 is an explanatory diagram showing an infrared detecting section of the thermopile type temperature sensor unit according to the first embodiment.

FIG. 6 is an explanatory diagram showing an arrangement mode of the thermistors of the thermopile type temperature sensor unit according to the first embodiment.

FIG. 7 is a perspective sectional view of a thermopile type temperature sensor unit according to a second embodiment.

FIG. 8 is a perspective sectional view of a thermopile type temperature sensor unit according to a third embodiment.

FIG. 9 is a perspective sectional view of a thermopile type temperature sensor unit according to a fourth embodiment.

[Explanation of symbols]

1 ... Object to be heated, 2 ... Heating source, 3 ... Non-contact type temperature sensor,
3a ... Substrate material, 4 ... Correction sensor, 5 ... Sensor unit,
6 ... Unit case, 6a ... Base member, 6b ... Can case, 7 ... Outer shell case, 7a ... First outer shell case, 7b ... Second outer shell case, 8 ... Temperature detecting device

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ryuichi Inamiya             Fuji Zero, 2274 Hongo, Ebina City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Hisao Ito             Fuji Zero, 2274 Hongo, Ebina City, Kanagawa Prefecture             X Co., Ltd. (72) Inventor Ryuichiro Maeyama             430 Sakai, Nakai-cho, Ashigarakami-gun, Kanagawa Prefecture             Kunakai Fuji Xerox Co., Ltd. (72) Inventor Kijima Masaru             Fuji Zero, 2274 Hongo, Ebina City, Kanagawa Prefecture             X Co., Ltd. F term (reference) 2G066 AC01 BA08 BA09 BB11 CB03                 2H033 AA18 BA31 BA32 CA02 CA27                       CA45

Claims (11)

[Claims] 1. A non-contact temperature sensor, which is arranged to face a heated body and measures infrared rays emitted from the heated body, and a correction sensor for correcting temperature information of the non-contact temperature sensor. A temperature detecting device having a sensor unit for detecting the surface temperature of an object to be heated which is heated by a heating source in a non-contact manner, wherein the sensor unit is a can-like member that is attached to cover the base member and the base member. The base member is provided with a non-contact temperature sensor and a correction sensor, and the non-contact temperature sensor and the correction sensor are made of a board material having the same thermal conductivity. A temperature detecting device, characterized in that it is mounted on a base member via. 2. The temperature detecting device according to claim 1, wherein a correction sensor is arranged on a part of a substrate material of the non-contact type temperature sensor, and the non-contact type temperature sensor and the correction sensor are based on a common substrate material. A temperature detecting device characterized by being mounted on a member. 3. The temperature detecting device according to claim 1, wherein the non-contact temperature sensor and the correction sensor are provided with a substrate material having an equal thermal conductivity, and the non-contact temperature sensor and the correction sensor are provided through the respective substrate materials. A temperature detecting device characterized in that and are respectively mounted on a base member. 4. The temperature detection device according to claim 3, wherein the non-contact temperature sensor and the correction sensor are configured so that the amounts of heat transferred from the side peripheral wall of the can-like housing to the non-contact temperature sensor and the correction sensor are substantially equal to each other. A temperature detecting device characterized in that and are mounted on a base member. 5. A non-contact type temperature sensor, which is arranged to face the object to be heated and measures infrared rays emitted from the object to be heated, and a correction sensor for correcting temperature information of the non-contact type temperature sensor. A temperature detecting device having a sensor unit for detecting the surface temperature of an object to be heated which is heated by a heating source in a non-contact manner, wherein the sensor unit is a can-like member that is attached to cover the base member and the base member. It has a unit case composed of a housing, and mounts the non-contact temperature sensor on the base member through the board material, and also has a substrate with thermal conductivity equivalent to that of the board material on which the non-contact temperature sensor is mounted. A temperature detecting device, wherein a correction sensor is mounted on the inner peripheral wall of a can-shaped housing via a plate material. 6. The temperature detecting device according to claim 1, wherein the non-contact type temperature sensor is a thermopile type temperature sensor. 7. The temperature detecting device according to claim 6, wherein a correction sensor is arranged close to a cold junction of the non-contact type temperature sensor. 8. The temperature detecting device according to claim 1, wherein the substrate material is silicon. 9. The temperature detecting device according to claim 1, wherein at least the side peripheral wall of the can-like housing and the base member are integrally molded of the same material. apparatus. 10. The temperature detecting device according to claim 1, further comprising an outer shell case for accommodating the sensor unit and keeping the ambient temperature of the sensor unit uniform. . 11. A fixing device in which the temperature detecting device according to claim 1 is incorporated.