JP3374640B2 - Temperature detector - Google Patents

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 detecting the surface temperature of a fixing roller in a heating roller type fixing device such as an electrophotographic copying machine. The present invention relates to a temperature detection device having a structure in which a heat sensitive element is arranged on an elastic material to detect the surface temperature.

[0002]

2. Description of the Related Art Conventionally, in a laser printer, an electrophotographic copying machine, or the like, for fixing an unfixed toner image transferred on a recording paper, for example, a fixing roller (heating roller) having a heater inside is used. A heating roller type fixing device is used. Then, the recording paper is pressed against the fixing roller and heated, whereby the toner of the unfixed toner image is fused to the recording paper, and the toner image is fixed to the recording paper. For this reason, the surface temperature of the heating roller of the fixing device must be maintained at a constant high temperature. Therefore, in the heating roller type fixing device, the temperature detecting device constantly detects the surface temperature of the fixing roller and controls the operation of the heater provided in the fixing roller according to the detected temperature.

FIG. 4 is a sectional view for explaining the structure of a conventional temperature detecting device. In FIG. 4, 40 is a temperature detecting device, 41 is a heat-resistant tape, 42 is a leaf spring, 43 is a lead wire, 44 is an elastic material, 45 is a recess, and 46 is a thermosensitive element. As shown in FIG. 4, in the conventional temperature detecting device 40, an elastic material 44 such as a silicon sponge is provided on a leaf spring 42 for contacting the surface of a measurement roller, for example, a measuring roller, and the elastic material 44 is provided. Is provided with a recessed portion 45 in the center thereof, and the heat sensitive element 46 of the bead type thermistor is embedded in the recessed portion 45 and is held inside the elastic member 44.
4 is covered with a heat resistant tape (adhesive polyimide tape) 41. Further, a lead wire 43 for extracting a temperature detection output signal is led out from the bead type thermistor of the heat sensitive element 46.

FIG. 5 is a view showing a state in which a fixing roller is equipped with a temperature detecting device. In FIG. 5, 40 is a temperature detecting device, 41 is a heat resistant tape, 42 is a leaf spring, 43 is a lead wire, 44 is an elastic material, and 46 is a heat sensitive element. Also, 5
Reference numeral 1 is a temperature detection circuit, 52 is a temperature control circuit, 53 is a heater for a fixing roller, and 54 is a fixing roller for the object to be measured. As shown in FIG. 5, in the temperature detecting device 40, the heat sensitive element 46 is brought into contact with the surface of the fixing roller 54 via the heat resistant tape 41 under the pressing force of the plate spring 42. The surface temperature of is being detected. The detected temperature detection signal is input to the temperature detection circuit 51 via the lead wire 43, and the temperature detection circuit 51 outputs the temperature control circuit 5
2, the temperature control circuit 52 controls the heater 53 so that the surface temperature of the fixing roller becomes a predetermined temperature.

In the temperature detecting device 40, the thermosensitive element 4
When the temperature of the fixing roller 54 is detected via the heat-resistant tape 41 by 6, the heat conducted to the heat-resistant tape 41 is transmitted to the heat-sensitive element 46 as well as to the elastic material 44, so that before raising the temperature of the heat-sensitive element 46. Moreover, the conducted heat is absorbed by the elastic material 44. Therefore, the temperature detection device 4
0 has a problem that its thermal response is poor and accurate temperature detection cannot be performed.

Therefore, there is a problem that an overshoot occurs in the temperature control of the fixing roller, the toner is fused to the surface of the fixing roller, and the surface of the fixing roller becomes dirty. The thermistor of the thermal element here is
Since it is a bead type thermistor enclosed with glass, it has poor adhesion to the fixing roller, which is another factor that deteriorates the thermal response. Further, since the bead type thermistor has a part protruding, there is a problem that a large force locally acts in the contact area with the fixing roller and the fixing roller is damaged.

[0007]

By the way, in order to improve the thermal response performance of the temperature sensor, for example, in the prior art,
A "surface temperature detecting device" as disclosed in Japanese Utility Model Laid-Open No. 60-181768 has been proposed. As shown in FIG. 6, in this “surface temperature detecting device”, the thermistor 69 of the heat sensitive element, the heat resistant film 68 that holds the thermistor 69, and the heat resistant film 68 are held in a state of being pulled from both ends. The holding member 67 is provided, and the thermistor 69, which is a thermosensitive element, is pressed against the surface of the fixing roller 54 of the object to be measured.

However, according to the structure of such a temperature detecting device, as is apparent from the structure shown in FIG. 6, the back surface of the heat-sensitive element is a space in which air flows, and the object to be measured (fixing roller). There is a problem that it is easily affected by the air flow of the surrounding atmosphere. If the object to be measured is flat or has a small curvature, the adhesion between the thermistor 69 in the temperature sensor portion and the fixing roller 54 of the object to be measured becomes weak, so that the accurate temperature cannot be obtained. There is also a problem that it is difficult to measure. Further, with such a structure, the size of the temperature sensor portion is increased by the amount of the heat resistant film 68 being pulled from both ends, which makes it difficult to apply to a small device.

As another example, the actual fair 1-2131
In the temperature detecting device according to the "heat fixing device" described in Japanese Patent Publication No. 5, the heat sensitive element such as the thermistor is surrounded by a heat absorbing member having good heat conductivity such as metal foil to increase the amount of heat applied to the thermistor. Proposals have been made.

However, in such a structure of the temperature detecting device, since the heat capacity of the temperature sensor itself increases, the responsiveness is not improved so much even though the amount of heat applied to the thermistor of the heat sensitive element is increased, and the cost is reduced. There is a problem that is raised.

Further, in the temperature detecting device, in order to improve the problem of scratches due to abrasion with the heat roller due to the thermistor element projecting from the silicon sponge surface, for example, it is described in Japanese Patent Application Laid-Open No. 2-145931. In the "temperature sensor", a concave portion is formed at a predetermined position of an elastic member such as silicon sponge, a thermistor element and a thin metal plate are attached to the concave portion so as to cover the periphery thereof, and a tape such as polyimide having heat resistance is attached from the upper surface thereof. The thing to attach to a mounting plate is proposed.

According to the structure as proposed, the contact surface of the temperature sensor portion for detecting the temperature of the heat roller as the fixing roller can be flattened by the strength of the metal plate, and the heat roller is damaged. Can be significantly reduced.
However, there is a problem that the thermal responsiveness is deteriorated due to poor adhesion between the metal plate and the bead type thermistor element, and increase in heat capacity of the sensor itself.

In order to improve the thermal response of the sensor element itself of the heat-sensitive element, instead of the conventional glass-enclosed bead-type thermistor, a thin film thermistor having a structure in which a film-like thermistor and electrodes are provided on the substrate or There is a proposal to use a thick film thermistor.

For example, the "temperature sensor" described in Japanese Patent Application Laid-Open No. 2-114135 has a thick film thermistor provided on a stainless steel plate. As shown in FIG.
In this temperature detecting device, a silicon resin mold 73 is mounted on a stainless steel mounting plate 72 fixed to a frame 74.
Due to this, the sensor element 71 is fixed. Therefore, only a part of the stainless steel mounting plate 72 can contact the heat roller 70, and the heat roller 70
There is a large temperature difference between the temperature of 1 and the temperature of the mounting plate 72 made of stainless steel, which sacrifices the thermal responsiveness, and the good responsiveness of the sensor element cannot be fully utilized. Further, with such a structure, as in the case described above, it is difficult to secure a close contact force with a flat surface or a curved surface having a small curvature, and there is a problem that it is easily affected by an air flow.

Further, as another conventional example, the actual development of Sho 64-4
There is a proposal of "a fixing device equipped with a temperature control mechanism" described in Japanese Patent No. 5869. This is a thin film thermistor element in which a silicon oxide layer, an electrode layer, and a thermistor layer are laminated on a silicon substrate, with the silicon substrate side facing the heat roller, and mounted on the silicon sponge, and the surface is further protected. For this purpose, a tape such as a polyamide-imide resin film for winding is used.

According to this structure, the sensor element itself of the heat-sensitive element has improved thermal responsiveness as compared with the conventional one, but as in the case described above, part of the heat conducted to the sensor element is The structure in which the elastic material and the lead wire transmit the heat and the heat is absorbed by the elastic material lead wire before the temperature of the heat-sensitive element rises has not been improved. There is a problem that it gets worse. In particular, when the temperature of the fixing roller is lowered, the thin film thermistor element having the laminated structure is in contact with the silicon sponge, which is hard to cool, so that there is a problem that the thermal response during cooling is poor. Further, there is another problem that the joint between the electrode of the thermistor element and the lead wire is subject to tension when the heating roller is repeatedly rotated and stopped, the joint is easily broken, and the reliability is low.

Further, in the "fixing device" described in Japanese Patent Application Laid-Open No. 2-85733, there is proposed a temperature detecting device which uses a thin film thermistor in a non-contact state with a heat roller. Responsiveness is poor, and it cannot follow a temperature change of about 10 ° C. per second.

The present invention has been made in order to solve these problems, and the first object of the present invention is to improve the thermal response, especially the thermal response during cooling, Reduces roll damage and is not affected by atmospheric airflow,
An object of the present invention is to provide a small-sized temperature detecting device which can cope with various curved surfaces and flat surfaces.

A second object of the present invention is to provide a temperature detecting device having a structure that maximizes the good thermal response of the thin film thermistor.

[0020]

To achieve the above object, according to an aspect of the temperature sensing device according to the invention, the temperature detecting device for detecting a surface temperature of 該被measured in contact with the surface of the object to be measured
In addition, if the temperature sensing device is a thin film thermistor,
A substrate on which a thermal element and the thin film thermistor are laminated, and the substrate
And a thin film metal plate supporting the thin film thermistor.
Between the frame plate, the frame plate and the object to be measured,
Has a heat-resistant film installed on the frame plate and a recess
A thin film thermistor of the substrate is laminated.
The frame plate is adhered to the surface opposite to the surface where
Before making the recess of the elastic material an air chamber for heat insulation
The serial elastic material recess inlet is characterized in that so as to block in the frame plate and the heat-resistant film.

Further, Te temperature detector odor present invention, thin metal plate, characterized in that it is a pair of electrode plates connected to a thin film thermistor electrically.

Further, in the temperature detecting device of the present invention, at least the thin film thermistor element, the terminal and the supporting member are integrally formed in advance, or a heat resistant film is attached or coated on the temperature detecting surface side together with these in advance. The thermosensitive element is integrally manufactured and is set in an elastic member supported by a supporting member other than the thermosensitive element near the entrance of the surface of the concave portion so as to face the object to be measured.

In the temperature detecting device of the present invention having such characteristics, specifically, the thermistor element used as the heat sensitive element is a thin film thermistor in which the electrode layer and the thermistor layer are laminated on the substrate. The substrate side is arranged so as to face the object to be measured, and is mounted on a substantially cubic elastic material such as a silicon sponge. Further, in order to protect the surface, a heat-resistant film such as a polyimide adhesive tape is coated.

The elastic silicon sponge used here is provided with an air chamber in the hollow portion of the concave portion at the center of the surface of the fixing roller of the object to be measured, and the thin film thermistor of the heat-sensitive element is provided in the concave portion. It is arranged with the air chamber as the back at the inlet position. That is, the thermistor layer and the electrode layer on the substrate of the thin film thermistor face the space (air chamber) of the concave portion of the silicon sponge, and the surface of the thermistor layer is covered with air in the air chamber (which functions as a heat insulating material). . Therefore, the heat absorbed by the element of the thin film thermistor does not dissipate to the silicon sponge, and the heat response is excellent. Regarding the thermal responsiveness during cooling, the thin film thermistor element itself is surrounded by air with a small specific heat and easy to cool, so the thermal responsiveness is much higher than when it is in direct contact with the silicon sponge surface. Is improved.

Further, with such a structure, even if the object to be measured is strongly pressed against the surface of the fixing roller, the substrate side of the thin film thermistor is only in contact through the heat resistant tape, and the thermistor layer of this element is in contact. Since the electrode layer is held at the space inlet of the concave portion of the silicon sponge, it does not rub against the silicon sponge, is in a stable state over time, and the lead wire is less likely to be broken. Furthermore, it has an advantage that it is hardly affected by the air flow of the atmosphere.

The element of the thin film thermistor is fixed at the entrance of the recess of the silicon sponge by bridging the pair of stainless frame electrodes so as to cover the entrance window of the recess. The surface to be measured of the stainless steel frame electrode is firmly fixed to the silicon sponge with the adhesive tape of polyimide, which is a heat resistant film, so the element of the thin film thermistor will be displaced even if it is pressed against a rotating object such as a fixing roller. There is no such thing.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view for explaining the structure of a temperature detecting device according to an embodiment of the present invention, and FIG. 2 is a perspective view for explaining the structure for mounting a thin film thermistor. 1 and 2, in FIG.
Is a silicon sponge made of an elastic material, 2 is an air chamber in the recess of the silicon sponge, 3 is a thin film thermistor of a heat sensitive element, 4 is a frame plate made of stainless steel, 5 is a heat resistant film such as a polyimide adhesive tape, and 12 is temperature detection. A leaf spring that presses the device against the object to be measured, 20 is a lead wire, and 21 is a terminal. 30 is an alumina substrate of the thermistor, 31 is an element body of the thin film thermistor, 32 is an electrode portion on the substrate,
34 is a gold wire of a bonding wire.

The temperature detecting device shown in FIG. 1 is used, for example, as a temperature detecting device for detecting the temperature of a fixing roller of a copying machine. In this case, the elastic silicon sponge 1
It has a substantially cubic shape with one side of 6 to 10 mm, and a substantially cubic recess with one side of 2 to 4 mm is formed in the center part of the surface thereof to form the air chamber 2 when assembled as a temperature detecting device.

On the other hand, a thin film thermistor 3 as a heat sensitive element.
For example, an FT thermistor element manufactured by Ishizuka Electronics Co., Ltd. is used, and as shown in FIG. 2, a 0.07 mm-thick stainless plate is used as the frame plate 4 on which the thin film thermistor 3 is mounted. The frame plate 4 also has a structure that also serves as an electrode plate for extracting a temperature detection signal from the thin film thermistor 3. The thin film thermistor 3, as shown in FIG.
The alumina substrate 3 is provided at the entrance of the recess of the silicon sponge 1.
Place and fix the back side of 0 with the back side facing up.

That is, the thin film thermistor 3 provided at the entrance of the concave portion of the silicon sponge 1 is located on the same plane as the surface of the silicon sponge 1 made of an elastic material, and the frame plate 4 made of stainless steel plate, Block the entrance of the recess,
A sealed air chamber 2 is formed inside a silicone sponge 1 made of an elastic material. The air chamber 2 acts on the thin film thermistor 3 as a heat insulating layer. Since the element body 31 of the thin film thermistor 3 is arranged facing the air chamber 2, the heat conducted from the fixing roller 6 of the object to be measured through the heat resistant film 5 is absorbed by the thin film thermistor 3, and this heat Does not radiate much heat, and the thermal responsiveness is correspondingly excellent.

Further, in order to improve the slidability of the object to be measured which comes in contact with the fixing roller, the temperature detecting device uses, for example, a heat resistant film 5 such as an adhesive polyimide tape to form the silicon sponge 1 and the silicon sponge 1. The surface of the frame plate 4 is covered. Then, a signal from the thin film thermistor 3 is taken out from the electrodes of the two stainless steel plates of the frame plate 4, and a temperature control circuit for controlling the operation of the temperature detection circuit and the heater in the fixing roller via the terminal 21 and the lead wire 20. (Fig. 5).

The back surface of the silicon sponge 1 holding the thin film thermistor 3 is brought into contact with the fixing roller of the object to be measured with a predetermined pressure, so that the leaf spring 12 is provided.
Is adhered to the tip of the sheet and is brought into contact with the fixing roll with a load of about 20 grams. Thereby, the surface temperature of the fixing roller of the object to be measured is detected, and the surface temperature of the fixing roller is controlled to a predetermined value by the temperature control circuit.

As shown in FIG. 2, the element structure of the thin film thermistor 3 includes a thin film thermistor chip in which an element body 31 of the thin film thermistor and electrode portions 32 are laminated on the alumina substrate 30 and the thermistor surface is formed. The substrate surface on the side opposite to is bonded to a pair of stainless steel frame plates 4, and the stainless plate 4 of the frame plate 4 and the electrode portion 32 are connected by a gold wire (Au wire) 34 of a bonding wire. There is. As a result, the pair of frame plates 4 serve as extraction electrodes, and the lead wires 20 from the end portions of the frame plate 4
Is withdrawn. Although not shown, the thermistor surface of the alumina substrate is overcoated with silicon varnish.

Further, in the configuration of the temperature detecting device here,
The thin film thermistor chip is designed to come into contact with the fixing roller of the object to be measured through the heat resistant film 5 on the side of the metal electrode plate of the frame plate 4 to which the substrate is adhered and fixed. It does not hurt itself. Further, the metal electrode plate of the frame plate 4 and the thin film thermistor adhered thereto have good thermal adhesion, and the metal electrode plate also acts as a heat collecting plate of the object to be measured, so that the thermal responsiveness is high. It also has the advantage of being improved.

FIG. 3 is a diagram for explaining a comparative example of the thermal response characteristics of the temperature detecting device according to the present invention and the conventional temperature detecting device. In the temperature detecting device of the present invention, the thin film thermistor 3
However, the thin film thermistor 3 detects the heat of the fixing roller via the heat resistant tape by contacting the fixing roller from the substrate side so as to face the fixing roller. Therefore, the thin film thermistor 3 can efficiently collect heat from the fixing roller via the heat resistant film 5 and the stainless steel frame plate 4, and the thin film thermistor 3 in contact with the stainless steel plate is made of the stainless steel plate. It reacts sensitively to the temperature, the resistance value changes due to the change in the detected temperature, and the heater control of the fixing roller 6 is accurately performed.

The thermal response characteristic of the temperature detecting device using the thin film thermistor of the present invention is shown by the curve a in FIG. 3, and the thermal response characteristic of the conventional temperature detecting device using the bead type thermistor is shown in the curve of FIG. It is as shown in b.

That is, as shown in FIG. 3, according to the temperature detecting device in which the conventional bead type thermistor is placed on the surface of the elastic material sponge, the temperature detected on the surface of the fixing roller is 180 degrees.
When set to ℃, set the temperature of the fixing roller from room temperature to 180
When the temperature is raised to 0 ° C., it takes 17 seconds for the temperature detection device to detect the temperature of 180 ° C. as shown by the curve b, and when the heater operation is stopped, the surface temperature of the fixing roller 6 is much higher than the detected temperature. And overshoot of 30 ° C has occurred.

On the other hand, according to the temperature detecting device using the thin film thermistor according to the present invention, under the same condition as the above case, the temperature detecting device detects the temperature of 180 ° C. for 15 seconds as shown by the curve a. It is later and can be detected in a shorter time than before. The amount of overshoot at that time is 12 ℃
Has become. Further, when the temperature detected on the surface of the fixing roller is controlled at 180 ° C. at rest, a temperature ripple of 12 ° C. is generated in the conventional temperature detector for the bead type thermistor, but the temperature detection of the thin film thermistor according to the present invention is performed. In the device, the temperature ripple is 4 ° C, which is a significant improvement. This is largely due to the effect of improving the thermal response during cooling by having the air chamber.

Next, a method for setting the element of the thin film thermistor at the entrance of the concave portion of the elastic body will be specifically described by a method different from the above-mentioned embodiment. FIG. 8 is a sectional view for explaining the configuration of a temperature detecting device according to another embodiment of the present invention,
Further, FIG. 9 is a perspective view of a main part for explaining a method of supporting an elastic material in a temperature detecting device of another embodiment. Figure 8
And in FIG. 9, the reference numerals of the respective members refer to the same members as those in the above-mentioned embodiment by the same reference numerals.

As shown in FIG. 8, the portion of the thin film thermistor assembly serving as the temperature detecting portion is composed of the thin film thermistor element 3 and
A terminal 21 that is electrically connected from the thin film thermistor element 3 which is the electrical connection path through the frame plate 14.
And the part up to the lead wire 20 are assembled in advance. For example, FR manufactured by Ishizuka Electronics Co., Ltd.
A sensor can be used. This frame plate 14
A supporting member made of stainless steel with a thickness of 0.07 mm,
A heat resistant film (not shown) having a thickness of 25 μm is attached to the surface not on the thin film thermistor side. Therefore, the heat from the object to be measured is transferred from the surface of the fixing roller 54 to the heat resistant film and the frame plate 14 as in the case of the above-described embodiment.
Will be conducted to the thin film thermistor element 3 via.

The end of the frame plate 14 opposite to the side on which the thin film thermistor element 3 is mounted is
It is embedded in the terminal 21, and through this terminal 21,
The lead wire 20 is drawn out. As a result, the change in the resistance value of the thin film thermistor element 3 is detected, the temperature is detected, and the heater 53 installed in the fixing roller 54 is detected.
To control the surface temperature of the fixing roller 54.

Further, as shown in FIG. 8, the terminal 21 here substantially supports the thin film thermistor element 3, the frame plate 14, and the heat-resistant film attached to the frame plate 14. By supporting the terminal 21, the temperature detecting portion (thermistor portion) of the thin film thermistor element 3 is supported. Therefore, the terminal 21 is screwed and fixed to the frame 82 of the casing of the fixing device with the screw 80 via the stainless steel plate 15 of the leaf spring having a thickness of 0.2 mm.

A silicone sponge (hereinafter abbreviated as sponge) 81, which is an elastic body, is adhered and fixed to the tip of the stainless plate 15 opposite to the terminal 21 side with an adhesive or a double-sided adhesive tape. Alternatively, as shown in FIG. 9, the spring plate tip portion 90 of the stainless steel plate 16 of the plate spring is bent to fix the sponge 81 so that it is sandwiched.

Similar to the case of the temperature detecting device of the above-mentioned embodiment, the sponge 81 has a recessed portion provided at substantially the center thereof, and the thin film thermistor element 3 is located at the entrance of the hole of the recessed portion. It is arranged so as to cover the part. This is the frame plate 1 on which the thin film thermistor element 3 is mounted.
4 and the stainless plate 15 are adjusted in length and arranged.

If the height of the sponge 81 is higher than the gap (height) between the stainless steel plate 15 and the frame plate 14 by 2 to 3 mm when the sponge 81 is removed, the concave portion of the sponge 81 will be formed. , Thin film thermistor element 3
Makes it easier to seal, and also improves workability.
In this case, even if the heights are the same or a little lower, there is no particular problem because the pressing force is applied by the stainless steel plate 15 during the temperature detection operation.

Further, the thin film thermistor element 3 is similar to that of the previous embodiment, and as shown in FIG. 2, the alumina substrate 30 and the alumina substrate 30 are provided on the frame plate 14 (frame plate 4).
Thin film thermistor main body 31 are laminated in this order, and the frame plate 14 and the thin film thermistor body portion 31 through the alumina substrate 30, the bonding wire Ya 34 are electrically connected. As a result, the thin film thermistor body 31 is set near the entrance of the recess of the sponge 1.

In this state, in order to detect the surface temperature of the fixing roller 54 at the measurement site to be controlled, the contact is made with a load of 20 grams under the same conditions as in the above-mentioned embodiment, and the temperature of the conventional temperature detecting device is reduced. As a result of conducting a comparative test with the case, almost the same result as the result of the above-mentioned embodiment shown in FIG. 3 was obtained, and its performance was confirmed.

By manufacturing and assembling the temperature detecting device of the present invention by such a method, unlike the above-described embodiment, the temperature detecting device of the present invention can be used even if the existing thermistor element available as a product is used as it is. Since the effect of the device can be obtained, the cost can be remarkably reduced.

[0049]

As described above, the temperature detecting device according to the present invention uses the thin film thermistor as the heat sensitive element,
A structure in which a thin film metal plate of a frame plate is adhered to the surface of the substrate opposite to the surface on which the thin film thermistors are laminated, the thin film metal plate closes the recessed inlet of the elastic sponge, and an air chamber in which the recessed part is sealed since a temperature sensing device, an improved temperature response is, that has become what enables quick and accurate temperature sensing. In addition, the temperature detection device reduces damage to the heat roller, is not affected by the air flow of the atmosphere, and is small in size and can cope with various curved surfaces and flat surfaces. Since the thermal responsiveness is good, control according to the detection result can be effectively performed, and for example, even if the copying machine is operated intermittently, there is no problem.

[Brief description of drawings]

FIG. 1 is a sectional view illustrating a structure of a temperature detecting device according to an embodiment of the present invention,

FIG. 2 is a perspective view illustrating a structure for mounting a thin film thermistor,

FIG. 3 is a diagram for explaining a comparative example of thermal response characteristics of a temperature detecting device according to the present invention and a conventional temperature detecting device;

FIG. 4 is a sectional view illustrating a structure of a conventional temperature detecting device,

FIG. 5 is a view showing a state in which a fixing roller is equipped with a temperature detecting device,

FIG. 6 is a cross-sectional view illustrating another example of the structure of the conventional temperature detecting device,

FIG. 7 is a perspective view illustrating another example of the structure of the conventional temperature detecting device,

FIG. 8 is a cross-sectional view illustrating the configuration of a temperature detecting device according to another embodiment of the present invention,

FIG. 9 is a perspective view of an essential part for explaining a method of supporting an elastic material in a temperature detecting device of another embodiment.

[Explanation of symbols]

1 ... Silicone sponge of elastic material, 2 ... Air chamber, 3 ... Thin film thermistor, 4 ... Frame plate, 5 ... Heat resistant film,
12 ... Leaf spring, 14 ... Frame plate, 15 ... Stainless steel plate, 16 ... Stainless steel plate, 20 ... Lead wire, 21 ... Terminal, 30 ... Alumina substrate, 31 ... Thin film thermistor main body portion, 32 ... Electrode portion on substrate, 34 ... Gold wire of bonding wire, 40 ... Temperature detecting device, 41 ... Heat resistant tape, 4
2 ... Leaf spring, 43 ... Lead wire, 44 ... Elastic material, 45 ... Recess, 46 ... Heat sensitive element, 51 ... Temperature detection circuit, 52 ... Temperature control circuit, 53 ... Fixing roller heater, 54 ... Fixing roller, 80 ... Screw, 81 ... Silicone sponge, 82 ... Frame, 90 ... Spring plate tip.

Front page continued (72) Inventor Mitsuhiro Matsumoto 430 Nakai-cho, Ashigagami-gun, Kanagawa Green Tech Nakakai Fuji Xerox Co., Ltd. (72) Inventor Yasuhiro Kusumoto 430 Nakai-cho, Ashigagami-gun, Kanagawa Fuji Xerox Co., Ltd. (56 ) Reference JP-A-2-145931 (JP, A) Actually opened 5-19929 (JP, U) Actually opened 62-37730 (JP, U) Actually opened 55-170638 (JP, U) Actually opened 60-39942 (JP, U) Actually open 63-163432 (JP, U) Actual public 1-21315 (JP, Y2) Actual public 3-34699 (JP, Y2) Actual public 58-54690 (JP, Y1) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01K 1/00-15/00 G03G 15/20 109

Claims (3)

(57) [Claims] 1. A temperature detecting device for detecting the surface temperature of an object to be measured by contacting the surface of the object to be measured, wherein the temperature detecting device is a thin film thermistor and a substrate on which the thin film thermistor is laminated. A frame plate which is a thin film metal plate supporting the substrate and the thin film thermistor; a heat resistant film placed between the frame plate and the object to be measured and installed on the frame plate; and an elastic material having a recess. The frame plate is adhered to the surface of the substrate opposite to the surface on which the thin film thermistor is laminated, and the elastic material concave portion inlet is formed so that the concave portion of the elastic material serves as an air chamber for heat insulation. The temperature detecting device is characterized in that the frame plate and the heat resistant film are closed. 2. The temperature detecting device according to claim 1, wherein the thin film metal plate is a pair of electrode plates electrically connected to the thin film thermistor. 3. The temperature detecting device according to claim 1, wherein at least the thin film thermistor element, the terminal and the supporting member are integrally formed in advance in the temperature detecting device, or
Along with these, a heat-resistant film is pasted or coated on the temperature detection surface side to be integrally prepared in advance, an elastic member supported by a supporting member other than this, and a heat-sensitive element near the entrance of the concave surface. A temperature detecting device, which is set in a direction facing an object to be measured.