JPH07140008A - Radiation thermometer - Google Patents

Abstract

PURPOSE:To provide a radiation thermometer capable of accurately and independently measuring surface temperature and the ambient temperature in a simple structure. CONSTITUTION:A sensor section 2 is so constituted that a series circuit of thermosensitive resistor 5 and a first reference thermosensitive resistor 6 and a series circuit of a second reference thermosensitive resistor 7 and a fixed resistor 8 are connected in parallel. The resistance value of the thermosensitive resistor 5 is varied by being reacted with the radiation energy of infrared radiation and the ambient temperature. The first and second reference thermosensitive resistor 6, 7 have resistance-temperature characteristics approximately the same as the thermosensitive resistor 5 and is reacted only with the ambient temperature. An output voltage Vr corresponding to the radiation energy of infrared radiation is obtained from a connection point (a) between the thermosensitive resistor 5 and first reference resistor 6. An output voltage Ve corresponding to the ambient temperature is obtained from a connection point (b) between the second reference thermosensitive resistor 7 and fixed resistor 8. It is possible to independently measure the surface temperature and the ambient temperature of an object to be measured by a non-contact manner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation thermometer for measuring the surface temperature and ambient temperature of an object to be measured in a non-contact manner by the radiant energy of infrared rays radiated from the object to be measured.

[0002]

2. Description of the Related Art Conventionally, as a radiation thermometer for detecting the amount of infrared radiation from an object to be measured by a pyroelectric element or a thermopile and measuring the surface temperature and the ambient temperature of the object to be measured in a non-contact manner, as shown in FIG. There is something like. The radiation thermometer shown in FIG. 4 uses an optical system 15 to detect infrared rays emitted from the object to be measured.
The infrared detector element 1 such as a pyroelectric element is focused on the light receiving surface of the infrared detector element 16 and the infrared rays incident on the light receiving surface of the infrared detector element 16 are blocked by the chopper 17.
6 causes a difference in temperature due to a difference between the amount of radiant energy of infrared rays incident on the light-receiving surface of 6 and the amount of radiant energy of infrared rays emitted to the surface of the chopper 17, and the surface temperature of the chopper 17 is controlled by the reference temperature detecting element 18. The infrared signal detecting element 16 and the reference temperature detecting element 1 are detected by the synchronizing signal generator 19.
Infrared detecting element 16
The surface temperature of the object to be measured is measured by synthesizing the output obtained by amplifying and detecting the output of the above with the amplifying phase detector 20 and the output obtained by amplifying the output of the reference temperature detecting element 18 by the amplifier 21 by the synthesizing unit 22. . That is, the infrared detection element 1 is determined according to the difference between the surface temperature of the object to be measured and the surface temperature of the chopper 17.
Since the output of 6 changes, the surface temperature of the object to be measured can be measured as described above.

Further, in JP-A-5-45219,
An infrared detection circuit using an infrared sensitive resistor Rt as shown in FIG. 5 has been proposed. As shown in FIG. 5, the infrared detecting circuit includes an infrared sensitive resistor Rt which is sensitive to the radiant energy of infrared rays radiated from the object to be measured and the ambient temperature.
And a reference resistor Rref having substantially the same resistance temperature characteristic as the infrared sensitive resistor Rt and sensitive only to the ambient temperature,
A direct current is supplied from the direct current power source E to the series circuit with the fixed resistor Riv, and the infrared sensitive resistor Rt and the reference resistor Rref are supplied.
The output voltage V ₂ corresponding to the radiant energy of infrared rays is taken out by amplifying the difference between the voltage Vin at the connection point with the predetermined reference voltage Vref by the amplifier 23 and further the infrared sensitive resistor Rt and the reference resistance. The surface temperature and the ambient temperature of the object to be measured can be measured in a non-contact manner by converting the direct current flowing through the body Rref into the direct voltage by the fixed resistance Riv and extracting the output voltage V ₃ corresponding to the ambient temperature. .

[0004]

However, in the former conventional configuration, the infrared detecting element detects the difference in the amount of radiant energy between the infrared rays radiated from the object to be measured and the infrared rays blocked by the reference object (chopper 17). The temperature difference between the temperature of the light receiving surface of the infrared detecting element 16 and the surface temperature of the chopper 17 is detected as the output of the infrared detecting element 16, and the surface temperature of the object to be measured is known. Therefore, it is necessary to separately provide a means for measuring the surface temperature of the chopper 17, which causes a problem that the configuration becomes complicated.

In the latter conventional configuration, the change in resistance value of the infrared sensitive resistor Rt due to the radiant energy of infrared rays is sufficiently smaller than the change in resistance value of the infrared sensitive resistor Rt due to ambient temperature. Since it is assumed that the surface temperature of the object to be measured becomes higher, the change in the resistance value of the infrared sensitive resistor Rt due to the radiant energy of infrared rays cannot be ignored with respect to the change in the ambient temperature. There is a problem that the error becomes large.

The present invention has been made in view of the above problems, and an object thereof is to provide a radiation thermometer capable of independently and accurately measuring the surface temperature and the ambient temperature of an object to be measured with a simple structure. To do.

[0007]

In order to achieve the above object, the invention of claim 1 is a thermal resistance whose resistance value changes in response to radiant energy of infrared rays radiated from an object to be measured and ambient temperature. The body, the first and second reference heat-sensitive resistors having substantially the same resistance temperature characteristics as the heat-sensitive resistor and sensitive only to the ambient temperature, and the fixed resistance, and the heat-sensitive resistor and the first reference heat-sensitive resistor. A power source is connected to a sensor unit formed by connecting a series circuit of the body and a series circuit of a second reference thermal resistor and a fixed resistor in parallel to each other, and the thermal resistor and the first reference thermal resistor are connected to each other. The output according to the radiant energy of infrared rays is taken out from the connection point of, and the output according to the ambient temperature is taken out from the connection point of the second reference thermosensitive resistor and the fixed resistor.

According to a second aspect of the present invention, a heat-sensitive resistor whose resistance value changes in response to radiant energy of infrared rays radiated from an object to be measured and ambient temperature, and a resistance temperature characteristic which is substantially the same as that of the heat-sensitive resistor. First and second reference thermosensitive resistors having sensitivity only to ambient temperature are formed on the surface of the semiconductor substrate, and the semiconductor substrate under each resistor is removed to thermally separate the resistors from the semiconductor substrate. A heat separation space is provided to connect the thermosensitive resistor and the first reference thermosensitive resistor in series, and also connect the second reference thermosensitive resistor and fixed resistor in series to connect the two series circuits in parallel. A power source is connected to the sensor unit formed by, and an output corresponding to the radiant energy of infrared rays is taken out from the connection point between the thermal resistor and the first reference thermal resistor, and the second reference thermal resistor and the fixed resistor are connected. Output from the connection point according to the ambient temperature It is characterized in.

According to a third aspect of the present invention, a heat sensitive resistor whose resistance value changes in response to radiant energy of infrared rays radiated from an object to be measured and ambient temperature, and a resistance temperature characteristic which is substantially the same as that of the heat sensitive resistor. First and second reference thermosensitive resistors having sensitivity only to ambient temperature and a fixed resistor are formed on the surface of the semiconductor substrate, and the semiconductor substrate under each resistor is removed to form each resistor and the semiconductor substrate. A heat separation space for thermally separating the two is connected, the heat-sensitive resistor and the first reference heat-sensitive resistor are connected in series, and the second reference heat-sensitive resistor and the fixed resistor are connected in series. A power source is connected to a sensor section formed by connecting in parallel with each other, and an output corresponding to the radiant energy of infrared rays is taken out from a connection point between the heat-sensitive resistor and the first reference heat-sensitive resistor, and a second reference heat-sensitive resistor. According to the ambient temperature from the connection point between Wherein the taking out force.

The invention of claim 4 is the first to third aspects of the invention.
In the invention described above, an infrared reflection film for blocking infrared rays is formed on the surfaces of the first and second reference thermosensitive resistors.

[0011]

According to the structure of the invention of claim 1, the heat sensitive resistor whose resistance value changes in response to the radiant energy of infrared rays radiated from the object to be measured and the ambient temperature, and the resistance temperature substantially the same as the heat sensitive resistor. First and second that have characteristics and are sensitive only to ambient temperature
Of the reference thermosensitive resistor and a fixed resistor, and a series circuit of the thermosensitive resistor and the first reference thermosensitive resistor and a series circuit of the second reference thermosensitive resistor and the fixed resistor are connected in parallel to each other. A power source is connected to the sensor unit formed by, and an output corresponding to the radiant energy of infrared rays is taken out from the connection point between the thermal resistor and the first reference thermal resistor, and the second reference thermal resistor and the fixed resistor are connected. Since the output according to the ambient temperature is extracted from the connection point of, the output extracted from the connection point of the thermal resistor and the first reference thermal resistor and the connection point of the second reference thermal resistor and the fixed resistor The surface temperature of the measured object can be measured in a non-contact manner by the output taken out, and the surface temperature of the measured object can be measured by the output taken out from the connection point between the second reference thermal resistor and the fixed resistor. Independent of measurement, the ambient temperature is measured without contact. Those which can often be measured.

According to the second aspect of the invention, the heat sensitive resistor whose resistance value changes in response to the radiant energy of infrared rays radiated from the object to be measured and the ambient temperature, and a resistance temperature substantially the same as the heat sensitive resistor. Forming on the surface of the semiconductor substrate first and second reference thermosensitive resistors having characteristics and being sensitive only to ambient temperature;
The semiconductor substrate under each resistor is removed to provide a thermal separation space for thermally separating each resistor and the semiconductor substrate, and the thermal resistor and the first reference thermal resistor are connected in series and the second thermal resistor is connected.
From the connection point between the thermosensitive resistor and the first reference thermosensitive resistor, the power source is connected to the sensor unit formed by connecting the reference thermosensitive resistor and the fixed resistor in series and connecting the two series circuits in parallel. In addition to taking out the output according to the radiant energy of infrared rays, taking out the output according to the ambient temperature from the connection point between the second reference thermosensitive resistor and the fixed resistor, the surface temperature and the ambient temperature of the object to be measured are independent. It is possible to perform non-contact and accurate measurement, and since the heat sensitive resistor and the first and second reference heat sensitive resistors are formed on the surface of the semiconductor substrate to form the sensor unit, substantially the same. Each of the resistors having resistance temperature characteristics can be formed inexpensively and in a small size, and the sensor portion can be downsized.

According to the third aspect of the invention, the heat sensitive resistor whose resistance value changes in response to the radiant energy of infrared rays radiated from the object to be measured and the ambient temperature, and the resistance temperature substantially the same as the heat sensitive resistor. First and second reference thermosensitive resistors that have characteristics and are sensitive only to ambient temperature, and fixed resistors are formed on the surface of the semiconductor substrate, and the semiconductor substrate below each resistor is removed to form each resistor. Providing a heat separation space for thermally separating the semiconductor substrate,
A power source is connected to a sensor unit formed by connecting a thermosensitive resistor and a first reference thermosensitive resistor in series, connecting a second reference thermosensitive resistor and a fixed resistor in series, and connecting the above two series circuits in parallel. And outputs an output corresponding to the radiant energy of infrared rays from the connection point between the heat-sensitive resistor and the first reference heat-sensitive resistor, and according to the ambient temperature from the connection point between the second reference heat-sensitive resistor and the fixed resistor. Since the output is taken out and the temperature of the object to be measured and the ambient temperature are measured, the surface temperature and the ambient temperature of the object to be measured can be independently and accurately measured without contact,
In addition, since the thermosensitive resistor, the first and second reference thermosensitive resistors, and the fixed resistor are formed on the surface of the semiconductor substrate to form the sensor portion, each of the resistors having substantially the same resistance temperature characteristic. Since the fixed resistance and the fixed resistance can be formed inexpensively and small, the sensor part can be downsized, and since the fixed resistance is formed on the surface of the semiconductor substrate, the radiation thermometer itself can be downsized. is there.

In the configuration of the invention of claim 4, the first and second aspects are provided.
Since the infrared reflective film for shielding infrared rays is formed on the surface of the reference thermosensitive resistor, the infrared rays incident on the reference thermosensitive resistor can be shielded with a simple structure.

[0015]

【Example】

(Embodiment 1) A schematic circuit configuration diagram of this embodiment is shown in FIG.
As shown in FIG. 1, the radiation thermometer of this embodiment includes two DC power supplies 1a and 1b having the same power supply voltage, a sensor unit 2 for detecting the surface temperature and the ambient temperature of an object to be measured, and a sensor unit 2.
The first amplifier 3 that amplifies one output voltage Vr and the second amplifier 4 that amplifies the other output voltage Ve of the sensor unit 2. And two DC power supplies 1a,
1b is connected in series, and its connection point is grounded. Further, the output voltage of the sensor unit 2 is both input to the inverting input terminals of the first and second amplifiers 3 and 4, and
And the non-inverting input terminals of the second amplifiers 3 and 4 are both grounded.

Further, the sensor section 2 is composed of a heat sensitive resistor 5 such as a thermistor whose resistance value changes in response to the radiant energy of infrared rays radiated from the object to be measured and the ambient temperature, and the heat sensitive resistor 5 are substantially the same. The first and second reference thermosensitive resistors 6 and 7 having the same resistance temperature characteristic and sensitive only to the ambient temperature, and the fixed resistor 8 are provided, and the thermosensitive resistor 5 and the first reference thermosensitive resistor 6 are provided. And a series circuit of the second reference thermosensitive resistor 7 and the fixed resistor 8 are connected in parallel.
The output voltage Vr is taken out from the connection point a between the thermosensitive resistor 5 and the first reference thermosensitive resistor 6, and the output voltage Ve is taken out from the connection point b between the second reference thermosensitive resistor 7 and the fixed resistor 8. There is.

In the above configuration, the infrared ray radiated from the object to be measured is incident on the thermal resistance element 5 so that the thermal resistance element 5 can be obtained.
Since the resistance value of the thermosensitive resistor 5 changes in accordance with the temperature change of, the output voltage Vr extracted from the connection point a depends on the radiant energy of infrared rays, and the second reference thermosensitive resistor depending on the ambient temperature. Since the resistance value of the second reference thermosensitive resistor 7 changes according to the temperature change of 7, the output voltage Ve taken out from the connection point b becomes according to the ambient temperature. Therefore, the ambient temperature can be measured by the output voltage Ve, and the amount of radiant energy of infrared rays incident on the heat-sensitive resistor 5 obtained from the output voltage Ve and the output voltage Vr can be used to measure the ambient temperature using the Stefan-Boltzmann law. The surface temperature of the measured object can be measured.

Next, a specific method of measuring the surface temperature and the ambient temperature of the object to be measured will be described. Here, the thermosensitive resistor 5 and the first and second reference thermosensitive resistors 6 and 7 are composed of thermistors having substantially the same resistance temperature characteristics, and the DC power source 1
The power supply voltage of a and 1b is V, the resistance value of the thermosensitive resistor 5 when the ambient temperature is T ₁ is R ₁ , the resistance value of the fixed resistor 8 is Rf,
The resistance change rate of the thermistor is B. Further, when the ambient temperature is Te, a certain amount of infrared rays are incident on the heat sensitive resistor 5, and the output voltages at the connection point a and the connection point b are respectively V.
It is assumed that they are r and Ve.

At this time, the resistance value Re of the second reference thermosensitive resistor 7 is expressed by the following equation by the output voltage Ve at the connection point b. Re = Rf (V−Ve) / (V + Ve) (Equation 1) Since the second reference thermal resistor 7 is sensitive only to the ambient temperature and not to the radiant energy of infrared rays, the ambient temperature Te is It is represented by a formula.

Te = 1 / (1 / T ₁ −ln (R ₁ / Re) / B) (Equation 2) ∵B = ln (R ₁ / Re) / (1 / T ₁ −1 / Te ) Therefore, the ambient temperature Te can be measured by the equations 1 and 2, and since the equations 1 and 2 do not include the term relating to the radiant energy of infrared rays, the ambient temperature Te can be measured. It is possible to measure accurately independently of the surface temperature.

On the other hand, assuming that the resistance value of the thermosensitive resistor 5 under the same conditions is Rr and the resistance value Re of the first reference thermosensitive resistor 6 is Re, the resistance value Rr of the thermosensitive resistor 5 is the output voltage V of the connection point a.
It is represented by the following equation by r. Rr = Re (V-Vr) / (V + Vr) (Equation 3) Therefore, the temperature change Tr of the thermal resistor 5 due to the radiant energy of infrared rays can be expressed by the following equation in the same manner as in Equation 2. .

Tr = 1 / (1 / T ₁ −ln (R ₁ / Rr) / B) (Equation 4) where Δt is the temperature change of the thermistor per unit amount of radiant energy of infrared rays. The amount of radiant energy Pr of infrared rays incident on the heat-sensitive resistor 5 is expressed as Pr = (Tr−Te) / Δt (Equation 5). Therefore, the surface temperature of the object to be measured can be measured from this radiant energy amount Pr according to the Stefan-Boltzmann law.

(Embodiment 2) In this embodiment, in the sensor section 2 of the radiation thermometer of Embodiment 1, the resistors 5 to 7 other than the fixed resistor 8 are formed on the surface of the semiconductor substrate.
Therefore, other configurations and operations are the same as those in the first embodiment, and the description thereof will be omitted. FIG. 2 shows a plan view and a side view of the sensor unit 2 (excluding the fixed resistor 8) of the radiation thermometer of this embodiment. As shown in FIG. 2, the insulating thin film 10 is formed on the surface of the semiconductor substrate 9, and the sensitive resistor 5 and the first and second reference thermosensitive resistors 6 and 7 are formed on the insulating thin film 2.

The resistors 5 to 7 are formed of amorphous silicon, polycrystalline silicon, or amorphous silicon by using a thin film forming technique or a fine processing technique similar to the semiconductor process in the usual IC circuit production. A thin film resistor thermistor made of silicon carbide and a plurality of electrodes formed on the surface of the thermistor. Further, an infrared absorbing film 12 is formed on the surface of the heat sensitive resistor 5, and an infrared reflecting film 11 is formed on the surfaces of the first and second reference sensitive resistors 6 and 7 so as not to be sensitive to infrared radiation energy. Has been done. The infrared reflective film 11 is preferably made of a semiconductor process, such as aluminum or chrome, but may be formed by any other method.

The insulating thin film 10 is made of a material having a small thermal conductivity and suitable for a semiconductor process.
It is composed of a silicon oxide film, a silicon nitride film, or a multilayer film thereof. Then, as shown in FIG. 2B, the semiconductor substrate 9 below the heat sensitive resistor 5 is removed by a method such as etching to thermally separate the heat sensitive resistor 5 and the semiconductor substrate 9 from each other. Is provided. Therefore, the thermal separation space 13 thermally separates the heat sensitive resistor 5 and the semiconductor substrate 9 from each other, so that the temperature rise of the heat sensitive resistor 5 due to the radiant energy of infrared rays increases, and the sensitivity of the heat sensitive resistor 5 is increased. Can be improved. Further, by removing the semiconductor substrate 9 below the first and second reference thermosensitive resistors 6 and 7 by a method such as etching,
The resistance temperature characteristics of the heat sensitive resistor 5 are made to be substantially the same.

As described above, by forming the thermosensitive resistor 5 and the first and second reference thermosensitive resistors 6 and 7 on the surface of the semiconductor substrate 9, the resistor 5 having substantially the same resistance temperature characteristic. It is possible to manufacture the sensor unit 2 including the elements 7 to 7 at low cost, and since the sensor unit 2 excluding the fixed resistor 8 can be configured by a semiconductor chip, the radiation thermometer itself can be downsized.

(Embodiment 3) In this embodiment, as shown in FIG. 3, the thermosensitive resistor 5 and the first and second reference thermosensitive resistors 6 and 7 are mounted on the semiconductor substrate 9 as in the second embodiment. By forming the fixed resistor 8 on the surface and the fixed resistor 8 on the surface of the same semiconductor substrate 9, the sensor portion 2 is configured by a semiconductor chip, and thereby the radiation thermometer can be downsized. . In this embodiment, the first and second reference thermosensitive resistors 6 and 7 have different shapes from those of the second embodiment in order to make the sensor unit 2 smaller. If the resistance temperature characteristics of the reference thermosensitive resistors 6 and 7 and the thermosensitive resistor 5 are substantially the same, the resistors 5 to 7 may be formed in any shape.

[0028]

According to the invention of claim 1, a heat-sensitive resistor whose resistance value changes in response to radiant energy of infrared rays radiated from an object to be measured and ambient temperature, and a resistance temperature substantially the same as that of the heat-sensitive resistor. A first and a second reference thermosensitive resistors that have characteristics and are sensitive only to the ambient temperature, and a fixed resistor, a series circuit of the thermosensitive resistor and the first reference thermosensitive resistor, and a second reference thermosensitive resistor. A power source is connected to a sensor unit formed by connecting a series circuit of a resistor and a fixed resistor in parallel to each other, and an output corresponding to radiant energy of infrared rays is output from a connection point between the thermosensitive resistor and the first reference thermosensitive resistor. And the output according to the ambient temperature is taken out from the connection point between the second reference thermosensitive resistor and the fixed resistor, the output taken out from the connection point between the thermosensitive resistor and the first reference thermosensitive resistor, Taken from the connection point between the second reference thermal resistor and the fixed resistor. The surface temperature of the object to be measured can be measured in a non-contact manner by the output, and the surface temperature of the object to be measured can be determined by the output taken from the connection point between the second reference thermosensitive resistor and the fixed resistor. Since the ambient temperature can be measured in a contactless manner independently of the measurement, there is an effect that the surface temperature of the object to be measured and the ambient temperature can be accurately measured with a simple configuration.

According to a second aspect of the present invention, a heat-sensitive resistor whose resistance value changes in response to radiant energy of infrared rays radiated from an object to be measured and ambient temperature, and resistance temperature characteristics which are substantially the same as those of the heat-sensitive resistor. First and second reference thermosensitive resistors having sensitivity only to ambient temperature are formed on the surface of the semiconductor substrate, and the semiconductor substrate under each resistor is removed to thermally separate the resistors from the semiconductor substrate. A heat separation space is provided to connect the thermosensitive resistor and the first reference thermosensitive resistor in series, and also connect the second reference thermosensitive resistor and fixed resistor in series to connect the two series circuits in parallel. Then, a power source is connected to the sensor unit formed by connecting the above two series circuits in parallel, and an output corresponding to the radiant energy of infrared rays is taken out from the connection point between the heat sensitive resistor and the first reference heat sensitive resistor. Connection point between the standard thermal resistor of 2 and the fixed resistor Since the output corresponding to the ambient temperature is taken out, it is possible to measure the surface temperature and the ambient temperature of the DUT independently and in a non-contact manner. There is an effect that the measurement can be performed accurately. Moreover, since the sensor portion is formed by forming the thermosensitive resistor and the first and second reference thermosensitive resistors on the surface of the semiconductor substrate, the above-mentioned resistors having substantially the same resistance temperature characteristics can be inexpensively manufactured. In addition, it is possible to form the sensor unit in a small size, and the size of the sensor unit can be reduced. Further, by thermally separating each resistor and the semiconductor substrate in the heat separation space, there is an effect that the heat insulating effect can be enhanced and the measurement accuracy can be improved.

According to a third aspect of the present invention, a heat-sensitive resistor whose resistance value changes in response to the radiant energy of infrared rays radiated from an object to be measured and the ambient temperature, and a resistance temperature characteristic which is substantially the same as that of the heat-sensitive resistor. First and second reference thermosensitive resistors having sensitivity only to ambient temperature and a fixed resistor are formed on the surface of the semiconductor substrate, and the semiconductor substrate under each resistor is removed to form each resistor and the semiconductor substrate. A heat separation space for thermally separating the two is connected, the heat-sensitive resistor and the first reference heat-sensitive resistor are connected in series, and the second reference heat-sensitive resistor and the fixed resistor are connected in series. A power source is connected to a sensor section formed by connecting in parallel with each other, and an output corresponding to the radiant energy of infrared rays is taken out from a connection point between the heat-sensitive resistor and the first reference heat-sensitive resistor to obtain a second reference heat-sensitive resistor. Take the output according to the ambient temperature from the connection point with the fixed resistor. Since the temperature of the DUT is measured and the ambient temperature is measured, the surface temperature and the ambient temperature of the DUT can be independently measured in a non-contact manner. There is an effect that can be accurately measured with a simple configuration. Moreover, since the sensor portion is formed by forming the thermosensitive resistor, the first and second reference thermosensitive resistors, and the fixed resistor on the surface of the semiconductor substrate, not only can the sensor portion be downsized, but also the radiation thermometer. There is an effect that the size of the device itself can be reduced.

According to the fourth aspect of the present invention, since the infrared reflecting film for blocking infrared rays is formed on the surfaces of the first and second reference thermosensitive resistors, the infrared rays incident on the reference thermosensitive resistor can be made simple. With the configuration, it is possible to shield light, and it is possible to simplify the configuration of the sensor unit and to reduce the size of the sensor unit.

[Brief description of drawings]

FIG. 1 is a schematic circuit configuration diagram showing a first embodiment.

FIG. 2 illustrates a sensor unit according to a second embodiment, which includes (a)
Is a plan view and (b) is a side view.

FIG. 3 illustrates a sensor unit according to a third embodiment (a).
Is a plan view and (b) is a side view.

FIG. 4 is a schematic block diagram showing a conventional example.

FIG. 5 is a schematic circuit configuration diagram showing another conventional example.

[Explanation of symbols]

 1a, 1b DC power supply 2 Sensor section 3 First amplifier 4 Second amplifier 5 Thermal resistor 6 First reference thermal resistor 7 Second reference thermal resistor 8 Fixed resistance

Claims (4)

[Claims] 1. A heat-sensitive resistor whose resistance value changes in response to radiant energy of infrared rays radiated from an object to be measured and ambient temperature, and a resistance temperature characteristic which is substantially the same as that of the heat-sensitive resistor and has only an ambient temperature. First and second reference thermal resistors sensitive to
A power supply is provided to a sensor unit that includes a fixed resistor and that is formed by connecting a series circuit of a thermosensitive resistor and a first reference thermosensitive resistor and a series circuit of a second reference thermosensitive resistor and a fixed resistor in parallel to each other. Is connected to extract the output corresponding to the radiant energy of infrared rays from the connection point between the heat-sensitive resistor and the first reference heat-sensitive resistor, and from the connection point between the second reference heat-sensitive resistor and the fixed resistor to the ambient temperature. A radiation thermometer, which is characterized by taking out an output corresponding to it. 2. A heat-sensitive resistor whose resistance value changes in response to radiant energy of infrared rays radiated from an object to be measured and ambient temperature, and has substantially the same resistance temperature characteristic as that of the heat-sensitive resistor and has only ambient temperature. A first and a second reference thermosensitive resistor which are sensitive to the above, are formed on the surface of the semiconductor substrate, and the semiconductor substrate under each resistor is removed to form a thermal separation space for thermally separating each resistor and the semiconductor substrate. A sensor unit provided by connecting the thermosensitive resistor and the first reference thermosensitive resistor in series, connecting the second reference thermosensitive resistor and the fixed resistor in series, and connecting the two series circuits in parallel. The power source is connected to, and the output corresponding to the radiant energy of the infrared rays is taken out from the connection point between the heat-sensitive resistor and the first reference heat-sensitive resistor, and the surroundings from the connection point between the second reference heat-sensitive resistor and the fixed resistor. Characterized by taking out the output according to the temperature Radiation thermometer. 3. A heat-sensitive resistor whose resistance value changes in response to radiant energy of infrared rays radiated from an object to be measured and ambient temperature, and has substantially the same resistance temperature characteristic as the heat-sensitive resistor and has only ambient temperature. First and second reference thermal resistors sensitive to
A fixed resistor is formed on the surface of the semiconductor substrate, and the semiconductor substrate under each resistor is removed to provide a heat separation space for thermally separating each resistor from the semiconductor substrate. A resistor is connected in series, a second reference thermosensitive resistor and a fixed resistor are connected in series, and a power source is connected to a sensor unit formed by connecting the above two series circuits in parallel. The output corresponding to the radiant energy of infrared rays is taken out from the connection point with the first reference thermal resistor and the output according to the ambient temperature is taken out from the connection point between the second reference thermal resistor and the fixed resistor. Radiation thermometer. 4. The radiation thermometer according to claim 1, wherein an infrared reflecting film for blocking infrared rays is formed on the surfaces of the first and second reference thermosensitive resistors.