Sensor element, bridge circuit, detector, and detection system

Abstract

To provide a sensor element, a bridge circuit, a detector, and a detection system that achieve quick and highly accurate detection of energy with a simple structure.SOLUTION: A sensor element has, on the principal plane of a substrate, a film-like resistive element and a film-like heater element which are electrically insulated from each other. A bridge circuit includes a first circuit unit in which the resistive element of the sensor element and a first resistor whose resistance value is equal thereto are connected in series, and a second circuit unit in which a reference resistive element included in a reference element which is equivalent to the sensor element and a second resistor whose resistance value is equal to the reference resistive element are connected in series. The first circuit unit and the second circuit unit are connected in parallel. The bridge circuit has a differential amplifier whose negative terminal is connected between the resistive element and the first resistor, positive terminal is connected between the reference resistive element and the second resistor, and output terminal is connected to one terminal of the heater element. The detection system performs feedback control so that the temperature of the resistive element is always constant.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to sensor elements, bridge circuits, detectors and detection systems for measuring the energy of radiation such as visible light and infrared light. [Background technology]

[0002] Conventionally, detectors that detect energy such as light have been known (see, for example, Patent Document 1). Patent Document 1 discloses a detector in which a temperature-sensing element is provided on one surface of a light-receiving plate, and a heater element is provided on the other surface. Such a conventional detector is configured to heat the light-receiving plate separately with light and the heater element, and derive the light energy from the power of the heater element when the temperatures measured by the temperature-sensing elements become equal to each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 3-107732 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the energy detector of Patent Document 1, the difference between the temperature gradient of the temperature sensor when irradiated with light or the like and the temperature gradient of the temperature sensor when current is passed through the heater element becomes large, so it is necessary to secure time to balance the two. Also, in the conventional configuration in which a light receiving plate is interposed between the heater element or the light irradiation surface and the temperature sensor, the heat conduction to the temperature sensor is hindered, which causes a problem of reduced detection accuracy.

[0005] The present invention has been made to solve the above-mentioned problems, and has an object to provide a sensor element, a bridge circuit, a detector, and a detection system that have a simple structure and can achieve rapid and highly accurate detection of energy. [Means for solving the problem]

[0006] A sensor element according to one embodiment of the present invention has an insulating substrate, a film-like resistor element formed on one surface of the substrate, and a film-like heater element formed on one surface of the substrate and electrically insulated from the resistor element.

[0007] A bridge circuit according to one embodiment of the present invention includes a first circuit section in which a resistive element provided in the sensor element and a first resistor having a resistance value equal to that of the resistive element are connected in series, and a second circuit section in which a reference resistive element provided in a reference element configured equivalent to the sensor element and a second resistor having a resistance value equal to that of the reference resistive element are connected in series, the first circuit section and the second circuit section being connected in parallel, and the bridge circuit further includes a differential amplifier having a negative terminal connected between the resistive element and the first resistor, a positive terminal connected between the reference resistive element and the second resistor, and an output terminal connected to one end of the heater element.

[0008] A detector according to one embodiment of the present invention has a cylindrical main body, a cover attached to one end of the main body and having an entrance hole in the center for the incidence of light, a detection section attached to the other end of the main body and having the above-mentioned sensor element disposed at a position where light entering through the entrance hole is irradiated, and a reference section attached to the detection section and including a reference element configured equivalently to the sensor element.

[0009] A detection system according to one embodiment of the present invention includes the above-mentioned sensor element and a management device that controls the temperature of the resistance element in the sensor element to be constant when light is not irradiated onto the sensor element and when light is irradiated onto the sensor element. A detection system according to one aspect of the present invention includes the above-mentioned bridge circuit, and a management device that determines the non-irradiated power, which is the power of the heater element, from the voltage across the heater element and the output current of the differential amplifier when no light is irradiated onto the sensor element, and determines the irradiated power, which is the power of the heater element, from the voltage across the heater element and the output current of the differential amplifier when light is irradiated onto the sensor element, and determines the energy of light irradiated to the sensor element from the difference between the non-irradiated power and the irradiated power.

[0010] A detection system according to one embodiment of the present invention includes the above-mentioned detector, a first resistor connected in series with the resistive element and having a resistance value equal to that of the resistive element, a second resistor connected in series with a reference resistive element provided in the reference element and having a resistance value equal to that of the reference resistive element, a differential amplifier having a negative terminal connected between the resistive element and the first resistor, a positive terminal connected between the reference resistive element and the second resistor, and an output terminal connected to one end of the heater element, and a management device that, when the entrance hole is closed, determines the non-irradiated power, which is the power of the heater element, from the voltage across the heater element and the output current of the differential amplifier, and, when the entrance hole is open, determines the irradiated power, which is the power of the heater element, from the voltage across the heater element and the output current of the differential amplifier, and determines the energy of light irradiated to the sensor element from the difference between the non-irradiated power and the irradiated power. Effect of the Invention

[0011] In the present invention, a resistance element and a heater element are formed on the same surface of a substrate, and since no substrate is interposed between the resistance element and the heater element, thermal conduction from the heater element to the resistance element is promoted, thereby enabling rapid and highly accurate detection of energy to be achieved with a simple structure. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic diagram illustrating an example of an overall configuration of a detection unit according to a first embodiment of the present invention. [Diagram 2] 2 is a configuration diagram illustrating a bridge circuit included in the detection unit of FIG. 1 and its peripheral configuration. [Diagram 3] FIG. 2 is an explanatory diagram for explaining each component of the detector in FIG. [Figure 4] FIG. 2 is a plan view showing an example of a sensor element according to the first embodiment of the present invention. [Diagram 5] 5 is a schematic cross-sectional view illustrating a cross section taken along line AA in FIG. 4. [Figure 6] 5 is a flowchart illustrating a flow of an energy detection operation performed by the detection unit according to the first embodiment of the present invention. [Figure 7] 1 is a plan view illustrating a sensor element according to a first modified example of the first embodiment of the present invention. FIG. [Figure 8] 10 is a plan view illustrating a sensor element according to a second modification of the first embodiment of the present invention. FIG. [Figure 9] 9 is an explanatory diagram illustrating the connection relationship between each terminal on the board of FIG. 8 and a lead wire. [Figure 10] FIG. 11 is a plan view showing an example of a sensor element according to a third modification of the first embodiment of the present invention. [Figure 11] FIG. 11 is a plan view showing another example of the sensor element according to the third modification of the first embodiment of the present invention. [Figure 12] FIG. 12 is a bottom view of the sensor element of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Embodiment 1 A configuration example of a sensor element 10 and a detection system 100 according to a first embodiment of the present invention will be described with reference to Figs. 1 to 5. In each drawing, some reference numerals may be omitted to avoid cluttering the drawings. First, an example of the overall configuration of the detection system 100 will be described with reference to Figs. 1 to 5.

[0014] As shown in Fig. 1, the detection system 100 includes a detector 30 equipped with a sensor element 10, an amplification processing unit 40, and a control unit 60. The detector 30 includes a cylindrical main body 31, a lid 32 attached to one end of the main body 31, a detection unit 34 attached to the other end of the main body 31, and a reference unit 36 ​​attached to the detection unit 34. The insides of the main body 31 and the lid 32 are black. The lid 32 has an entrance hole 32h for the entrance of light at its center. The detector 30 also includes an opening / closing mechanism 38 for opening and closing the entrance hole 32h.

[0015] Inside the main body 31, two baffles 31n formed in a funnel shape are provided. Each baffle 31n is fixed to the main body 31 with a screw or the like. Each baffle 31n of the main body 31 has a light control hole 31h at the center, which allows light to pass through. The light control hole 31h of the baffle 31n on the cover 32 side is smaller than the entrance hole 32h, and is larger than the light control hole 31h of the baffle 31n on the detection unit 34 side. The detection unit 34 has the sensor element 10 disposed at a position where the light entering through the entrance hole 32h is irradiated. The detection unit 34 has a diaphragm portion 34g disposed on the entrance hole 32h side of the sensor element 10, and an aperture 34h is formed in the center of the diaphragm portion 34g. That is, the light entering through the entrance hole 32h (incident light hν) passes through the two light control holes 31h and the aperture 34h and is irradiated to the sensor element 10.

[0016] The reference section 36 includes a reference element 20 configured in the same manner as the sensor element 10. The reference element 20 is for eliminating data disturbances caused by external factors such as fluctuations in outside air temperature, and is configured in the same manner as the sensor element 10. The opening / closing mechanism section 38 has a motor 38a, for example a stepping motor, and a shutter blade 38b arranged to enable blocking of the entrance hole 32h. The operation of the motor 38a is controlled by a control unit 60.

[0017] The amplification processing unit 40 includes a power supply device 55 and a differential amplifier (differential amplifier) ​​50. The power supply device 55 is configured, for example, by a DC stabilized power supply, and supplies power to a bridge circuit B described later. However, when the detector 30 is used in an environment where condensation occurs due to high temperature and humidity, measures against electrolytic corrosion of the sensor element 10 are required, so that the power supply device 55 should preferably be an AC stabilized power supply that outputs a sine wave, triangular wave, or rectangular wave with a symmetrical waveform.

[0018] The control unit 60 has a management device 70, an ammeter 71, a voltmeter 72, and a motor driver 75. The management device 70 is configured with a PC (Personal Computer) or the like, and calculates energy E based on a current value (Ia, Ib) measured by the ammeter 71 and a voltage value (Va, Vb) measured by the voltmeter 72. The PC includes a tablet PC, a notebook PC, a desktop PC, and the like. The ammeter 71 is, for example, a digital ammeter, and measures a current output from the differential amplifier 50 to the heater element 12. The voltmeter 72 is, for example, a digital voltmeter, and measures a voltage across the heater element 12. The motor driver 75 is, for example, a dedicated IC (integrated circuit) for controlling the motor 38a. However, the control unit 60 may be configured not to have the motor driver 75, and the management device 70 may directly control the motor 38a.

[0019] The differential amplifier 50 is configured by, for example, an operational amplifier or a power operational amplifier, and is connected to an external power supply (not shown). As shown in FIG. 2, the differential amplifier 50 amplifies the potential difference between the negative terminal 50a and the positive terminal 50b (the difference between the potential of the negative terminal 50a and the potential of the positive terminal 50b) and outputs it from the output terminal 50c. The output terminal 50c of the differential amplifier 50 is connected to the heater element 12, and controls the current flowing through the heater element 12. The differential amplifier 50 operates so that the potential difference (terminal voltage) between the negative terminal 50a and the positive terminal 50b becomes 0 [V]. More specifically, the differential amplifier 50 adjusts the temperature of the resistance element 11 to be always constant by feedback control that outputs a current based on the terminal voltage to the heater element 12 so that the bridge circuit B is always in a balanced state. That is, the detection system 100 controls the temperature of the resistance element 11 to be always constant through the heat generated by the heater element 12 by a feedback system of the bridge circuit B including the resistance element 11. The sensor element 10 has good thermal conductivity so that the entire temperature converges to a constant temperature.

[0020] The detection system 100 has a bridge circuit B including a first circuit section 18 and a second circuit section 28. The first circuit section 18 is a circuit in which a resistive element 11 provided in the sensor element 10 and a first resistor 35 having the same resistance value as the resistive element 11 are connected in series. The second circuit section 28 is a circuit in which a reference resistive element 21 provided in a reference element 20 configured in the same manner as the sensor element 10 and a second resistor 37 having the same resistance value as the reference resistive element 21 are connected in series. Furthermore, the bridge circuit B has a differential amplifier 50 having a negative terminal 50a, a positive terminal 50b, and an output terminal 50c. The negative terminal 50a is connected between the resistive element 11 and the first resistor 35. The positive terminal 50b is connected between the reference resistive element 21 and the second resistor 37. The output terminal 50c is connected to one end of the heater element 12. In the bridge circuit B, the first circuit section 18 and the second circuit section 28 are connected in parallel. That is, the bridge circuit B constitutes a so-called Wheatstone bridge circuit by the above-mentioned components and the conductors connecting them.

[0021] In FIG. 2, the negative terminal 50a of the differential amplifier 50 is connected to a first terminal 1t between the resistor element 11 and the first resistor 35 through an input resistor 51. The positive terminal 50b of the differential amplifier 50 is connected to a second terminal 2t between the reference resistor element 21 and the second resistor 37 through an input resistor 52. A power supply device 55 is connected to a third terminal 3t between the resistor element 11 and the reference resistor element 21, and a GND is connected to a fourth terminal 4t between the first resistor 35 and the second resistor 37. An output terminal 50c is connected to a fifth terminal 5t corresponding to one end of the heater element 12 through an ammeter 71. A voltmeter 72 is connected between the fifth terminal 5t and a sixth terminal 6t corresponding to the other end of the heater element 12.

[0022] The reference element 20 has a reference substrate (not shown) having a configuration equivalent to that of the substrate 15 described later, a film-like reference resistance element 21 having a configuration equivalent to that of the resistance element 11 and formed on one surface of the reference substrate, and a film-like reference heater element 22 having a configuration equivalent to that of the heater element 12 and formed on one surface of the reference substrate. The reference heater element 22 is provided to make the sensor element 10 and the reference element 20 thermally equivalent, and is not electrically conductive. The reference element 20 is covered with a dark box 36x to block out external light, and is light-shielded.

[0023] As shown in the functional block diagram of FIG. 2, the management device 70 has a communication unit 70a, a control unit 70b, and a storage unit 70c. The communication unit 70a is an interface for the control unit 70b to communicate with an external device by wire or wirelessly. The storage unit 70c stores various information in addition to the operation program of the control unit 70b. The storage unit 70c is configured by a RAM (Random Access Memory), a ROM (Read Only Memory), a PROM (Programmable ROM) such as a flash memory, an SSD (Solid State Drive), or an HDD (Hard Disk Drive).

[0024] The management device 70 may have an input unit 70d and a display unit 70e as shown in FIG. 2. The input unit 70d includes, for example, a keyboard and a pointing device such as a mouse or a trackball. The input unit 70d receives an input operation by a user and transmits an operation signal corresponding to the received content to the control unit 70b. The display unit 70e includes, for example, a liquid crystal display (LCD) and displays various information according to an instruction from the control unit 70b. Instead of the input unit 70d and the display unit 70e, the management device 70 may have a touch panel including a display panel that displays characters or images, and a detection means that is stacked on the display panel and detects a touch operation. The management device 70 may have both a touch panel and the input unit 70d.

[0025] The control unit 70b determines the energy E of the incident light hν from the entrance hole 32h. The control unit 70b determines the non-irradiated power Pa, which is the power of the heater element 12, from the voltage across the heater element 12 and the output current of the differential amplifier 50 when the sensor element 10 is not irradiated with light. The control unit 70b also determines the irradiated power Pb, which is the power of the heater element 12, from the voltage across the heater element 12 and the output current of the differential amplifier 50 when the sensor element 10 is irradiated with light. The control unit 70b then determines the energy E of the light irradiated to the sensor element 10 from the difference between the non-irradiated power Pa and the irradiated power Pb.

[0026] In the detection system 100 of the first embodiment, the heater element 10 is constantly energized. That is, the differential amplifier 50 is configured to output a current to the heater element 12 not only when the sensor element 10 is not irradiated with light, but also when the sensor element 10 is irradiated with light. This can improve the stability of the process related to the calculation of the energy E.

[0027] 3, the detection unit 34 has a peripheral wall portion 34a, a bottom portion (back plate) 34b fixed to the peripheral wall portion 34a, a cup holder 34c fixed to the center of the bottom portion 34b, and a cup 34d fixed to the cup holder 34c. The cup 34d is thin and made of a material such as silver or copper, and the sensor element 10 is attached to the center of the cup 34d. The detection unit 34 also has a throttling portion 34g arranged such that an aperture 34h faces the sensor element 10, and a support portion 34e that supports the throttling portion 34g. The detection unit 34 has an end portion of the peripheral wall portion 34a opposite to the bottom portion 34b connected to the main body portion 31.

[0028] The reference unit 36 ​​has a peripheral wall 36a, a bottom (back plate) 36b fixed to the peripheral wall 36a, a cup holder 36c fixed to the center of the bottom 36b, and a cup 36d fixed to the cup holder 36c. The cup 36d is equivalent to the cup 34d, and the reference element 20 is attached to the center. The reference unit 36 ​​also has an aperture 36g arranged so that an aperture 36h faces the reference element 20, and a black body 36m that supports the aperture 36g and blocks light. The bottom 36b of the reference unit 36 ​​is connected to the bottom 34b of the detection unit 34. The black body 36m has a groove 36u formed in correspondence with the aperture 36h of the aperture 36g. The reference unit 36 ​​includes a configuration equivalent to that of the detection unit 34 to ensure thermal equivalence with the detection unit 34. The above-mentioned dark box 36x is composed of a peripheral wall portion 36a, a bottom portion 36b, and a black body portion 36m.

[0029] As illustrated in FIG. 4, the sensor element 10 includes an insulating substrate 15, a film-like resistor element 11 formed on one surface of the substrate 15, and a film-like heater element 12 formed on one surface of the substrate 15. Hereinafter, the surface of the substrate 15 on which the resistor element 11 and the heater element 12 are formed is also referred to as the "principal surface", and the opposite surface is also referred to as the "rear surface". The resistor element 11 is formed of a conductive metal such as platinum (Pt), tungsten (W), or copper (Cu). The heater element 12, like the resistor element 11, is formed of a conductive metal such as platinum (Pt), tungsten (W), or copper (Cu). The resistor element 11 and the heater element 12 are electrically insulated from each other.

[0030] The substrate 15 in Fig. 4 is formed in a rectangular shape in a plan view. When attaching the sensor element 10, the user may grasp the outer peripheral portion of the substrate 15 (the portion where the resistance element 11 and the heater element 12 are not provided). The substrate 15 is made of a so-called ceramic substrate, which uses a highly thermally conductive material such as alumina, aluminum nitride, or beryllium oxide as a base material. Therefore, the substrate 15 has excellent thermal conductivity and can quickly transfer heat from the heater element 12 to the resistance element 11.

[0031] The resistive element 11 in FIG. 4 is formed so as to extend in a meandering manner with a predetermined first width W1. More specifically, the resistive element 11 is formed so as to meander repeatedly between one end and the other end of the substrate 15. The resistive element 11 is integrally formed of a plurality of resistive elements 1n continuously connected at their ends, and adjacent resistive elements 1n are partially separated by a slit-shaped gap S1 and connected at their one ends. The resistive element 11 is provided with a terminal 1a at one end and a terminal 1b at the other end. Two lead wires extend from each of the terminals 1a and 1b. In FIG. 4, the lead wires extending from the terminal 1a are labeled L1 and L2, respectively, and the lead wires extending from the terminal 1b are labeled L3 and L4, respectively.

[0032] The resistive element 11 is a thin film pattern formed of a conductive metal. The resistive element 11 is formed on the substrate 15 by various methods such as vapor deposition and sputtering. The gap S1 is preferably formed to have a width as narrow as possible. If the width of the gap S1 is too narrow, it may cause a short circuit, so the lower limit of the width of the gap S1 is preferably set to about 50 μm. On the other hand, if the width of the gap S1 is too wide, the effective area for light absorption becomes narrow, so the upper limit of the width of the gap S1 is preferably set to about 1 mm (1000 μm), preferably about 400 μm or less, and more preferably about 100 μm or less. The effective area is the ratio of the resistive element 11 to the entire sensor element 10 in a plan view.

[0033] The film thickness Tn of the resistor element 11 is preferably as thin as possible so that the resistance value is increased while ensuring the effective area. For example, the resistor element 11 is preferably formed so that the film thickness Tn is within the range of 10 μm to 100 μm. The film thickness Tn of the resistor element 11 may be adjusted by controlling the deposition time during formation, or may be adjusted by polishing the entire resistor element 11 with a grindstone or the like after formation. When adjusting the film thickness Tn by polishing after formation, it should be noted that if the resistor element 11 is too thin before polishing, missing parts may occur, depending on the surface roughness of the substrate 15 and the material of the resistor element 11. The resistance value of the resistor element 11 can be finely adjusted by adjusting the width of each slit or adjusting the film thickness Tn with a grindstone or the like. After finely adjusting the resistance value, the surface of the resistor element 11 is preferably subjected to black low reflection treatment. The first width W1, film thickness Tn, and overall length of the resistor element 11 are preferably adjusted so that the resistance value of the resistor element 11 is about 100Ω to 1000Ω.

[0034] The heater element 12 in FIG. 4 is formed to extend in a meandering manner with a predetermined second width W2. More specifically, the heater element 12 is formed to meander repeatedly between one end and the other end of the substrate 15. The heater element 12 is integrally formed of a plurality of heater elements 2n continuously connected at their ends, and adjacent heater elements 2n are partially separated by a slit-shaped gap S2 and connected at one end. The heater element 12 is formed of a metal thin film as a heating element. The heater element 12 is provided with a terminal 2a at one end and a terminal 2b at the other end. Two lead wires extend from each of the terminals 2a and 2b. In FIG. 4, the lead wires extending from the terminal 2a are labeled L5 and L6, respectively, and the lead wires extending from the terminal 1b are labeled L3 and L4, respectively.

[0035] The heater element 12 is a thin film pattern formed of a conductive metal. The heater element 12 is formed on the substrate 15 by various methods such as deposition and sputtering. The gap S2 is preferably formed to have a width as narrow as possible. The width of the gap S2 is preferably set within a range of about 50 μm or more and about 1 mm (1000 μm) or less, taking into consideration that if the gap S2 is too narrow, it may cause a short circuit, and if the gap S2 is too wide, the effective area for light absorption may be narrow. The width of the gap S2 is more preferably set to about 400 μm or less, and even more preferably to about 100 μm or less.

[0036] The heater element 12 is preferably formed to have a thickness Tn as thin as possible so that the resistance value is large while ensuring the effective area. For example, the heater element 12 is preferably formed to have a thickness Tn in the range of 10 μm to 100 μm. The thickness Tn of the heater element 12 may be adjusted by controlling the deposition time during formation, or may be adjusted by polishing the entire heater element 12 with a grindstone or the like after formation. When adjusting the thickness Tn by polishing after formation, it should be noted that if the heater element 12 is too thin before polishing, missing parts may occur, depending on the surface roughness of the substrate 15 and the material of the heater element 12. The resistance value of the heater element 12 can be finely adjusted by adjusting the width of each slit or adjusting the thickness Tn with a grindstone or the like. After finely adjusting the resistance value, the heater element 12 is preferably subjected to a black low-reflection treatment on the surface. The second width W2, film thickness Tn, overall length, etc. of the heater element 12 are preferably adjusted so that the resistance value of the heater element 12 is about 100Ω to 1000Ω.

[0037] More specifically, the resistance element 11 has a plurality of adjacent resistance parts 1m each composed of two resistance elements 1n adjacent to each other with a gap S1 therebetween. The heater element 12 has a plurality of adjacent heater parts 2m each composed of two heater elements 2n adjacent to each other with a gap S2 therebetween. In the sensor element 10 of FIG. 4, the adjacent resistance parts 1m and the adjacent heater parts 2m are arranged alternately. Therefore, between the adjacent resistance parts 1m and the adjacent heater parts 2m, a slit-shaped gap S3 is formed so as to repeatedly meander between one end and the other end of the substrate 15. The gap S3 between the resistance element 11 and the heater element 12 is set to be approximately the same as the gap S1 and the gap S2. The gaps S1 to S3 are formed by etching, laser processing, mechanical processing, or the like. The widths of the gaps S1 to S3 may all be equal, may all be different, or only two of them may be equal.

[0038] Here, the differential amplifier 50 connected to one end of the heater element 12 controls the temperature of the resistance element 11 to be constant when the sensor element 10 is not irradiated with light and when it is irradiated with light. That is, the differential amplifier 50 constituting a feedback system including the resistance element 11 controls the temperature of the resistance element 11 to be constant by current feedback to the heater element 12 to keep the bridge circuit B in a balanced state, both when the sensor element 10 is irradiated with incident light hν and when it is not irradiated with incident light hν. In the sensor element 10 illustrated in FIG. 4, the adjacent resistance portion 1m and the adjacent heater portion 2m are arranged alternately, and the thermal conductivity from the heater element 12 to the resistance element 11 is extremely good, and the temperature is uniform as a whole.

[0039] FIG. 5 is a schematic cross-sectional view taken along the line AA in FIG. 4. As shown in FIG. 5, the sensor element 10 has a surface protection layer 13 for protecting the surface on the main surface side, and a surface treatment layer 14 for suppressing light reflection (omitted in FIG. 4). The surface protection layer 13 is formed on the main surface side of the sensor element 10 so as to cover the resistance element 11 and the heater element 12. The surface protection layer 13 is formed of a material that has insulating properties and exhibits high transmittance over a wide band. The surface protection layer 13 is formed of, for example, a glass material, and particularly, a glass material based on calcium, barium, and aluminum is suitable. The material and thickness of the surface protection layer 13 may be determined according to the wavelength range of the incident light hν. The surface protection layer 13 can be formed by coating or vapor deposition at high temperatures.

[0040] The surface treatment layer 14 is laminated on the surface protection layer 13 on the main surface side of the sensor element 10. The surface treatment layer 14 is formed of a material with low reflectance and flat spectral reflectance. The surface treatment layer 14 may be formed of Vantablack, for example. The surface treatment layer 14 can be formed by deposition, painting, or the like. In FIG. 5, the film thickness of the resistance element 11 and the film thickness of the heater element 12 are given the same reference symbol "Tn", but the film thickness of the resistance element 11 and the film thickness of the heater element 12 may be different.

[0041] Next, the flow of operations related to the calculation of the energy E of the incident light hν by the management device 70 will be described with reference to the flowchart in Fig. 6. Here, it is assumed that the management device 70 calculates the energy E of a preset number k. Therefore, the energy is represented as E(n) (the number of measurements n=1, 2, ..., k), the non-irradiation power is represented as Pa(n), and the irradiation power is represented as Pb(n).

[0042] First, when the control unit 70b of the management device 70 receives an operation to start the detection system 100 via the input unit 70d, the control unit 70b starts the system and displays an initial screen on the display unit 70e. The user sets conditions and parameters related to the measurement of the energy E(n) through the initial screen or a screen transitioned therefrom as necessary. When the control unit 70b receives a setting operation of the conditions by the user, the control unit 70b stores the set numerical values ​​in the storage unit 70c. For example, the control unit 70b displays a confirmation screen on the display unit 70e for the user to confirm the conditions and parameters, and accepts changes to numerical values ​​upon request. However, if the conditions have been set in advance, this step is omitted (step S101).

[0043] If the waiting time for warming up the measurement system has not elapsed (step S102 / No), the control unit 70b waits until the waiting time has elapsed. When the waiting time has elapsed (step S102 / Yes), the control unit 70b acquires a current value (Ia) from the ammeter 71 and a voltage value (Va) from the voltmeter 72, and stores them in the storage unit 70c (step S103). Then, the control unit 70b uses the acquired current value (Ia) and voltage value (Va) to determine a non-irradiation power Pa(n). The non-irradiation power Pa(n) is the power value of the heater element 12 when the sensor element 10 is not irradiated with light, that is, when the entrance hole 32h is blocked by the shutter blade 38b (when the entrance hole 32h is closed) (step S104).

[0044] Next, the control unit 70b drives the motor 38a via the motor driver 75 to move the shutter blade 38b to open the entrance hole 32h, and allows light to enter the detector 30 through the entrance hole 32h (step S105). Next, the control unit 70b obtains a current value (Ib) from the ammeter 71 and a voltage value (Vb) from the voltmeter 72, and stores them in the storage unit 70c (step S106). Then, the control unit 70b uses the obtained current value (Ib) and voltage value (Vb) to determine the irradiation power Pb(n). The irradiation power Pb(n) is the power value of the heater element 12 when the sensor element 10 is irradiated with light, that is, when the entrance hole 32h is open (step S107).

[0045] Next, the control unit 70b drives the motor 38a via the motor driver 75 to move the shutter blade 38b to close the entrance hole 32h, so that no light is incident from the entrance hole 32h into the detector 30 (step S108). The control unit 70b obtains the energy E(n) of the incident light hv by subtracting the irradiation power Pb(n) from the non-irradiation power Pa(n) (Pa(n) - Pb(n) = E(n)) and stores it in the memory unit 70c. The energy E(n) of the incident light hv corresponds to the energy of the light irradiated to the sensor element 10 (step S109). The control unit 70b also updates the number of measurements n (step S110). Since the initial number of measurements n is "1", the control unit 70b increments the number of measurements n from "1" to "2" in step S110.

[0046] Next, the control unit 70b judges whether the number of measurements n has reached the set number k. The set number k can be changed as appropriate (step S111). If the number of measurements n is less than the set number k (step S111 / No), it judges whether the temperature condition is met (step S112). That is, the control unit 70b waits until the temperature condition is met (step S112 / No), and if the temperature condition is met (step S112 / Yes), it proceeds to the process of step S103. That is, the control unit 70b repeatedly executes the series of processes from step S103 to S112 until the number of measurements n reaches the set number k, and ends the series of processes when the number of measurements n reaches the set number k (step S111 / Yes).

[0047] The temperature condition in step S112 corresponds to "the temperature inside the detector 30 has decreased to a certain degree." For example, a temperature sensor may be provided inside the detector 30, and the temperature detected by the temperature sensor may be equal to or lower than a temperature threshold value as the temperature condition. In this case, the control unit 70b proceeds to the process of step S103 when the detected temperature acquired from the temperature sensor is equal to or lower than the temperature threshold value (step S112 / Yes). The temperature threshold value is set in advance and can be changed as appropriate depending on the use environment of the system. Alternatively, for example, the temperature condition may be the passage of a predetermined time from the timing of performing the process of step S108. In this case, the control unit 70b proceeds to the process of step S103 when a predetermined time has passed since the entrance hole 32h was closed (step S112 / Yes). The predetermined time is set in advance and can be changed as appropriate depending on the use environment of the system. The control unit 70b may display information such as the calculated energy E(n) on the display unit 70e, or may print the information on a paper medium or output it in CSV format if a user instructs to print it.

[0048] In the above description, each step of the detection method in the present embodiment 1 has been described in the order of the step numbers in Fig. 6, but this is not limiting, and each step may be changed as appropriate within a range that does not excessively impair the calculation accuracy of the energy E(n). For example, the process of step S108 is a preparation for quickly determining the non-irradiation power Pa(n) in the calculation process of the energy E(n) that follows, so the timing does not matter as long as it is performed after the process of step S106. However, from the viewpoint of speeding up the process, it is desirable to perform the process of step S108 simultaneously with the process of step S107 (parallel process) or immediately after step S107.

[0049] The control unit 70b may determine whether the bridge circuit B is in a balanced state at least at one of the following times: when the waiting time has elapsed (step S102 / Yes), immediately after step S105, and when the temperature condition is satisfied and the process proceeds to step S103 (step S112 / Yes). In this case, for example, the control unit 70b may wait for the waiting time for the bridge circuit B to settle in a balanced state to elapse, and then proceed to the process of step S103 or step S106. Alternatively, the control unit 70b may determine whether the bridge circuit B is in a balanced state based on the stability of the current value (Ia) obtained from the ammeter 71. Alternatively, a voltmeter may be provided to measure the voltage between the first terminal 1t and the second terminal 2t, and the control unit 70b may determine whether the bridge circuit B is in a balanced state based on the voltage value obtained from the voltmeter.

[0050] As described above, the sensor element 10 in the present embodiment 1 has a film-like resistance element 11 and a film-like heater element 12 formed on the main surface of the substrate 15, and the substrate 15 is not interposed between the resistance element 11 and the heater element 12. Therefore, the resistance element 11 can be heated by the heater element 12 from the irradiation side of light, etc. In other words, in addition to the heat transferred from the heater element 12 via the substrate 15, the radiant heat of the heater element 12 is also transferred to the resistance element 11, so that the heat conduction from the heater element 12 to the resistance element 11 is promoted. Therefore, a quick and highly accurate detection of energy can be realized with a simple structure.

[0051] Moreover, the resistive element 11 and the heater element 12 are formed to extend in a meandering manner. Therefore, the resistance of the resistive element 11 increases, which increases the sensitivity as a resistance temperature detector and also enables the heater element 12 to generate heat more quickly and efficiently. This increases the detection accuracy of the power (Pa, Pb) of the heater element 12, and allows the energy E to be determined with high accuracy.

[0052] 4, the substrate 15 is formed in a rectangular shape in a plan view, and the resistance element 11 and the heater element 12 are each formed to repeatedly meander between one end and the other end of the substrate 15. This makes it possible to increase the overall length of the resistance element 11 and to increase the effective area, thereby improving the sensitivity of the resistance element 11. At the same time, the overall length of the heater element 12 can be increased to improve heat generation efficiency and save space.

[0053] As shown in Fig. 4, the resistance element 11 may be integrally formed of a plurality of resistance elements 1n continuously connected at their ends, with adjacent resistance elements 1n partially separated by a slit-like gap S1. As shown in Fig. 4, the heater element 12 may be integrally formed of a plurality of heater elements 2n continuously connected at their ends, with adjacent heater elements 2n partially separated by a slit-like gap S2. With this configuration, the sensitivity of the resistance element 11 can be further increased, and the heat generation efficiency of the heater element 12 can be further increased.

[0054] In addition, the sensor element 10 may be configured such that a plurality of adjacent resistor portions 1m in the resistor element 11 and a plurality of adjacent heater portions 2m in the heater element 12 are arranged alternately as shown in Fig. 4. This further promotes heat conduction from the heater element 12 to the resistor element 11, thereby speeding up the calculation process of the energy E shown in Fig. 6.

[0055] The bridge circuit B has a first circuit section 18 in which the resistance element 11 of the sensor element 10 is connected in series with a first resistor 35, and a second circuit section 28 in which the reference resistance element 21 of the reference element 20 is connected in series with a second resistor 37, and the first circuit section 18 and the second circuit section 28 are connected in parallel. The bridge circuit B has a differential amplifier 50 that outputs a current generated so as to eliminate a potential difference between a negative terminal 50a connected to the first terminal 1t and a positive terminal 50b connected to the second terminal 2t, from an output terminal 50c to the heater element 12.

[0056] In this way, the bridge circuit B is configured to control the resistance value of the resistor element 11 by the heat of the heater element 12 by passing the output current of the differential amplifier 50 through the heater element 12. More specifically, the differential amplifier 50 outputs a current to the heater element 12 to keep the bridge circuit B in equilibrium between a state in which the sensor element 10 is not irradiated with light and a state in which the sensor element 10 is irradiated with light, and controls the temperature of the resistor element 11 to be constant. In other words, when the sensor element 10 is exposed to external light, the bridge circuit B controls the current flowing through the heater element 12 according to the contribution of the external light, thereby realizing constant temperature control of the resistor element 11. Therefore, by utilizing the characteristics of the Wheatstone bridge circuit, it is possible to quickly and accurately measure the change in power with a simple structure. Then, the change in power of the heater element 12 can be accurately converted into the energy E of the incident light hν.

[0057] That is, in the detection system 100, the management device 70 determines the non-irradiated power Pa from the voltage across the heater element 12 and the output current of the differential amplifier 50 when the sensor element 10 is not irradiated with light, and determines the irradiated power Pb from the voltage across the heater element 12 and the output current of the differential amplifier 50 when the sensor element 10 is irradiated with light, and then subtracts the irradiated power Pb from the non-irradiated power Pa, thereby quickly and accurately determining the energy E of light irradiated to the sensor element 10.

[0058] The detector 30 includes a cylindrical body 31, a cover 32 having an entrance hole 32h formed in the center for the entrance of light, a detection section 34 in which the sensor element 10 is disposed at a position where the light entering through the entrance hole 32h is irradiated, and a reference section 36 including a reference element 20 configured in the same manner as the sensor element 10. The detection system 100 includes the detector 30, a first resistor 35, a second resistor 37, a differential amplifier 50, and a management device 70. The management device 70 therefore obtains the non-irradiation power Pa from the voltage across the heater element 10 and the output current of the differential amplifier 50 when the entrance hole 32h is closed, and obtains the irradiation power Pb from the voltage across the heater element 12 and the output current of the differential amplifier 50 when the entrance hole 32h is open, thereby quickly and accurately obtaining the energy E of the light irradiated to the sensor element 10 from the difference between the non-irradiation power Pa and the irradiation power Pb.

[0059] <Variation 1> Next, a sensor element 10A according to Modification 1 of the first embodiment of the present invention will be described with reference to Fig. 7. The detection system in Modification 1 is similar to the detection system 100 illustrated in Figs. 1 to 3, so the same reference numerals are used for equivalent configurations and descriptions thereof will be omitted or simplified.

[0060] The sensor element 10A illustrated in FIG. 7 has a substrate 15, a film-like resistor element 11A formed on the main surface of the substrate 15, and a film-like heater element 12A formed on the main surface of the substrate 15, with the resistor element 11A and the heater element 12A being electrically insulated from each other.

[0061] The resistor element 11A is formed to extend in a meandering manner with a predetermined first width W1. More specifically, the resistor element 11 is formed to meander repeatedly between one end and the other end of the substrate 15. The resistor element 11A is integrally formed of a plurality of resistor elements 1n continuously connected at their ends, and adjacent resistor elements 1n are partially separated by a slit-shaped gap S1 and connected at one end. In the resistor element 11A of FIG. 7, the repeatedly meandering portion (hereinafter also referred to as a resistor meander group) is provided biased toward the terminal 1a side. The material and film formation method of the resistor element 11A are the same as those of the resistor element 11.

[0062] The heater element 12A is formed to extend with a second width W2 determined in advance while meandering. More specifically, the heater element 12A is formed to meander repeatedly between one end and the other end of the substrate 15. The heater element 12A is integrally formed of a plurality of heater elements 2n continuously connected at the ends, and adjacent heater elements 2n are partially separated by a slit-shaped gap S2 and connected at one end. In the heater element 12A of FIG. 7, the repeatedly meandering portion (hereinafter also referred to as a heater meander group) is provided biased toward the terminal 2b side. That is, in the sensor element 10A, the resistor meander group and the heater meander group are provided in regions opposite to each other. The material and film formation method of the heater element 12A are the same as those of the heater element 12.

[0063] As described above, the sensor element 10A in the present modified example 1 has a film-like resistor element 11A and a film-like heater element 12A formed on the main surface of the substrate 15, and the substrate 15A is not interposed between the resistor element 11A and the heater element 12A. Therefore, the heater element 12A can heat the resistor element 11A from the irradiation side of light or the like. That is, in addition to the heat transferred from the heater element 12A via the substrate 15A, the radiant heat of the heater element 12A is also transferred to the resistor element 11A, so that the heat conduction from the heater element 12A to the resistor element 11A is promoted. Therefore, a simple structure can realize rapid and highly accurate detection of energy. And, the differential amplifier 50 controls the output current to the heater element 12A to maintain the balanced state of the bridge circuit B including the resistor element 11A, so that the temperature of the resistor element 11A can be controlled to be constant. Therefore, the energy E of the light irradiated to the sensor element 10A can be obtained quickly and highly accurately. In comparison with sensor element 10, sensor element 10A in FIG. 7 is less responsive to temperature changes in the resistor element in response to temperature changes in the heater element, but the overall temperature becomes uniform after a certain amount of time has passed.

[0064] Incidentally, the sensor element 10 and the sensor element 10A can be applied not only to the detector 30, the bridge circuit B, and the detection system 100, but also to other systems such as existing detectors, detection circuits, or detection systems. However, depending on the configuration of the system, if the thermal conductivity from the heater element to the resistance element is too high, the calculation processing of power and energy may not go well. In this regard, the sensor element 10A has a resistor meander group and a heater meander group arranged in different regions, and the thermal conductivity from the heater element to the resistance element is lower than that of the sensor element 10 except for the area where they are adjacent to each other. Therefore, it is preferable to use the sensor element differently, such as adopting a configuration like the sensor element 10A when it is necessary to adjust the thermal conductivity. Other configurations, detection methods, effects, etc. are the same as those of the sensor element, bridge circuit, detector, and detection system in the main part of the above-mentioned embodiment 1. <Variation 2> A sensor element 10B according to Modification 2 of the first embodiment of the present invention will be described with reference to Fig. 8 and Fig. 9. The detection system in Modification 2 is similar to the detection system 100 illustrated in Figs. 1 to 3, so the same reference numerals are used for equivalent configurations and descriptions thereof will be omitted or simplified.

[0065] 8, the sensor element 10B includes an insulating substrate 15B, a film-like resistor element 11B formed on one surface of the substrate 15B, and a film-like heater element 12B formed on one surface of the substrate 15B. The resistor element 11B is formed so as to extend in a curved manner with a predetermined first width W1. The heater element 12B is formed so as to extend in a curved manner with a predetermined second width W2.

[0066] More specifically, the resistance element 11B is formed in a spiral shape from the center of the substrate 15B to the outside. The heater element 12B is formed in a spiral shape from the center of the substrate 15B to the outside between the resistance elements 11B. The resistance element 11B and the heater element 12B are electrically insulated from each other. The substrate 15B illustrated in FIG. 8 has a circular shape in a plan view. Therefore, slit-like gaps S4 and S5 are substantially formed between the resistance element 11B and the heater element 12B. The gaps S4 and S5 are both formed in a spiral shape and are connected at the center.

[0067] Incidentally, among the terminals of the sensor element 10B, for terminals 1b and 2b, lead wires can be extended from the main surface side of the substrate 15B, similarly to the sensor element 10 in FIG. 4. However, for terminals 1a and 2a, lead wires cannot be extended from the main surface side of the substrate 15B. Therefore, it is preferable to extend lead wires from terminals 1a and 2a from the rear surface side of the substrate 15B, as shown in FIG. 9, for example. However, the sensor element 10B may be configured such that a metal pattern is formed on the rear surface of the substrate 15B, extending from each terminal to an edge terminal provided on the edge of the substrate 15B, and two lead wires are extended from each edge terminal, similarly to the configuration example in FIG. 11 and FIG. 12 of Modification 4 described later.

[0068] As described above, the sensor element 10B in the present modified example 2 has a film-like resistance element 11B and a film-like heater element 12B formed on the main surface of the substrate 15B, and the substrate 15B is not interposed between the resistance element 11B and the heater element 12B. Therefore, the resistance element 11B can be heated by the heater element 12B from the irradiation side of light, etc. In other words, in addition to the heat transferred from the heater element 12B via the substrate 15B, the radiant heat of the heater element 12B is also transferred to the resistance element 11B, so that the heat conduction from the heater element 12B to the resistance element 11B is promoted. Therefore, a quick and highly accurate detection of energy can be realized with a simple structure.

[0069] Moreover, the resistive element 11B and the heater element 12B are formed so as to extend while being curved. Therefore, the resistance of the resistive element 11B is increased, and the sensitivity as a temperature measuring resistor is increased, and the heating of the heater element 12B can be accelerated and efficiently performed. This improves the detection accuracy of the power (Pa, Pb) of the heater element 12, and the energy E can be obtained with high accuracy. More specifically, the resistive element 11B is formed in a spiral shape from the center of the substrate 15B to the outside, and the heater element 12B is formed between the resistive elements 11B in a spiral shape from the center of the substrate 15B to the outside. This further promotes the thermal conduction from the heater element 12B to the resistive element 11B, and the calculation processing of the energy E can be accelerated.

[0070] In addition, in the sensor element 10B illustrated in FIG. 8, the resistor element 11B and the heater element 12B are arranged alternately from the center toward the outside, and the thermal conductivity from the heater element 12B to the resistor element 11B is very good, and the temperature is uniform as a whole. The differential amplifier 50 adjusts the heat generation amount of the heater element 12 by feedback control that maintains the equilibrium state of the bridge circuit B including the resistor element 11B, both when the incident light hν is irradiated to the sensor element 10B and when it is not irradiated, and realizes a state in which the temperature of the resistor element 11B is constant. Therefore, the detection system 100 can derive the energy E of the incident light hν from the power change of the heater element 12B. Other configurations, detection methods, effects, etc. are the same as those of the sensor element, bridge circuit, detector, and detection system of the main part of the first embodiment and the first modification described above.

[0071] <Variation 3> Sensor elements 10C and 10D according to Modification 3 of the first embodiment of the present invention will be described with reference to Figures 10 to 12. The detection system in Modification 3 is similar to the detection system 100 illustrated in Figures 1 to 3, so the same reference numerals are used for equivalent configurations and descriptions thereof will be omitted or simplified.

[0072] 10, the sensor element 10C of the third modification includes an insulating substrate 15B, a film-like resistor element 11C formed on one surface of the substrate 15B, and a film-like heater element 12C formed on one surface of the substrate 15B. The resistor element 11C is formed so as to extend in a curved manner with a first width W1 that is determined in advance. The heater element 12C is formed so as to extend in a curved manner with a second width W2 that is determined in advance.

[0073] More specifically, the resistive element 11C is formed in a spiral shape near the center of the substrate 15B. The resistive element 11C has a slit-shaped gap S1 formed in a spiral shape. The heater element 12C is formed in a spiral shape near the outer periphery of the substrate 15B. A space S is provided between the resistive element 11C and the heater element 12C to reduce the thermal conduction from the heater element 12C to the resistive element 11C. The size of the space S may be determined according to the degree of thermal conduction to be reduced. The distance R between the resistive element 11C and the heater element 12C varies depending on the location, but it is recommended to design it so that it is as uniform as possible over the entire area.

[0074] The basic configuration of the sensor element 10D shown in Fig. 11 and Fig. 12 is the same as that of the sensor element 10C shown in Fig. 10, but the configuration of the lead wires extending to the outside is different. That is, the sensor element 10D has edge terminals T1 to T6, which are terminals for connecting lead wires, in addition to the terminals 1a, 1b, 2a, and 2b. The edge terminals T1 to T6 are each provided on the edge of the substrate 15B. As shown in Fig. 12, the sensor element 10D has patterns P1, P3, and P5 formed of a conductive metal such as copper on the back surface. The pattern P1 extends from the terminal 1a to both the edge terminal T1 and the edge terminal T2. The pattern P3 extends from the terminal 1b to both the edge terminal T3 and the edge terminal T4. The pattern P5 extends from the terminal 2a to both the edge terminal T5 and the edge terminal T6. Then, the lead wires L1 to L6 extend from the edge terminals T1 to T6, respectively. In addition, lead wires L7 and L8 extend from terminal 2b. With this configuration, sensor element 10D is capable of performing measurement processing by the four-terminal method, similar to sensor elements 10 and 10A to 10C.

[0075] As described above, the sensor elements 10C and 10D in the present modified example 3 have a film-like resistor element 11C and a film-like heater element 12C formed on the main surface of the substrate 15B, and the substrate 15B is not interposed between the resistor element 11C and the heater element 12C. Therefore, the resistor element 11C can be heated by the heater element 12C from the irradiation side of light, etc. That is, in addition to the heat transferred from the heater element 12C via the substrate 15B, the radiant heat of the heater element 12C is also transferred to the resistor element 11C, so that the heat conduction from the heater element 12C to the resistor element 11C is promoted. Therefore, a simple structure can realize rapid and highly accurate detection of energy. And, the differential amplifier 50 controls the output current to the heater element 12C to maintain the balanced state of the bridge circuit B including the resistor element 11C, so that the temperature of the resistor element 11C can be controlled to be constant. Therefore, the energy E of the light irradiated to the sensor elements 10C and 10D can be obtained quickly and highly accurately.

[0076] Incidentally, the sensor elements 10B to 10D can be applied not only to the detector 30, the bridge circuit B, and the detection system 100, but also to other systems such as existing detectors, detection circuits, and detection systems. However, depending on the configuration of the system, if the thermal conductivity from the heater element to the resistance element is too high, the calculation processing of power and energy may not go well. In this regard, the sensor elements 10C and 10D are provided with a space S between the resistance element 11B and the heater element 12B to suppress the thermal conductivity from the heater element 12B to the resistance element 11B. The space S can be adjusted according to the degree of thermal conductivity to be suppressed. Therefore, the sensor elements 10C and 10D can be suitably applied to various detection systems. In addition, the sensor elements 10C and 10D have a low ability to follow the temperature change of the resistance element in response to the temperature change of the heater element compared to the sensor element 10, but the overall temperature becomes uniform after a certain period of time. Other configurations, detection methods, effects, and the like are similar to those of the sensor element, bridge circuit, detector, and detection system of the first embodiment and the first and second modifications described above.

[0077] Here, the above-mentioned embodiments (including each modified example) are specific examples of the sensor element, bridge circuit, detector, and detection system, and the technical scope of the present invention is not limited to these aspects. For example, the substrate 15 is not limited to a rectangular shape in a plan view, and may have various shapes such as a circular shape in a plan view or an elliptical shape in a plan view. The substrate 15B is not limited to a circular shape in a plan view, and may be an elliptical shape in a plan view or a rectangular shape in a plan view. The sensor element 10 may be configured so that lead wires extend downward from each terminal, as shown in FIG. 9.

[0078] The detection system 100 in each embodiment may be configured without providing a bridge circuit B as shown in FIG. 2. In such a configuration, when the sensor elements 10, 10A to 10D (reference numbers omitted below) are used, for example, a plurality of measuring instruments (digital multimeters, etc.) for measuring various data related to the sensor elements may be provided. Then, the management device 70 may use the measured values ​​of each measuring instrument to control the temperature of the resistance elements 11, 11A to 11C (reference numbers omitted below) so that they are always constant. That is, the control unit 70b may be configured to calculate the output current to the heater element for keeping the temperature of the resistance element constant by using the measured values ​​of each measuring instrument, and to pass the obtained output current through the heater element. However, if the detection system 100 is configured without providing the bridge circuit B, the number of measuring instruments increases, the control content becomes complicated, and the processing speed becomes slow, so it is more preferable to provide the bridge circuit B including the differential amplifier 50.

[0079] In each embodiment, the resistor element and the heater element are clearly distinguished from each other, but the use of these elements can be changed between them. That is, each sensor element may have the resistor element function as a heater element and the heater element function as a resistor element. In short, the arrangement of the resistor element and the heater element in the sensor element in each figure is only an example, and each sensor element may be configured by swapping the arrangement of the resistor element and the heater element. In addition, each sensor element may have the resistor element and the heater element interchangeably used by changing the connection relationship. However, when the processing accuracy of the resistor element and the heater element is to be determined, it is preferable to adjust the resistor element to be of higher quality than the heater element.

[0080] In addition, the sensor elements 10C and 10D have a low ability to follow the temperature change of the resistor element relative to the heater element because a space S is provided between the resistor element 11C and the heater element 12C. Therefore, sunlight, which is highly stable, is desirable as the light hν incident on the sensor elements 10C and 10D. On the other hand, the sensor elements 10, 10A, and 10B have a high ability to follow the temperature change of the resistor element relative to the heater element. Therefore, not only sunlight but also light from a semiconductor laser or an LED, which has relatively low stability, can be preferably used as the light hν incident on these elements. [Explanation of symbols]

[0081] 1a, 1b, 2a, 2b terminal, 1m adjacent resistor portion, 1n resistor element, 1t first terminal, 2t second terminal, 3t third terminal, 4t fourth terminal, 5t fifth terminal, 6t sixth terminal, 2m adjacent heater portion, 2n heater element, 10, 10A to 10D sensor element, 11, 11A to 11C resistor element, 12, 12A to 12C heater element, 13 surface treatment layer, 15, 15A, 15B substrate, 18 first circuit portion, 20 reference element, 21 reference resistor element, 22 reference heater element, 28 second circuit portion, 30 detector, 31 main body portion, 31h light control hole, 31n baffle, 32 lid portion, 32h entrance hole, 34 detection portion, 34a peripheral wall portion, 34b, 36b Bottom, 34c, 36c cup holder, 34d, 36d cup, 34e support, 34g, 36g aperture, 34h, 36h aperture, 35 first resistor, 36 reference, 36a peripheral wall, 36m black body, 36u groove, 36x dark box, 37 second resistor, 38 opening / closing mechanism, 38a motor, 38b shutter blade, 40 amplification processing unit, 50 differential amplifier, 50a negative terminal, 50b positive terminal, 50c output terminal, 51, 52 input resistor, 55 power supply, 60 control unit, 70 management device, 70a communication unit, 70b control unit, 70c memory unit, 70d input unit, 70e display unit, 71 ammeter, 71 communication unit, 72 voltmeter, 75 motor driver, 100 Detection system.

Claims

1. An insulating substrate; a film-like resistor element formed on one surface of the substrate; A sensor element having a film-like heater element formed on the one surface of the substrate and electrically insulated from the resistor element.

2. The resistive element is The wire is formed to extend in a meandering or curved manner, The heater element is 2. The sensor element according to claim 1, which is formed so as to extend in a meandering or curved manner.

3. The substrate is formed in a rectangular shape in a plan view, The resistive element is The substrate is formed so as to repeatedly meander between one end and the other end, The heater element is 3. The sensor element according to claim 1, wherein the substrate is formed so as to repeatedly meander between one end and the other end.

4. The resistive element is It is integrally composed of a plurality of resistance elements continuously connected at the ends, Each adjacent resistance element is They are partially separated by slit-like gaps, The heater element is It is integrally constructed of multiple heater elements connected continuously at the ends, Each adjacent heater element has 4. The sensor element according to claim 3, which is partially separated by a slit-like gap.

5. The resistive element is The resistor element has a plurality of adjacent resistor portions each composed of two adjacent resistor elements, The heater element is A plurality of adjacent heater sections each consisting of two adjacent heater elements are provided, The sensor element according to claim 4 , wherein the adjacent resistor portions and the adjacent heater portions are arranged in a staggered manner.

6. The resistive element is The substrate is formed in a spiral shape from the center to the outside, The heater element is The sensor element according to claim 1 , wherein the sensor element is formed in a spiral shape from a center portion of the substrate toward an outer side between the resistor elements.

7. The resistive element is The substrate is formed in a spiral shape near the center of the substrate, The heater element is 3. The sensor element according to claim 1, wherein the sensor element is formed in a spiral shape at a location near an outer periphery of the substrate.

8. A first circuit portion in which the resistive element included in the sensor element according to any one of claims 1 to 7 and a first resistor having a resistance value equal to that of the resistive element are connected in series; a second circuit section in which a reference resistor element provided in a reference element configured in the same manner as the sensor element and a second resistor having the same resistance value as the reference resistor element are connected in series; the first circuit portion and the second circuit portion are connected in parallel, a bridge circuit further comprising a differential amplifier having a negative terminal connected between the resistive element and the first resistor, a positive terminal connected between the reference resistive element and the second resistor, and an output terminal connected to one end of the heater element.

9. The differential amplifier comprises:

9. The bridge circuit according to claim 8, wherein a current for keeping the bridge circuit in a balanced state is output to the heater element when the sensor element is not irradiated with light and when the sensor element is irradiated with light, and the temperature of the resistor element is controlled to be constant.

10. A main body portion formed in a cylindrical shape; A cover portion attached to one end of the main body portion and having an entrance hole for entering light at a central location; a detection unit attached to the other end of the main body and having the sensor element according to any one of claims 1 to 7 disposed at a position where light entering through the entrance hole is irradiated; A detector having a reference portion attached to the detection portion and including a reference element configured identically to the sensor element.

11. A sensor element according to any one of claims 1 to 7; a management device that controls the temperature of the resistance element to be constant when the sensor element is not irradiated with light and when the sensor element is irradiated with light.

12. A bridge circuit according to claim 8; a management device that, when the sensor element is not irradiated with light, determines a non-irradiated power, which is the power of the heater element, from a voltage across the heater element and an output current of the differential amplifier, and, when the sensor element is irradiated with light, determines an irradiated power, which is the power of the heater element, from the voltage across the heater element and the output current of the differential amplifier, and determines the energy of light irradiated to the sensor element from the difference between the non-irradiated power and the irradiated power.

13. The differential amplifier comprises:

13. The detection system according to claim 12, wherein a current for keeping the bridge circuit in a balanced state is output to the heater element when the sensor element is not irradiated with light and when the sensor element is irradiated with light, and the temperature of the resistor element is controlled to be constant.

14. A detector according to claim 10; a first resistor connected in series with the resistive element and having a resistance value equal to that of the resistive element; a second resistor connected in series with a reference resistor element included in the reference element and having a resistance value equal to that of the reference resistor element; a differential amplifier having a negative terminal connected between the resistive element and the first resistor, a positive terminal connected between the reference resistive element and the second resistor, and an output terminal connected to one end of the heater element; a management device that, when the entrance hole is closed, determines a non-irradiated power, which is the power of the heater element, from the voltage across the heater element and the output current of the differential amplifier, and, when the entrance hole is open, determines an irradiated power, which is the power of the heater element, from the voltage across the heater element and the output current of the differential amplifier, and determines the energy of light irradiated to the sensor element from the difference between the non-irradiated power and the irradiated power.

15. The differential amplifier comprises:

15. The detection system according to claim 14, wherein the temperature of the resistance element is controlled to be constant when the entrance hole is closed and when the entrance hole is open.

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