Sensor device

Abstract

To provide a sensor device having high measurement accuracy.SOLUTION: The sensor device comprises an element array circuit and a control circuit. The element array circuit includes: a plurality of first wires; a plurality of second wires each extending in a direction different from the plurality of first wires; and a plurality of impedance elements each connected to both of one of the plurality of first wires and one of the plurality of second wires. The control circuit uses at least two of output voltages due to each of some of the plurality of correction impedance elements connected to one first correction wire selected from the plurality of first wires to correct output voltage due to at least one of the plurality of measurement impedance elements connected to one first measurement wire other than the first correction wires selected from the plurality of first wires from among the plurality of impedance elements.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sensor device including an element array circuit having an element array in which a plurality of impedance elements are arranged. [Background technology]

[0002] A resistor array circuit having a plurality of resistor elements arranged in a matrix has been disclosed. Such resistor array circuits are used, for example, as infrared detection circuits (see, for example, Patent Document 1). In such infrared detection circuits, a plurality of infrared sensitive resistors, such as thermistors, whose resistance values ​​change in response to temperature changes, are arranged. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 08-94443 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, a sensor device equipped with an element array circuit having a plurality of sensor elements is desired to have high measurement accuracy for the physical quantity to be measured. [Means for solving the problem]

[0005] A sensor device according to one embodiment of the present disclosure includes an element array circuit and a control circuit. The element array circuit includes a plurality of first wirings, a plurality of second wirings each extending in a direction different from the plurality of first wirings, and a plurality of impedance elements each connected to both one of the plurality of first wirings and one of the plurality of second wirings. The control circuit corrects an output voltage resulting from at least one of the plurality of measurement impedance elements connected to one measurement first wiring other than the correction first wiring selected from the plurality of first wirings among the plurality of impedance elements, using at least two of the output voltages resulting from each of the plurality of correction impedance elements connected to one correction first wiring selected from the plurality of first wirings among the plurality of impedance elements.

[0006] In a sensor device according to an embodiment of the present disclosure, the output voltage due to the measurement impedance element is corrected by a control circuit using at least two of the output voltages due to the plurality of correction impedance elements, thereby mitigating the influence of the wiring resistance of each of the plurality of first wirings on the measurement accuracy. [Effects of the Invention]

[0007] According to a sensor device according to an embodiment of the present disclosure, high measurement accuracy can be achieved for a physical quantity to be measured. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a circuit diagram illustrating a configuration example of a sensor device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a characteristic diagram that schematically shows the relationship between the positions of the connection points and the potentials at the connection points in the element array circuit of FIG. [Figure 3] FIG. 3 is an explanatory diagram showing the relationship between an increase in the number of resistance elements connected in parallel and an increase in the voltage drop in the element array circuit of FIG. [Figure 4]FIG. 4 is a flowchart illustrating an example of the measurement operation of the sensor device shown in FIG. [Figure 5A] FIG. 5A is a first explanatory diagram illustrating an example of the measurement operation of the sensor device shown in FIG. [Figure 5B] FIG. 5B is a second explanatory diagram illustrating an example of the measurement operation of the sensor device shown in FIG. [Figure 6] FIG. 6 is a circuit diagram illustrating a configuration example of a sensor device according to the second embodiment of the present disclosure. [Figure 7] FIG. 7 is a circuit diagram illustrating a configuration example of a sensor device according to the third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The description will be made in the following order: 1. First embodiment (example of a sensor device including a first element array circuit including a plurality of power supply lines, a plurality of readout lines, and a plurality of operational amplifiers) 2. Second embodiment (example of a sensor device including a second element array circuit including a plurality of power supply lines, a plurality of readout lines, and a plurality of operational amplifiers) 3. Third embodiment (example of a sensor device including a third element array circuit including multiple power supply lines, multiple readout lines, multiple operational amplifiers, and an electromagnetic wave shield) 4. Variations

[0010] <1. First embodiment> [Overall configuration example of sensor device] 1 is a circuit diagram schematically illustrating an example configuration of a sensor device 1 according to a first embodiment of the present disclosure. This sensor device includes, for example, an element array circuit 10 and a control circuit 20. The element array circuit 10 is mounted on an electromagnetic wave sensor (such as an infrared thermograph) that detects electromagnetic waves such as infrared rays, and is configured to output an output voltage corresponding to the intensity of the electromagnetic waves such as infrared rays irradiated onto the element array circuit 10. The measurement operation in the element array circuit 10 is performed in response to a command from the control circuit 20.

[0011] As shown in FIG. 1, the element array circuit 10 includes, for example, a plurality of feed lines A (denoted as A1 to Am in FIG. 1), a plurality of readout lines B (denoted as B1 to Bn in FIG. 1), a plurality of resistive elements Z (denoted as Z(1,1) to Z(m,n) in FIG. 1), a plurality of operational amplifiers OP (denoted as OP1 to OPn in FIG. 1), a plurality of resistive elements RE (denoted as RE1 to REn in FIG. 1), and a feed line selector SA. Note that while FIG. 1 illustrates an example in which m feed lines A are provided, the number m of the plurality of feed lines A can be arbitrarily selected from integers equal to or greater than 2. Similarly, FIG. 1 illustrates an example in which n readout lines B are provided, the number n of the plurality of readout lines B can be arbitrarily selected from integers equal to or greater than 2. In FIG. 1, the resistive element Z connected to both the a-th (a is a natural number equal to or less than m) feed line Aa among the m feed lines A1 to Am and the b-th (b is a natural number equal to or less than n) readout line Bb among the n readout lines B1 to Bn is denoted as Z(a, b). The same notation is used in the drawings subsequent to FIG. 1. The multiple feed lines A and the multiple readout lines B are not in direct contact with each other. Furthermore, in FIG. 1, the connection point P between the a-th feed line Aa among the m feed lines A1 to Am and the resistive element Z(a, b) is denoted as P(a, b). Furthermore, in FIG. 1, the connection point K between the b-th readout line Bb among the n readout lines B1 to Bn and the resistive element Z(a, b) is denoted as K(a, b).

[0012] (Feed line A) The power supply line A is a specific example that corresponds to a "first wiring" of the present disclosure. Each of the multiple power feeders A (A1 to Am in FIG. 1) is a conductor extending from a DC power supply PS1 (described later) to a connection point P(a,n). Each of the multiple power feeders A includes a first portion PA (denoted as PA1 to PAm in FIG. 1) extending in a first direction. Each of the first portions PA1 to PAm is a corresponding portion of the power feeders A1 to Am. The multiple first portions PA are arranged adjacent to each other in a second direction different from the first direction. In the example of FIG. 1, each of the m first portions PA extends in the X-axis direction, and the m first portions PA are arranged adjacent to each other in the Y-axis direction perpendicular to the X-axis direction. The first portion PA1 is a portion of the power feeder A1 from the connection point P(1,1) to the connection point P(1,n). The first portion PA2 is a portion of the power feeder A2 from the connection point P(2,1) to the connection point P(2,n). The first portion PAm is a portion of the power supply line Am from the connection point P(m,1) to the connection point P(m,n). That is, the first portion PAa is a portion of the power supply line Aa from the connection point P(a,1) to the connection point P(a,n). That is, the first portion PA is a section portion to which the multiple resistance elements Z in each of the multiple power supply lines A are connected.

[0013] As shown in FIG. 1, a first end of each of the multiple power feeders A (A1 to Am) is connected to a DC power source PS1. Each of the multiple power feeders A (A1 to Am) further includes a connection portion WA (denoted as WA1 to WAm in FIG. 1). The connection portion WA1 is the portion of the power feeder A1 that runs from the DC power source PS1 to the connection point P(1,1). The connection portion WA2 is the portion of the power feeder A2 that runs from the DC power source PS1 to the connection point P(2,1). The connection portion WAm is the portion of the power feeder Am that runs from the DC power source PS1 to the connection point P(m,1). That is, the connection portion WAa ​​is the portion of the power feeder Aa that runs from the DC power source PS1 to the connection point P(a,1). Furthermore, a connection wiring WB (denoted as WB1 to WBm in FIG. 1) is connected to each of the multiple connection portions WA (WA1 to WAm). Specifically, the second end of the connection wiring WB1 is connected to the connection portion WA1 at the connection point J1, the second end of the connection wiring WB2 is connected to the connection portion WA2 at the connection point J2, and the second end of the connection wiring WBm is connected to the connection portion WAm at the connection point Jm. That is, the second end of the connection wiring WBa is connected to the connection portion WAa ​​at the connection point Ja. However, the second end of the connection wiring WBa may be connected to the connection portion WAa ​​at the connection point P(a,1). That is, the connection point Ja and the connection point P(a,1) may coincide. Furthermore, the first end of the connection wiring WBa, which is opposite to the second end, is connected to the DC power supply PS2. As shown in FIG. 1, the multiple connection portions WA (WA1-WAm) may share parts with each other, or each of the multiple connection portions WA (WA1-WAm) may be independently connected to the DC power supply PS1. The DC power supply PS1 may be provided inside or outside the element array circuit 10. Similarly, the DC power supply PS2 may be provided inside or outside the element array circuit 10. A voltage can be applied from the DC power supply PS1 to the first ends of the plurality of power supply lines A (A1 to Am) so that the potential of the first ends of each of the plurality of power supply lines A (A1 to Am) becomes a first potential V1.A voltage can be applied to the first ends of each of the multiple connection wirings WB (WB1 to WBm) by a DC power supply PS2 so that the potential of the first ends of each of the multiple connection wirings WB (WB1 to WBm) becomes a second potential V2.

[0014] A switch SWA1 (SWA1-1 to SWA1-m) is provided in a portion of the power supply line Aa between the DC power supply PS1 and the connection point P(a,1). For example, a switch SWA1-1 is provided in a portion of the power supply line A1 between the DC power supply PS1 and the connection point P(1,1), a switch SWA1-2 is provided in a portion of the power supply line A2 between the DC power supply PS1 and the connection point P(2,1), and a switch SWA1-m is provided in a portion of the power supply line Am between the DC power supply PS1 and the connection point P(m,1). In addition, switches SWA2 (SWA2-1 to SWA2-m) are provided in the connection wiring WBa. For example, a switch SWA2-1 is provided in the connection wiring WB1, a switch SWA2-2 is provided in the connection wiring WB2, and a switch SWA2-m is provided in the connection wiring WBm.

[0015] Furthermore, first ends of multiple resistive elements Z are connected to each of the multiple power feed lines A. In the example of FIG. 1, n resistive elements Z are connected in parallel to each of m power feed lines A. Specifically, first ends of each of resistive elements Z(1,1) to Z(1,n) are connected to power feed line A1 extending in the X-axis direction. More specifically, power feed line A1 and resistive element Z(1,1) are connected to each other at connection point P(1,1). Power feed line A1 and resistive element Z(1,2) are connected to each other at connection point P(1,2). Power feed line A1 and resistive element Z(1,n) are connected to each other at connection point P(1,n). That is, Z(1,b), which is the b-th element counting from connection point P(1,1), is connected to power feed line A1 at connection point P(1,b), which is the b-th element counting from connection point P(1,1).

[0016] Similarly, a first end of each of resistive elements Z(2,1) to Z(2,n) is connected to a power supply line A2 extending in the X-axis direction. Specifically, the power supply line A2 and resistive element Z(2,1) are connected to each other at a connection point P(2,1). The power supply line A2 and resistive element Z(2,2) are connected to each other at a connection point P(2,2). The power supply line A2 and resistive element Z(2,n) are connected to each other at a connection point P(2,n). That is, Z(2,b), which is the b-th element counting from the connection point P(2,1), is connected to the power supply line A2 at the b-th element counting from the connection point P(2,1).

[0017] Furthermore, a first end of each of the resistive elements Z(m,1) to Z(m,n) is connected to a power supply line Am extending in the X-axis direction. Specifically, the power supply line Am and the resistive element Z(m,1) are connected to each other at a connection point P(m,1). The power supply line Am and the resistive element Z(m,2) are connected to each other at a connection point P(m,2). The power supply line Am and the resistive element Z(m,n) are connected to each other at a connection point P(m,n). That is, Z(m,b), which is the b-th element counting from the connection point P(m,1), is connected to the power supply line A2 at the b-th element counting from the connection point P(m,1).

[0018] In this way, the first end of each of the resistor elements Z(a,1) to Z(a,n) is connected to the power supply line Aa extending in the X-axis direction. In the example of Fig. 1, the first end of a corresponding one of the resistor elements Z(1,n) to Z(m,n) aligned in the Y-axis direction is connected to each of the connection points P(1,n) to P(m,n), which are second ends opposite the first ends of each of the m power supply lines A.

[0019] (Power supply line selection unit SA) The power supply line selection unit SA has a plurality of switches SWA1 (SWA1-1 to SWA1-m) and a plurality of switches SWA2 (SWA2-1 to SWA2-m). Each of the plurality of switches SWA1 (SWA1-1 to SWA1-m) and the plurality of switches SWA2 (SWA2-1 to SWA2-m) is capable of switching between a conductive state and a non-conductive state. Each of the plurality of switches SWA1 (SWA1-1 to SWA1-m) is provided in a portion of the corresponding power supply line Aa between the DC power supply PS1 and the connection point P(a,1). Each of the plurality of switches SWA2 (SWA2-1 to SWA2-m) is provided in a corresponding connection wiring WB (WB1 to WBm).

[0020] The power feed line selector SA selects one power feed line A (for convenience, referred to as the selected power feed line AS) from among the multiple power feed lines A, connects a first portion PA of the selected power feed line AS to a DC power supply PS1, and connects first portions PA of all power feed lines A other than the selected power feed line AS (for convenience, referred to as unselected power feed lines AU) to a DC power supply PS2. A voltage is applied to a first end of the selected power feed line AS by the DC power supply PS1 so that the potential of the first end of the selected power feed line AS becomes a first potential V1. However, a voltage drop occurs in the selected power feed line AS due to the wiring resistance of the selected power feed line AS and the current flowing through the selected power feed line AS. A voltage is applied to the first portion PA of the unselected power feed line AU by the DC power supply PS2 so that the potential of the first portion PA of the unselected power feed line AU becomes a second potential V2. The second potential V2 is different from the first potential V1. The potential of the first portion PA of the selected power supply line AS is different from the potential (second potential V2) of the first portion PA of the unselected power supply line AU. The operation of the power supply line selector SA is controlled by the control circuit 20. That is, the switching operations of the plurality of switches SWA1 (SWA1-1 to SWA1-m) and the plurality of switches SWA2 (SWA2-1 to SWA2-m) in the power supply line selector SA are executed based on commands from the control circuit 20.

[0021] (Control circuit 20) The control circuit 20 includes, for example, a microcomputer, and a CPU (Central Processing Unit) executes a control program to perform predetermined control processing. The control circuit 20 controls, for example, the switching operations of a plurality of switches SW.

[0022] Specifically, the control circuit 20 controls the switching operation of the power supply line selector SA. That is, the control circuit 20 turns on one switch SWA1 corresponding to the selected power supply line AS and turns off the other switches SWA1 corresponding to the unselected power supply lines AU. At the same time, the control circuit 20 turns on one switch SWA2 corresponding to the selected power supply line AS and turns on the other switches SWA2 corresponding to the unselected power supply lines AU. Here, the selected power supply line AS is the one power supply line A corresponding to the selected resistor element ZS. The unselected power supply lines AU are all power supply lines A other than the selected power supply line AS.

[0023] The control circuit 20 also measures output voltages corresponding to each of the multiple resistor elements Z in the element array circuit 10. That is, the control circuit 20 measures an output voltage from the output terminal T3 of one operational amplifier OP corresponding to each readout line B, which is caused by a resistor element Z (a resistor element selected from the multiple resistor elements Z, and for convenience, referred to as a selected resistor element ZS) connected to both the selected feed line AS and each readout line B. At this time, the control circuit 20 uses at least two of the output voltages caused by each of the multiple correction resistor elements Z (for convenience, referred to as a correction resistor element ZC) connected to one correction feed line A (for convenience, referred to as a correction feed line AC) selected from the multiple feed lines A to correct an output voltage caused by at least one of the multiple resistor elements Z (for convenience, referred to as a measurement resistor element ZM) connected to one measurement feed line A (for convenience, referred to as a measurement feed line AM) other than the correction feed line AC selected from the multiple feed lines A, among the multiple resistor elements Z.

[0024] In the element array circuit 10, a voltage is applied from a DC power supply PS2 to both the first portion PA of the unselected power feeder AU and the positive input terminal T1 of the operational amplifier OP so that the potentials of both the first portion PA of the unselected power feeder AU and the positive input terminal T1 of the operational amplifier OP are set to a second potential V2 that is different in value from the first potential V1 of the first end of one selected power feeder AS selected from the multiple power feeders A. In other words, both the first portion PA of the unselected power feeder AU and the positive input terminal T1 of the operational amplifier OP are set to the same potential (second potential V2).

[0025] (Readout line B) The readout line B is a specific example that corresponds to the "second wiring" of the disclosure. Each of the multiple readout lines B (B1 to Bn in FIG. 1) is a conductor extending from a connection point K(1,b) to an operational amplifier OPb. Each of the multiple readout lines B includes a second portion PB (denoted as PB1 to PBn in FIG. 1) extending in a second direction different from the first direction. Each of the second portions PB1 to PBn is a corresponding portion of the readout lines B1 to Bn. The multiple second portions PB are arranged adjacent to each other in a first direction different from the second direction. In the example of FIG. 1, each of the n second portions PB extends in the Y-axis direction, and the n second portions PB are arranged adjacent to each other in the X-axis direction. The second portion PB1 is a portion of the readout line B1 from the connection point K(1,1) to the connection point K(m,1). The second portion PB2 is a portion of the readout line B2 from the connection point K(1,2) to the connection point K(m,2). The second portion PBn is the portion of the readout line Bn from the connection point K(1,n) to the connection point K(m,n). That is, the second portion PBb is the portion of the readout line Bb from the connection point K(1,b) to the connection point K(m,b). That is, the second portion PB is the section portion to which the multiple resistance elements Z in each of the multiple readout lines B are connected.

[0026] A first end of the readout line Bb is connected to a second end of the resistor element Z(1,b). The second end of the resistor element Z(1,b) is the end of the resistor element Z(1,b) opposite to the first end connected to the power supply line A1. In the example of FIG. 1, m resistor elements Z are connected to the readout line Bb. Specifically, a second end of the resistor element Z(1,1) is connected to a first end of a readout line B1 extending in the Y-axis direction. The readout line B1 and the resistor element Z(1,1) are connected to each other at a connection point K(1,1). The readout line B1 is further connected to a resistor element Z(2,1) at a connection point K(2,1) and to a resistor element Z(m,1) at a connection point K(m,1). In addition, a second end of the resistor element Z(1,2) is connected to a first end of a readout line B2 extending in the Y-axis direction. The readout line B2 and the resistive element Z(1,2) are connected to each other at a connection point K(1,2). The readout line B2 is further connected to a resistive element Z(2,2) at a connection point K(2,2) and to a resistive element Z(m,2) at a connection point K(m,2). Furthermore, a second end of the resistive element Z(1,n) is connected to a first end of a readout line Bn extending in the Y-axis direction. The readout line Bn and the resistive element Z(1,n) are connected to each other at a connection point K(1,n). The readout line Bn is further connected to a resistive element Z(2,n) at a connection point K(2,n) and to a resistive element Z(m,n) at a connection point K(m,n).

[0027] Further, the second end of each of the plurality of readout lines B is connected to a corresponding one of the plurality of operational amplifiers OP. The second end of each of the plurality of readout lines B is the end of each of the plurality of readout lines B opposite to the first end connected to a corresponding one of the plurality of resistance elements Z(1,b). Specifically, the second end of the readout line B1 is connected to the negative input terminal T2 of the operational amplifier OP1, the second end of the readout line B2 is connected to the negative input terminal T2 of the operational amplifier OP2, and the second end of the readout line Bn is connected to the negative input terminal T2 of the operational amplifier OPn. A signal indicating the state of each of the resistance elements Z connected to the corresponding readout line B flows through each of the readout lines B.

[0028] (resistance element Z) Resistance element Z is a specific example corresponding to "impedance element" of the present disclosure. Each of the multiple resistance elements Z is connected to both one of the multiple power supply lines A and one of the multiple readout lines B. Each of the multiple resistance elements R has a first end connected to the power supply line A and a second end connected to the readout line B. As described above, in the example of FIG. 1, n resistance elements Z are connected to each of the multiple power supply lines A, and m resistance elements Z are connected to each of the multiple readout lines B1 to Bn. There is one resistance element Z connected to both one power supply line A of the multiple power supply lines A and one readout line B of the multiple readout lines B. Therefore, by selecting one power supply line A from the multiple power supply lines A and one readout line B from the multiple readout lines B, it is possible to identify one resistance element Z.

[0029] Regarding the n resistor elements Z connected to the power supply line A1, specifically, a first end of the resistor element Z(1,1) is connected to the power supply line A1 at a connection point P(1,1), and a second end of the resistor element Z(1,1) is connected to a first end of the readout line B1 at a connection point K(1,1). A first end of the resistor element Z(1,2) is connected to the power supply line A1 at a connection point P(1,2), and a second end of the resistor element Z(1,2) is connected to a first end of the readout line B2 at a connection point K(1,2). A first end of the resistor element Z(1,n) is connected to the power supply line A1 at a connection point P(1,n), and a second end of the resistor element Z(1,n) is connected to a first end of the readout line Bn at a connection point K(1,n). The same applies to the n resistor elements Z connected to each of the other power supply lines A other than the power supply line A1.

[0030] The resistance element Z is a part of an infrared light receiving element that converts infrared light focused by, for example, a lens or the like into an electrical signal. Specifically, it has a resistance change layer that exhibits a resistance change due to, for example, a temperature change. The resistance change layer is, for example, a thermistor film. The thermistor film contains, for example, vanadium oxide, amorphous silicon, polycrystalline silicon, an oxide with a spinel crystal structure containing manganese, titanium oxide, or yttrium-barium-copper oxide. In addition, an infrared absorption layer that absorbs infrared light and generates heat is provided adjacent to the thermistor film. The infrared absorption layer contains, for example, silicon oxide (SiO2), aluminum oxide (Al2O3), silicon nitride (Si3N4), or aluminum nitride (AlN). The temperature change of the infrared absorption layer and the resistance change layer occurs depending on the intensity of the infrared light received, resulting in a change in the resistance value of the resistance change layer of the resistance element R.

[0031] When measuring the selected resistance element ZS, one switch SWA1 corresponding to the selected power supply line AS is made conductive so that a voltage is applied from the DC power supply PS1 to a first end of one power supply line A (selected power supply line AS) to which the selected resistance element ZS is connected. Also, when measuring the selected resistance element ZS, a voltage is applied from the DC power supply PS2 to first portions PA of all power supply lines A (unselected power supply lines AU) other than the selected power supply line AS via the conductive switch SWA2 corresponding to the unselected power supply line AU.

[0032] 1 shows, as an example, a state in which resistance elements Z(1,1) to Z(1,n) are selected. That is, FIG. 1 shows a state in which, with switch SWA1-1 in a conductive state, a voltage is applied from DC power supply PS1 to a first end of power supply line A1, which serves as a selected power supply line AS corresponding to selected resistance elements Z(1,1) to Z(1,n), and the potential of the first end of power supply line A1 is a first potential V1. Furthermore, FIG. 1 shows a state in which, with switches SWA2-2 to SWA2-m in a conductive state, a voltage is applied from DC power supply PS2 to a first portion PA of power supply lines A2 to Am, which serve as all unselected power supply lines AU other than power supply line A1, and the potential of the first portion PA of power supply lines A2 to Am is a second potential V2 (≠ V1). At this time, the switches SWA1-2 to SWA1-m provided for the power feed lines A2 to Am as the unselected power feed lines AU are all in a non-conductive state, and the switch SWA2-1 corresponding to the power feed line A1 as the selected power feed line is also in a non-conductive state. Note that the first potential V1 and the second potential V2 only need to be different from each other. Either the first potential V1 or the second potential V2 may be 0 V.

[0033] (op-amp OP) Each of the operational amplifiers OP is connected to a corresponding one of the readout lines B. Each of the operational amplifiers OP (denoted as OP1 to OPn in FIG. 1) includes a positive input terminal T1, a negative input terminal T2, and an output terminal T3. The positive input terminal T1 of each of the operational amplifiers OP is connected to, for example, a DC power supply PS2, and the potential of each positive input terminal T1 is set to a second potential V2 different from a first potential V1. The second potential V2 is, for example, 0 V. Each of the negative input terminals T2 of the operational amplifiers OP is connected to a corresponding one of the readout lines B. Each of the operational amplifiers OP operates so that the positive input terminal T1 and the negative input terminal T2 have the same potential, so the potential of the negative input terminal T2 is approximately the second potential V2. The output terminal T3 of each of the operational amplifiers OP is connected to a corresponding one of the negative input terminals T2 via a corresponding one of the resistor elements RE.

[0034] (Resistance element RE) The resistor element RE includes, for example, a resistor made of a metal material having a predetermined specific resistance. Each of the multiple resistor elements RE is connected to both the negative input terminal T2 and the output terminal T3 of a corresponding operational amplifier OP and converts the current flowing through the readout line B connected to the negative input terminal T2 into a voltage. Specifically, in the example of FIG. 1, the resistor element RE1 is connected to both the negative input terminal T2 and the output terminal T3 of the operational amplifier OP1 and converts the current flowing through the readout line B1 into a voltage. Similarly, the resistor element RE2 is connected to both the negative input terminal T2 and the output terminal T3 of the operational amplifier OP2 and converts the current flowing through the readout line B2 into a voltage, and the resistor element REn is connected to both the negative input terminal T2 and the output terminal T3 of the operational amplifier OPn and converts the current flowing through the readout line Bn into a voltage.

[0035] [Measurement operation in sensor device 1] In the sensor device 1, in a measurement environment where electromagnetic waves such as infrared rays are irradiated, the output voltages corresponding to the plurality of resistance elements Z can be measured, for example, as follows. Note that the following measurement operation is performed in response to a command from the control circuit 20.

[0036] First, a selected power supply line AS corresponding to a selected resistance element ZS to be measured is selected. Specifically, the switch SWA1 of the selected power supply line AS to which the selected resistance element ZS is connected is turned on, and a voltage is applied from a DC power supply PS1 to a first end of the selected power supply line AS so that the first end of the selected power supply line AS has a first potential V1. The switch SWA1 corresponding to an unselected power supply line AU is turned off. Furthermore, the switch SWA2 corresponding to the unselected power supply line AU is turned on, and a voltage is applied from a DC power supply PS2 to the first portion PA of the unselected power supply line AU so that the first portion PA of the unselected power supply line AU has a second potential V2. The switch SWA2 corresponding to the selected power supply line AS is turned off. The example in FIG. 1 shows a state in which resistance elements Z(1,1) to Z(1,n) are selected as the selected resistance element ZS. That is, the switch SWA1-1 corresponding to the power feed line A1 as the selected power feed line AS is set to a conductive state, and a voltage is applied from the DC power supply PS1 to the first end of the power feed line A1. Meanwhile, the switches SWA1-2 to SWA1-m corresponding to the power feed lines A2 to Am as the unselected power feed lines AU are set to a non-conductive state. Furthermore, the switches SWA2-2 to SWA2-m corresponding to the power feed lines A2 to Am as the unselected power feed lines AU are set to a conductive state, and a voltage is applied from the DC power supply PS2 to the first portions PA2 to PAm of the power feed lines A2 to Am. Meanwhile, the switch SWA2-1 corresponding to the power feed line A1 as the selected power feed line AS is set to a non-conductive state. Also, the potential of the positive input terminal T1 of each of the operational amplifiers OP1 to OPn is set to the second potential V2. As a result, the voltage applied to the resistance elements Z other than the resistance elements Z(1,1) to Z(1,n) as the selected resistance elements ZS is 0, so that no current flows through the resistance elements Z other than the resistance elements Z(1,1) to Z(1,n).

[0037] Next, the output voltage corresponding to each selected resistor element ZS is measured. Specifically, the output voltage from the output terminal T3 of one operational amplifier OP corresponding to each readout line B, which is caused by the selected resistor element ZS connected to both the selected power supply line AS and each readout line B, is measured. In the example of Figure 1, when the resistor element Z(1,1) connected to both the power supply line A1 and the readout line B1 is designated as the selected resistor element ZS, the output voltage Vout from the output terminal T3 of the operational amplifier OP1 corresponding to the resistor element Z(1,1) is measured. When the resistor element Z(1,2) connected to both the power supply line A1 and the readout line B2 is designated as the selected resistor element ZS, the output voltage Vout from the output terminal T3 of the operational amplifier OP2 corresponding to the resistor element Z(1,2) is measured. When the resistor element Z(1,n) connected to both the power supply line A1 and the readout line Bn is designated as the selected resistor element ZS, the output voltage Vout from the output terminal T3 of the operational amplifier OPn corresponding to the resistor element Z(1,n) is measured. The potential Vf (Vf1 to Vfn) of each connection point P (P(1,1) to P(1,n)) in the power supply line A1 is different from the potential of the connection point K (a corresponding one of K(1,1) to K(1,n)) corresponding to each connection point P (the potential of the readout line B (a corresponding one of readout lines B1 to Bn) corresponding to each connection point P). In other words, the potential of each connection point P in the selection power supply line AS (the potential of each connection point P to which the selection resistance element ZS is connected) is different from the potential of the connection point K corresponding to each connection point P (the potential of the readout line B corresponding to each connection point P). The potential of the connection point K (the potential of the readout line B) is approximately equal to the second potential V2, which is the potential of the negative input terminal T2. A voltage corresponding to the difference between the potential Vf1 to Vfn at the corresponding connection points P(1,1) to P(1,n) and the potential of the corresponding readout lines B1 to Bn is applied to each of the resistance elements Z(1,1) to Z(1,n), and a current corresponding to the resistance value of each of the resistance elements Z(1,1) to Z(1,n) flows. The current flowing through each of the resistance elements Z(1,1) to Z(1,n) flows through a corresponding one of the readout lines B1 to Bn.The current flowing through each of the readout lines B1 to Bn is converted into a voltage by a corresponding one of the resistance elements RE1 to REn, and is output as an output voltage Vout from the output terminal T3 of one of the operational amplifiers OP1 to OPn corresponding to each of the resistance elements Z(1,1) to Z(1,n). The output voltage Vout can be expressed as the following equation (1):

[0038] Vout=-(Re / Rz)×(V1-V2)+V2 ……(1) Re: The resistance value of one resistor RE connected to the operational amplifier OP corresponding to each selected resistor element ZS. Rz: the resistance value of each selective resistance element ZS. Vf: The potential of the connection point P corresponding to each selective resistance element ZS. V2: A second potential which is the potential of the positive input terminal T1.

[0039] Here, the voltage Vf is ideally equal to the first potential V1, which is the potential at the first end of the power supply line A. However, in reality, since there is a voltage drop due to the wiring resistance of the power supply line A itself, the potential Vf becomes smaller than the first potential V1 (Vf < V1). FIG. 2 is a characteristic diagram schematically showing the relationship between the positions of the connection points P(1,1) to P(1,n) on the power supply line A1 and the potential Vf at each position of the connection points P(1,1) to P(1,n) in the element array circuit 10 when n = 600. The horizontal axis of FIG. 2 represents the positions of the connection points P(1,1) to P(1,n) on the power supply line A1, and the vertical axis of FIG. 2 represents the potential Vf. As shown in FIG. 2, as the distance from the connection point P(1,1), which is the first end of the first part PA, increases, the potential Vf of the connection point P drops and deviates from the first potential V1. For example, the potential Vf200 at the connection point P(1,200) to which the 200th resistance element Z(1,200) is connected, counted from the first end of the first part PA, is lower than the potential Vf1 at the connection point P(1,1). Also, the potential Vf400 at the connection point P(1,400) to which the 400th resistance element Z(1,400) is connected, counted from the first end of the first part PA, is even lower than the potential Vf200. The potential Vf600 at the connection point P(1,600) to which the 600th resistance element Z(1,600) is connected, counted from the first end of the first part PA, is even lower than the potential Vf400. The potential Vf600 has dropped by ΔV compared to the potential Vf1. Here, if the current flowing through the b-th section among the plurality of sections from the connection point P(1,1) to the connection point P(1,600) is I(1,b) and the electrical resistance value of the b-th section is R(1,b), the voltage drop ΔV from the connection point P(1,1) to the connection point P(1,n) is ΔV = Σ{I(1,b) × R(1,b)}. However, b in the formula representing this voltage drop ΔV is an integer from 1 to n - 1.

[0040] The voltage drop ΔV increases as the number of resistor elements Z connected in parallel increases. FIG. 3 is an explanatory diagram showing the relationship between the increase in the number of resistor elements Z connected in parallel in the element array circuit 10 and the increase in the voltage drop ΔV. If the voltage at the connection point P(1,n) is Vf(n), then the voltage drop ΔV(n-1) occurring in the section S(n-1) is Vf(n-1) - Vf(n), the voltage drop ΔV(n-2) occurring in the section S(n-2) is Vf(n-2) - Vf(n-1), and the voltage drop ΔV(1) occurring in the section S(1) is Vf(1) - Vf(2). Note that the section S(n-1) is the portion of the power supply line A1 between the connection point P(1,n) and the connection point P(1,n-1) immediately before it. The connection point P(1,n-1) is the connection point between the power supply line A1 and the resistive element Z(1,n-1). Similarly, the section S(n-2) is the portion of the power supply line A1 between the connection point P(1,n-1) and the previous connection point P(1,n-2). The section S(1) is the portion of the power supply line A1 between the connection point P(1,2) and the previous connection point P(1,1).

[0041] Therefore, if the voltage drop occurring between the DC power supply PS1 and the connection point P(1,1) is ΔV(0), the potential Vf(1) at the connection point P(1,1) will be lower than V1 by ΔV(0). Vf(1)=V1-ΔV(0) is. Similarly, the potential Vf(2) at the connection point P(1,2) is Vf(2)=V1-{ΔV(0)+ΔV(1)} And The potential Vf(n-1) at the connection point P(1,n-1) is Vf(n-1)=V1-{ΔV(0)+ΔV(1)+···+ΔV(n-2)} And The potential Vf(n) at the connection point P(1,n) is Vf(n)=V1-{ΔV(0)+ΔV(1)+...+ΔV(n-2)+ΔV(n-1)} This becomes: Therefore, the voltage drop ΔV of the potential Vf(n) at the connection point P(1,n), which is located farthest from the first end of the first portion PA among the connection points P(1,1) to P(1,n), relative to V1 becomes larger as the number n of resistance elements Z connected in parallel increases.

[0042] Also, as shown in FIG. 3, only the current I(n) passing through the connection point P(1,n) flows through the resistance element Z(1,n) that is farthest from the connection point P(1,1), which is the first end of the first portion PA. That is, only the current I(n) flows through the section S(n-1) of the first portion PA. The current I(n) is the current that flows through the resistance element Z(1,n). Furthermore, in the section S(n-2) of the first portion PA, the current I(n-1) also flows in addition to the current I(n). The current I(n-1) is the current that flows through the resistance element Z(1,n-1). Furthermore, all of the currents I(2) to I(n) that flow through the resistance elements Z(1,2) to Z(1,n) respectively flow through the section S(1). Furthermore, all of the currents I(1) to I(n) flowing through the resistive elements Z(1,1) to Z(1,n) flow through the section between DC power supply PS1 and connection point P(1,1). The voltage drop in section S between adjacent connection points P increases in proportion to the product of the electrical resistance of that section S and the current flowing through that section S. Because the total amount of current I flowing increases in sections closer to connection point P(1,1), which is the first end of first portion PA, the voltage drop occurring in those sections tends to increase the closer to connection point P(1,1). Thus, the voltage drop due to the current flowing through feeder line A and the resistance of feeder line B tends to increase.

[0043] Due to this voltage drop, the potential Vf varies depending on the connection position of each of the multiple resistor elements Z relative to the power supply line A. This naturally results in low accuracy of the measured output voltage Vout relative to the physical quantity being measured. For example, even if the same intensity of infrared light is irradiated onto each of the multiple resistor elements Z, the output voltage Vout will vary depending on the connection position of each of the multiple resistor elements Z relative to the power supply line A, resulting in different infrared intensities. This results in measurement errors. Therefore, measures such as correcting the measured value based on the voltage drop are required. However, the voltage drop varies depending on the multiple currents I flowing through each of the multiple resistor elements Z. That is, the voltage drop also fluctuates due to changes in the electrical resistance of each of the multiple resistor elements Z. For example, fluctuations in the ambient temperature cause changes in the resistance value of the resistor element Z, which in turn fluctuates the voltage drop. Therefore, correcting the measurement error described above is not easy.

[0044] Therefore, in the sensor device 1 of this embodiment, the control circuit 20 uses at least two of the output voltages resulting from the multiple correction resistor elements ZC connected to one correction feeder line AC to correct the output voltage resulting from at least one of the multiple measurement resistor elements ZM connected to one measurement feeder line AM. However, for ease of understanding, this specification will be described assuming that the current flowing through the readout line B and the voltage drop due to the resistance of the readout line B are negligible. The correction process by the control circuit 20 will be described with reference to the flowchart shown in FIG. 4 and the explanatory diagrams shown in FIGS. 5A and 5B in addition to FIG. 1. FIG. 4 is a flowchart illustrating an example of the measurement operation of the sensor device 1 shown in FIG. 1. FIG. 5A is a first explanatory diagram illustrating an example of the measurement operation of the sensor device 1 shown in FIG. 1, and FIG. 5B is a second explanatory diagram illustrating an example of the measurement operation of the sensor device 1 shown in FIG. 1. In the following description, the feeder line A1 will be referred to as the measurement feeder line AM, and the feeder line Am will be referred to as the correction feeder line AC. Therefore, the resistor elements Z(1,1) to Z(1,n) are the measurement resistor elements ZM(1,1) to ZM(1,n), and the resistor elements Z(m,1) to Z(m,n) are the correction resistor elements ZC(m,1) to ZC(m,n).

[0045] First, the control circuit 20 selects the correction feed line AC as the selected feed line AS and measures the correction output voltage VCout of each of the multiple correction resistor elements ZC as the selected resistor elements ZC (step S101). Specifically, as shown in FIG. 5A, the switch SWA1-m corresponding to the feed line Am, which is the correction feed line AC, is set to a conductive state, and the switch SWA2-m is set to a non-conductive state. That is, in the feed line selection unit SA, among the multiple switches SWA1 (SWA1-1 to SWA1-m), only the switch SWA1-m is set to a conductive state, and the switches SWA1-1 to SWA1-(m-1) other than the switch SWA1-m are set to a non-conductive state. Also, in the feed line selection unit SA, among the multiple switches SWA2 (SWA2-1 to SWA2-m), only the switch SWA2-m is set to a non-conductive state, and the switches SWA2-1 to SWA2-(m-1) other than the switch SWA2-m are set to a conductive state. By doing so, the potential of the connection point P(m,1) becomes potential Vfc(1), the potential of the connection point P(m,2) becomes potential Vfc(2), and the potential of the connection point P(m,n) becomes potential Vfc(n). As a result, it is possible to measure the correction output voltages VCout(1) to VCout(n) from the output terminals T3 of the operational amplifiers OP1 to OPn corresponding to the correction resistance elements ZC(m,1) to ZC(m,n), respectively.

[0046] Next, the control circuit 20 selects the measurement feeder AM as the selected feeder AS and measures the measurement output voltage VMout corresponding to the measurement resistor ZM as the selected resistor ZS (step S102). Specifically, as shown in FIG. 5B, the switch SWA1-1 corresponding to the feeder A1, which is the measurement feeder AM, is set to a conductive state, and the switch SWA2-1 is set to a non-conductive state. That is, in the feeder selector SA, of the multiple switches SWA1 (SWA1-1 to SWA1-m), only the switch SWA1-1 is set to a conductive state, and the switches SWA1-2 to SWA1-m other than the switch SWA1-1 are set to a non-conductive state. Also, in the feeder selector SA, of the multiple switches SWA2 (SWA2-1 to SWA2-m), only the switch SWA2-1 is set to a non-conductive state, and the switches SWA2-2 to SWA2-m other than the switch SWA2-1 are set to a conductive state. By doing so, the potential of the connection point P(1,1) becomes potential Vf(1), the potential of the connection point P(1,2) becomes potential Vf(2), and the potential of the connection point P(1,n) becomes potential Vf(n). As a result, it is possible to measure the measurement output voltages VMout(1) to VMout(n) from the output terminals T3 of the operational amplifiers OP1 to OPn) corresponding to the measurement resistor elements ZM(1,1) to ZM(1,n). In the above explanation, the measurement output voltages VMout(1) to VMout(n) corresponding to all of the measurement resistor elements ZM(1,1) to ZM(1,n) are measured, but it is also possible to measure only some of the measurement output voltages VMout(1) to VMout(n).

[0047] Finally, the control circuit 20 corrects the measured value of the measurement output voltage VMout using the measured value of the correction output voltage VCout (step S103). Specifically, the measurement output voltages VMout(1) to VMout(n) corresponding to the resistance elements ZM(1,1) to ZM(1,n) connected to the measurement feeder line AM (feeder line A1 in FIGS. 5A and 5B) are corrected as shown in the following equations (2.1) to (2.n). Note that, as shown in equation (2.1), the measurement output voltage VMout(1) corresponding to the resistance element ZM(1,1) has the same value before and after the correction.

[0048]

number

[0049] That is, the measurement output voltage VMout(b) corresponding to, for example, the b-th resistor element ZM(1,b) connected from the connection point P(1,1) among the resistor elements ZM(1,1) to ZM(1,n) is corrected as shown in the following equation (2.b), where b is an integer from 1 to n.

[0050]

number

[0051] Therefore, the resistance values ​​Rz(1,1) to Rz(1,n) of the resistive elements ZM(1,1) to ZM(1,n) can be calculated using the following equations (3.1) to (3.n). Note that, in practice, the measurement output voltages VMout(1) to VMout(n) are corrected without calculating the resistance values ​​Rz(1,1) to Rz(1,n), but to aid understanding, the procedure for calculating the resistance values ​​Rz(1,1) to Rz(1,n) is described below. However, in equations (3.1) to (3.n), Re(1) to Re(n) are the resistance values ​​of the resistance elements RE1 to REn connected to the operational amplifiers OP1 to OPn corresponding to the resistance elements ZM(1,1) to ZM(1,n), respectively; VMout(1) to VMout(n) are the measurement output voltages from the output terminals T3 of the operational amplifiers OP1 to OPn corresponding to the measurement resistance elements ZM(1,1) to ZM(1,n), respectively; and VCout(1) to VCout(n) are the correction output voltages from the output terminals T3 of the operational amplifiers OP1 to OPn corresponding to the correction resistance elements ZC(1,1) to ZC(1,n), respectively.

[0052]

number

[0053] That is, the resistance value Rz(1,b) of the resistor element ZM(1,b), which is connected b-th among the resistor elements ZM(1,1) to ZM(1,n) counting from the connection point P(1,1), for example, can be calculated using the following formula (3.b): where Re(b) is the resistance value of the resistor element REb connected to the operational amplifier OPb corresponding to the resistor element ZM(1,b). Note that if a feeder line A other than the feeder line A1 is used as the measurement feeder line AM, the corrected resistance value Rz of the measurement resistor element ZM can be calculated using the same procedure as for the feeder line A1.

[0054]

number

[0055] The above formulas (3.1) to (3.n) are derived as follows. First, the theoretical formulas for the correction output voltages VCout(1) to VCout(n) in the state shown in Fig. 5A are as shown in the following formulas (4.1) to (4.n). In formulas (4.1) to (4.n), Vfc(1) to Vfc(n) represent the potentials of the connection points P(m,1) to P(m,n), respectively, Re(1) to Re(n) represent the resistance values ​​of the resistance elements RE1 to REn connected to the operational amplifiers OP1 to OPn, and Rc(1) to Rc(n) represent the resistance values ​​of the correction resistance elements ZC(m,1) to ZC(m,n).

[0056]

number

[0057] Here, by dividing formulas (4.2) to (4.n) by formula (4.1), the following formulas (5.1) to (5.n) are obtained.

[0058]

number

[0059] Furthermore, by transforming equations (5.1) to (5.n), we obtain the following equations (6.1) to (6.n).

[0060]

number

[0061] In the element array circuit 10, if the resistance value of the portion from the DC power supply PS1 to the connection point P(m,1) is sufficiently small, Vfc(1) can be replaced with V1. That is, by replacing Vfc(1) in equations (6.1) to (6.n) with V1, the following equations (7.1) to (7.n) are obtained.

[0062]

number

[0063] Next, the theoretical formulas for the measurement output voltages VMout(1) to VMout(n) in the state shown in Figure 5B are as shown in the following formulas (8.1) to (8.n). In formulas (8.1) to (8.n), Vf(1) to Vf(n) represent the potentials of connection points P(1,1) to P(1,n), respectively, Re(1) to Re(n) represent the resistance values ​​of resistor elements RE1 to REn connected to operational amplifiers OP1 to OPn, and Rz(1,1) to Rz(1,n) represent the resistance values ​​of measurement resistor elements Z(1,1) to ZM(1,n).

[0064]

number

[0065] Transforming equations (8.1) to (8.n) into equations for calculating the resistance values ​​Rz(1,1) to Rz(1,n) gives equations (9.1) to (9.n).

[0066]

number

[0067] In the element array circuit 10, if the difference between the electrical resistance value of section S of the correction feeder AC during measurement and the electrical resistance value of the corresponding section S of the measurement feeder AM during measurement is sufficiently small, and the difference between the electrical resistance value of the correction resistor ZC during measurement and the electrical resistance value of the measurement resistor ZM is sufficiently small (substantially the same), then Vf(1) to Vf(n) can be replaced with Vfc(1) to Vfc(n), respectively. That is, the following equations (10.1) to (10.n) can be obtained from equations (9.1) to (9.n):

[0068]

number

[0069] Furthermore, substituting the right-hand sides of equations (7.1) through (7.n) for Vfc(1) through Vfc(n) in equations (10.1) through (10.n) yields the above-described equations (3.1) through (3.n). That is, the control circuit 20 corrects the measurement output voltage VMout(b) corresponding to, for example, the b-th resistor element ZM(1,b) connected from node P(1,1) among resistor elements ZM(1,1) through ZM(1,n), as shown in equation (2.b). It can be assumed that, at the same ambient temperature, the voltage drop from the first end of the correction feeder AC to the correction resistor element ZC(m,b) is approximately the same as the voltage drop from the first end of the measurement feeder AM to the resistor element ZM(1,b). Therefore, as shown in equation (2.b), the output voltage VCout(r) resulting from the resistor ZM(1,r) is corrected using the output voltage VCout(1) resulting from the q-th (q is a natural number; in this example, q = 1) correction resistor ZC(m,1) counting from the first end of the correction feeder AC and connected to a connection point where the voltage drop from the potential V1 is relatively small, and the output voltage VCout(r) resulting from the r-th (r is a natural number greater than q) correction resistor ZC(m,r) counting from the first end of the correction feeder AC and connected to a connection point where the voltage drop from the potential V1 is relatively large. This mitigates the effect of the voltage drop on the measurement accuracy of the physical quantity to be measured by the resistor ZM(1,r) connected to a connection point where the voltage drop from the potential V1 is relatively large. Note that although the case of q = 1 is described here, q may be a natural number greater than or equal to 2. Furthermore, the correction of the output voltage resulting from the resistor ZM(1,q) connected to a connection point where the voltage drop is relatively small (i.e., when the value of q is small) may be omitted.

[0070] [Actions and effects of sensor device 1] As described above, in the sensor device 1 of this embodiment, the control circuit 20 uses at least two of the correction output voltages VCout resulting from the correction resistor elements ZC connected to the correction feeder line AC (e.g., the correction output voltage VCout(1) and the correction output voltage VCout(b)) to correct the measurement output voltage VMout resulting from at least one of the measurement resistor elements ZM connected to one measurement feeder line AM other than the correction feeder line AC. This reduces the effect of the wiring resistance of the measurement feeder line AM on the measurement accuracy of the physical quantity to be measured.

[0071] Therefore, the sensor device 1 of this embodiment can achieve high measurement accuracy for the physical quantity to be measured, for example, the intensity of electromagnetic waves such as infrared rays irradiated onto the element array circuit 10.

[0072] <2. Second Embodiment> [Overall configuration example of sensor device 2] Fig. 6 is a circuit diagram schematically illustrating an example configuration of a sensor device 2 according to a second embodiment of the present disclosure. The sensor device 2 includes, for example, an element array circuit 30 and a control circuit 20. As shown in Fig. 6, the configuration of the element array circuit 30 differs from the configuration of the element array circuit 10 in Fig. 1 in that, instead of a plurality of resistive elements RE (RE1 to REn), a plurality of capacitive elements CP (CP1 to CPn) and a plurality of switches SW (SW1 to SWn) are provided corresponding to a plurality of operational amplifiers OP (OP1 to OPn).

[0073] Each of the multiple capacitive elements CP is connected to both the negative input terminal T2 and the output terminal T3 of a corresponding operational amplifier OP and converts the current flowing through the readout line B connected to the negative input terminal T2 into a voltage. Specifically, in the example of Figure 6, capacitive element CP1 is connected to both the negative input terminal T2 and the output terminal T3 of operational amplifier OP1 and converts the current flowing through the readout line B1 into a voltage. Similarly, capacitive element CP2 is connected to both the negative input terminal T2 and the output terminal T3 of operational amplifier OP2 and converts the current flowing through the readout line B2 into a voltage, and capacitive element CPn is connected to both the negative input terminal T2 and the output terminal T3 of operational amplifier OPn and converts the current flowing through the readout line Bn into a voltage.

[0074] Each of the switches SW is connected to a corresponding one of the operational amplifiers OP. Each of the switches SW is connected in parallel with a corresponding one of the capacitive elements CP between the negative input terminal T2 and the output terminal T3 of the corresponding operational amplifier OP. Each of the switches SW can be in a conductive state or a non-conductive state. Specifically, in the example of FIG. 6 , the switch SW1 is connected in parallel with the capacitive element CP1 between the negative input terminal T2 and the output terminal T3 of the operational amplifier OP1, and can be in a conductive state or a non-conductive state. Similarly, the switch SW2 is connected in parallel with the capacitive element CP2 between the negative input terminal T2 and the output terminal T3 of the operational amplifier OP2, and can be in a conductive state or a non-conductive state. The switch SWn is connected in parallel with the capacitive element CPn between the negative input terminal T2 and the output terminal T3 of the operational amplifier OPn, and can be in a conductive state or a non-conductive state.

[0075] [Measurement operation in sensor device 2] In the sensor device 2, in a measurement environment where electromagnetic waves such as infrared rays are irradiated, the output voltages corresponding to the plurality of resistance elements Z can be measured in the same manner as the measurement operation in the sensor device 1 (FIG. 4).

[0076] However, in step S101 (FIG. 4), all switches SW1 to SWn are set to a conductive state, and for example, switch SWA1-m corresponding to the power feeder Am serving as the correction power feeder AC is set to a conductive state, and switch SWA2-m is set to a non-conductive state. Also, switches SWA1-1, SWA1-2, . . . , SWA1-m-1 are set to a non-conductive state, and switches SWA2-1, SWA2-2, . . . , SWA1-m-1 are set to a conductive state. Next, after all switches SW1 to SWn are set to a non-conductive state, the correction output voltages VCout(1) to VCout(n) are measured after time T has elapsed. Also, in step S102 (FIG. 4), all switches SW1 to SWn are set to a conductive state, and for example, switch SWA1-1 corresponding to the power feeder A1 serving as the measurement power feeder AM is set to a conductive state, and switch SWA2-1 is set to a non-conductive state. Also, switches SWA1-2,...,SWA1-m are set to a non-conductive state, and switches SWA2-2,...,SWA2-m are set to a conductive state. Next, after switches SW1 to SWn are all set to a non-conductive state, measurement output voltages VMout(1) to VMout(n) are measured after time T has elapsed.

[0077] The output voltage Vout can be expressed as the following equation (11). Vout={(V2-Vf) / (Cz×Rz)}×T+V2 ……(11) where: Vf: The potential of the connection point P corresponding to each selective resistance element ZS. V2: A second potential which is the potential of the positive input terminal T1. Cz: the capacitance value of one capacitance element CP connected to the operational amplifier OP corresponding to each selected resistance element ZS. Rz: the resistance value of each selective resistance element ZS. T: The time elapsed after one switch SW connected to the operational amplifier OP corresponding to each selective resistance element ZS is turned off. Vout: the output voltage of one operational amplifier OP corresponding to each selective resistance element ZS after the time T has elapsed.

[0078] In step S103 (FIG. 4), which corrects the measured value of the measurement output voltage VMout using the measured value of the correction output voltage VCout, the measurement output voltages VMout(1) through VMout(n) corresponding to the respective resistive elements ZM(1,1) through ZM(1,n) connected to the measurement feeder line AM (e.g., feeder line A1) are corrected as shown in the above-described equations (2.1) through (2.n). Therefore, the resistance values ​​Rz(1,1) through Rz(1,n) of the respective resistive elements ZM(1,1) through ZM(1,n) are calculated using the following equations (12.1) through (12.n). Note that Cz(1) through Cz(n) in equations (12.1) through (12.n) are the capacitance values ​​of the capacitive elements CP1 through CPn corresponding to the respective resistive elements ZM(1,1) through ZM(1,n).

[0079]

number

[0080] [Actions and effects of sensor device 2] In the sensor device 2 of this embodiment, the control circuit 20 also uses at least two of the correction output voltages VCout resulting from the multiple correction resistor elements ZC connected to the correction feed line AC (e.g., the correction output voltage VCout(1) and the correction output voltage VCout(c), where c is a natural number greater than 1 and less than or equal to n) to correct the measurement output voltage VMout resulting from at least one of the multiple measurement resistor elements ZM connected to one measurement feed line AM other than the correction feed line AC. This reduces the effect of the wiring resistance of the measurement feed line AM on the measurement accuracy of the physical quantity to be measured.

[0081] Therefore, the sensor device 2 of this embodiment can achieve high measurement accuracy for the physical quantity to be measured, for example, the intensity of electromagnetic waves such as infrared rays irradiated onto the element array circuit 10.

[0082] <3. Third Embodiment> [Overall configuration example of sensor device 3] 7 is a circuit diagram schematically illustrating an example configuration of a sensor device 3 according to a third embodiment of the present disclosure. The sensor device 3 includes, for example, an element array circuit 40 and a control circuit 20. In the sensor device 3, a first end of a power supply line Am serving as a correction power supply line AC is connected to a DC power supply PS3 different from the DC power supply PS1. A voltage is applied to the first end of the power supply line Am by the DC power supply PS3 so that the potential of the first end of the power supply line Am becomes a third potential V3. Here, the sign of the potential (third potential V3) at the first end of the correction feed line Am relative to the potential (second potential V2) at the positive input terminal T1 of the operational amplifier OP (the sign of the potential difference between the second potential V2 and the third potential V3) is opposite to the sign of the potential (first potential) V1 at the first end of the measurement feed line A1 relative to the potential (second potential V2) at the positive input terminal T1 of the operational amplifier OP (the sign of the potential difference between the second potential V2 and the first potential V1). For example, when the potential of the positive input terminal T1 of the operational amplifier OP is 0 V and a voltage is applied from DC power supply PS1 to the feed line A1 so that the potential of the first end of the feed line A1 serving as the measurement feed line AM is +Vf, a voltage from DC power supply PS3 may be applied to the feed line Am so that the potential of the first end of the feed line Am serving as the correction feed line AC is −Vf. However, the absolute value of the potential difference between the potential of the positive input terminal T1 of the operational amplifier OP and the potential of the first end of the feeder line A1 serving as the measurement feeder line AM may be different from the absolute value of the potential difference between the potential of the positive input terminal T1 of the operational amplifier OP and the potential of the first end of the feeder line Am serving as the correction feeder line AC.

[0083] Furthermore, the sensor device 3 is provided with an electromagnetic wave shield 41 that covers the correction resistor element ZC, which is provided along the correction power supply line AC. Therefore, in the sensor device 3, the correction resistor element ZC can be used as a reference element to correct measurement errors that depend on environmental factors surrounding the sensor device 3, such as measurement errors that depend on ambient temperature. For example, as shown in FIG. 7, when a current I1 flows through resistor element Z(1,1) serving as the measurement resistor element ZM that measures the electromagnetic wave to be measured (e.g., infrared radiation), and a current I2 flows through resistor element Z(m,1) serving as the correction resistor element ZC, which also serves as the reference element, a current I3, which is the difference between current I1 and current I2, is input to the negative input terminal T2 of the operational amplifier OP1. Here, resistor element Z(1,1) has a resistance value that reflects the influence of the irradiated electromagnetic wave in addition to the influence of the ambient temperature, so current I1 reflects both the influence of the ambient temperature and the influence of the electromagnetic wave. On the other hand, resistor element Z(m,1) is affected by the ambient temperature but not by the irradiated electromagnetic wave. Therefore, current I2 is a current value that reflects only the influence of environmental temperature out of the influence of environmental temperature and the influence of electromagnetic waves. Therefore, current I3, which is the difference between current I1 and current I2, is a current value that reflects only the influence of electromagnetic waves, with the influence of environmental temperature canceled out.

[0084] [Measurement operation in sensor device 3] The sensor device 3 can also measure output voltages corresponding to each of the multiple resistance elements Z in a measurement environment where infrared rays or other electromagnetic waves are irradiated, similar to the measurement operation of the sensor device 1 (FIG. 4). However, in step S102 (FIG. 4), when measuring the measurement output voltage VMout, the switch SWA1-m is set to a conductive state, the switch SWA2-m is set to a non-conductive state, and a voltage is applied from a DC power supply PS1 to the measurement power supply A1 while a voltage is applied from a DC power supply PS3 to the correction power supply Am to which the correction resistance elements ZC(m,1) to ZC(m,n), which also serve as reference elements, are connected. The sensor device 3 also corrects the measurement value of the measurement output voltage VMout using the measurement value of the correction output voltage VCout (step S103).

[0085] [Actions and effects of sensor device 3] In the sensor device 2 of this embodiment, the control circuit 20 also uses at least two of the correction output voltages VCout resulting from the multiple correction resistor elements ZC connected to the correction feeder line AC (e.g., the correction output voltage VCout(1) and the correction output voltage VCout(d), where d is a natural number greater than 1 and less than or equal to n) to correct the measurement output voltage VMout resulting from at least one of the multiple measurement resistor elements ZM connected to one measurement feeder line VM other than the correction feeder line AC. This reduces the effect of the wiring resistance of the measurement feeder line AM on the measurement accuracy of the physical quantity to be measured.

[0086] Furthermore, in the sensor device 3, the positive / negative sign of the potential at the first end of the feeder line A1 serving as the measurement feeder line AM relative to the potential at the positive input terminal T1 of the operational amplifier OP is opposite to the positive / negative sign of the potential at the first end of the feeder line Am serving as the correction feeder line AC relative to the potential at the positive input terminal T1 of the operational amplifier OP. Therefore, by using the correction resistor element ZC as a reference element, it is possible to correct measurement errors that depend on environmental factors around where the sensor device 3 is placed, such as measurement errors that depend on the ambient temperature.

[0087] Therefore, the sensor device 2 of this embodiment can achieve high measurement accuracy for the physical quantity to be measured, for example, the intensity of electromagnetic waves such as infrared rays irradiated onto the element array circuit 10.

[0088] <4. Modifications> Although the present disclosure has been described above by giving several embodiments, the present disclosure is not limited to these embodiments and various modifications are possible.

[0089] For example, in the sensor devices 1 to 3 of the first to third embodiments described above, the resistive element Z in the element array circuits 10, 30, and 40 is a light-receiving element that converts electromagnetic waves such as infrared rays into an electrical signal, but the sensor device of the present disclosure is not limited to this case.

[0090] For example, the impedance element of the present disclosure may be a temperature-sensitive resistor using a thermistor material or a temperature-sensitive conductive ink material. Such a temperature-sensitive resistor changes its electrical resistance depending on the temperature. In this case, the sensor device becomes a temperature sensor capable of measuring the temperature distribution within a surface.

[0091] Alternatively, the impedance element of the present disclosure may be a pressure-sensitive element using a pressure-sensitive conductive ink material or the like. Such a pressure-sensitive element has an electrical resistance that changes depending on the strength of the pressure applied. A sensor device using a pressure-sensitive element as an impedance element serves as a pressure sensor that can measure pressure distribution within a surface.

[0092] Furthermore, a strain gauge may be used as the impedance element of the present disclosure. Such a strain gauge has an electrical resistance that changes depending on the strength of the applied stress. A sensor device using a strain gauge as an impedance element serves as a strain sensor that can measure the stress distribution in a plane.

[0093] Furthermore, for example, in the sensor device 1 of the first embodiment, among the m power feeders A1 to Am in the element array circuit 10, the power feeder Am is used as the correction power feeder AC, and the other power feeders A are used as the measurement power feeders AM. However, among the power feeders A1 to Am, the power feeders A other than the power feeder Am may be used as the correction power feeder AC.

[0094] Furthermore, for example, while the drawings illustrating the sensor devices 1 to 3 of the first to third embodiments illustrate an example in which the extension directions of the multiple first wirings are parallel to each other, the present disclosure is not limited to this, and the multiple first wirings may be non-parallel to each other. Furthermore, the multiple first wirings are not limited to extending in a straight line, and may extend in a curved line as a whole, or may have a shape that includes a curved or bent portion. Similarly, while the drawings illustrating the sensor devices 1 to 3 of the first to third embodiments illustrate an example in which the extension directions of the multiple second wirings are parallel to each other, the present disclosure is not limited to this, and the multiple second wirings may be non-parallel to each other. Furthermore, the present disclosure is not limited to an example in which the multiple first wirings and the multiple second wirings extend in directions that are perpendicular to each other. Furthermore, the multiple second wirings are not limited to extending in a straight line, and may extend in a curved line as a whole, or may have a shape that includes a curved or bent portion.

[0095] Furthermore, while the sensor devices 1 to 3 of the first to third embodiments described above have multiple resistance elements as multiple impedance elements, the sensor device of the present disclosure is not limited to this and may, for example, have multiple semiconductor elements. Such semiconductor elements, for example, have electrical characteristics that change with temperature, such as diodes. Furthermore, while the sensor devices 1 to 3 of the first to third embodiments described above have multiple operational amplifiers, the sensor device of the present disclosure is not limited to this and may, for example, have only one operational amplifier, and the readout line B connected to the output terminal T3 of the single operational amplifier OP may be switched by a switch.

[0096] The effects described in this specification are merely examples and are not limiting, and other effects may also be present. [Explanation of symbols]

[0097] 1 to 3...sensor devices, 10, 30, 40...element array circuit, 20...control circuit, A (A1 to Am)...power supply line, B (B1 to Bn)...readout line, OP (OP1 to OPn)...operational amplifier, PS1, PS2...DC power supply, R (R(1,1) to R(m,n))...resistance element.

Claims

1. an element array circuit including a plurality of first wirings, a plurality of second wirings each extending in a direction different from that of the plurality of first wirings, and a plurality of impedance elements each connected to both one of the plurality of first wirings and one of the plurality of second wirings; a control circuit that uses at least two of output voltages resulting from a plurality of compensation impedance elements connected to one compensation first wiring selected from the plurality of first wirings among the plurality of impedance elements to compensate an output voltage resulting from at least one of a plurality of measurement impedance elements connected to one measurement first wiring other than the compensation first wiring selected from the plurality of first wirings among the plurality of impedance elements; A sensor device comprising:

2. each of the plurality of first wirings includes a first end connected to a power supply or a ground and a second end on the opposite side of the first end from the power supply or the ground; The control circuit The output voltage resulting from the r-th measurement impedance element, counting from the first end of the first measurement wiring, among the plurality of measurement impedance elements connected to the first measurement wiring is corrected using a ratio between an output voltage resulting from the q-th (q is a natural number) correction impedance element, counting from the first end of the first correction wiring, among the plurality of correction impedance elements connected to the first correction wiring, and an output voltage resulting from the r-th (r is a natural number greater than q) correction impedance element, counting from the first end of the first measurement wiring, among the plurality of measurement impedance elements connected to the first measurement wiring. The sensor device according to claim 1 .

3. The q is 1. The sensor device according to claim 2.

4. The method further includes providing an electromagnetic wave shield that covers the plurality of impedance elements for correction. The sensor device according to claim 1 .

5. the element array circuit further includes one or more operational amplifiers, each having one positive input terminal set to a first potential and one negative input terminal connectable to one of the plurality of second wirings; each of the plurality of first wirings includes a first end connected to a power supply or a ground and a second end on the opposite side of the first end from the power supply or the ground; The sign of the potential at the first end of the first measurement wiring relative to the first potential is opposite to the sign of the potential at the first end of the first correction wiring relative to the first potential. The sensor device according to claim 4.

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