Signal output device and concentration measuring system

Abstract

To provide a signal output device and a concentration measuring system that can correct deviation due to characteristic variations of each device and achieve concentration measurement with high accuracy.SOLUTION: A signal output unit includes: a support portion 318; a light receiving unit 111 that is provided on the support portion 318, receives infrared radiated to a measurement object, and outputs a detection signal S111 according to the received infrared; a storage unit 112 that is provided on the support portion 318, and stores a parameter according to at least one characteristic as a calibration parameter among a plurality of components including the light receiving unit 111 used for concentration calculation of the measurement object; and an interface unit 113 that is provided on the support portion 318, does not execute concentration calculation, and outputs an output signal S113 including a signal based on a calibration parameter signal S112 according to the calibration parameter input from the storage unit 112 and the detection signal S111 input from the light receiving unit 111 to a signal calculation processing unit 13 provided outside.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a signal output device for a concentration measurement system and a concentration measurement system. [Background technology]

[0002] A quantum infrared gas concentration meter that calculates the concentration of a measurement object based on a detection signal corresponding to received infrared light is disclosed in, for example, Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-203004 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional quantum infrared gas concentration meters are capable of calculating the concentration of the substance being measured using a predetermined calculation process, but they have the problem of difficulty in correcting deviations caused by variations in the characteristics of each element that makes up the quantum infrared gas concentration meter.

[0005] The conventional quantum infrared gas concentration meter described in Patent Document 1 has a calculation means, and by using desired calibration parameters in this calculation means, it is possible to accurately calculate the concentration of the object to be measured. However, the calculation means is large in size compared to the entire quantum infrared gas concentration meter, which hinders miniaturization of the entire device.

[0006] On the other hand, if the calculation means is an external device, it is not easy for the calculation means to correct deviations due to variations in the characteristics of each quantum infrared gas concentration meter. In other words, it is necessary to connect the quantum infrared gas concentration meter to an external device having the calculation means, perform calibration in a desired environment, and store the calibration parameters obtained in the calculation means, which makes it difficult to easily achieve high-precision gas concentration measurement.

[0007] That is, an object of the present invention is to provide a small signal output device and a concentration measurement system that can easily correct deviations caused by characteristic variations of each element and achieve highly accurate concentration measurements. [Means for solving the problem]

[0008] In order to achieve the above object, a signal output device according to one aspect of the present invention comprises: a support section; a light receiving section provided in the support section, which receives infrared light irradiated onto an object to be measured and outputs a detection signal corresponding to the received infrared light; a memory section provided in the support section, which stores parameters used in calculating the concentration of the object to be measured and corresponding to the characteristics of at least one of a plurality of components including the light receiving section as calibration parameters; and an interface section provided in the support section, which outputs an output signal to an external signal calculation processing section, without performing the concentration calculation, the output signal including a calibration parameter signal corresponding to the calibration parameter input from the memory section and a signal based on the detection signal input from the light receiving section.

[0009] In addition, in order to achieve the above-mentioned object, a concentration measurement system according to one aspect of the present invention comprises a signal output device according to the above-mentioned aspect of the present invention, and a signal calculation processing unit that is provided externally and calculates the concentration of the object to be measured based on a signal based on the detection signal included in the output signal input from the interface unit and the calibration parameter signal.

[0010] In addition, in order to achieve the above-mentioned object, a concentration measurement system according to another aspect of the present invention comprises a signal output device according to the above-mentioned one aspect of the present invention, and a signal calculation processing unit that is provided externally and calculates the concentration of the object to be measured based on a signal based on the detection signal included in the output signal input from the interface unit, the calibration parameter signal, and a drive signal for driving the light-emitting unit. [Effects of the Invention]

[0011] According to the signal output device of one aspect of the present invention and the concentration measurement system of each aspect of the present invention, deviations caused by variations in the characteristics of each element can be easily corrected to achieve high-precision concentration measurement, and miniaturization can be achieved. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a block diagram showing an example of a schematic configuration of a signal output device and a concentration measurement system according to a first embodiment of the present invention. [Figure 2] FIG. 10 is a block diagram showing an example of a schematic configuration of a signal output device and a concentration measurement system according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a block diagram showing an example of a schematic configuration of a signal output device and a concentration measurement system according to a third embodiment of the present invention. [Figure 4] FIG. 10 is a cross-sectional view showing an example of the schematic configuration of a signal output device and a concentration measurement system according to a third embodiment of the present invention. [Figure 5] FIG. 11 is a cross-sectional view showing an example of a schematic configuration of a signal output device and a concentration measurement system according to a modified example of the third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0014] [First embodiment] A signal output device and a concentration measurement system according to a first embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a block diagram showing an example of a schematic configuration of a signal output device 11 and a concentration measurement system 1 according to this embodiment. Below, the signal output device according to this embodiment will be described using a signal output device 11 for a concentration measurement system as an example.

[0015] As shown in FIG. 1, the signal output device 11 according to this embodiment includes a light-receiving unit 111 that receives infrared rays (IR) irradiated onto a measurement object and outputs a detection signal S111 corresponding to the received infrared rays. The signal output device 11 also includes a memory unit 112 that stores, as calibration parameters, parameters corresponding to the characteristics of at least one of a plurality of components, including the light-receiving unit 111, used in calculating the concentration of the measurement object. That is, the memory unit 112 stores, as calibration parameters, parameters corresponding to the characteristics of the signal output device 11 (i.e., the characteristics of the components of the signal output device 11). The signal output device 11 also includes an interface unit 113 that outputs, to an external signal calculation processor 13, a calibration parameter signal S112 corresponding to the calibration parameters input from the memory unit 112 and an output signal S113 based on the detection signal S111 input from the light-receiving unit 111, without performing concentration calculation. The interface unit 113 is electrically connected to the light-receiving unit 111 and the memory unit 112. The light receiving unit 111 is configured by, for example, a photodetector. The signal output device 11 includes a support unit that supports the light receiving unit 111, the storage unit 112, and the interface unit 113 (see FIG. 4). The light receiving unit 111, the storage unit 112, and the interface unit 113 are provided on the support unit.

[0016] The "calibration parameter signal according to the calibration parameter" is a signal configured so that the calibration parameter can be extracted. Furthermore, the "calibration parameter signal according to the parameter" described later is a signal configured so that the parameter can be extracted. The concepts of the "calibration parameter signal according to the calibration parameter" and the "calibration parameter signal according to the parameter" are the same in the second and third embodiments described later.

[0017] The phrase "the output signal S113 includes a signal based on the calibration parameter signal S112 and the detection signal S111" includes the concept of collectively referring to the output signal S113 as a signal based on the calibration parameter signal S112 and the detection signal S111 that are individually output from the signal output device 11 to the signal calculation processing unit 13. Furthermore, the phrase "the output signal S113 includes a signal based on the calibration parameter signal S112 and the detection signal S111" includes the concept of embedding in the output signal S113 a signal based on the calibration parameter signal S112 and the detection signal S111 that has been converted into a format that complies with a signal standard for transmitting and receiving signals between predetermined components.

[0018] The output signal S113 also includes a digital detection signal S111d. The analog detection signal S111 and the digital detection signal S111d output from the light receiving unit 111 are signals that have the same information but differ only in signal format. Therefore, in this embodiment, the signal based on the detection signal S111 refers to the signal that is actually included between the analog detection signal S111 and the digital detection signal S111d. In other words, as in this embodiment, when the output signal S113 includes the digital detection signal S111d, the signal based on the detection signal S111 becomes the detection signal S111d. On the other hand, when the output signal S113 includes the analog detection signal S111, the signal based on the detection signal S111 becomes the detection signal S111.

[0019] The interface unit 113 receives the detection signal S111 output by the light receiving unit 111 and the calibration parameter signal S112 output by the storage unit 112. The interface unit 113 may be configured to amplify the input detection signal S111 and perform analog-to-digital conversion of the amplified detection signal S111 to generate a digital detection signal S111d. In this way, the interface unit 113 may be configured to amplify and perform analog-to-digital conversion of the detection signal S111, but is configured not to perform arithmetic processing of the detection signal S111.

[0020] The signal output device 11 may include an amplifier unit that amplifies the detection signal S111 output by the light receiving unit 111, and an analog-to-digital converter unit that performs analog-to-digital conversion on the detection signal S111 amplified by the amplifier unit and outputs a digital detection signal S111d to the interface unit 113.

[0021] Furthermore, from the viewpoint of miniaturization, the signal output device 11 includes an integrated circuit 110 that integrates a storage unit 112 and an interface unit 113. However, the signal output device 11 may of course have a configuration in which the storage unit 112 and the interface unit 113 are not integrated.

[0022] 1, the concentration measurement system 1 according to this embodiment includes a signal output device 11 having the above-described configuration, and a signal calculation processing unit 13 that is provided externally and calculates the concentration of a measurement object (not shown) based on a signal based on a detection signal S111 included in an output signal S113 input from an interface unit 113 and a calibration parameter signal S112. The signal calculation processing unit 13 is configured to output the calculation result as a concentration signal S13 from the concentration measurement system 1. Here, "external" means outside the signal output device 11, and specifically refers to a part that is not included in the signal output device 11 supported by a support unit, and "provided externally" means that it is not provided on the support unit and is not integrated with the signal output device 11.

[0023] The storage unit 112 stores parameters corresponding to the characteristics of the light receiving unit 111, one of the multiple components provided in the signal output device 11, as calibration parameters, and outputs a calibration parameter signal S112 corresponding to the calibration parameters to the interface unit 113. The interface unit 113 outputs an output signal S113 including the detection signal S111 input from the light receiving unit 111 and the calibration parameter signal S112 input from the storage unit 112 to the signal calculation processing unit 13 provided externally.

[0024] The concentration measurement system 1 outputs a calibration parameter signal S112 stored in advance in a storage unit 112 from the signal output device 11 to the signal calculation processing unit 13, and the signal calculation processing unit 13, which corresponds to an external component as viewed from the signal output device 11, corrects the concentration calculation of the object to be measured using the calibration parameter signal S112. The storage unit 112 stores parameters corresponding to the characteristics of the light receiving unit 111 (e.g., at least one of electrical characteristics and non-electrical characteristics) as parameters corresponding to the characteristics of at least one of the multiple components provided in the signal output device 11. The interface unit 113 is capable of including the calibration parameter signal S112 corresponding to the parameters of the characteristics of the light receiving unit 111 (i.e., parameters corresponding to the characteristics of the light receiving unit 111) in an output signal S113 and outputting the output signal S113 to the signal calculation processing unit 13. This enables the concentration measurement system 1 to output a concentration signal S13 corrected according to the characteristics specific to each component (the light receiving unit 111 in this embodiment) provided in the signal output device 11. When the parameters according to the characteristics of the light receiving unit 111 stored in the memory unit 112 are parameters for correcting the characteristic variations of the light receiving unit 111, the signal calculation processing unit 13 can generate and output a density signal S13 in which the characteristic variations of the light receiving unit 111 have been corrected. Here, the characteristic variations of the light receiving unit 111 include, for example, variations in photoelectric conversion characteristics caused by variations in the electrical characteristics of the photodetector constituting the photoelectric conversion unit of the light receiving unit 111, variations in the voltage or current of the output signal caused by variations in the electrical characteristics of the photodetector constituting the output unit of the light receiving unit 111, etc.

[0025] The calibration parameter signal S112 is not particularly limited as long as it can ultimately correct the concentration calculation of the object to be measured in accordance with, for example, the characteristics of the light receiving unit 111. In other words, the calibration parameter signal S112 is not particularly limited as long as it can ultimately correct the concentration calculation of the object to be measured in accordance with, for example, the characteristic variations of the light receiving unit 111. When the signal calculation processing unit 13 calculates the concentration by applying the input detection signal S111 to, for example, a predetermined mathematical formula, the parameters of the calibration parameter signal S112 may be used as coefficients of the predetermined mathematical formula. For example, if the predetermined mathematical formula is a cubic function "y=a×x 3 +b×x 2 +c×x+d", the coefficients a, b, c, and d can be parameters of the calibration parameter signal (i.e., calibration parameters stored in the storage unit 112). In this cubic function, y may be the concentration result of the object to be measured, and x may be a signal corresponding to the detection signal S111 output from the light receiving unit 111.

[0026] Furthermore, in the signal output device 11 according to this embodiment, the interface unit 113 outputs the calibration parameter signal S112 to the signal calculation processing unit 13 without performing a concentration calculation. The interface unit 113 not only performs concentration calculations using the calibration parameters included in the calibration parameter signal S112, but also concentration calculations without using the calibration parameters. Here, the concentration calculation includes not only the actual concentration calculation but also correction of the output signal according to the concentration. In other words, the signal output device 11 does not include a calculation unit that performs calculations based on the input signal. This allows the signal output device 11 and the concentration measurement system 1 to reduce thermal and electromagnetic effects that may be exerted on the light receiving unit 111 by heat and electromagnetic waves generated by the calculation operation of the calculation unit. This enables the concentration measurement system 1 to measure the concentration of the object to be measured with high accuracy.

[0027] The storage unit 112 stores, as calibration parameters, for example, a plurality of parameters corresponding to the characteristics of the light-receiving unit 111 as parameters corresponding to the characteristics of at least one of a plurality of components included in the signal output device 11. The storage unit 112 stores, as calibration parameters, for example, parameters associated with the magnitude of characteristic variation of the light-receiving unit 111. During a shipping inspection of the concentration measurement system 1, concentration measurements of a standard measurement object with a known concentration are repeatedly performed while changing the parameters. The concentration measurement system 1 sets, as calibration parameters to be used during actual operation, parameters that provide a concentration closest to the known concentration. This allows the concentration measurement system 1 to measure the concentration of the measurement object according to the characteristics of the light-receiving unit 111 (for example, characteristic variation of the light-receiving unit). Setting of the calibration parameters according to the characteristics of the light-receiving unit 111 is not limited to during shipping inspection of the concentration measurement system 1, and may be performed before operation of the concentration measurement system 1.

[0028] The setting of the calibration parameters according to the characteristics of the light receiving unit 111 may be performed, for example, by a control unit (not shown) provided in the signal output device 11 for overall control of the signal output device 11, and a control unit provided in the signal calculation processing unit 13 for overall control of the signal calculation processing unit 13. Furthermore, the setting of the calibration parameters according to the characteristics of the light receiving unit 111 may be performed, for example, by a control unit (not shown) provided in the concentration measurement system 1 for overall control of both the signal output device 11 and the signal calculation processing unit 13.

[0029] As described above, the signal output device 11 according to this embodiment includes a support section, a light receiving section 111 that is provided in the support section and receives infrared light irradiated onto the object to be measured and outputs a detection signal S111 corresponding to the received infrared light, a memory section 112 that is provided in the support section and stores parameters that are used to calculate the concentration of the object to be measured and correspond to the characteristics of at least one of a plurality of components including the light receiving section 111 as calibration parameters, and an interface section 113 that is provided in the support section and is capable of outputting an output signal S113 to an external signal calculation processing section 13, the output signal S113 including a calibration parameter signal S112 corresponding to the calibration parameters input from the memory section 112 without performing concentration calculation and a signal based on the detection signal S111 input from the light receiving section 111.

[0030] The concentration measurement system 1 according to this embodiment also includes a signal output device 11 according to this embodiment, and a signal calculation processing unit 13 that is provided externally and calculates the concentration of the object to be measured based on a signal based on the detection signal S111 included in the output signal S113 input from an interface unit 113 and a calibration parameter signal S112.

[0031] As a result, the signal output device 11 and the concentration measurement system 1 can easily correct deviations caused by variations in the characteristics of each device (in this embodiment, the light receiving unit 111), thereby achieving high-precision concentration measurement and also achieving miniaturization.

[0032] [Second embodiment] A signal output device and a concentration measurement system according to a second embodiment of the present invention will be described with reference to Fig. 2. Fig. 2 is a block diagram showing an example of a schematic configuration of a signal output device 21 and a concentration measurement system 2 according to this embodiment. Below, the signal output device according to this embodiment will be described using the signal output device 21 for a concentration measurement system as an example.

[0033] As shown in FIG. 2, the signal output device 21 according to this embodiment includes a light-receiving unit 211 that receives infrared light irradiated onto the object to be measured and outputs a detection signal S211 corresponding to the received infrared light. The signal output device 21 also includes a memory unit 212 that stores, as calibration parameters, parameters used in calculating the concentration of the object to be measured and corresponding to the characteristics of at least one of the components including the light-receiving unit 211. The signal output device 21 also includes an interface unit 213 that can output, to an external signal calculation processor 23, an output signal S213 including a calibration parameter signal S212 corresponding to the calibration parameter input from the memory unit 212 and a signal based on the detection signal S211 input from the light-receiving unit 211, without performing concentration calculation. The interface unit 213 is electrically connected to the light-receiving unit 211 and the memory unit 212. The light-receiving unit 211 is, for example, a photodetector. The signal output device 21 also includes a support unit that supports the light-receiving unit 211, the memory unit 212, and the interface unit 213 (see FIG. 4). The light receiving section 111, the storage section 112, and the interface section 113 are provided on the support section.

[0034] The concept of "the output signal S213 includes a signal based on the calibration parameter signal S212 and the detection signal S211" is similar to the concept of "the output signal S113 includes a signal based on the calibration parameter signal S112 and the detection signal S111" in the first embodiment. Similarly to the interface unit 113 in the first embodiment, the interface unit 213 may be configured to amplify the input detection signal S211 and perform analog-to-digital conversion of the amplified detection signal S211 to generate a digital detection signal S211d. In this case, the output signal S213 includes the digital detection signal S211d. The interface unit 213 may be configured to amplify and analog-to-digital convert the detection signal S211, but is configured not to perform concentration calculation processing on the detection signal S211.

[0035] Here, the output signal S213 includes a digital detection signal S211d. The analog detection signal S211 and the digital detection signal S211d output from the light receiving unit 211 are signals having the same information but differing only in signal format. Therefore, in this embodiment, the signal based on the detection signal S211 refers to the signal actually included between the analog detection signal S211 and the digital detection signal S211d. In other words, as in this embodiment, when the output signal S213 includes the digital detection signal S211d, the signal based on the detection signal S211 becomes the detection signal S211d. On the other hand, when the output signal S213 includes the analog detection signal S211, the signal based on the detection signal S211 becomes the detection signal S211d.

[0036] 2, compared to the signal output device 11 according to the first embodiment, the signal output device 21 includes, as its multiple components, at least one of a light-emitting unit 214 that emits infrared rays, an optical member 215 that is arranged in an optical path through which the infrared rays emitted by the light-emitting unit 214 reach the light-receiving unit 211, or an optical path section 216 that guides the infrared rays emitted by the light-emitting unit 214 to the light-receiving unit 211. That is, in this embodiment, in addition to the light-receiving unit 211, the multiple components include at least one of the light-emitting unit 214 that is arranged on a support section (not shown) and emits infrared rays, the optical member 215 that is arranged on the support section and is arranged in an optical path through which the infrared rays emitted by the light-emitting unit 214 reach the light-receiving unit 211, or an optical path section 216 that is arranged on the support section and guides the infrared rays emitted by the light-emitting unit 214 to the light-receiving unit 211. In this way, the signal output device 21 according to this embodiment includes, as its multiple components, the light-emitting unit 214, the optical member 215, and the optical path section 216. Here, the light-emitting unit 214, the optical member 215, and the optical path unit 216 are also supported by the support (see FIG. 4). The light-emitting unit 214 is, for example, a light-emitting diode. The optical member 215 is formed of a material (e.g., silicon) that can transmit infrared rays. The optical member 215 may be a so-called optical filter that selectively transmits a predetermined wavelength band of infrared rays incident from the light-emitting unit 214. This allows the infrared rays emitted by the light-emitting unit 214 to select only the wavelength band absorbed by the object to be measured, enabling high-sensitivity and high-precision measurement. The optical member 215 may be provided near the light-emitting unit 214, near the light-receiving unit 211, or along the optical path from the light output from the light-emitting unit 214 to the light-receiving unit 211. The optical path unit 216 is formed of a material (e.g., aluminum) that can reflect infrared rays. The optical path unit 216 may also have a reflective film formed of a material that can reflect infrared rays on the surface onto which the infrared rays are incident. The optical path section 216 reflects the infrared light that has passed through the object to be measured once or multiple times and guides it to the light receiving section 211. This allows the signal output device 21 to improve the light receiving efficiency of the light receiving section 211 for the infrared light that has passed through the object to be measured. As a result, the concentration measurement system 2 according to this embodiment can improve the detection accuracy of the concentration of the object to be measured.

[0037] The storage unit 212 stores, as a calibration parameter, a parameter corresponding to the characteristics of the light receiving unit 211 as a parameter corresponding to the characteristics of at least one of the multiple components included in the signal output device 21. Furthermore, the storage unit 212 stores, as a calibration parameter, at least one parameter corresponding to the characteristics of a component other than the light receiving unit 211 among the multiple components included in the signal output device 21 as a parameter corresponding to the characteristics of at least one of the multiple components included in the signal output device 21. In this embodiment, the light emitting unit 214, the optical member 215, and the optical path unit 216 correspond to the components other than the light receiving unit 211 among the multiple components. Here, the respective characteristics of the light receiving unit 211 and the light emitting unit 214 are, for example, at least one of electrical characteristics and optical characteristics. Furthermore, the respective characteristics of the optical member 215 and the optical path unit 216 are, for example, optical characteristics.

[0038] The interface unit 213 is capable of including in the output signal S213 a calibration parameter signal S212 corresponding to a parameter of the characteristic of the light receiving unit 211 (i.e., a parameter corresponding to the characteristic of the light receiving unit 211) and outputting the output signal S213 to the signal calculation processing unit 23. Furthermore, the interface unit 213 is capable of including in the output signal S213 a calibration parameter signal S212 corresponding to at least one of the parameters (i.e., at least one of the parameters corresponding to the characteristics) stored in the storage unit 212 and outputting the output signal S213 to the signal calculation processing unit 23. Specifically, the interface unit 213 is capable of including in the output signal S213 a calibration parameter signal S212 corresponding to a parameter corresponding to the characteristic of the light receiving unit 211 and at least one of the parameters corresponding to the characteristics of the components (each of the light emitting unit 214, the optical member 215, and the optical path unit 216) other than the light receiving unit 211 among the multiple components provided in the signal output device 21 and outputting the output signal S213 to the signal calculation processing unit 23. Alternatively, the interface unit 213 can include in the output signal S213 a calibration parameter signal S212 corresponding to at least one of the parameters corresponding to the characteristics of the components other than the light receiving unit 211 (each of the light emitting unit 214, the optical member 215, and the optical path unit 216) among the multiple components provided in the signal output device 21, and output the signal to an externally provided signal calculation processing unit 23.

[0039] Here, the parameter according to the characteristic of the light receiving unit 211 may be a parameter for correcting characteristic variations of the light receiving unit 211. The parameter according to the characteristic of the light emitting unit 214 may be a parameter for correcting characteristic variations of the light emitting unit 214. The parameter according to the characteristic of the optical member 215 may be a parameter for correcting characteristic variations of the optical member 215. The parameter according to the characteristic of the optical path unit 216 may be a parameter for correcting characteristic variations of the optical path unit 216.

[0040] Furthermore, from the viewpoint of miniaturization, the signal output device 21 includes an integrated circuit 210 that integrates a storage unit 212 and an interface unit 213. However, the signal output device 21 may of course have a configuration in which the storage unit 212 and the interface unit 213 are not integrated.

[0041] As shown in FIG. 2, the concentration measurement system 2 according to this embodiment includes a signal output device 21 having the above-described configuration, and a signal calculation processing unit 23 that calculates the concentration of the object to be measured based on a signal based on the detection signal S211d included in the output signal S213 input from an external interface unit 213, a calibration parameter signal S212, and a drive signal S214dv for driving the light-emitting unit 214.

[0042] A drive signal S214dv for driving the light-emitting unit 214 is input to the interface unit 213 from the signal calculation processing unit 23. The interface unit 213 outputs the drive signal S214dv input from the signal calculation processing unit 23 to the light-emitting unit 214. Therefore, the signal calculation processing unit 23 outputs the drive signal S214dv to the light-emitting unit 214 via the interface unit 213. The drive signal S214dv includes information for driving the light-emitting unit 214. The drive signal S214dv may include information such as the ratio between operating time and non-operating time (duty ratio) for pulse-driving the light-emitting unit 214 and the amount of drive current to be passed through the light-emitting unit 214. The light-emitting unit 214 operates based on the information included in the drive signal S214dv input from the interface unit 213, and emits infrared light.

[0043] Information included in the drive signal S214dv output from the signal calculation processing unit 23 may be stored in the storage unit 212 via the interface unit 213. In this case, the interface unit 213 generates the drive signal S214dv based on the information input from the storage unit 212, and outputs the generated drive signal S214dv to the light-emitting unit 214. This allows the concentration measurement system 2 to change the drive conditions of the light-emitting unit 214 within the signal output device 21 without transmitting or receiving the drive signal S214dv between the signal output device 21 and the signal calculation processing unit 23, thereby reducing the load of the process of changing the drive conditions.

[0044] The concentration measurement system 2 is capable of outputting a concentration signal S23 corrected according to the characteristics specific to each of the multiple components (in this embodiment, the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216) provided in the signal output device 21. The signal calculation processing unit 23 is capable of generating and outputting the concentration signal S23, which is a signal resulting from a concentration calculation performed using at least one of parameters corresponding to the characteristics of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216.

[0045] Here, the characteristic variations of the light receiving unit 111 include, for example, variations in photoelectric conversion characteristics due to variations in the electrical characteristics of the photodetector constituting the photoelectric conversion unit of the light receiving unit 111, and variations in the voltage and current of the output signal due to variations in the electrical characteristics of the photodetector constituting the output unit of the light receiving unit 111. The characteristic variations of the light emitting unit 214 include, for example, variations in electrical-to-optical conversion characteristics due to variations in the electrical-to-optical conversion efficiency of the light emitting unit 214. The characteristic variations of the optical member 215 include, for example, variations in transmission characteristics due to variations in the refractive index of the members constituting the optical member 215, variations in the refraction angle of the output infrared light due to variations in the transmitted central wavelength and transmittance, etc. The characteristic variations of the optical path unit 216 include, for example, light arrival loss, variations in the reflectivity of the material forming the reflecting portion that reflects infrared light, and variations in the shape of the reflecting portion.

[0046] The signal calculation processing unit 23 is configured to use information contained in the drive signal S214dv to calculate the concentration of the object to be measured, in addition to the variations in the characteristics of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216 that make up the signal output device 21. This enables the signal calculation processing unit 23 to achieve more accurate concentration calculation.

[0047] The calibration parameter signal S212 is not particularly limited as long as it can ultimately correct the concentration calculation of the object to be measured in accordance with the characteristics of at least one of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216. In other words, the calibration parameter signal S212 is not particularly limited as long as it can ultimately correct the concentration calculation of the object to be measured in accordance with at least one of the characteristic variations of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216. As in the first embodiment, when the signal calculation processing unit 23 calculates the concentration by applying the input detection signal S211 to a predetermined formula, for example, the calibration parameter signal S212 may be used as a coefficient of the predetermined formula.

[0048] In the signal output device 21 according to this embodiment, similar to the signal output device 11 according to the first embodiment, the interface unit 213 outputs the calibration parameter signal S212 included in the output signal S213 to the external signal calculation processor 23 without calculating the concentration of the object to be measured. The interface unit 213 neither calculates the concentration using the calibration parameters included in the calibration parameter signal S212 nor calculates the concentration without using the calibration parameters. Here, the concentration calculation includes not only the actual concentration calculation but also correction of the output signal according to the concentration. That is, the signal output device 21 does not include a calculation unit that performs calculation based on the input signal. Therefore, the signal output device 21 and the concentration measurement system 2 can reduce thermal and electromagnetic effects that may be exerted on at least one of the light emitter 214 and the light receiver 211 due to heat and electromagnetic waves generated by the calculation operation of the calculation unit. This enables the concentration measurement system 2 to measure the concentration of the object to be measured with high accuracy.

[0049] The storage unit 212 stores, as calibration parameters, for example, a plurality of parameters corresponding to the characteristics of at least one of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216, as parameters corresponding to the characteristics of at least one of the plurality of components provided in the signal output device 21. The storage unit 212 stores, as calibration parameters, for example, parameters associated with the magnitude of characteristic variation of at least one of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216. As with the concentration measurement system 1 according to the first embodiment described above, in the shipping inspection of the concentration measurement system 2, concentration measurements of a standard measurement object with a known concentration are repeatedly performed while changing the parameters. The concentration measurement system 2 sets the parameters that provide a concentration closest to the known concentration as the calibration parameters to be used during actual operation. This allows the concentration measurement system 2 to measure the concentration of the object to be measured in accordance with at least one characteristic (e.g., characteristic variation of at least one of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216) of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216. Setting of the calibration parameters in accordance with at least one characteristic of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216 is not limited to when the concentration measurement system 2 is inspected for shipment, and may be performed before the operation of the concentration measurement system 2.

[0050] As described above, the signal output device 21 and the concentration measurement system 2 according to this embodiment include at least one (all of them in this embodiment) of the light-emitting unit 214 that is provided on the support part and emits infrared light, the optical member 215 that is provided on the support part and arranged in the optical path from when the infrared light emitted by the light-emitting unit 214 reaches the light-receiving unit 211, or the optical path unit 216 that is provided on the support part and guides the infrared light emitted by the light-emitting unit 214 to the light-receiving unit 211. The storage unit 212 provided in the signal output device 21 is configured to store at least one of the parameters according to the characteristics of the light-receiving unit 211, the parameters according to the characteristics of the light-emitting unit 214, the parameters according to the characteristics of the optical member 215, and the parameters according to the characteristics of the optical path unit 216 as calibration parameters, as parameters according to the characteristics of at least one of the plurality of components provided in the signal output device 21. Furthermore, the interface unit 213 can include a calibration parameter signal S212 corresponding to at least one of the parameters stored in the storage unit 212 in the output signal S213 and output the output signal S213 to the signal calculation processing unit .

[0051] As a result, the concentration measurement system 2 can calculate the concentration of the object to be measured using at least one of the parameters corresponding to the characteristics of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216, and therefore can calculate the concentration of the object to be measured with higher accuracy compared to the concentration measurement system 1 according to the first embodiment.

[0052] The concentration measurement system 2 also includes an external signal calculation processing unit 23 that calculates the concentration of the object to be measured based on a signal based on the detection signal S211d included in the output signal S213 input from the interface unit 213, the calibration parameter signal S212, and a drive signal S214dv for driving the light-emitting unit 214.

[0053] This allows the concentration measurement system 2 to calculate the concentration of the measurement object with higher accuracy than when the drive signal S214dv is not used.

[0054] (Variation) A signal output device and a concentration measurement system according to a modification of this embodiment will be described again with reference to Figure 2. The concentration measurement system 2 according to this modification is characterized in that it calculates the concentration of the object to be measured using parameters according to at least two composite characteristics of at least two of the characteristics of the multiple components provided in the signal output device 21, that is, parameters according to the characteristics of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216.

[0055] The memory unit 212 included in the signal output device 21 according to this modification stores, as calibration parameters, at least two composite characteristics among the characteristics of a plurality of components (in this modification, the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216) included in the signal output device 21. The interface unit 213 is configured to be able to include a calibration parameter signal S212 corresponding to the parameters of the composite characteristics in an output signal S213 and output the output signal S213 to the externally provided signal calculation processing unit 23. The parameters corresponding to the composite characteristics are parameters for correcting composite characteristic variations of at least two of the characteristics of the light receiving unit 211, the characteristics of the light emitting unit 214, the characteristics of the optical member 215, and the characteristics of the optical path unit 216.

[0056] In the signal output device 21 according to this modification, the storage unit 212 stores, as calibration parameters, parameters corresponding to at least two composite characteristics of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216, as parameters corresponding to composite characteristics of at least two of the multiple components included in the signal output device 21. This allows the storage unit 212 to output a calibration parameter signal S212 corresponding to the composite characteristics to the interface unit 213. However, although the storage unit 212 stores parameters corresponding to at least two characteristics of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216, it is not necessary for the storage unit 212 to store a parameter corresponding to the composite characteristic. In this case, the storage unit 212 outputs a calibration parameter signal S212 corresponding to the at least two stored parameters to the interface unit 213. The interface unit 213 may generate a parameter according to a composite characteristic obtained by combining parameters included in the calibration parameter signal S212, and output an output signal S213 having a parameter according to the generated composite characteristic to the signal calculation processing unit 23. Alternatively, the signal calculation processing unit 23, rather than the interface unit 213, may be configured to generate a parameter according to a composite characteristic obtained by combining parameters included in the calibration parameter signal S212 and included in the output signal S213.

[0057] The signal calculation processing unit 23 provided in the concentration measurement system 2 according to this modification can calculate the concentration of the object to be measured using parameters corresponding to the composite characteristics included in the output signal S213 input from the interface unit 213. In this way, the concentration measurement system 2 according to this modification can calibrate the calculation of the concentration of the object to be measured even if the signal output device 21 has composite characteristic variations that are a combination of characteristic variations of at least two of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216. This allows the concentration measurement system 2 according to this modification to improve the measurement accuracy of the concentration of the object to be measured.

[0058] [Third embodiment] A signal output device and a concentration measurement system according to a third embodiment of the present invention will be described with reference to Figs. 3 and 4. Fig. 3 is a block diagram showing an example of the general configuration of a signal output device 31 and a concentration measurement system 3 according to this embodiment. Fig. 4 is a cross-sectional schematic diagram showing an example of the general configuration of the concentration measurement system 3 according to this embodiment. Below, the signal output device according to this embodiment will be described using the signal output device 31 for a concentration measurement system as an example. In addition, in describing the signal output device 31 and the concentration measurement system 3 according to this embodiment, components that have the same actions and functions as those of the signal output device 21 and the concentration measurement system 2 according to the second embodiment described above will be assigned the same reference numerals, and description thereof will be omitted.

[0059] As shown in FIG. 3, the signal output device 31 according to this embodiment includes a light-receiving unit 211 that receives infrared light irradiated onto a measurement object and outputs a detection signal S211 corresponding to the received infrared light. The signal output device 31 also includes a memory unit 312 that stores, as calibration parameters, parameters used in calculating the concentration of the measurement object and corresponding to the characteristics of at least one of the components including the light-receiving unit 211. The signal output device 31 also includes an interface unit 313 that can output, to an external signal calculation processor 33, an output signal S313 including a calibration parameter signal S312 corresponding to the calibration parameter input from the memory unit 312 and a signal based on the detection signal S211 input from the light-receiving unit 211, without performing concentration calculation. The interface unit 313 is electrically connected to the light-receiving unit 211 and the memory unit 312. The signal output device 31 also includes a support unit 318 that supports the light-receiving unit 311, the memory unit 312, and the interface unit 313 (see FIG. 4).

[0060] The concept of "the output signal S313 includes a signal based on the calibration parameter signal S312 and the detection signal S211" is similar to the concept of "the output signal S113 includes a signal based on the calibration parameter signal S112 and the detection signal S111" in the first embodiment. Furthermore, like the interface unit 113 in the first embodiment, the interface unit 313 may be configured to perform the functions of amplifying the input detection signal S211 and performing analog-to-digital conversion of the amplified detection signal S211 to generate a digital detection signal S211d. In this case, the output signal S313 includes the digital detection signal S211d. The interface unit 313 may be configured to amplify or perform analog-to-digital conversion of the detection signal S211, but is configured not to perform arithmetic processing of the detection signal S211.

[0061] Here, the output signal S313 includes the digital detection signal S211d. The analog detection signal S211 and the digital detection signal S211d output from the light receiving unit 211 are signals having the same information but differing only in signal format. Therefore, in this embodiment, the signal based on the detection signal S211 refers to the signal actually included between the analog detection signal S211 and the digital detection signal S211d. In other words, as in this embodiment, when the output signal S313 includes the digital detection signal S211d, the signal based on the detection signal S211 becomes the detection signal S211d. On the other hand, when the output signal S313 includes the analog detection signal S211, the signal based on the detection signal S211 becomes the detection signal S211d.

[0062] The signal output device 31 further includes a temperature measurement unit 317 that measures temperature. The temperature measurement unit 317 measures, for example, the temperature of the light emitting unit 214. The temperature measurement unit 317 may be configured with, for example, a thermistor, a thermocouple, a diode, or any other element that can measure temperature.

[0063] The temperature measurement unit 317 is configured to output a temperature signal S317 corresponding to the measured temperature to the storage unit 312. The storage unit 312 stores parameters related to temperature as calibration parameters, and is configured to output a calibration parameter signal S312 corresponding to the parameter corresponding to the temperature input from the temperature measurement unit 317 to the interface unit 313. More specifically, when the temperature signal S317 corresponding to the temperature is input from the temperature measurement unit 317 to the storage unit 312, the storage unit 312 selects a parameter related to the temperature associated with the input temperature signal S317, and outputs a calibration parameter signal S312 corresponding to the selected parameter to the interface unit 313.

[0064] As shown in FIG. 3 , the signal output device 31 includes, as multiple components, a light-receiving unit 211 and at least one of a light-emitting unit 214, an optical member 215, and an optical path unit 216. That is, the signal output device 31 according to this embodiment includes, as the multiple components, the light-receiving unit 211, the light-emitting unit 214, the optical member 215, and the optical path unit 216. Here, the light-emitting unit 214, the optical member 215, and the optical path unit 216 are also supported by a support unit 318 (see FIG. 4 ). The storage unit 312 stores, as calibration parameters, parameters corresponding to the characteristics of the light-receiving unit 211 as parameters corresponding to the characteristics of at least one of the multiple components included in the signal output device 21. Furthermore, the storage unit 312 stores, as calibration parameters, at least one parameter corresponding to the characteristics of a component other than the light-receiving unit 211 among the multiple components included in the signal output device 31. In this embodiment, the light-emitting unit 214, the optical member 215, and the optical path unit 216 correspond to the multiple components other than the light-receiving unit 211. This allows the memory unit 312 to output to the interface unit 313 a calibration parameter signal S312 that corresponds to at least one of a parameter corresponding to the characteristics of the light receiving unit 211, a parameter corresponding to the characteristics of the light emitting unit 214, a parameter corresponding to the characteristics of the optical member 215, and a parameter corresponding to the characteristics of the optical path unit 216. Note that the respective characteristics of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216 are the same as the respective characteristics of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216 in the second embodiment described above.

[0065] The interface unit 313 is capable of including in the output signal S213 a calibration parameter signal S212 corresponding to a parameter of the characteristic of the light receiving unit 211 (i.e., a parameter corresponding to the characteristic of the light receiving unit 211), and outputting the output signal S213 to the signal calculation processing unit 23. The interface unit 313 is also capable of including in the output signal S213 a calibration parameter signal S212 corresponding to at least one of the parameters stored in the storage unit 212 (i.e., at least one of the parameters corresponding to the characteristic of each of the light emitting unit 214, the optical member 215, and the optical path unit 216), and outputting the output signal S213 to the signal calculation processing unit 23. The interface unit 313 is also capable of including in the output signal S313 a calibration parameter signal S312 corresponding to a parameter corresponding to temperature, and outputting the output signal S313 to the signal calculation processing unit 23. Furthermore, the interface unit 313 can include in the output signal S313 a calibration parameter signal S312 corresponding to at least one of the characteristics of the light receiving unit 211, the characteristics of the light emitting unit 214, the characteristics of the optical member 215, the characteristics of the optical path unit 216, and the temperature, and output this signal to the externally provided signal calculation processing unit 23. Note that the parameters corresponding to the respective characteristics of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216 may be calibration parameters that are the variations in the characteristics of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216, as in the second embodiment.

[0066] From the viewpoint of miniaturization, the signal output device 31 includes an integrated circuit 310 that integrates a storage unit 312, an interface unit 313, and a temperature measurement unit 317. However, the signal output device 31 may of course have a configuration in which the storage unit 312, the interface unit 313, and the temperature measurement unit 317 are not integrated.

[0067] 3, the concentration measurement system 3 according to this embodiment includes a signal output device 31 having the above-described configuration, and a signal calculation processing unit 33 that calculates the concentration of the object to be measured based on a signal based on the detection signal S211d included in the output signal S313 input from an external interface unit 313, a calibration parameter signal S312, and a drive signal S214dv for driving the light-emitting unit 214. Furthermore, when the calibration parameter signal S312 included in the output signal S313 has a parameter corresponding to temperature, the signal calculation processing unit 33 is configured to calculate the concentration of the object to be measured using the other parameter and the parameter corresponding to the temperature.

[0068] The concentration measurement system 3 is capable of outputting a concentration signal S33 corrected according to the specific characteristics of each of the multiple components (in this embodiment, the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216) provided in the signal output device 21 and the temperature measured by the temperature measurement unit 317. The signal calculation processing unit 33 is capable of generating and outputting the concentration signal S33, which is a signal resulting from a concentration calculation using at least one of the parameters corresponding to the characteristics of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216, and a parameter corresponding to the temperature.

[0069] The signal calculation processing unit 33 is configured to use the temperature measured by the temperature measurement unit 317 to calculate the concentration of the object to be measured, in addition to the characteristic variations of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216 that constitute the signal output device 31 and the information contained in the drive signal S214dv. This enables the signal calculation processing unit 23 to achieve more accurate concentration calculation.

[0070] Furthermore, the temperature measurement unit 317 may be configured to output the temperature signal S317 to the signal calculation processing unit 33 via the interface unit 313. In this case, the signal calculation processing unit 33 stores temperature-related parameters in association with the temperature. The signal calculation processing unit 33 can select the temperature-related parameter corresponding to the temperature signal S317 input from the temperature measurement unit 317 and correct the concentration calculation of the object to be measured using the selected parameter.

[0071] The calibration parameter signal S312 is not particularly limited as long as it can correct the concentration calculation of the object to be measured in accordance with at least one of the characteristics of at least one of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216, the information included in the drive signal S214dv, and the temperature measured by the temperature measurement unit 317. In other words, the calibration parameter signal S312 is not particularly limited as long as it can correct the concentration calculation of the object to be measured in accordance with at least one of the characteristic variations of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216, and the temperature of the drive of the light emitting unit 214 and the signal output device 31 (mainly the temperature of the light emitting unit 214). As in the second embodiment, the calibration parameter signal S312 may be used as a coefficient of a predetermined formula when the signal calculation processing unit 33 calculates the concentration by applying the input detection signal S211 to the formula, for example. Here, the predetermined formula is a cubic function "y=a×x" 3 +b×x 2 +c×x+d", the coefficients a, b, c, and d can be parameters of the calibration parameter signal (i.e., calibration parameters stored in the storage unit 212). In this cubic function, y may be the concentration result of the object to be measured, and x may be a signal corresponding to the detection signal S211 output from the light receiving unit 111 and the temperature signal S317 output from the temperature measurement unit 317.

[0072] In the signal output device 31 according to this embodiment, similar to the signal output device 21 according to the second embodiment, the interface unit 313 outputs the calibration parameter signal S312 included in the output signal S313 to the external signal calculation processor 33 without calculating the concentration of the object to be measured. The interface unit 313 neither calculates the concentration using the calibration parameters included in the calibration parameter signal S312 nor calculates the concentration without using the calibration parameters. Here, the concentration calculation includes not only the actual concentration calculation but also correction of the output signal according to the concentration. That is, the signal output device 31 does not include a calculation unit that performs calculations based on the input signal. This allows the signal output device 31 and the concentration measurement system 3 to reduce thermal and electromagnetic effects that may be exerted on at least one of the light emitter 214 and the light receiver 211 due to heat and electromagnetic waves generated by the calculation operation of the calculation unit. This allows the concentration measurement system 3 to measure the concentration of the object to be measured with high accuracy.

[0073] In this way, similar to the concentration measurement system 2 according to the second embodiment, the concentration measurement system 3 can calculate the concentration of the object to be measured using the detection signal S211 configured from at least one parameter of the characteristics (e.g., characteristic variations) of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216, and drive information for the light emitting unit 214 included in the drive signal S214dv. Furthermore, the concentration measurement system 3 can use the calibration parameter signal S312 that can also correct characteristic variations due to temperature. This allows the concentration measurement system 3 to achieve higher accuracy in concentration measurement.

[0074] Next, an example of the structure of the signal output device 31 and the concentration measurement system 3 according to this embodiment will be described with reference to Fig. 4. In Fig. 4, the structure of the signal calculation processing unit 33 provided in the concentration measurement system 3 is not shown, and the signal calculation processing unit 33 is shown in block form.

[0075] As shown in FIG. 4 , the signal output device 31 includes a support section 318 that supports the light receiving section 211, the memory section 312, the light emitting section 214, the temperature measuring section 317, the interface section 313, and the wiring section 319. The support section 318 is formed of, for example, resin, and the light receiving section 211, the memory section 312, the light emitting section 214, the temperature measuring section 317, the interface section 313, and the wiring section 319 are sealed in the support section 318. In this manner, the signal output device 31 has a structure in which the light receiving section 211 and the like are packaged in the support section 318. The light receiving section 211, the memory section 312, the light emitting section 214, the temperature measuring section 317, the interface section 313, and the wiring section 319 are electrically connected via conductive wires (not shown) inside the support section 318. The integrated circuit 310 includes the memory section 312, the temperature measuring section 317, and the interface section 313 in the same package. The wiring section 319 has a plurality of electrically independent terminals (not shown). The terminals are connected to the signal calculation processing section 33 via metal bumps, wiring on a mounting board, or the like (neither of which are shown). This enables the concentration measurement system 3 to transmit an output signal S313 from the interface section 313 to the signal calculation processing section 33 and to transmit a drive signal S214dv from the signal calculation processing section 33 to the interface section 313.

[0076] An optical member 215 is disposed on the support member 318, covering a portion of the light-emitting member 214 and the wiring member 319. Furthermore, an optical path member 216 is disposed, entirely covering the support member 318 and the optical member 215, and is supported by the support member 318. The optical path member 216 has a spherical recess extending from the center to the periphery. The optical path member 216 is disposed with this recess facing the support member 318. As a result, the signal output device 31 has a space 35 formed between the optical path member 216 and the support member 318. A vent hole 216b is formed in the optical path member 216, penetrating the optical path member 216. The vent hole 216b is formed directly above the support member 318, with a portion of the surface of the support member 318 exposed to the space of the vent hole 216b; however, the vent hole 216b may be formed in another location on the optical path member 216. The measurement object, for example, gas, is introduced into the space 35 through the vent hole 216b, and the gas is discharged to the outside of the space 35.

[0077] The surface 216a of the optical path section 216 on the side of the space section 35 has a curved surface shape. The infrared rays emitted by the light-emitting section 214 are incident on the optical member 215 with a predetermined spread. The optical path section 216 is arranged to be exposed in the space section 35. Therefore, the infrared rays that have passed through the optical member 215 are emitted from the optical member 215 with a predetermined spread toward the space section 35. The surface 216a of the optical path section 216 has a curved surface shape, so that the infrared rays emitted from the optical member 215 with a predetermined spread can be reflected once or multiple times and guided to the light-receiving section 211 that is arranged to be exposed in the space section 35.

[0078] The concentration measurement system 3 according to this embodiment has a configuration in which the signal output device 31 and the signal calculation processing unit 33 are separated. Therefore, compared to a configuration in which the signal calculation processing unit is provided inside the signal output device and packaged with a sealing member, the concentration measurement system 3 reduces at least one of the thermal and electromagnetic effects emitted from the signal calculation processing unit 33, and since calibration parameters are stored in the memory unit 312, the concentration measurement system 3 as a whole can measure concentrations with high accuracy. Furthermore, the concentration measurement system 3 can be easily assembled by simply attaching the signal output device 31 to a mounting board or the like. Note that the signal output device 21 and the concentration measurement system 2 according to the second embodiment may have a structure similar to that shown in FIG. 4, except that they do not have the temperature measurement unit 317.

[0079] As described above, the signal output device 31 and the concentration measurement system 3 according to this embodiment include a temperature measurement unit 317 that measures temperature, in addition to the configuration of the signal output device 21 and the concentration measurement system 2 according to the second embodiment. Furthermore, information related to the temperature measured by the temperature measurement unit 317 is input to the memory unit 312 provided in the signal output device 31. The memory unit 312 can output a calibration parameter signal S312 corresponding to a parameter corresponding to the temperature associated with the input information about the temperature to the interface unit 313. The interface unit 313 can output an output signal S313 including a calibration parameter signal corresponding to the parameter corresponding to the temperature to the signal calculation processing unit 23.

[0080] As a result, the signal output device 31 and the concentration measurement system 3 can obtain the same effects as the signal output device 21 and the concentration measurement system 2 according to the second embodiment. Furthermore, the concentration measurement system 3 can correct characteristic fluctuations caused by temperature, so that the concentration of the object to be measured can be calculated with higher accuracy.

[0081] (Variation) A signal output device and a concentration measurement system according to a modification of this embodiment will be described again with reference to Figure 3. Similar to the concentration measurement system 2 according to the modification of the second embodiment, the concentration measurement system 3 according to this modification is characterized in that it calculates the concentration of the object to be measured using parameters according to the composite characteristics of at least two of the parameters according to the characteristics of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216.

[0082] The memory unit 312 provided in the signal output device 31 according to this modification stores, as calibration parameters, at least two composite characteristics among the characteristics of the components provided in the signal output device 31 (in this modification, the light emitting unit 214, the optical member 215, and the optical path unit 216) and the characteristics of the light receiving unit 211. The interface unit 313 is configured to be able to include a calibration parameter signal S312 corresponding to the parameters of the composite characteristics in the output signal S313 and output the output signal S313 to the externally provided signal calculation processing unit 33. The parameters corresponding to the composite characteristics in this modification are the same as the parameters corresponding to the composite characteristics in the modification of the second embodiment described above.

[0083] The storage unit 312 can output a calibration parameter signal S312 corresponding to the composite characteristic to the interface unit 313. However, the storage unit 312 stores parameters corresponding to at least two characteristics of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216, but may not store a parameter corresponding to the composite characteristic. In this case, the storage unit 312 outputs a calibration parameter signal S312 corresponding to at least two stored parameters to the interface unit 313. The interface unit 313 may generate a parameter corresponding to the composite characteristic by combining parameters included in the calibration parameter signal S312, and output an output signal S313 having the generated parameter corresponding to the composite characteristic to the signal calculation processing unit 33. Alternatively, the signal calculation processing unit 33, rather than the interface unit 313, may be configured to generate a parameter corresponding to the composite characteristic by combining parameters included in the calibration parameter signal S312 included in the output signal S313.

[0084] The signal calculation processing unit 33 provided in the concentration measurement system 3 according to this modification can calculate the concentration of the object to be measured using parameters corresponding to the composite characteristics included in the output signal S313 input from the interface unit 313. In this way, the concentration measurement system 3 according to this modification can correct the calculation of the concentration of the object to be measured even if the signal output device 31 has composite characteristic variations that are a combination of characteristic variations of at least two of the light receiving unit 211, the light emitting unit 214, the optical member 215, and the optical path unit 216. This allows the concentration measurement system 3 according to this modification to improve the measurement accuracy of the concentration of the object to be measured.

[0085] Next, another modified example of the signal output device 31 and concentration measurement system 3 according to this embodiment will be described with reference to Fig. 5. In Fig. 5, the structure of the signal calculation processing unit 33 provided in the concentration measurement system 4 according to this modified example is not shown, and the signal calculation processing unit 33 is illustrated in block form. In describing the signal output device 31 and concentration measurement system 4 according to this modified example, components that have the same actions and functions as those of the signal output device 31 and concentration measurement system 3 according to the third embodiment described above will be assigned the same reference numerals, and their description will be omitted.

[0086] 5, the signal output device 41 includes a light receiving unit 411, a storage unit 412, a light emitting unit 414, an interface unit 413, and a support unit 418 that supports these. The support unit 418 is made of, for example, resin, but may also be made of metal, ceramic, or the like.

[0087] In the signal output device 41 according to this modification, a light receiving unit 411, a memory unit 412, a light emitting unit 414, and an interface unit 413 are independently provided on a support unit 418. The light receiving unit 411, the memory unit 412, the light emitting unit 414, and the interface unit 413 are supported by the support unit 418 while being independently sealed with a sealing member 420. The light emitting unit 414 is sealed in the sealing member 420 with a region (not shown) that emits infrared light exposed to the space 35. The light receiving unit 411 is sealed in the sealing member 420 with a light receiving region (not shown) that receives infrared light reflected by the surface 216a of the optical path unit 216 exposed to the space 35. The memory unit 412 and the interface unit 413 are sealed in the sealing member 420 without being exposed to the space 35. The light receiving section 411, the storage section 412, the light emitting section 414, and the interface section 413 are electrically connected via wiring (not shown) provided on the support section 418.

[0088] Although the light receiving unit 411, the memory unit 412, the light emitting unit 414, and the interface unit 413 are each independently sealed with a sealing member 420, two or more of the light receiving unit 411, the memory unit 412, the light emitting unit 414, and the interface unit 413 may be sealed in a single sealing member 420, for example, the light receiving unit 411 and the interface unit 413 may be sealed in a single sealing member 420. [Explanation of symbols]

[0089] 1,2,3,4 Concentration Measurement System 11, 21, 31, 41 Signal output device 13, 23, 33 Signal processing unit 35 Space section 110,210,310 Integrated Circuits 111,211,411 Light receiving section 112,212,312,412 Storage section 113,213,313,413 Interface section 214,414 Light-emitting part 215 Optical Components 216 Optical path section 216a surface 216b Ventilation hole 317 Temperature measurement section 318,418 Support part 319 Wiring section 420 Sealing member S13,S23,S33 concentration signal S111, S111d, S211, S211d detection signal S112, S212, S312 Calibration parameter signals S113, S213, S313 output signal S214dv drive signal S311 detection signal S317 Temperature signal

Claims

1. A support part; a light receiving unit that is provided on the support unit and receives infrared light irradiated onto the measurement object and outputs a detection signal corresponding to the received infrared light; a storage unit provided on the support unit, the storage unit storing, as a calibration parameter, a parameter corresponding to a characteristic of at least one of a plurality of components including the light receiving unit, which is used in calculating the concentration of the object to be measured; an interface unit provided in the support unit, which outputs an output signal including a calibration parameter signal corresponding to the calibration parameter input from the storage unit and a signal based on the detection signal input from the light receiving unit to an externally provided signal calculation processing unit without performing the concentration calculation; A signal output device comprising:

2. The storage unit stores, as the calibration parameters, parameters corresponding to the characteristics of the light receiving unit among the plurality of components.

2. The signal output device according to claim 1.

3. The interface unit includes the calibration parameter signal corresponding to the parameter of the characteristic of the light receiving unit in the output signal and outputs the output signal to the signal calculation processing unit.

3. The signal output device according to claim 2.

4. In addition to the light receiving section, the plurality of components include at least one of a light emitting section that is provided on the support section and emits infrared rays, an optical member that is provided on the support section and disposed in an optical path until the infrared rays emitted by the light emitting section reach the light receiving section, or an optical path section that is provided on the support section and guides the infrared rays emitted by the light emitting section to the light receiving section, the storage unit stores at least one of parameters according to characteristics of the plurality of components provided as the calibration parameter; The interface unit includes the calibration parameter signal corresponding to the at least one parameter stored in the storage unit in the output signal and outputs the output signal to the signal calculation processing unit.

4. The signal output device according to claim 2 or 3.

5. In addition to the light receiving section, the plurality of components include at least one of: a light emitting section that is provided on the support section and emits infrared rays; an optical member that is provided on the support section and is arranged in an optical path until the infrared rays emitted by the light emitting section reach the light receiving section; or an optical path section that is provided on the support section and guides the infrared rays emitted by the light emitting section to the light receiving section, the storage unit stores, as the calibration parameters, parameters corresponding to composite characteristics of at least two of the characteristics of the plurality of components provided; The interface unit includes the calibration parameter signal corresponding to the parameter of the composite characteristic in the output signal and outputs the output signal to the signal calculation processing unit.

4. The signal output device according to claim 2 or 3.

6. the parameter according to the characteristic of the light receiving unit is a parameter for correcting characteristic variations of the light receiving unit, the parameter according to the characteristic of the light-emitting unit is a parameter for correcting characteristic variation of the light-emitting unit, the parameter according to the characteristic of the optical member is a parameter for correcting characteristic variations of the optical member, The parameter according to the characteristic of the optical path section is a parameter for correcting the characteristic variation of the optical path section.

5. The signal output device according to claim 4.

7. The parameter according to the composite characteristic is a parameter for correcting composite characteristic variations of at least two of the characteristics of the light receiving unit, the characteristics of the light emitting unit, the characteristics of the optical member, and the characteristics of the optical path unit.

6. The signal output device according to claim 5.

8. an integrated circuit in which the memory unit and the interface unit are integrated; 8. A signal output device according to claim 1.

9. a temperature measuring unit that is provided on the support unit and measures the temperature 9. A signal output device according to claim 1.

10. The storage unit stores a parameter related to temperature as the calibration parameter, and outputs the calibration parameter signal corresponding to the parameter corresponding to the temperature input from the temperature measurement unit to the interface unit. The signal output device according to claim 9.

11. an integrated circuit that integrates the memory unit, the interface unit, and the temperature measurement unit; 11. The signal output device according to claim 9 or 10.

12. A signal output device according to any one of claims 1 to 11; a signal calculation processing unit that is provided externally and calculates the concentration of the measurement object based on a signal based on the detection signal included in the output signal input from the interface unit and the calibration parameter signal; A concentration measurement system comprising:

13. A signal output device according to any one of claims 4 to 7; a signal calculation processing unit that is provided externally and calculates the concentration of the object to be measured based on a signal based on the detection signal included in the output signal input from the interface unit, the calibration parameter signal, and a drive signal for driving the light-emitting unit; A concentration measurement system comprising:

14. The interface unit outputs the drive signal to the light emitting unit. The concentration measurement system according to claim 13.

15. The signal output device includes an integrated circuit that integrates the memory unit and the interface unit. The concentration measurement system according to claim 13 or 14.

16. The signal output device further includes a temperature measurement unit for measuring a temperature. A concentration measurement system according to any one of claims 13 to 15.

17. The storage unit stores a parameter related to temperature as the calibration parameter, and outputs the calibration parameter signal corresponding to the parameter corresponding to the temperature input from the temperature measurement unit to the interface unit. The concentration measurement system according to claim 16.

18. The signal output device includes an integrated circuit that integrates the memory unit, the interface unit, and the temperature measurement unit.

18. The concentration measurement system according to claim 16 or 17.

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