JP2016095171A - Signal output device, particle measuring apparatus, and storage method for signal output device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a signal output device which has a simplified circuit constitution for writing correction data.SOLUTION: A sensor module 150 comprises a particle detection sensor 110 which outputs an electric signal, a storage unit 140 which enables writing of correction information in response to application of a ground voltage to a write prevention terminal WP, and a substrate 2 on which the storage unit 140 is mounted. The substrate 2 comprises a first conduction part 21 which is formed in an opening 23 and connected to the write prevention terminal WP, and a second conduction part 22 which is formed in the opening 23 opposite the first conduction part 21 and applied with the ground voltage. A washer 30 is disposed fixedly in the opening 23 to allow the first conduction part 21 and washer 30 to contact each other and also allow the second conduction part 22 and washer 30 to contact each other, thereby holding the first conduction part 21 at the ground voltage.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a signal output device, a particle measuring device, and a storage method for the signal output device.

  The light scattering type particle measuring apparatus has a photoelectric particle detection sensor composed of a light projecting element and a light receiving element, takes in a gas to be measured, irradiates the light of the light projecting element, and the scattered light. This is a device that outputs the presence / absence and particle size of gas particles detected by the above as an electrical signal. The light scattering particle measuring apparatus can detect, for example, particles such as dust, pollen, and smoke floating in the atmosphere.

  As this kind of light scattering type particle detection sensor, a sensor provided with a light trap at a position facing a light projecting element or a light receiving element is known in order to reduce the generation of stray light (see, for example, Patent Document 1). .

Japanese Patent Laid-Open No. 11-248629

  In the particle detection sensor disclosed in Patent Document 1, characteristics may be different for each individual. In such a case, even if the same gas is introduced, the output from the plurality of particle detection sensors may vary due to the variation in characteristics. For this reason, the signal output device that outputs the electrical signal from the particle detection sensor needs to hold correction information for correcting the sensor output. Specifically, the particle measuring device corrects the output from the particle detection sensor based on the correction data stored in advance in the storage unit of the signal output device. However, although the step of storing correction data in the storage unit is necessary only at the time of manufacture (before shipment), a write control circuit for turning on and off the erroneous write prevention function to store correction data accurately Is required separately. For this reason, a writing control circuit resulting from the correction data writing operation is required, and there is a problem that the circuit scales of the signal output device and the particle measuring device increase.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a signal output device, a particle measuring device, and a storage method for the signal output device with a simplified circuit configuration for writing correction data. To do.

  In order to achieve the above object, an aspect of a signal output device according to the present invention includes a signal output unit that outputs an electrical signal and a write control terminal, and a first voltage is applied to the write control terminal. A storage unit capable of writing correction information for the electrical signal and a substrate on which the storage unit is mounted. The substrate is formed in a predetermined region on the substrate and is electrically connected to the write control terminal. Connected to the first conductive portion and the second region electrically connected to the portion on the substrate to which the first voltage is applied, and is formed in the predetermined region apart from the first conductive portion. And a conductive connecting member fixedly disposed in the predetermined region so that the first conductive portion and the connecting member are in contact with each other, and the second conductive portion and the connecting member are in contact with each other. By doing so, the voltage of the first conductive part is The serial first voltage.

  In addition, an aspect of the signal output device according to the present invention includes a signal output unit that outputs an electrical signal and a write control terminal, and the first voltage is applied to the write control terminal to correct the electrical signal. A storage unit on which information can be written; and a substrate on which the storage unit is mounted. The substrate includes an opening having a through hole, an inner wall of the opening that forms the through hole, and the through hole. A first conductive portion formed on at least one of the portions along the outer periphery of the hole and electrically connected to the write control terminal, wherein the conductive connection member to which the first voltage is applied is the through-hole. When the connection member and the first conductive portion come into contact with each other by being fixedly arranged, the voltage of the first conductive portion becomes the first voltage.

  In the signal output device storage method according to the present invention, the correction information for correcting the electrical signal output from the signal output unit can be written by applying the first voltage to the write control terminal. A storage method of a signal output device to be stored in a unit, wherein the storage unit is mounted on a substrate, formed in a predetermined region on the substrate, and electrically connected to the write control terminal A conductive connecting member in the predetermined region with respect to the substrate including the first conductive portion in the predetermined region and the second conductive portion to which the first voltage is applied. The first voltage is applied to the write control terminal by bringing the connection member and the first conductive part into contact with each other and by placing the connection member and the second conductive part in contact with each other. , The write control end In a state in which the first voltage is applied to, writing the correction information in the storage unit.

  In the signal output device storage method according to the present invention, the correction information for correcting the electrical signal output from the signal output unit can be written by applying the first voltage to the write control terminal. A signal output device storage method for storing in a section, the substrate on which the storage section is mounted, an opening having a through hole, an inner wall of the opening forming the through hole, and the through hole Conductivity in which the first voltage is applied to the opening with respect to the substrate including a first conductive portion formed on at least one of the portions along the outer periphery and electrically connected to the write control terminal. By connecting the connecting member in a fixed manner, the first voltage is applied to the write control terminal by bringing the connection member into contact with the first conductive portion, and the first voltage is applied to the write control terminal. State In, writing the correction information in the storage unit.

  According to the signal output device, the particle measuring device, or the signal output device storage method according to the present invention, the conductive portion formed on the substrate on which the storage portion is mounted and the connection member are brought into contact with each other, thereby correcting the storage portion. Can write information. Therefore, a write control circuit for turning on and off the erroneous write prevention function is not required separately, and a circuit for writing correction information can be simplified.

1 is a block diagram illustrating an example of a configuration of a particle measuring device according to Embodiment 1. FIG. It is sectional drawing for demonstrating operation | movement of the particle | grain detection sensor in case the particle | grains do not exist in air | atmosphere. It is sectional drawing for demonstrating operation | movement of the particle | grain detection sensor in case the particle | grains with a small particle diameter exist in air | atmosphere. It is sectional drawing for demonstrating operation | movement of the particle | grain detection sensor in case the particle | grains with a large particle diameter exist in air | atmosphere. It is a graph which shows the light intensity detected with a light receiving element. It is a block diagram for demonstrating the initialization process (writing process) of the correction coefficient to a memory | storage part in a manufacturing process. 4 is a circuit configuration diagram of a storage unit included in the particle measuring apparatus according to Embodiment 1. FIG. It is a figure showing the connection structure of the board | substrate with which the memory | storage part which concerns on Embodiment 1 was mounted. It is a connection block diagram of the board | substrate which concerns on Embodiment 1 in the case of memorize | stored correction information. It is sectional drawing in the A-A 'cross section of FIG. 7A. It is a flowchart which shows the initialization process of the correction coefficient performed by the writing part in a manufacturing process. It is a graph for demonstrating the correction coefficient computed by the writing part. It is a flowchart which shows the calculation process of the particle size performed by the calculating part. 6 is a diagram illustrating a shape of a conductive portion according to Modification 1 of Embodiment 1. FIG. It is a figure showing the shape of the electroconductive part which concerns on the modification 2 of Embodiment 1. FIG. It is a figure showing the connection structure of the board | substrate with which the memory | storage part which concerns on Embodiment 2 was mounted. It is a connection block diagram of the board | substrate which concerns on Embodiment 2 in the case of memorize | stored correction information. It is sectional drawing in the B-B 'cross section of FIG. 13A.

  Hereinafter, a signal output device, a particle measuring device, and a storage method of the signal output device according to an embodiment of the present invention will be described in detail with reference to the drawings. Each of the embodiments described below shows a preferred specific example of the present invention. Therefore, the numerical values, shapes, materials, components, arrangement of components, connection forms, and the like shown in the following embodiments are merely examples, and are not intended to limit the present invention. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims showing the highest concept of the present invention are described as optional constituent elements.

  Each figure is a mimetic diagram and is not necessarily illustrated strictly. Moreover, in each figure, the same code | symbol is attached | subjected about the same structural member.

(Embodiment 1)
[1. Overall configuration of particle measuring apparatus]
First, the overall configuration of the particle measuring apparatus according to Embodiment 1 of the present invention will be described. FIG. 1 is a block diagram showing an example of the configuration of the particle measuring apparatus according to the present embodiment.

  As shown in the figure, the particle measuring apparatus 100 includes a particle detection sensor 110, an analog signal processing unit 120, a sensor module 150 including a power supply unit 130, and a general-purpose MPU (Micro Processing Unit) 160. Here, the sensor module 150 is a signal output device that outputs an electrical signal corresponding to the particle size of particles contained in the atmosphere. The general-purpose MPU 160 is a signal processing unit that processes a signal output from the sensor module 150. With the above configuration, the particle measuring apparatus 100 measures the particle size of particles contained in the atmosphere by performing signal processing on the electrical signal and correction coefficient output from the sensor module 150 by the general-purpose MPU 160.

  Hereinafter, each structure of the particle | grain measuring apparatus 100 is demonstrated concretely.

[1-1. Configuration of particle detection sensor]
The particle detection sensor 110 is a photoelectric sensor including a light projecting element 111 and a light receiving element 112, and the light receiving element 112 receives scattered light of light from the light projecting element 111 due to particles in the detection area DA. The particle | grains contained in are detected. The particle detection sensor 110 is a signal output unit that generates a current signal corresponding to the light intensity received by the light receiving element 112. The particle detection sensor 110 in the present embodiment further includes a reflector 114 having a reflecting surface and a heating unit 115 that heats the atmosphere.

  The light projecting element 111 is a light source (light emitting unit) that emits light of a predetermined wavelength, and is, for example, a solid light emitting element such as an LED or a semiconductor laser. As the light projecting element 111, a light emitting element that emits infrared light, blue light, green light, red light, or ultraviolet light can be used.

  In addition, it becomes easy to detect a particle | grain with a small particle size, so that the light emission wavelength of the light projection element 111 is short. The light emission control method of the light projecting element 111 is not particularly limited, and the light emitted from the light projecting element 111 can be continuous light or pulsed light by DC driving. Moreover, the magnitude | size of the output of the light projection element 111 may be changing temporally.

  The light receiving element 112 is a light receiving unit that receives light, and is an element (photodetector) that receives light and converts it into an electric signal, such as a photodiode, a photo IC diode, a phototransistor, or a photomultiplier tube. Specifically, the light receiving element 112 generates a current signal as an electrical signal. That is, the light receiving element 112 outputs a current signal corresponding to the received light intensity.

  The light projecting element 111 and the light receiving element 112 are operated by the power supplied from the power supply unit 130.

  As shown in FIG. 1, the light projecting element 111 and the light receiving element 112 are arranged in a housing 113. The housing 113 is configured to hold the light projecting element 111 and the light receiving element 112. In the present embodiment, the light projecting element 111 and the light receiving element 112 are arranged in the housing 113 so that their optical axes intersect each other.

  The housing 113 is provided with a particle flow path that is a cylindrical space region through which air (gas) containing particles flows.

  The detection area DA is an aerosol detection area (aerosol measurement unit) that is an area for detecting particles (aerosol) contained in the gas to be measured. The detection area DA is projected with a space area where light from the light projecting element 111 is projected. This is a spatial region that overlaps the spatial region for guiding the scattered light generated when the light of the optical device 111 hits the particles to the light receiving device 112. Moreover, the detection area DA exists in the particle flow path, and the gas to be measured is guided to the detection area DA through the particle flow path.

  In the present embodiment, the flow direction of the particle flow path (the direction in which the gas to be measured flows) is the vertical direction on the paper surface of FIG. 1, but may be the vertical direction on the paper surface of FIG. That is, in the present embodiment, the flow path axis of the particle flow path exists on a plane through which each optical axis of the light projecting element 111 and the light receiving element 112 passes, but may be orthogonal to the plane.

  The reflector 114 (reflecting plate) is a reflecting member that reflects scattered light of the light projecting element 111 due to particles in the detection area DA and guides the scattered light to the light receiving element 112. In the present embodiment, the reflector 114 reflects the scattered light of the particles and collects it on the light receiving element 112. More specifically, the reflector 114 reflects the scattered light of the particles toward the light receiving element 112.

  As the reflector 114, the base member itself may be made of a reflective material such as metal so that the surface of the base member itself becomes a reflective surface, or a reflective film that becomes a reflective surface on the surface of a resin or metal base member May be formed.

  The optical system for detecting the particles of the particle detection sensor 110 is not limited to the above configuration. For example, the structure provided with the optical lens etc. which condense the light of the light projection element 111 or the said scattered light may be sufficient.

As the reflective film, a metal reflective film such as aluminum, gold, silver or copper, a specular reflective film, a dielectric multilayer film, or the like can be used. As the reflective film, a film having a low absorptance and a high reflectance is preferable. Moreover, you may use as a reflecting film what laminated | stacked the thin film thinner than the said aluminum film on the surface of the aluminum film formed by vapor deposition. As the thin film laminated on the aluminum film, for example, an MgF film, an SiO ₂ film, an SiO film, an AlN film, an alumina film, an enhanced reflection film, or the like is used. Thus, by laminating these thin films on the aluminum film, it is possible to suppress deterioration (corrosion and the like) of the aluminum film and improve optical characteristics by optical amplification.

  The heating unit 115 heats the atmosphere in order to introduce the atmosphere containing particles into the detection area DA, and functions as an airflow generation device that generates an airflow for promoting the flow of the gas flowing in the particle flow path. . Specifically, the heating unit 115 is a low-cost heater resistor or the like, and is disposed in the particle channel in the present embodiment. That is, the heating unit 115 heats the atmosphere in the particle channel.

  For example, when the heating unit 115 is a heater resistor, the heater resistor is heated when a voltage is applied to the heater resistor. As a result, the atmosphere around the heater resistor is heated to decrease the density, and moves upward in the direction opposite to gravity. That is, when the air in the particle flow path is heated by the heating unit 115, an upward air flow (upward air flow) can be generated.

  Thus, by heating the atmosphere in the particle flow path by the heating unit 115, the measurement target gas (atmosphere) can be easily drawn into the housing 113 (particle flow path). More particles can be taken into the particle detection sensor 110 than when not provided. Therefore, since the amount of particles per unit volume in the detection area DA included in the particle flow path can be increased, the sensitivity can be increased.

  Moreover, since the heating unit 115 generates an upward air flow, it is preferable to install the heating unit 115 in a lower part of the particle channel as shown in FIG. Even when the heating unit 115 is not operating, the atmosphere can pass through the particle flow path. That is, even when the heating unit 115 is not operating, it is possible to detect particles contained in the atmosphere.

[1-2. Operation of particle detection sensor]
Next, the operation of the particle detection sensor 110 in the present embodiment will be described with reference to FIGS. 2A, 2B, 2C, and 3. FIG. 2A to 2C show the operation of the particle detection sensor 110 when there are no particles in the atmosphere, when particles with a small particle diameter exist in the atmosphere, and when particles with a large particle diameter exist in the atmosphere, respectively. It is sectional drawing for demonstrating. FIG. 3 is a graph showing the light intensity detected by the light receiving element 112 in the state shown in FIGS. 2A to 2C.

  When the heating unit 115 is operated to generate an air flow in the particle passage, the atmosphere is drawn into the particle detection sensor 110 from the atmosphere introduction hole, and the atmosphere is guided to the detection area DA via the particle passage.

  In this case, as shown in FIG. 2A, when there is no particle (aerosol) in the atmosphere introduced into the particle detection sensor 110, that is, when the particle does not flow into the detection area DA, the light is emitted from the light projecting element 111. Since the light passes straight through the detection area DA, light scattered by particles is not generated. Therefore, in this case, basically, there is no reaction of the light receiving element 112, so that it can be seen that there are no particles in the atmosphere introduced into the particle detection sensor 110.

  In this case, light traveling straight through the detection area DA may be reflected in the housing 113 and enter the light receiving element 112 as stray light. However, in this case, the light intensity detected by the light receiving element 112 is smaller than when the particles are present in the detection area DA. Therefore, it can be seen that there are no particles in the atmosphere introduced into the particle detection sensor 110.

  In addition, as shown in FIG. 2B, when there is a particle (aerosol) P1 having a small particle size in the atmosphere introduced into the particle detection sensor 110, that is, when a particle P1 having a small particle size flows into the detection area DA. The light of the light projecting element 111 strikes the particles P1 existing in the detection area DA and is scattered, and the scattered light is reflected directly or by the reflector 114 and enters the light receiving element 112.

  Specifically, in this case, scattered light having a light intensity as indicated by “particle size: small” in FIG. Here, as described above, the light receiving element 112 outputs a current signal corresponding to the received light intensity. Therefore, in this case, the current signal output from the light receiving element 112 is relatively small. Thereby, it can be seen that particles having a small particle diameter exist in the atmosphere introduced into the particle detection sensor 110.

  In addition, as shown in FIG. 2C, when particles (aerosol) P2 having a large particle size exist in the atmosphere introduced into the particle detection sensor 110, that is, when particles P2 having a large particle size flow into the detection area DA. The light of the light projecting element 111 strikes the particles P2 existing in the detection area DA and is scattered, and the scattered light is reflected directly or by the reflector 114 and enters the light receiving element 112.

  Specifically, in this case, scattered light having a light intensity as indicated by “particle size: large” in FIG. Therefore, in this case, the current signal output from the light receiving element 112 is relatively large. Thus, it can be seen that particles P2 having a large particle size exist in the atmosphere introduced into the particle detection sensor 110.

  In this way, the particle detection sensor 110 can detect whether or not particles are included in the atmosphere introduced into the particle detection sensor 110 (the presence or absence of particles). That is, particles in the atmosphere can be detected. Further, when particles are included in the atmosphere, a current signal corresponding to the particle size of the particles is output.

[1-3. Configuration of analog signal processor]
The analog signal processing unit 120 performs various signal processing on the current signal output from the particle detection sensor 110 to output an analog voltage signal based on the current signal. Here, various types of signal processing include, for example, I / V conversion for converting current (I) to voltage (V), bandpass filter processing for passing a desired frequency band of an input signal, and input Amplification processing for amplifying and outputting the received signal.

  The analog signal processing unit 120 is not limited to the processes exemplified here, and may perform other signal processes (for example, a high-pass filter process, a low-pass filter process, an attenuation process, and the like).

  As illustrated in FIG. 1, the analog signal processing unit 120 includes an IV conversion unit 121 and an amplification unit 122.

  The IV converter 121 converts the current output from the light receiving element 112 into a voltage (IV conversion). That is, the IV conversion unit 121 converts the current signal output from the particle detection sensor 110 into a voltage signal. By converting the voltage signal in this way, the design of the amplifying unit 122 connected to the subsequent stage of the IV converting unit 121 is facilitated.

  The amplification unit 122 amplifies a predetermined band of the voltage signal converted by the IV conversion unit 121. Specifically, a frequency component in a predetermined band among frequency components included in the voltage signal is amplified with a higher amplification factor than frequency components in other bands. Here, the predetermined band is, for example, a band in which the frequency f1 corresponding to the flow velocity v1 of the atmosphere flowing in the particle flow path of the particle detection sensor 110 is the center frequency and the bandwidth is fbw. Note that fbw may be a predetermined frequency, or may be a frequency that is appropriately set according to the noise floor of the voltage signal. In other words, the amplification unit 122 amplifies the voltage signal converted by the IV conversion unit 121 and converts it to a voltage signal including a pulse waveform corresponding to the particle.

  For example, as illustrated in FIG. 1, the amplifying unit 122 includes a band-pass filter 122 a that passes a frequency component in a predetermined band among frequency components included in the voltage signal output from the IV conversion unit 121, and a band-pass filter. And an amplifier 122b that amplifies a signal composed of frequency components that have passed through 122a. Note that the connection order of the bandpass filter 122a and the amplifier 122b is not limited to this, and the amplifier 122b may be provided in front of the bandpass filter 122a.

  With such a configuration, the analog signal processing unit 120 outputs a voltage signal based on the current signal output from the particle detection sensor 110.

[1-4. Power supply part]
The power supply unit 130 supplies power to the components (particle detection sensor 110 and analog signal processing unit 120) other than the power supply unit 130 among the configurations included in the sensor module 150. The power supply unit 130 is configured by, for example, a regulator that converts a voltage supplied from the outside of the sensor module 150 into a desired voltage.

[1-5. Storage unit]
The storage unit 140 is, for example, a memory that stores a correction coefficient corresponding to the sensitivity of the particle detection sensor 110. Specifically, a correction coefficient corresponding to the sensitivity of the particle detection sensor 110 mounted on the sensor module 150 on which the storage unit 140 is mounted is stored.

  Here, the correction coefficient is, for example, a value calculated based on the current output from the light receiving element 112 when standard particles having a predetermined particle diameter are introduced into the detection area DA. This correction coefficient is generated by being written in the manufacturing process of the particle measuring apparatus 100. In other words, the correction coefficient is initially set in the manufacturing process of the particle measuring apparatus 100. The correction coefficient initial setting process in the manufacturing process will be described later.

[2. General-purpose MPU configuration]
The general-purpose MPU 160 uses the analog voltage signal output from the analog signal processing unit 120 to calculate the particle size of particles contained in the atmosphere flowing in the particle flow path of the particle detection sensor 110. The general-purpose MPU 160 is realized by, for example, a system LSI that is an integrated circuit, and may be individually made into one chip for each configuration described below, or may be made into one chip so as to include some or all of them. .

  The general-purpose MPU 160 is not limited to the system LSI, and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

  As shown in FIG. 1, such a general-purpose MPU 160 includes an AD conversion unit 161, and is included in the air flowing in the particle flow path of the particle detection sensor 110 using the digital data generated by the AD conversion unit 161. Various analyzes can be performed on the particles to be collected. The various analyzes include, for example, calculation of the particle size of the particle or identification of the particle.

  In the present embodiment, the general-purpose MPU 160 further includes a calculation unit 162 as shown in FIG. Hereinafter, each configuration of the general-purpose MPU 160 will be described.

[2-1. AD conversion unit]
The AD conversion unit 161 samples (samples) and quantizes the voltage signal amplified by the amplification unit 122. In other words, the AD converter 161 generates time-series digital data corresponding to the voltage signal by performing AD (Analog to Digital) conversion on the analog voltage signal output from the analog signal processor 120. That is, the AD conversion unit 161 generates time-series digital data based on the current signal output from the particle detection sensor 110.

  Specifically, the AD conversion unit 161 is an AD conversion module incorporated in advance in the general-purpose MPU 160, and converts a voltage signal input to an analog input terminal of the general-purpose MPU 160 into digital data. For example, the AD converter 161 samples a voltage signal in a range of 0.0 to 5.0 V input to an analog input terminal in the general-purpose MPU 160 at a predetermined sampling period, and uses the voltage of the sampled voltage signal. Digital data is generated by converting into a 10-bit digital value.

  The range of the voltage input to the analog input terminal of the general-purpose MPU 160 is not limited to the above example. For example, the maximum value of the input voltage is a voltage specified from the outside of the general-purpose MPU 160 (eg, 3.3 V). It may be. Further, the number of bits of digital data generated by the AD conversion unit 161 is not limited to the above example, and may be, for example, 8 bits or 12 bits.

[2-2. Calculation unit]
The calculation unit 162 calculates the particle size of particles contained in the gas flowing in the particle flow path of the particle detection sensor 110 using the digital data generated by the AD conversion unit 161.

  Here, the calculating part 162 demonstrates the outline | summary of the calculation process of the particle size of the particle | grains by the calculating part 162. FIG.

  As described above, the current signal output from the particle detection sensor 110 is a signal corresponding to the particle size of particles contained in the gas flowing in the particle flow path of the particle detection sensor 110. Therefore, the digital data input from the AD conversion unit 161 to the calculation unit 162 also has a size corresponding to the particle size of the particles. Specifically, since the current signal increases as the particle size of the particle increases, the digital data also increases as the particle size of the particle increases.

  However, the particle detection sensor 110 may have different characteristics for each individual. In such a case, even if the same gas is introduced into the particle flow path of each particle detection sensor 110, the current signal output from each particle detection sensor 110 may vary due to characteristic variations. There is. Such a variation in the current signal corresponds to a variation in sensitivity of the plurality of particle detection sensors 110.

  Therefore, in the present embodiment, in the particle size calculation process by the calculation unit 162, the particle size of the particles is calculated using the digital data generated by the AD conversion unit 161 and the correction coefficient stored in the storage unit 140. (Calculate).

  Thereby, the particle | grain measuring apparatus 100 which concerns on this Embodiment can reduce the influence by the sensitivity of the particle | grain detection sensor 110, and can calculate a particle size. That is, the particle size of particles contained in the atmosphere can be calculated with high accuracy.

  Specifically, in the present embodiment, calculation unit 162 corrects the threshold value for calculating the particle size of the particle using a correction coefficient, and calculates the particle size of the particle using the corrected threshold value. The details of the particle size calculation process performed by the calculation unit 162 will be described later.

[3. Highly accurate measurement of particle size]
Hereinafter, the fact that the particle measuring apparatus 100 according to the present embodiment can measure the particle diameter of particles contained in the air with high accuracy will be described in detail with reference to the correction coefficient initial setting process and the particle diameter calculation process.

[3-1. Correction coefficient initialization process]
First, correction coefficient initial setting processing for the storage unit 140 will be described with reference to FIGS. As described above, the correction coefficient is written in the manufacturing process of the particle measuring apparatus 100, for example.

  FIG. 4 is a block diagram for explaining the correction coefficient initial setting process (write process) to the storage unit 140 in the manufacturing process of the sensor module 150 according to the first embodiment.

  As shown in the figure, in the manufacturing process, the correction coefficient is written into the storage unit 140 by the writing unit 500 connected to the sensor module 150 on which the storage unit 140 is mounted.

  The writing unit 500 calculates a correction coefficient corresponding to the sensitivity of the particle detection sensor 110 based on the current output from the light receiving element 112 when standard particles having a predetermined particle diameter are introduced into the detection area DA. . Further, the writing unit 500 writes the calculated correction coefficient in the storage unit 140.

  FIG. 5 is a circuit configuration diagram of the storage unit 140 included in the particle measuring apparatus 100 according to the first embodiment. The storage unit 140 shown in the figure includes a nonvolatile memory 141 having a plurality of control terminals and a peripheral circuit that connects the plurality of control terminals. Although not shown, in the present embodiment, the particle detection sensor 110 is mounted on the substrate 2.

  Here, when a power supply voltage (for example, a positive power supply voltage) Vcc, which is the second voltage, is applied to the write prevention terminal WP (write protect) that is the write control terminal (when the logic is “1”), Data cannot be written to the nonvolatile memory 141. On the other hand, when the GND voltage, which is the first voltage, is applied to the write prevention terminal WP (when the logic is “0”), data can be written from the terminals SCL and SDA to the nonvolatile memory 141. .

  Note that the above logic in data writing may be reversed. That is, the logic “1” may be in a writable state, and the logic “0” may be in a writable state.

  The power supply voltage Vcc is always applied to the power supply voltage terminal VCC of the nonvolatile memory 141 when the particle measuring apparatus 100 is in an operating (ON) state. Further, the node connecting the write prevention terminal WP and the resistor R3 and the GND connection terminal are connected, but the GND connection terminal is opened in the mode in which the particle measuring apparatus 100 is in the on state and the particles are actually measured. State and not at ground potential. That is, in the mode in which the particle measuring apparatus 100 measures the particles, the power supply voltage Vcc is applied to the write prevention terminal WP via the resistor R3, which makes the nonvolatile memory 141 in a state in which writing is impossible. Yes.

  On the other hand, when a ground voltage is applied to the GND connection terminal, for example, a minute current flows from the power supply to the GND connection terminal, and the ground voltage is applied to the write prevention terminal WP. That is, in the mode in which the particle measuring apparatus 100 stores the correction data, the ground voltage is applied to the write prevention terminal WP via the GND connection terminal, and thus the nonvolatile memory 141 is in a writable state. ing.

  FIG. 6 is a diagram illustrating a connection configuration of the substrate 2 on which the storage unit 140 according to the embodiment is mounted. A storage unit 140 is mounted on the substrate 2 shown in the figure, and the substrate 2 further includes a first conductive unit 21, a second conductive unit 22, and an opening 23.

  The opening 23 is provided with a through hole.

  The first conductive portion 21 is a conductive pattern formed on the substrate 2 and is formed of, for example, a metal film. The first conductive portion 21 has a semicircular shape in plan view of the substrate 2 so as to follow the outer periphery of the opening 23. The first conductive unit 21 is electrically connected to the GND connection terminal of the storage unit 140 via a wiring formed on the substrate 2.

  The second conductive portion 22 is a conductive pattern formed on the substrate 2 and is formed of, for example, a metal film. The second conductive portion 22 has a semicircular shape in plan view of the substrate 2 so as to follow the outer periphery of the opening 23. The second conductive portion 22 is electrically connected to a portion to which the ground voltage (first voltage) on the substrate 2 is applied via a wiring formed on the substrate 2.

  The first conductive portion 21 and the second conductive portion 22 are electrically insulated from each other and are formed with the opening 23 interposed therebetween.

  The configuration of the substrate 2 shown in FIG. 6 is a configuration in a mode in which the particle measuring apparatus 100 actually measures particles. That is, the ground voltage is not applied to the GND connection terminal of the storage unit 140. In addition, the power supply voltage Vcc is applied to the write prevention terminal WP of the storage unit 140, so that the nonvolatile memory 141 is in a non-writable state.

  FIG. 7A is a diagram illustrating a connection configuration of the substrate 2 when correction information is stored. FIG. 7B is a cross-sectional view taken along the line A-A ′ of FIG. 7A. FIGS. 7A and 7B show the configuration of the substrate 2 in the case where the correction coefficient initial setting process (write process) to the storage unit 140 is executed in the manufacturing process of the sensor module 150. In other words, the configuration of the substrate 2 shown in FIGS. 7A and 7B is a configuration in a mode in which the sensor module 150 stores correction data. As shown in FIGS. 7A and 7B, the bolt 40 is passed through the through hole of the annular washer 30 and the opening 23 which are conductive connection members, and the washer 30 and the substrate 2 are tightened with a nut 41, The washer 30 is press-contacted with the first conductive portion 21 and the second conductive portion 22.

  With the above configuration, the GND connection terminal of the storage unit 140 is electrically connected to the portion to which the ground voltage (first voltage) is applied on the substrate 2 via the first conductive unit 21, the washer 30, and the second conductive unit 22. Connected. As a result, the ground voltage is applied to the write prevention terminal WP of the storage unit 140, and the nonvolatile memory 141 is in a writable state.

  In the present embodiment, the connecting member that connects the first conductive portion 21 and the second conductive portion 22 is the washer 30, but the connecting member is not limited to the washer. The connection member may be, for example, a conductive cushion material.

  Hereinafter, the correction coefficient writing process performed by the writing unit 500 will be described with reference to FIGS. 8 and 9. FIG. 8 is a flowchart showing a correction coefficient initial setting process executed by the writing unit 500 in the manufacturing process. FIG. 9 is a graph for explaining the correction coefficient calculated by the writing unit 500.

  First, the washer 30 is fixedly disposed in the opening 23 which is a predetermined region on the substrate 2 to bring the washer 30 into contact with the first conductive portion 21 and the second conductive portion 22 (S11). Specifically, the washer 30 is fixedly disposed in the opening 23 of the substrate 2 by passing the bolt 40 through the through hole and the washer 30 and fastening the substrate 2 and the washer 30 with the nut 41. As a result, the ground voltage is applied to the write prevention terminal WP of the storage unit 140, and the nonvolatile memory 141 is in a writable state.

  Further, the particle detection sensor 110 is mounted on the substrate 2, and the substrate 2 and the particle detection sensor 110 can be fixedly disposed on a predetermined measurement jig or the like simultaneously with the fixed disposition of the washer 30 by the bolt 40 and the nut 41. In order to correct the characteristic variation among individuals in the plurality of particle detection sensors 110, it is desirable to install the plurality of particle detection sensors 110 in the same arrangement state and simultaneously measure standard particles. In this respect, by using the fixed arrangement using the opening 23, it is possible to install the plurality of substrates 2 on which the particle detection sensors 110 are mounted in the same arrangement state. In other words, by fixing the washer 30 in a predetermined area on the substrate 2, the nonvolatile memory 141 can be made in a writable state, and a high-accuracy correction coefficient resulting from characteristic variations among individuals can be acquired. It becomes.

  The nut 41 is not limited to this as long as it is a member for fixing and arranging the washer 30 in the opening 23 of the substrate 2. For example, if the bolt 40 is directly fixed to the measurement jig described above, the nut 41 is not necessary.

  Next, the writing unit 500 introduces standard particles having a predetermined particle size into the particle flow path of the particle detection sensor 110 of the particle detection sensor 110 (S12). That is, the standard particles are introduced into the detection area DA. The introduction of the standard particles may not be performed by the writing unit 500, and may be realized by arranging the particle detection sensor 110 in a chamber filled with a gas containing standard particles.

  Next, the writing unit 500 acquires a peak value based on the current output from the particle detection sensor 110 in a state where the standard particles are introduced (S13). Specifically, the writing unit 500 acquires the peak value of the voltage output from the sensor module 150.

  For example, when the voltage signal output from the sensor module 150 is indicated by the first acquisition waveform in FIG. 9, the writing unit 500 acquires the peak value P1 of the first acquisition waveform. Similarly, when the voltage waveform is as shown by the second acquired waveform in FIG. 6, the peak value P2 of the second acquired waveform is acquired.

  Next, the writing unit 500 calculates a correction coefficient based on the acquired peak value (S14), and writes the calculated correction coefficient in the storage unit 140 (S15).

  Here, in the correction coefficient calculation process (S14), the writing unit 500 specifically calculates the correction coefficient fk using the acquired peak value and a predetermined ideal peak value PI.

  For example, the writing unit 500 calculates a value obtained by dividing the ideal peak value PI by the peak value of the voltage signal output from the sensor module 150 as the correction coefficient fk.

  That is, when the voltage signal output from the sensor module 150 is the first acquisition waveform in FIG. 9, that is, when the peak value acquired in the peak value acquisition process (S13 above) is P1, the writing unit 500 performs PI. / P1 is calculated as the correction coefficient fk. Thereby, when the voltage signal output from the sensor module 150 is relatively small, a value larger than 1 is calculated as the correction coefficient fk.

  Similarly, for example, in the case where the voltage signal output from the sensor module 150 is the second acquired waveform in FIG. 9, the writing unit 500 has a peak value acquired in the peak value acquisition process (S13 above) of P2. In this case, PI / P2 is calculated as the correction coefficient fk. Thereby, when the voltage signal output from the sensor module 150 is relatively large, a value smaller than 1 is calculated as the correction coefficient fk.

  Here, as described above, the voltage signal output from the sensor module 150 corresponds to the current output from the particle detection sensor 110, and the current corresponds to the sensitivity of the particle detection sensor 110. Therefore, the ideal peak value PI and the actual peak value correspond to the reference sensitivity that is a reference for the sensitivity of the particle detection sensor 110 and the actual sensitivity of the particle detection sensor 110.

  Therefore, when the voltage signal output from the sensor module 150 is relatively small, that is, when the sensitivity is low, the writing unit 500 calculates a value larger than 1 as the correction coefficient fk. On the other hand, when the voltage signal output from the sensor module 150 is relatively large, that is, when the sensitivity is high, a value smaller than 1 is calculated as the correction coefficient fk. By calculating the correction coefficient fk according to the sensitivity of the particle detection sensor 110 as described above, it is possible to calculate the particle size while reducing the influence of the sensitivity of the particle detection sensor 110 in the particle size calculation processing described later. .

  Thus, the writing unit 500 writes the correction coefficient fk corresponding to the sensitivity of the particle detection sensor 110 with respect to the reference sensitivity in the storage unit 140.

  Here, the “ideal peak value” is, for example, a peak value of an ideal waveform output from the sensor module 150 including the particle detection sensor 110 when standard particles are introduced into the detection area DA of the particle detection sensor 110. It is. For example, when the ideal waveform is a waveform as shown in FIG. 9, the ideal peak value is PI.

  The ideal peak value is not limited to the value determined by the ideal waveform, and may be determined by the design value of the sensor module 150 including the particle detection sensor 110, for example. Further, for example, when standard particles are introduced into the detection area DA of each of the particle detection sensors 110 of the plurality of sensor modules 150, the average value or median value of the peak values of the voltage signals output from the plurality of sensor modules 150 Etc.

  Through the initial setting process as described above, the correction coefficient fk corresponding to the sensitivity of the particle detection sensor 110 with respect to the reference sensitivity is written in the storage unit 140.

  Therefore, in the particle size calculation process by the calculation unit 162, the particle size of the particle is calculated using the correction coefficient fk calculated in this way, thereby reducing the influence of the sensitivity of the particle detection sensor 110, thereby reducing the particle size. Can be calculated. That is, the particle size of particles contained in the atmosphere can be calculated with high accuracy.

  Note that step S11 may be executed after step S14 and immediately before step S15. That is, at the time of measuring standard particles, the fixed arrangement of the washer 30 on the substrate 2 may not be performed, and the fixed arrangement may be performed after the correction coefficient is calculated.

[3-2. Particle size calculation process]
Next, particle size calculation processing (calculation processing) by the calculation unit 162 will be described with reference to FIG. As described above, the calculation unit 162 of the particle measurement device 100 calculates the particle size of the particles using the correction coefficient written in the storage unit 140 in the manufacturing process of the particle measurement device 100. FIG. 10 is a flowchart showing a particle size calculation process executed by the calculation unit 162.

  In the mode in which the particle measuring apparatus 100 measures the particles, the substrate 2 has the connection configuration shown in FIG. 6, and the bolt 40, the nut 41, and the washer 30 are not fixedly arranged. As a result, the nonvolatile memory 141 is in a non-writable state.

  First, the calculation unit 162 reads the correction coefficient fk from the storage unit 140 (S21).

  Thereafter, the calculation unit 162 corrects the threshold value for calculating the particle diameter of the particles by the correction coefficient fk (S22), and calculates (calculates) the particle diameter using the corrected threshold value (S23).

  For example, when the particle size is calculated using the 10-step threshold values Vth1 to Vth10, the calculation unit 162 has a range in which the peak value of the digital data generated by the AD conversion unit 161 is divided by the 10-step threshold values Vth1 to Vth10. The particle size is calculated by determining where it is located.

  Here, the digital data generated by the AD conversion unit 161 is a value depending on the sensitivity of the particle detection sensor 110. That is, even when particles having the same particle diameter are introduced, if the sensitivity of the particle detection sensor 110 is high, the value of the digital data becomes a relatively large value, whereas the sensitivity of the particle detection sensor 110 is low. The value of digital data is a relatively small value.

  Therefore, when the particle size of the particles is calculated using the same threshold values Vth1 to Vth10 regardless of the sensitivity of the particle detection sensor 110, the following problem may occur.

  Specifically, when the sensitivity of the particle detection sensor 110 is low, the particle size calculated by the calculation unit 162 may be calculated smaller than the actual particle size. On the other hand, when the sensitivity of the particle detection sensor 110 is high, the particle size calculated by the calculation unit 162 may be calculated larger than the actual particle size.

  As described above, when the calculation unit 162 calculates the particle size without correcting the threshold values Vth1 to Vth10, it may be difficult to calculate the particle size with high accuracy.

  On the other hand, in the present embodiment, the arithmetic unit 162 corrects the threshold values Vth1 to Vth10 using the correction coefficient fk stored in the storage unit 140 in the correction process (S22). Thereafter, in the particle size calculation process (S23), the particle size of the particles is calculated using the corrected threshold values Vth1 'to Vth10'. For example, the calculation unit 162 calculates the particle size using the values obtained by multiplying the correction coefficients fk stored in the storage unit 140 by the threshold values Vth1 to Vth10 before correction as the threshold values Vth1 'to Vth10' after correction.

  Thereby, the calculating part 162 can reduce the influence by the sensitivity of the particle | grain detection sensor 110, and can calculate a particle size. That is, the particle size of the particles can be calculated with high accuracy. That is, by the particle diameter calculation process as described above, the particle measuring apparatus 100 according to the present embodiment can accurately calculate the particle diameter of particles contained in the gas flowing in the particle flow path of the particle detection sensor 110. .

  Furthermore, the calculation unit 162 can calculate the particle diameter of the particles with high accuracy by a simple process that only corrects the threshold values Vth1 to Vth10. Therefore, the particle size of the particles can be calculated with high accuracy without using a high-performance device as the general-purpose MPU 160.

[4. Modification of conductive part]
In addition, the pattern shape of the 1st electroconductive part 21 and the 2nd electroconductive part 22 is not limited to what was shown by FIG. That is, in the region where the first conductive portion 21 and the second conductive portion 22 face each other, as shown in FIG. 6, the first conductive portion 21 and the second conductive portion 22 do not face each other at a certain distance. May be.

  FIG. 11A is a diagram illustrating the shape of a conductive portion according to Modification 1 of Embodiment 1. FIG. 11B is a diagram illustrating the shape of the conductive portion according to the second modification of the first embodiment. For example, as shown in FIG. 11A, the first conductive portion 21A and the second conductive portion 22A having a comb shape may be opposed to each other in a region where the conductive portions are opposed to each other. Further, for example, as shown in FIG. 11B, the first conductive portion 21 </ b> B and the second conductive portion 22 </ b> B having an uneven shape may face each other in a region where the conductive portions face each other. According to such a shape, the first conductive portion and the second conductive portion are disposed between the first conductive portion and the second conductive portion while arranging the first conductive portion and the second conductive portion along the outer periphery of the opening portion 23 with the opening portion 23 therebetween. The interval can be reduced. Thereby, since the intensity | strength for fixing the connection member like the washer 30 which conducts the 1st conductive part and the 2nd conductive part to the opening part 23 can be reduced, dimensional accuracy, such as a board | substrate and a connection member, can be eased.

  In addition, the pattern shape of the 1st electroconductive part and 2nd electroconductive part which concern on this Embodiment is not limited to the said pattern shape. The connecting member such as the washer 30 may be in a shape in which the first conductive portion and the second conductive portion are electrically connected by being fixedly disposed at the opening 23.

  For example, the first conductive portion and the second conductive portion may be formed apart from each other on the inner wall of the opening 23 that forms the through hole. In this case, the connection member that conducts the first conductive portion and the second conductive portion may be a metallic screw that is in close contact with the inner wall of the opening 23 and penetrates the through hole.

  In addition, one of the first conductive part and the second conductive part is formed on the substrate plane at the outer periphery of the through hole of the opening 23, and the other of the first conductive part and the second conductive part forms a through hole. You may form in the inner wall of the opening part 23 to do. In this case, the connection member that conducts the first conductive portion and the second conductive portion is sandwiched between the metal screw that is in close contact with the inner wall of the opening 23 and penetrates the through hole, and the metal screw and the substrate. It may be a washer.

[5. Example of substrate modification]
The substrate 2 may be configured without the opening 23 having a through hole. That is, the area where the opening 23 is provided may be a predetermined area where a member that forms the base of the substrate 2 is present. In this case, as a configuration in which the washer 30 as a connecting member is brought into contact with the first conductive portion 21 and the second conductive portion 22, for example, a configuration in which the substrate 2 and the washer 30 are sandwiched by conductive clips may be used. .

[6. Modified example of particle size calculation]
In the first embodiment, the calculation unit 162 corrects the threshold value for calculating the particle diameter of the particle using the correction coefficient, and calculates the particle diameter of the particle using the corrected threshold value. On the other hand, in the present modification, the calculation unit 162 corrects the digital data generated by the AD conversion unit 161 with the correction coefficient, and calculates the particle size of the particles using the corrected digital data.

  Hereinafter, the particle size calculation process (calculation process) by the calculation unit 162 in this modification will be described. The calculation process is substantially the same as the particle diameter calculation process in the above-described embodiment described with reference to FIG. 10, but the processes in the correction process (S22) and the particle diameter calculation process (S23) are different.

  Specifically, the calculation unit 162 in the present modification corrects the digital data generated by the AD conversion unit 161 in the correction process (S22).

  Here, as described above, the digital data generated by the AD conversion unit 161 is a value depending on the sensitivity of the particle detection sensor 110. That is, even when particles having the same particle diameter are introduced, if the sensitivity of the particle detection sensor 110 is high, the value of the digital data becomes a relatively large value, whereas the sensitivity of the particle detection sensor 110 is low. The value of digital data is a relatively small value.

  Specifically, as described above, when the sensitivity of the particle detection sensor 110 is low, the particle size calculated by the calculation unit 162 may be calculated smaller than the actual particle size. On the other hand, when the sensitivity of the particle detection sensor 110 is high, the particle size calculated by the calculation unit 162 may be calculated larger than the actual particle size.

  Therefore, when the calculation unit 162 in this modification calculates the particle size without correcting the digital data, it may be difficult to calculate the particle size with high accuracy.

  On the other hand, in the present modification, the calculation unit 162 corrects the digital data and calculates the particle size of the particles using the corrected digital data. For example, the calculation unit 162 calculates the particle size using data obtained by multiplying the correction coefficient fk stored in the storage unit 140 by digital data before correction as digital data after correction.

  That is, the calculation unit 162 in the present modification corrects the digital data to be larger when the sensitivity of the particle detection sensor 110 mounted on the particle measuring device 100 is low. On the other hand, when the sensitivity of the particle detection sensor 110 mounted on the particle measuring apparatus 100 is high, the digital data is corrected to be small.

  Thereby, the calculating part 162 in this modification produces the same effect as the said embodiment. That is, the particle size can be calculated while reducing the influence of the sensitivity of the particle detection sensor 110. That is, the particle size of the particles can be calculated with high accuracy.

  Here, as a configuration for accurately calculating the particle size of the particle by reducing the influence of the sensitivity of the particle detection sensor 110, a configuration in which the amplification factor of the amplification unit 122 is changed according to the sensitivity of the particle detection sensor 110 is considered. It is done. As such a configuration, for example, a configuration in which the circuit constant of the amplifier 122b is designed to be adjustable with a variable resistor or the like, and the circuit constant is adjusted according to the sensitivity of the particle detection sensor 110 is conceivable.

  However, when the circuit constant of an analog circuit such as the amplifier 122b is adjusted, the temperature coefficient of the circuit constant may be different before and after the adjustment. That is, depending on the sensitivity of the particle detection sensor 110, the temperature dependence of the circuit constant of the analog circuit may be different.

  On the other hand, in this modification, digital data is corrected according to the sensitivity of the particle detection sensor 110. Therefore, the temperature dependence of the circuit constant of the analog circuit can be made substantially the same regardless of the sensitivity of the particle detection sensor 110.

  Furthermore, when adjusting the circuit constants of an analog circuit such as the amplifier 122b, the long-term reliability of the particle measuring device may be lowered. This is because the analog circuit has a large long-term performance drift due to vibration or moisture absorption of circuit elements constituting the analog circuit.

  On the other hand, in this modification, digital data is corrected according to the sensitivity of the particle detection sensor 110. Therefore, long-term performance drift of the analog circuit can be suppressed, and long-term reliability can be ensured.

  In addition, the calculation unit 162 may always perform the above-described particle size calculation process (S23), that is, calculation (peak search) for detecting the peak value of the digital data, or when a predetermined condition is satisfied. May only go to.

  For example, when the digital data after correction is larger than the lowest threshold value (for example, Vth1) among a plurality of threshold values (for example, threshold values Vth1 to Vth10 in 10 steps) for calculating the particle diameter, A peak search may be performed. In other words, the arithmetic unit 162 may start the peak search when the digital data exceeds the minimum threshold value.

  As described above, the calculation unit 162 can reduce the calculation amount (processing amount) by performing the peak search only when a predetermined condition is satisfied, as compared with the case of performing the constant peak search. That is, the particle size of the particles can be calculated without using a high-performance device as the general-purpose MPU 160.

  Here, the lowest threshold value Vth1 may be a value larger than a value obtained by correcting the digital value corresponding to the noise floor of the voltage signal input to the AD converter 161 with the correction coefficient fk.

  Thereby, the various misdetections which arise when the calculating part 162 calculates the peak of a noise can be reduced. Note that various misdetections include, for example, misdetection of the particle diameter of particles and misdetection of the number of particles.

  Note that the timing for starting the peak search is not limited to the timing when the corrected digital data exceeds the minimum threshold value Vth1, but may be the timing when the digital data before correction exceeds the minimum threshold value Vth1.

[7. effect]
The sensor module 150 according to the present embodiment includes a particle detection sensor 110 that outputs an electrical signal, and a storage unit that can write correction information for the electrical signal by applying a ground voltage to the write prevention terminal WP. 140 and the substrate 2 on which the storage unit 140 is mounted. Further, the substrate 2 is formed in a predetermined region on the substrate 2 and is formed separately from the first conductive portion 21 in the predetermined region and the first conductive portion 21 electrically connected to the write prevention terminal WP. And a second conductive portion 22 electrically connected to a portion of the substrate 2 to which a ground voltage is applied. In the above configuration, the first conductive portion 21 and the washer 30 are in contact with each other by the washer 30 being fixedly disposed in the predetermined region, and the first conductive portion 22 and the washer 30 are in contact with each other. The voltage of the unit 21 becomes the ground voltage.

  Thus, the correction information can be written to the storage unit 140 by bringing the conductive unit and the washer 30 formed on the substrate 2 on which the storage unit 140 is mounted into contact with each other. Therefore, a write control circuit for turning on and off the erroneous write prevention function is not required separately, and a circuit for writing correction information can be simplified.

  The predetermined region is provided with an opening 23 having a through-hole for fixing the washer 30. The first conductive portion 21 and the second conductive portion 22 are arranged along the outer periphery of the opening 23, respectively. It may be formed.

  According to this configuration, the bolt 40 is passed through the washer 30 and the through hole, and the washer 30 and the substrate 2 are fastened by the nut 41, so that the washer 30 and the first conductive portion 21 and the second conductive portion 22 are pressed. The As a result, the GND connection terminal of the storage unit 140 is electrically connected to the portion to which the ground voltage is applied on the substrate 2 via the first conductive unit 21, the washer 30, and the second conductive unit 22. Therefore, the ground voltage can be applied to the write prevention terminal WP of the storage unit 140 with a simplified circuit configuration, and the nonvolatile memory 141 can be set in a writable state.

  The sensor module 150 includes, in addition to the particle detection sensor 110 and the storage unit 140, an IV conversion unit 121 that generates a voltage signal by converting the current output from the light receiving element 112 into a voltage, The particle measuring apparatus 100 further includes an AD converter 161 that samples and quantizes the voltage signal amplified by the amplifier 122, and is sampled and quantized by the AD converter 161. And a calculation unit 162 that calculates the particle size of the particles using time-series digital data that is a voltage signal and a correction coefficient.

  Thereby, the calculating part 162 can reduce the influence by the sensitivity of the particle | grain detection sensor 110, and can calculate a particle size. Therefore, the particle measuring apparatus 100 according to the present embodiment can calculate the particle diameter of the particles contained in the gas flowing in the particle flow path of the particle detection sensor 110 with high accuracy.

  Further, the correction coefficient fk may be a value calculated based on the current output from the light receiving element 112 when standard particles having a predetermined particle diameter are introduced into the detection region.

  In addition, the calculation unit 162 may correct the threshold value for calculating the particle diameter of the particle with the correction coefficient fk, and calculate the particle diameter of the particle using the corrected threshold value.

  By these, the particle diameter of the particle | grains contained in the gas which flows in the particle | grain flow path of the particle | grain detection sensor 110 can be accurately calculated by simple processing which only corrects a threshold value.

  The calculation unit 162 may correct the digital data with the correction coefficient fk and calculate the particle size of the particles using the corrected digital data.

  Further, the storage method of the sensor module 150 according to the present embodiment is achieved by fixing the washer 30 in a predetermined area with respect to the substrate 2 provided with the first conductive portion 21 and the second conductive portion 22. 30 and the first conductive part 21 are brought into contact with each other, and the washer 30 and the second conductive part 22 are brought into contact with each other, whereby a ground voltage is applied to the write prevention terminal WP and a ground voltage is applied to the write prevention terminal WP. In this state, the correction information is written in the storage unit 140.

  This eliminates the need for a separate write control circuit for turning on and off the erroneous write prevention function, and allows the write process to be executed with the circuit for writing correction information simplified.

(Embodiment 2)
The sensor module according to the present embodiment is different from the sensor module 150 according to the first embodiment in the configuration in which the ground voltage is applied to the GND connection terminal of the storage unit 140 in the mode for storing correction data. Hereinafter, the configuration different from the sensor module 150 according to Embodiment 1 will be mainly described.

  The overall configuration of the particle measuring apparatus, the configuration and operation of the particle detection sensor 110, the configuration of the analog signal processing unit 120, the configuration of the general-purpose MPU 160, the configuration of the storage unit 140, and the calculation processing in the particle size measurement mode are described in the first embodiment. Since it is the same as the particle | grain measuring apparatus 100 which concerns, description is abbreviate | omitted.

[8. Correction coefficient initialization process]
As shown in FIG. 4, the initial setting process of the correction coefficient to the storage unit 140 in the present embodiment is executed by the writing unit 500 connected to the sensor module 150 on which the storage unit 140 is mounted.

  The writing unit 500 calculates a correction coefficient corresponding to the sensitivity of the particle detection sensor 110 based on the current output from the light receiving element 112 when standard particles having a predetermined particle diameter are introduced into the detection area DA. . Further, the writing unit 500 writes the calculated correction coefficient in the storage unit 140.

  FIG. 12 is a diagram illustrating a connection configuration of the board 3 on which the storage unit 140 according to the embodiment is mounted. The storage unit 140 is mounted on the substrate 3 shown in the figure, and the substrate 3 further includes a first conductive unit 24 and an opening 25.

  The opening 25 is provided with a through hole.

  The first conductive portion 24 is a conductive pattern formed on the substrate 3 and is formed of, for example, a metal film. The first conductive portion 24 has a semicircular shape in plan view of the substrate 3 so as to follow the outer periphery of the opening 25. The first conductive unit 24 is electrically connected to the GND connection terminal of the storage unit 140 via a wiring formed on the substrate 3.

  FIG. 12 shows the configuration of the substrate 3 in a mode in which the particle measuring apparatus according to the second embodiment measures the particles. That is, the GND connection terminal of the storage unit 140 is in an open state and is not at the ground potential. In addition, the power supply voltage Vcc (second voltage) is applied to the write prevention terminal WP of the storage unit 140, and thus the nonvolatile memory 141 is in a non-writable state.

  FIG. 13A is a diagram illustrating a connection configuration of the substrate 3 when correction information is stored. FIG. 13B is a cross-sectional view taken along the line B-B ′ of FIG. 13A. FIG. 13A and FIG. 13B show the configuration of the substrate 3 when the correction coefficient initial setting process (write process) to the storage unit 140 is executed in the sensor module manufacturing process. In other words, FIGS. 13A and 13B show the configuration of the substrate 3 in the mode in which the sensor module according to Embodiment 2 stores the correction data. As shown in FIGS. 13A and 13B, the bolt 40 is passed through the annular washer 31 that is a conductive connecting member and the through hole of the opening 25, and the washer 31 and the substrate 3 are tightened with a nut 41, The washer 31 and the first conductive portion 24 are pressed against each other. In the present embodiment, the ground voltage is applied to the washer 31 in the mode for storing the correction data.

  With the above configuration, the GND connection terminal of the storage unit 140 is electrically connected to the washer 31 to which the ground voltage (first voltage) is applied via the first conductive unit 24. As a result, the ground voltage is applied to the write prevention terminal WP of the storage unit 140, and the nonvolatile memory 141 is in a writable state.

  The correction coefficient initial setting process by the writing unit 500 will be described below.

  First, the washer 31 to which the ground voltage is applied is fixedly disposed in the opening 25 on the substrate 3 so that the washer 31 and the first conductive portion 24 are brought into contact with each other. Specifically, the washer 31 is fixedly disposed in the opening 25 of the substrate 3 by passing the bolt 40 through the through hole and the washer 31 and tightening the substrate 3 and the washer 31 with the nut 41. As a result, the ground voltage is applied to the write prevention terminal WP of the storage unit 140, and the nonvolatile memory 141 is in a writable state.

  Further, the particle detection sensor 110 is mounted on the substrate 3, and the substrate 3 and the particle detection sensor 110 are fixedly disposed on a predetermined measuring jig or the like simultaneously with the fixed disposition of the washer 31 by the bolt 40 and the nut 41. . In order to correct the characteristic variation among individuals in the plurality of particle detection sensors 110, it is desirable to install the plurality of particle detection sensors 110 in the same arrangement state and simultaneously measure standard particles. From this viewpoint, the fixed arrangement using the opening 25 enables the plurality of substrates 3 on which the particle detection sensors 110 are mounted to be installed in the same arrangement state. That is, by fixing the washer 31 in the opening 25 on the substrate 3, the nonvolatile memory 141 can be made writable, and a high-accuracy correction coefficient resulting from characteristic variations among individuals can be acquired. It becomes possible.

  The following correction coefficient initial setting process is the same as the writing process in the first embodiment, and executes Steps S12 to S15 shown in FIG.

  Note that the step of fixing the washer 31 in the opening 25 may be performed after step S14 and immediately before step S15. That is, at the time of measuring standard particles, the fixed arrangement of the washer 31 on the substrate 3 may not be performed, and the fixed arrangement may be performed after the correction coefficient is calculated.

  In addition, the pattern shape of the 1st electroconductive part which concerns on this Embodiment is not limited to the said pattern shape. The connecting member such as the washer 31 may be fixed in the opening 25 so that the first conductive portion is in contact with the connecting member.

  For example, the first conductive portion may be formed on the inner wall of the opening 25 that forms the through hole. In this case, the connection member that applies the ground voltage to the first conductive portion may be a metal screw that is in close contact with the inner wall of the opening 25 and penetrates the through hole.

[9. effect]
The sensor module according to the present embodiment includes a particle detection sensor 110 that outputs an electrical signal, and a storage unit 140 that can write correction information for the electrical signal by applying a ground voltage to the write prevention terminal WP. And a substrate 3 on which the storage unit 140 is mounted. The substrate 3 includes an opening 25 having a through hole, and a first conductive portion 24 formed along the outer periphery of the through hole and electrically connected to the write prevention terminal WP, and applies a ground voltage. When the washer 31 is fixedly disposed through the through-hole, the washer 31 and the first conductive portion 24 come into contact with each other, whereby the voltage of the first conductive portion 24 becomes the ground voltage.

  Thereby, the correction information can be written to the storage unit 140 by bringing the first conductive unit 24 and the washer 31 formed on the substrate 3 on which the storage unit 140 is mounted into contact with each other. Therefore, a write control circuit for turning on and off the erroneous write prevention function is not required separately, and a circuit for writing correction information can be simplified.

  In the memory method of the sensor module according to the present embodiment, the ground voltage is applied to the opening 25 with respect to the substrate 3 including the opening 25 having the through hole and the first conductive portion 24. By arranging the washer 31 in a fixed manner, the washer 31 and the first conductive portion 24 are brought into contact with each other, a ground voltage is applied to the write prevention terminal WP, and a ground voltage is applied to the write prevention terminal WP. Write correction information to.

  This eliminates the need for a separate write control circuit for turning on and off the erroneous write prevention function, and allows the write process to be executed with the circuit for writing correction information simplified.

(Other embodiments)
As described above, the signal output device, the particle measuring device, and the storage method of the signal output device according to the present invention have been described based on the embodiment and the modification. However, the present invention is limited to the above embodiment and the modification. It is not something.

  For example, as the conductive connection member, the washer 30 is exemplified in the first embodiment and the washer 31 is exemplified in the second embodiment. However, the conductive connection member may be formed on a substrate such as a metal clip or a metal screw. Any member that can apply a ground voltage (first voltage) to the first conductive portion by being fixedly disposed on the first conductive portion may be used.

  In the above description, the medium containing particles is the atmosphere (air), but may be a medium other than the atmosphere (liquid such as water).

  The configuration of the particle detection sensor 110 is not limited to the configuration described above, and includes at least a light projecting element 111 and a light receiving element 112, and receives light scattered from the light projecting element by particles in the detection area DA. The particles contained in the atmosphere may be detected by receiving the light. Even with such a configuration, the particle measuring apparatus including the particle detection sensor can accurately measure the particle size of particles contained in the gas.

  The configuration of the amplifying unit is not limited to the configuration described above, and at least the voltage signal output from the IV conversion unit 121 may be amplified in a predetermined band. That is, the amplifying unit may not include the bandpass filter 122a, and may include a high-pass filter or a low-pass filter. Further, the amplifier 122b may be a single stage or a plurality of stages.

  In the above description, each component in the general-purpose MPU may be configured by dedicated hardware or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or a processor reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory.

  Further, the calculation unit is not limited to the above description, and it is only necessary to calculate (calculate) the particle size of the particles using at least the digital data and the correction coefficient. For example, the calculation unit obtains the peak value of the digital data, corrects the peak value using the obtained peak value and the correction coefficient fk stored in the storage unit 140, and uses the corrected peak value to determine the particle size of the particles. The diameter may be calculated.

  The correction coefficient is not limited to the one generated by writing in the manufacturing process as described above, and may be generated every time a predetermined time elapses after the particle detection sensor 110 is activated, for example. . As described above, by using the correction coefficient generated after the activation of the particle detection sensor 110, the particle measurement apparatus 100 can suppress deterioration in accuracy of particle size calculation due to deterioration of components constituting the particle detection sensor 110 or the like. .

  In the above description, the correction coefficient stored in the storage unit 140 is based on a value calculated based on the current output from the light receiving element 112 when standard particles are introduced into the detection area DA. Not limited to this. The correction coefficient only needs to correspond to at least the sensitivity of the particle detection sensor 110 mounted on the sensor module on which the storage unit 140 is mounted. For example, the particle detection sensor 110 with respect to the average sensitivity of a plurality of particle detection sensors. May correspond to the sensitivity.

  In addition, any combination of the components and functions in the embodiment and the modification may be arbitrarily combined without departing from the gist of the present invention, and the form obtained by making various modifications conceived by those skilled in the art with respect to the embodiment and the modification. The embodiment realized by the above is also included in the present invention.

  For example, various devices (a smoke detector, an air cleaner, a ventilation fan, or the like) including the particle measuring device according to the above-described embodiment and modification are also included in the scope of the present invention.

2, 3 Substrate 21, 21A, 21B, 24 First conductive part 22, 22A, 22B Second conductive part 23, 25 Opening part 30, 31 Washer (connection member)
100 Particle Measuring Device 110 Particle Detection Sensor (Signal Output Unit)
111 Light Emitting Element 112 Light Receiving Element 121 IV Conversion Unit 122 Amplifying Unit 140 Storage Unit 150 Sensor Module (Signal Output Device)
161 AD converter 162 Calculation unit

Claims (9)

A signal output unit for outputting an electrical signal;
A storage unit that has a write control terminal and can write correction information for the electrical signal by applying a first voltage to the write control terminal;
A board on which the storage unit is mounted,
The substrate is
A first conductive portion formed in a predetermined region on the substrate and electrically connected to the write control terminal;
A second conductive portion formed in the predetermined region and spaced apart from the first conductive portion and electrically connected to a portion of the substrate to which the first voltage is applied;
When the conductive connection member is fixedly disposed in the predetermined region, the first conductive portion and the connection member are in contact with each other, and the second conductive portion and the connection member are in contact with each other, thereby The signal output device in which the voltage of one conductive part is the first voltage. In the predetermined region, an opening having a through hole for fixing the connection member is provided,
The said 1st electroconductive part and the said 2nd electroconductive part are each formed in at least any one of the inner wall of the said opening part which forms the said through-hole, and the part along the outer periphery of the said through-hole. Signal output device. A signal output unit for outputting an electrical signal;
A storage unit that has a write control terminal and can write correction information for the electrical signal by applying a first voltage to the write control terminal;
A board on which the storage unit is mounted,
The substrate is
An opening having a through hole;
A first conductive portion formed on at least one of an inner wall of the opening forming the through hole and a portion along an outer periphery of the through hole, and electrically connected to the write control terminal;
The conductive connecting member to which the first voltage is applied is fixedly disposed by the through hole, so that the connecting member and the first conductive portion come into contact with each other, whereby the voltage of the first conductive portion is changed to the first conductive portion. A signal output device with 1 voltage. The signal output device according to any one of claims 1 to 3,
A signal processing unit for processing a signal output from the signal output device,
The signal output unit is
A light projecting element and a light receiving element are provided, and the particles contained in the atmosphere are detected by receiving the scattered light of the light of the light projecting element by the particles in the detection region by the light receiving element and outputting it as the electric signal. A particle detection sensor,
The storage unit stores a correction coefficient that is the correction information according to the sensitivity of the particle detection sensor,
The signal output device further includes:
An IV converter that generates a voltage signal by converting the current output from the light receiving element into a voltage;
An amplifying unit for amplifying the voltage signal in a predetermined band;
The signal processing unit
An AD converter for sampling and quantizing the amplified voltage signal;
A particle measuring apparatus comprising: an arithmetic unit that calculates the particle size of the particles using time-series digital data that is the voltage signal sampled and quantized by the AD converter and the correction coefficient. The particle measuring apparatus according to claim 4, wherein the correction coefficient is a value calculated based on a current output from the light receiving element when standard particles having a predetermined particle diameter are introduced into the detection region. 6. The particle measurement according to claim 4, wherein the calculation unit corrects a threshold value for calculating the particle diameter of the particles by the correction coefficient, and calculates the particle diameter of the particles using the corrected threshold value. apparatus. The particle measuring apparatus according to claim 4, wherein the calculation unit corrects the digital data with the correction coefficient, and calculates the particle diameter of the particles using the corrected digital data. A storage method of a signal output device that stores correction information for correcting an electrical signal output from a signal output unit in a storage unit that can be written by applying a first voltage to a write control terminal,
A substrate on which the storage unit is mounted, the first conductive unit formed in a predetermined region on the substrate and electrically connected to the write control terminal, and the first conductive unit spaced apart from the first region The conductive member is fixedly disposed in the predetermined region with respect to the substrate including the second conductive portion to which the first voltage is applied, so that the connection member and the first conductive member are disposed. The first voltage is applied to the write control terminal by bringing the connection member into contact with the second conductive portion.
The storage method of the signal output device, wherein the correction information is written in the storage unit in a state where the first voltage is applied to the write control terminal. A storage method of a signal output device that stores correction information for correcting an electrical signal output from a signal output unit in a storage unit that can be written by applying a first voltage to a write control terminal,
The write control formed on at least one of a substrate on which the storage unit is mounted, the opening having a through-hole, and an inner wall of the opening that forms the through-hole and a portion along the outer periphery of the through-hole. A conductive connecting member to which the first voltage is applied is fixedly disposed in the opening with respect to the substrate including a first conductive portion electrically connected to a terminal. And applying the first voltage to the write control terminal by bringing the first conductive part into contact with the write control terminal,
The storage method of the signal output device, wherein the correction information is written in the storage unit in a state where the first voltage is applied to the write control terminal.

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