JP2012193976A5 - - Google Patents

Description

Ethyl alcohol detection device and detection method

  The present invention relates to an ethyl alcohol detection device and a detection method for detecting drought driving by detecting ethyl alcohol dissolved in blood based on infrared rays radiated from a human body.

  Conventionally, a device for preventing drunk driving is configured to detect ethyl alcohol contained in a driver's breath with a gas sensor and not to start the automobile when a predetermined amount or more of ethyl alcohol is detected. doing. (Patent Document 1).

  In general, the concentration of alcohol contained in exhaled breath is proportional to the alcohol concentration in blood. The standard for drunken driving stipulated by law is an alcohol concentration of 0.15 mg / L in exhaled breath, which corresponds to a blood alcohol concentration of 0.03%. For this reason, by measuring the alcohol concentration in the exhaled breath, it is possible to detect the drunk state and to prohibit the operation by performing predetermined control on the engine starting device or the like.

  However, in such a conventional anti-drinking device, the air in the space near the head where the driver is located is sucked by a fan and alcohol is indirectly detected by a gas sensor. Compared with the case where the alcohol concentration is directly collected and the alcohol concentration is measured, the measured value is lower than the actual alcohol concentration in exhaled breath, which may prevent the drunk driving from being surely prevented.

  In addition, the sensitivity of gas sensors that detect alcohol changes during use due to the adhesion or oxidation of foreign matter, so calibration is required to automatically adjust the sensitivity, and maintenance such as periodic cleaning inspections is also required. Otherwise, there is a problem that the detection accuracy cannot be maintained.

  In order to solve such a problem, the inventors of the present application have an absorption wavelength λ (1) of ethyl alcohol out of infrared radiation from a subject, and a wavelength λ (2) having a small absorption rate by ethyl alcohol in the vicinity thereof. Infrared intensity is detected by a detector for each of the characteristic absorption wavelengths λ (3) of the disturbance substance having the same absorption wavelength as ethyl alcohol, and ethyl alcohol is detected based on the infrared intensity at wavelengths λ (1) and λ (2). The content is obtained, and a disturbance substance detection value is obtained based on the infrared intensity of the wavelengths λ (2) and λ (3), and the ethyl alcohol content is determined based on the blood ethyl alcohol content in the subject and the disturbance substance detection value. An apparatus for determining detection or non-detection has been proposed (Patent Document 2).

Japanese Patent Laid-Open No. 8-150853 JP 2009-148401 A

  However, from the conventional infrared absorption wavelength λ (1) of ethyl alcohol, the wavelength λ (2) having a small ethyl alcohol absorption rate in the vicinity thereof, and the infrared intensity of the characteristic absorption wavelength λ (3) of the disturbance material described above, In the method of determining the alcoholic content by determining the blood ethyl alcohol content and the disturbance substance detection value, when the temperature (body temperature) of the subject changes greatly, the wavelengths λ (1), λ (2) and λ Since the detection value of the detector in (3) changes, there is a problem that the accurate ethyl alcohol content cannot be obtained, and the determination accuracy (detection accuracy) of alcoholic taste is lowered.

  The present invention relates to an ethyl alcohol detection device that accurately detects the ethyl alcohol content in blood or the index indicating it from the infrared rays radiated by the subject without being affected by the body temperature of the subject, An object is to provide a detection method.

(Detecting device A)
The present invention provides an ethyl alcohol detector,
An image sensor having sensitivity in the infrared wavelength band;
An optical system for forming an image of a subject on an image sensor;
A first transmission window that selectively transmits infrared light in a first wavelength band including an absorption wavelength (λ1) of ethyl alcohol from a subject;
A second transmission window that selectively transmits infrared light in a second wavelength band including a wavelength (λ2) having a low absorption rate by ethyl alcohol in the vicinity of the first wavelength band from the subject;
A third transmission window that selectively transmits infrared light in a third wavelength band different from the second wavelength band including a wavelength (λ3) having a low absorption rate by ethyl alcohol in the vicinity of the first wavelength band from the subject; ,
The first subject image imaged through the first transmission window, the second subject image imaged through the second transmission window, and the third subject imaged through the third transmission window An imaging control unit that captures an image by an image sensor and stores the image in a memory;
An ethyl alcohol detector that calculates the ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first subject image and the second subject image stored in the memory;
A temperature detector that calculates the temperature of the subject based on the second subject image and the third subject image stored in the memory;
A determination unit that determines the detection and non-detection of ethyl alcohol based on the ethyl alcohol content and the detected temperature of the subject,
It is provided with.

Here, the first transmission window selectively transmits infrared light in a wavelength band including the wavelength λ1 = 9.5 μm as the first wavelength band,
The second transmission window and the third transmission window selectively transmit infrared light in the second wavelength band and the third wavelength band not including the first wavelength band.

The second transmission window selectively transmits infrared light in a wavelength band including the wavelength λ2 = 9.0 μm as the second wavelength band,
The third transmission window selectively transmits infrared light in a wavelength band that includes the wavelength λ3 = 8.3 μm as the third wavelength band.

  The ethyl alcohol detection unit corresponds to the ethyl alcohol concentration as the difference value (ΔVd = Vd1−Vd2) of the sum or average value (Vd1, Vd2) of the correlation values between the pixels at the same position in the first subject image and the second subject image. The ethyl alcohol content (ΔVd) is calculated.

  A temperature detection part calculates a test subject's temperature from the sum total or average value of the correlation value between the pixels of the same position of a 2nd test subject image and a 3rd test subject image.

The determination unit, based on a predetermined temperature correction coefficient (K), temperature-corrects a predetermined threshold value (Vtho) set at a predetermined reference temperature (To) to a threshold value (Vth) at the detected temperature (T) of the subject, When the ethyl alcohol content (ΔVd) is equal to or lower than the temperature-corrected threshold value (Vth), the detection of ethyl alcohol is determined, and when the ethyl alcohol content (ΔVd) exceeds the temperature-corrected threshold value (Vth), ethyl alcohol is detected. Non-detection is determined. In this case, the temperature correction of the threshold value is corrected by the following equation.
Vth = Vtho + K (T-To)

The determination unit determines the ethyl alcohol content (ΔVd) at the detected temperature (T) of the subject based on the predetermined temperature correction coefficient (K), and the ethyl alcohol at the reference temperature (To) at which the predetermined threshold (Vtho) is set. When the ethyl alcohol content (ΔVdo) corrected to the content (ΔVdo) and the temperature-corrected ethyl alcohol content (ΔVdo) is equal to or lower than the threshold (Vtho), the detection of ethyl alcohol is determined, and the temperature-corrected ethyl alcohol content (ΔVdo) is determined to be the threshold (Vtho). ) Is exceeded, it is determined that ethyl alcohol is not detected. In this case, the temperature correction of the ethyl alcohol content is corrected by the following equation.
ΔVdo = ΔVd + K (T−To)

  A cooling mechanism for cooling the imaging device, the optical system, the first transmission window, the second transmission window, and the third transmission window is provided.

(Detecting device B)
The present invention provides an ethyl alcohol detector,
An image sensor having sensitivity in the infrared wavelength band;
An optical system for forming an image of a subject on an image sensor;
A first transmission window that selectively transmits infrared light in a first wavelength band including an absorption wavelength (λ1) of ethyl alcohol from a subject;
A second transmission window that selectively transmits infrared light in a second wavelength band including a wavelength (λ2) having a low absorption rate by ethyl alcohol in the vicinity of the first wavelength band from the subject;
A first subject image formed through the first transmission window and a second subject image formed through the second subject image formed through the second transmission window, the imaging element An imaging control unit for imaging and storing in a memory;
An ethyl alcohol detector that calculates the ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first subject image and the second subject image stored in the memory;
A temperature detector that calculates the temperature of the subject based on the second subject image stored in the memory;
A determination unit that determines the detection and non-detection of ethyl alcohol based on the ethyl alcohol content and the detected temperature of the subject,
It is provided with.

Here, the first transmission window selectively transmits infrared light in a wavelength band including the wavelength λ1 = 9.5 μm as the first wavelength band,
The second transmission window selectively transmits infrared light in the second wavelength band that does not include the first wavelength band.

  The second transmission window selectively transmits infrared light in a wavelength band including the wavelength λ2 = 9.0 μm or 8.3 μm as the second wavelength band.

  The ethyl alcohol detection unit calculates the ethyl alcohol content corresponding to the ethyl alcohol concentration as a difference value of the sum or average value of correlation values between pixels at the same position in the first subject image and the second subject image. An ethyl alcohol detector.

  A temperature detection part calculates a test subject's temperature from the sum total or average value of the correlation value between the pixels of the same position as the 1st test subject image in the 2nd test subject image.

  The determination unit corrects the predetermined threshold set at the predetermined reference temperature to a threshold at the detected temperature of the subject based on the predetermined temperature correction coefficient, and the ethyl alcohol content is equal to or lower than the temperature corrected threshold. When the ethyl alcohol content exceeds the temperature-corrected threshold value, the non-detection of ethyl alcohol is determined.

  The determination unit corrects the ethyl alcohol content at the detected temperature of the subject based on a predetermined temperature correction coefficient to the ethyl alcohol content at a reference temperature set with a predetermined threshold, and the temperature-corrected ethyl alcohol content is a threshold. The detection of ethyl alcohol is determined in the following cases, and the non-detection of ethyl alcohol is determined when the temperature-corrected ethyl alcohol content exceeds a threshold value.

  A cooling mechanism for cooling the imaging device, the optical system, the first transmission window, and the second transmission window is provided.

(Detecting device C)
The present invention provides an ethyl alcohol detector,
An infrared sensor comprising one or more infrared light receiving elements;
An optical system for forming an image of a subject on an infrared sensor;
A first transmission window that selectively transmits infrared light in a first wavelength band including an absorption wavelength wavelength (λ1) of ethyl alcohol from a subject;
A second transmission window that selectively transmits infrared light in a second wavelength band including a wavelength (λ2) having a low absorption rate by ethyl alcohol in the vicinity of the first wavelength band from the subject;
A third transmission window that selectively transmits infrared light in a third wavelength band different from the second wavelength band including a wavelength (λ3) having a low absorption rate by ethyl alcohol in the vicinity of the first wavelength band from the subject; ,
A first light reception signal received through the first transmission window, a second light reception signal received through the second transmission window, and a third light received through the third transmission window by the infrared sensor. A light reception control unit for detecting a light reception signal and storing it in a memory;
An ethyl alcohol detector that calculates an ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first light receiving signal and the second light receiving signal stored in the memory;
A temperature detector that calculates the temperature of the subject based on the second received light signal and the third received light signal stored in the memory;
A determination unit that determines the detection and non-detection of ethyl alcohol based on the ethyl alcohol content and the detected temperature of the subject,
It is provided with.

Here, the first transmission window selectively transmits infrared light in a wavelength band including the wavelength λ1 = 9.5 μm as the first wavelength band,
The second transmission window and the third transmission window selectively transmit infrared light in the second wavelength band and the third wavelength band not including the first wavelength band.

The second transmission window selectively transmits infrared light in a wavelength band including λ2 = 9.0 μm as the second wavelength band,
The third transmission window selectively transmits infrared light in a wavelength band including λ3 = 8.3 μm as the third wavelength band.

  The ethyl alcohol detection unit calculates the ethyl alcohol content corresponding to the ethyl alcohol concentration as a difference value between the first light reception signal and the second light reception signal.

  A temperature detection part calculates a test subject's temperature based on the ratio of a 2nd light reception signal and a 3rd light reception signal.

  The determination unit corrects the predetermined threshold set at the predetermined reference temperature to a threshold at the detected temperature of the subject based on the predetermined temperature correction coefficient, and the ethyl alcohol content is equal to or lower than the temperature corrected threshold. When the ethyl alcohol content exceeds the temperature-corrected threshold value, the non-detection of ethyl alcohol is determined.

  The determination unit corrects the ethyl alcohol content at the detected temperature of the subject based on a predetermined temperature correction coefficient to the ethyl alcohol content at a reference temperature set with a predetermined threshold, and the temperature-corrected ethyl alcohol content is a threshold. The detection of ethyl alcohol is determined in the following cases, and the non-detection of ethyl alcohol is determined when the temperature-corrected ethyl alcohol content exceeds a threshold value.

  A cooling mechanism for cooling the infrared sensor, the optical system, the first transmission window, the second transmission window, and the third transmission window is provided.

(Detecting device D)
The present invention provides an ethyl alcohol detector,
An infrared sensor comprising one or more infrared light receiving elements;
An optical system for forming an image of a subject on an infrared sensor;
A first transmission window that selectively transmits infrared light in a first wavelength band including the absorption wavelength (λ1) of ethyl alcohol from the subject;
A second transmission window that selectively transmits infrared light in a second wavelength band including a wavelength (λ2) having a low absorption rate by ethyl alcohol in the vicinity of the first wavelength band from the subject;
A light receiving control unit for detecting a first light receiving signal received through the first transmission window and a second light receiving signal received through the second transmission window by the infrared sensor, and storing them in the memory;
An ethyl alcohol detector that calculates an ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first light receiving signal and the second light receiving signal stored in the memory;
A temperature detector that calculates the temperature of the subject based on the second received light signal stored in the memory;
A determination unit that determines the detection and non-detection of ethyl alcohol based on the ethyl alcohol content and the detected temperature of the subject,
It is provided with.

Here, the first transmission window selectively transmits infrared light in a wavelength band including λ1 = 9.5 μm as the first wavelength band,
The second transmission window selectively transmits infrared light in a second wavelength band that does not include the first wavelength band.

  The second transmission window selectively transmits infrared light in a wavelength band including λ2 = 9.0 μm or 8.3 μm as the second wavelength band.

  The ethyl alcohol detection unit calculates the ethyl alcohol content corresponding to the ethyl alcohol concentration as a difference value between the first light reception signal and the second light reception signal.

  The determination unit corrects the predetermined threshold set at the predetermined reference temperature to a threshold at the detected temperature of the subject based on the predetermined temperature correction coefficient, and the ethyl alcohol content is equal to or lower than the temperature corrected threshold. When the ethyl alcohol content exceeds the temperature-corrected threshold value, the non-detection of ethyl alcohol is determined.

  The determination unit corrects the ethyl alcohol content at the detected temperature of the subject based on a predetermined temperature correction coefficient to the ethyl alcohol content at a reference temperature set with a predetermined threshold, and the temperature-corrected ethyl alcohol content is a threshold. The detection of ethyl alcohol is determined in the following cases, and the non-detection of ethyl alcohol is determined when the temperature-corrected ethyl alcohol content exceeds the threshold value.

  A cooling mechanism for cooling the infrared sensor, the optical system, the first transmission window, and the second transmission window is provided.

(Detection method A)
The present invention provides an ethyl alcohol detection method,
Infrared light in the first wavelength band including the absorption wavelength (λ1) of ethyl alcohol from the subject is selectively transmitted through the first transmission window and imaged on an image sensor having sensitivity in the infrared wavelength band. Storing the first subject image in memory;
Infrared light in the second wavelength band including a wavelength (λ2) having a small absorption rate by ethyl alcohol in the vicinity of the first wavelength band from the subject is selectively transmitted through the second transmission window to form an image on the image sensor. And storing the second subject image captured in the memory,
The infrared light in the third wavelength band different from the second wavelength band including the wavelength (λ3) having a small absorption rate by ethyl alcohol in the vicinity of the first wavelength band from the subject is selectively selected by the third transmission window. Storing in the memory a third subject image that is transmitted through and imaged on the imaging device;
Calculating the ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first subject image and the second subject image stored in the memory;
Calculating the temperature of the subject based on the second subject image and the third subject image stored in the memory;
Determine the detection and non-detection of ethyl alcohol based on the ethyl alcohol content and the detected temperature of the subject,
It is characterized by that.

  Other features are basically the same as those of the detection device A described above.

(Detection method B)
The present invention provides an ethyl alcohol detection method,
Infrared light in the first wavelength band including the absorption wavelength (λ1) of ethyl alcohol from the subject is selectively transmitted through the first transmission window and imaged on an image sensor having sensitivity in the infrared wavelength band. Storing the first subject image in memory;
Infrared light in the second wavelength band including the wavelength (λ2) having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject is selectively transmitted through the second transmission window and is connected to the imaging device. Storing a second subject image captured in an image in a memory;
Calculating the ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first subject image and the second subject image stored in the memory;
Calculating the temperature of the subject based on the second subject image stored in the memory;
Determine the detection and non-detection of the ethyl alcohol based on the ethyl alcohol content and the subject's detection temperature,
It is characterized by that.

  Other features are basically the same as those of the detection device B described above.

(Detection method C)
The present invention provides an ethyl alcohol detection method,
Infrared light in the first wavelength band including the absorption wavelength (λ1) of ethyl alcohol from the subject is selectively transmitted through the first transmission window to form an image on an infrared sensor including one or more infrared light receiving elements. Store the first received light signal received in the memory,
Infrared light in the second wavelength band including a wavelength (λ2) having a low absorption rate by ethyl alcohol in the vicinity of the first wavelength band from the subject is selectively transmitted through the second transmission window and connected to the infrared sensor. The second received light signal received by imaging is stored in the memory,
Infrared light in a third wavelength band different from the second wavelength band including the wavelength (λ3) having a small absorption rate by ethyl alcohol in the vicinity of the first wavelength band from the subject is selectively transmitted through the third transmission window. Then, the third received light signal formed on the infrared sensor and received is stored in the memory,
Based on the first light reception signal and the second light reception signal stored in the memory, the ethyl alcohol content corresponding to the ethyl alcohol concentration is calculated,
Calculating the temperature of the subject based on the second received light signal and the third received light signal stored in the memory;
Determine the detection and non-detection of the ethyl alcohol based on the ethyl alcohol content and the detected temperature of the subject,
It is characterized by that.

  Other features are basically the same as those of the detection device C described above.

(Detection method D)
The present invention provides an ethyl alcohol detection method,
Infrared light in the first wavelength band including the absorption wavelength (λ1) of ethyl alcohol from the subject is selectively transmitted through the first transmission window to form an image on an infrared sensor including one or more infrared light receiving elements. Store the first received light signal received in the memory,
Infrared light in the second wavelength band including a wavelength (λ2) with a low absorption rate by ethyl alcohol in the vicinity of the first wavelength band from the subject is selectively transmitted through the second transmission window and imaged on the infrared sensor. Store the second received light signal received in the memory,
Based on the first light reception signal and the second light reception signal stored in the memory, the ethyl alcohol content corresponding to the ethyl alcohol concentration is calculated,
Calculating the temperature of the subject based on the second received light signal stored in the memory;
Determine the detection and non-detection of ethyl alcohol based on the ethyl alcohol content and the detected temperature of the subject,
It is characterized by that.

Other features are basically the same as those of the detection device D described above.

  According to the present invention, among infrared radiation from a subject, the amount of light received by the detector in the first wavelength band including the absorption wavelength λ1 of ethyl alcohol, Vd1, and the absorption rate by ethyl alcohol in the vicinity of the first wavelength band are small. The received light amount Vd2 in the second wavelength band including the wavelength λ2 and the received light amount Vd3 in the third wavelength band including the wavelength λ3 having a low absorption rate by ethyl alcohol in the vicinity of the first wavelength band are detected, and the wavelengths λ1 and λ2 are detected. The ethyl alcohol content is calculated as the difference ΔVd between the corresponding received light amounts Vd1 and Vd2, and the temperature (body temperature) of the subject is calculated from the received light amounts Vd2 and Vd3 corresponding to the wavelengths λ2 and λ3. Since the presence or absence of alcohol is determined by correcting the temperature according to the temperature, the determination error associated with the change in the body temperature of the subject can be reduced.

  Since the temperature of the subject can also be calculated from the amount of infrared light received corresponding to a single wavelength, the temperature of the subject is calculated from any one of the wavelength received amounts Vd2 or Vd3 corresponding to the wavelength λ2 or λ3. The temperature of the ethyl alcohol content can be corrected. In this case, since only two wavelengths are required, the structure and electrical circuit related to wavelength extraction can be reduced, and the apparatus configuration can be simplified and reduced in cost. Can do.

  Further, the absorption wavelength λ1 of ethyl alcohol is set to 9.5 μm, and the wavelengths λ2 and λ3 having a small absorption rate by the adjacent ethyl alcohol are set to, for example, 9.0 μm and 8.3 μm. By using a high wavelength band, it is possible to increase the amount of infrared light incident on the infrared camera or the infrared light receiving element and increase the light receiving output.

  In addition, a cooling mechanism for cooling the imaging device, the optical system, the first transmission window, the second transmission window, and the third transmission window is provided, and the noise component that affects the amount of received infrared light is reduced by cooling to, for example, room temperature or lower. Can do.

Block diagram showing an embodiment of an ethyl alcohol detector according to the present invention based on three-wavelength infrared detection Explanatory drawing showing a filter-switching infrared camera used in this embodiment Explanatory drawing showing the cooling mechanism used in this embodiment Explanatory diagram showing the wavelength spectrum distribution of ethyl alcohol Characteristic graph showing spectral radiation divergence versus wavelength according to Planck's law Explanatory drawing which showed extraction of the feature area in this embodiment Explanatory drawing which showed the graph distribution of the measurement result of the alcohol concentration in the breath of the subject in the normal state and the drinking state and the measurement point temperature, and the two-wavelength infrared output difference (ethyl alcohol content) The graph which showed distribution of the measurement point of the test subject's temperature and the output difference value (ethyl alcohol content) of two wavelength infrared rays by the measurement result of FIG. The characteristic graph figure which showed the temperature detection characteristic by 2 wavelengths in this embodiment The characteristic graph figure which showed temperature correction of output difference value 2deltaVd (ethyl alcohol content) of 2 wavelength infrared rays in this embodiment, and temperature correction of a threshold value The flowchart which showed the detection process of the ethyl alcohol by embodiment of FIG. Explanatory drawing showing an infrared camera using a wavelength tunable filter used in this embodiment The block diagram which showed other embodiment of the ethyl alcohol detection apparatus by this invention based on 2 wavelength infrared detection The flowchart which showed the detection process of the ethyl alcohol by embodiment of FIG. The block diagram which showed other embodiment of the ethyl alcohol detection apparatus by this invention based on the three-wavelength infrared detection using an infrared sensor Explanatory drawing which showed the infrared sensor of FIG. The flowchart which showed the detection process of the ethyl alcohol by embodiment of FIG. The block diagram which showed other embodiment of the ethyl alcohol detection apparatus by this invention based on 2 wavelength infrared detection using an infrared sensor The flowchart which showed the detection process of the ethyl alcohol by embodiment of FIG. Explanatory drawing which showed the infrared sensor provided with the some infrared rays light receiving element used in FIG. 15 or FIG. Explanatory drawing showing the multi-infrared sensor used in FIG. 15 or FIG.

  FIG. 1 is an explanatory view showing a configuration example of a main part of an embodiment of an ethyl alcohol detector according to the present invention based on three-wavelength infrared detection.

  In FIG. 1, the ethyl alcohol detection processing unit 10 of the ethyl alcohol detection device is functionally configured with a hardware environment and a software environment of a computer. For the ethyl alcohol detection processing unit 10, an infrared camera 12 and filter switching are performed. A unit 14 is provided. This is an example, and the separation and integration of each function can be performed arbitrarily. Some or all of the functions may be executed by software (programs) or may be executed by hardware.

  The infrared camera 12 is built in, for example, a dashboard of an automobile vehicle. In the present embodiment, for example, infrared rays emitted from the face of the driver 18 serving as a subject (subject) via the filter switching unit 14. Take an image with synchrotron radiation.

  As shown in FIG. 2, the filter switching unit 14 constituting the wavelength extracting means is an optical filter having a different band at, for example, three openings on the surface of the rotating disk disposed in front of the infrared camera 12. In this embodiment, a λ1 filter 20-1 that forms a first transmission window, a λ2 filter 20-2 that forms a second transmission window, and a λ3 filter 20-3 that forms a third transmission window are mounted. While sequentially switching the filters, an image of infrared light emitted from the driver's heel is captured.

  Hereinafter, the λ1 filter 20-1, the λ2 filter 20-2, and the λ3 filter 20-3 are collectively referred to as “filter 20”. In the present embodiment, each filter is a band pass filter that selectively transmits a wavelength band that does not overlap with other filters. However, the present invention is not limited thereby, and overlapping of transmission wavelengths is allowed as long as all or part of the object of the present invention can be achieved.

  Referring to FIG. 1 again, the infrared camera 12 is provided with an optical system 22 and, as a detector, an image sensor 24 (for example, a CCD) having sensitivity in the infrared wavelength band. The filter switching unit 14 can perform filter switching by rotating the above disk by a driving unit 16 having a motor or the like.

  As shown in FIG. 3, a cooling mechanism is provided for the infrared camera 12 and the filter switching unit 14. In FIG. 3, a lens barrel 76 is attached to the lens opening of the infrared camera 12, and in front of the lens barrel 76 arranged in the incident system of the infrared camera 12 (imaging target side = object surface side of the lens) As shown in FIG. 2, a rotatable rotating disk 78 in which a λ1 filter 20-1, a λ2 filter 20-2, and a λ3 filter 20-3 are disposed in each opening 80 is disposed. A cooling fan 82 installed outside is connected to the side surface of the lens barrel 76 via a tube 84.

  The cooling fan 82 cools the lens of the infrared camera 12 and the filter 20 of the rotating disk 78 to below normal temperature by supplying cooling air sucked from the outside to the lens barrel 76 via the tube 84.

  All objects emit infrared rays corresponding to the temperature, and infrared rays corresponding to the temperature are also emitted from the optical system 22 and the filter 20 placed in front of the image sensor 24 in the present embodiment. This spontaneous infrared ray is superimposed on the infrared ray from the driver 18 as background light (noise component) and is incident on the image sensor, thereby reducing the S / N ratio. Therefore, a noise component is reduced by providing a cooling mechanism as shown in FIG. 2 to cool the optical system 22 and the filter 20 to room temperature or lower.

  Instead of or in addition to such a cooling mechanism, a cooler such as a Peltier element may be attached to the filter 20 or the lens portion of the optical system 22 for cooling.

  In addition, on the surface of the λ1 filter 20, in order to prevent radiation infrared rays from the inside of the apparatus from being reflected and entering the image sensor 24, the filter surface is inclined at a predetermined angle so as not to be orthogonal to the optical axis, It is also possible to adopt a structure that makes it difficult for the infrared radiation from the inside to recur in the apparatus. Note that the cooling mechanism of FIG. 3 is similarly applied to other embodiments that will be clarified later.

  Referring to FIG. 1 again, the ethyl alcohol detection processing unit 10 is provided with a CPU 26, and an AD converter 30, output interfaces 32, 34, 35 and a memory 36 are connected to a bus 28 of the CPU 26.

  An imaging signal output line of the infrared camera 12 is connected to the AD converter 30, and an infrared image (still image in the present embodiment) of the driver 18 imaged by the imaging device 24 is converted into digital image data and captured here. The λ1 image 46-1, the λ2 image 46-2, and the λ3 image 46-3 are stored in the memory 36. Such image capturing control operation using the infrared camera 12 is performed by the imaging control unit 38 provided in the CPU 26. Hereinafter, the λ1 image 46-1, the λ2 image 46-2, and the λ3 image 46-3 are collectively referred to as “image 46”.

  The drive unit 16 is connected to the output interface 32, and the drive unit 16 is switched and controlled by a control signal from the ethyl alcohol detection processing unit 10, and the filter switching of the filter switching unit 14 is performed in conjunction with the imaging operation of the infrared camera 12. . That is, the above image data capture is sequentially performed for each wavelength while switching the filter 20 corresponding to each wavelength.

  A display unit 52 is connected to the output interface 34, and a control unit 54 is connected to the output interface 35. Under the control of the imaging control unit 38, the display unit 52 displays the detection, determination, and detection results processed by the ethyl alcohol detection processing unit 10, for example, whether or not the driver 18 is drunk, as necessary. The Instead of or in addition to the display unit, an acoustic notification unit that performs various notifications using sound may be provided as necessary.

  When the ethyl alcohol detection processing unit 10 determines that the driver 18 is drunk, the control unit 54 receives control from the imaging control unit 38 and prohibits the engine starting device or the like from starting the engine, for example. Doing drunk driving prevention control.

  The CPU 26 is provided with an imaging control unit 38, an ethyl alcohol detection unit 40, a temperature detection unit 42, and a determination unit 44 as functions realized by executing the program. In the ethyl alcohol detection processing unit 10 of the present embodiment, the alcoholic state of the driver 18 is detected from the contained ethyl alcohol appearing in capillaries directly under the skin such as the face.

  The detection of ethyl alcohol contained in capillaries is based on detecting attenuation due to absorption of a specific wavelength by ethyl alcohol from infrared radiation from the human body due to the body temperature of the driver 18.

FIG. 4 is an explanatory diagram showing the absorption wavelength spectrum distribution of ethyl alcohol to be detected. Ethyl alcohol C ₂ H ₅ OH is derived from its molecular structure and has absorption wavelengths such as 2.77 μm, 3.37 μm, and 9.5 μm. For example, the absorption wavelength of 9.5 μm is a wavelength at which ethyl alcohol molecules absorb with the bond stretching of —CH ₃ in ethyl alcohol.

Therefore, among the infrared light from the driver, as the absorption wavelength λ1 of ethyl alcohol, for example,
When infrared light is monitored through the λ1 filter 20-1 as a first filter that forms a first transmission window that selectively transmits the first wavelength band including λ1 = 9.5 μm, a predetermined amount of ethyl alcohol is reduced. In a state of being contained in a blood vessel, that is, in an alcoholic state, infrared light in one wavelength band shows absorbance corresponding to the concentration (content) of ethyl alcohol in the capillary blood vessel, and at this time, λ1 imaged by the image sensor 24 The received light amount Vd1 obtained from each pixel in the image 46-1 becomes small. In the present embodiment, when obtaining the received light amount Vd1 and Vd2 and Vd3 described later, for example, a predetermined pixel group in a predetermined region (described later) of the driver image is extracted and extracted from the image 46. This is performed based on the pixel group.

  Here, the reason for setting λ1 = 9.5 μm on the relatively long wavelength side instead of 2.77 μm, 3.37 μm, etc., for example, as the absorption wavelength λ1 of ethyl alcohol will be described. Infrared rays radiated from an object vary depending on the temperature of the object, and the spectral radiant divergence for each wavelength is obtained by Planck's law. If the temperature of the human body is now 35 ° C., the spectral radiation divergence according to Planck's law has the characteristics shown in FIG.

In FIG. 5, the spectral radiant divergence at a human body temperature of 35 ° C. rises from a wavelength of about 3.0 μm and peaks at about 9 μm. Therefore, the absorption wavelength spectrum distribution of ethyl alcohol in FIG. 4 has absorption spectra at about 3.4 μm and 9.5 μm, but the spectral radiant divergence at 3.4 μm is 5.59 × 10 ⁵ (W / m ² · m), and the spectral radiation divergence at 9.5 μm is 3.56 × 10 ⁷ (W / m ² · m). Therefore, in the present invention, by using λ1 = 9.5 μm, the amount of infrared light incident on the image sensor is about 64 times that when using about 3.4 μm, and a large amount of received infrared light can be obtained. This also applies to wavelengths λ2 and λ3 described below.

  Next, in the present embodiment, the second wavelength band including, for example, λ2 = 9.0 μm is selectively used as the wavelength λ2 having a small absorption rate by ethyl alcohol in the vicinity of the absorption wavelength λ1 = 9.5 μm of ethyl alcohol. A λ2 filter 20-2 is provided as a second filter that forms a second transmission window that transmits light, and infrared light from the driver 18 is monitored via the λ2 filter 20-2. The received light amount Vd2 obtained from a predetermined pixel of the λ2 image 46-2 which is an infrared light captured image from the driver 18 obtained through the λ2 filter 20-2 is irrespective of the presence or absence of ethyl alcohol. Thus, the amount of received light corresponding to the amount of infrared radiation corresponding to the body temperature is obtained.

Therefore, in the present invention, as the ethyl alcohol content A corresponding to the ethyl alcohol concentration in the capillary blood vessel, the influence of the amount of received infrared light Vd1 including the absorption wavelength λ1 of 9.5 μm of ethyl alcohol and the absorption by ethyl alcohol. For example, a difference value ΔVd from the amount of received infrared light Vd2 including λ2 = 9.0 μm not received is calculated.
ΔVd = Vd1−Vd2 (1)

  The calculation of the ethyl alcohol content (index indicating) ΔVd in the present embodiment is performed by the imaging control unit 38 and the ethyl alcohol detection unit 40 provided in the CPU 26 of FIG. That is, since the second wavelength band is close to the first wavelength band, the infrared light reception amount Vd2 of the second wavelength band is the infrared light reception amount vd1 that should be obtained from the first wavelength band when there is no ethyl alcohol absorption. From the approximation, the ethyl alcohol content ΔV can be obtained from the equation (1).

When the second wavelength band is not close to the first wavelength band, or when more accurate ethyl alcohol detection is performed, the first wavelength band is determined when there is no ethyl alcohol absorption according to Planck's law described later. The amount of received infrared light Vd1 ′ to be obtained from
ΔVd = Vd1′−Vd2
Ask for.

  The imaging control unit 38 switches the filter to the drive unit 16 of the filter switching unit 14 via the output interface 32 when detecting a predetermined timing such as when the driver 18 turns on the ignition key to start driving, for example. An optical filter that operates and is located on the incident side of the lens barrel 76 shown in FIG. 3 and selectively extracts an infrared wavelength band incident on the optical system of the infrared camera 12 is a λ1 filter 20-1, a λ2 filter 20-2, and The face of the driver 18 is imaged by the infrared camera 12 through each filter while sequentially switching to the λ3 filter 20-3, which will be described later.

  The λ1 image 46-1, which is the first subject image captured through the λ1 filter 20-1, the λ2 image 46-2, which is the second subject image captured through the λ2 filter 20-2, and further Each of the λ3 images 46-3 that are the third subject images picked up through the λ3 filter 20-3 is converted into digital image data by the AD converter 30 and stored in the memory 36.

  Based on the λ1 image 46-1 and the λ2 image 46-2 stored in the memory 36, the ethyl alcohol detection unit 40 calculates the ethyl alcohol content ΔVd given by the equation (1) corresponding to the ethyl alcohol concentration. To do.

  FIG. 6 illustrates an image (pixel group) extraction image of the characteristic area of the driver 18 used when the ethyl alcohol detection unit 40 of FIG. 1 calculates the ethyl alcohol content ΔVd and the like. In order to detect the content of ethyl alcohol in the capillaries of the driver 18 from the amount of received infrared light, the capillaries of the driver's face appear on the skin surface, and the received light amount attenuation due to absorption by ethyl alcohol is sufficient. Therefore, it is necessary to calculate the ethyl alcohol content A based on the image data in the region.

  In the case of FIG. 6, infrared radiation due to body temperature is targeted for a λ2 image 46-2 generated based on the amount of received light according to the amount of infrared rays emitted from the driver 18 without being affected by the presence or absence of ethyl alcohol. Image data in a predetermined pixel group in any one region such as a feature extraction region 50-1 with thin skin such as lips and feature extraction regions 50-2 and 50-3 set around both eyes. Are used to obtain Vd1, Vd2, and Vd3, and based on these, the ethyl alcohol content A = ΔVd, the temperature coefficient K, and the like are calculated.

  Calculation of the received light amount Vd1 of the λ1 image 46-1 and the received light amount Vd2 in the extracted image region of the λ2 image 46-2 using the ethyl alcohol content ΔVd in the equation (1) is included in the feature extraction region pixel group. The total or average value of each pixel value (the light level received for each pixel: here the voltage value) is obtained, and this is used as Vd1 and Vd2, and the ethyl alcohol content ΔVd is calculated from the equation (1) (Vd3 to be described later also) The same). Of course, it is possible to obtain Vd1, Vd2, and Vd3 by substituting for the sum or average value.

In the above equation (1), the subtraction value (Vd1−Vd2) of Vd1 and VdI2 is calculated. Instead, the ratio (Vd1 / Vd2) and the square difference (Vd1−Vd2) ² are calculated. Then, the ethyl alcohol content A may be set.

  If the ethyl alcohol content A = ΔVd given by the equation (1) is equal to or less than a predetermined threshold value Vth, it can be determined that the degree of alcohol is high (or is in an alcoholic state). Of course, by comparing with another threshold value, it is also possible to determine a drinking state having a higher alcohol content than alcohol.

  However, the ethyl alcohol content A = ΔVd given by the equation (1) is to accurately determine the degree of drunkness because the infrared intensity of the wavelengths λ1 and λ2 differs depending on the body temperature of the driver 18 as the subject. I can't.

  FIG. 7 (A) shows the measurement results of the breath alcohol concentration and measurement temperature (corresponding to body temperature) of five subjects A to E in the normal state and the drinking state, and FIG. 7 (B) shows the normal state and drinking. It is the graph which plotted the output difference value (DELTA) Vd (equivalent to the ethyl alcohol content degree A) of 2 wavelength infrared rays in the alcoholic state. In addition, alcoholic beverage is a case where 0.15 mg or more of alcohol is contained in 1 liter of exhaled air, and is stipulated by law.

  When the graph of FIG. 7 (B) is seen, the tendency of the output difference value of a normal state to become small is seen with respect to the output difference value of the test subject AE's drinking and drunk state. This is because the λ1 received light amount Vd1 decreases due to the infrared absorption of the wavelength λ1 = 9.5 μm by the ethyl alcohol contained in the blood, whereas the λ2 received light amount Vd2 which is hardly affected by the absorption by the ethyl alcohol is substantially unchanged, For this reason, the output difference value ΔVd between drinking and drinking is reduced.

  On the other hand, the output difference value and its change in the normal state, drinking, and drinking are different depending on the individual, and it is difficult to discriminate whether the drinking or drinking state is based on a uniform fixed threshold. This is due to the difference in the amount of alcohol consumed and the difference in the alcohol content of the body due to the act of drinking, as well as the difference in the body temperature of each person and the difference in the body temperature between drinking, alcoholic and normal, Presumed. For example, when comparing a subject E in a drinking state and a subject A in a normal state, the ΔVd is almost the same, and it is difficult to determine whether or not the subject is drunk with a uniform fixed threshold.

  However, if the body temperature of the subject can be known, the influence of the body temperature can be eliminated, and accurate determination and identification of the alcoholic state can be performed.

  FIG. 8 shows a graph in which the output difference value ΔVd (corresponding to the ethyl alcohol content A) of the two-wavelength infrared in FIG. 7 (B) is plotted corresponding to the temperature of the subject (corresponding to body temperature) in FIG. 7 (A). . In FIG. 8, ΔVd in normal times is distributed generally on the upper side in the vertical axis direction, while measurement points during drinking are distributed on the lower side, and both are distributed on the upper right as the temperature rises.

Therefore, it is possible to set a determination threshold line 100 that can clearly divide both the distribution area during normal time and the measurement point set distribution area during drinking. The determination threshold line 100 has a positive temperature coefficient K,
K = (0.1−0.04) / (35−31) = 0.012 [volt / ° C.]
have.

  If the temperature coefficient K of the determination threshold line 100 is determined in this way, the determination threshold value of the alcoholic state is corrected according to the temperature of the subject, and the temperature is affected by comparing with the ethyl alcohol content ΔVd. It is possible to correctly determine whether or not the person is drunk.

  In setting the discrimination threshold line 100 in FIG. 8, in actuality, each ΔV is plotted as shown in FIG. 8 based on data for a sufficient number of subjects, and a highly accurate discrimination threshold line is set. The temperature correction coefficient K is obtained by setting. Further, the temperature correction coefficient K may be obtained by setting an optimum discrimination threshold line for each sex and age.

  Therefore, in the embodiment of FIG. 1, in order to measure the temperature of the driver 18 as a test subject, the wavelength λ3 having a small absorption rate by ethyl alcohol is set in the vicinity of the absorption wavelength λ1 = 9.5 μm of ethyl alcohol. A λ3 filter 20-3 that forms a third transmission window that selectively transmits a different third wavelength band including, for example, λ3 = 8.3 μm is provided as shown in FIG. The light reception amount Vd3 is obtained from a predetermined pixel group of the image 46-3, and the temperature T of the driver 18 is calculated by the principle of a two-color thermometer using this and the light reception amount Vd2 of the λ2 image 46-2 obtained separately. Calculation is performed by the temperature detection unit 42 provided in the CPU 26. The temperature measurement of the human body based on the principle of the two-color thermometer will be described as follows.

  Assuming that the two wavelengths λ2 and λ3 having a small absorption rate by ethyl alcohol are λ2 = 9.0 μm and λ3 = 8.3 μm, the infrared radiation intensity from the black body is obtained by the following formula known as Planck's law. .

That is, the radiant energy density Mλ (J / m ³ ) due to the wavelength λ (m) from the black body at temperature T (K) is given by

Here Planck constant ^{h = 6.63 × 10- 34 (J} · Sec)
Boltzmann constant κ ^B = 1.38 × 10 ^-23 (J / K)
Speed of light c = 3 × 10 ⁸ (m / Sec)
If you assign this,

It becomes.

Therefore, if the temperature is constant, the radiant divergence W (W / m ² ) from the black body becomes the energy per ^second of the radiant energy density Mλ (J / m ³ ),
W = k · Mλ
It becomes. However, k is a proportional constant.

Assuming that the radiation divergence from a black body is W (W / m ² ), the black body area is S (m ² ), the distance to the receiver is L (m), and the light receiving area is Ad (m ² ), The energy Wd (W) received by the light receiver is expressed by the following equation.
Wd = W · S · Ad / πL ² (W)
Here, if S, L and Ad are constant,
Wd = k ′ · W = k · Mλ
Wd is also proportional to the received light output Vd.

Therefore two wavelengths .lambda.2, Taking the ratio of the light receiving energy at λ3 Vd2 / Vd3 = Wd2 / Wd3 = Mλ 2 / Mλ 3
It becomes.

Therefore, the temperature T of the subject can be obtained from the received light output at λ ₂ = 9.0 × 10 ⁻⁶ (m) and λ ₃ = 8.3 × 10 ⁻⁶ (m) by the above-described equation for Mλ. .

That is, Mλ ₁ and Mλ _{2 at} wavelengths λ2 and λ3 are

And
Vd2 / Vd3 = Mλ ₂ / Mλ ₃
The temperature (body temperature) T of the subject can be obtained by substituting the ratio (Vd2 / Vd3) of the infrared light reception output for.

FIG. 9 shows a case where λ ₂ = 9.0 × 10 ⁻⁶ (m) and λ ₃ = 8.3 × 10 ⁻⁶ (m), and two infrared light receiving output ratios Mλ ₁ / Mλ ₂ (= Vd2 / Vd3). The relationship (theoretical value) of the temperature T (° C.) of the subject is shown. Accordingly, the temperature T of the subject can be obtained by obtaining the infrared light reception output ratio (Mλ ₁ / Mλ ₂ ), that is, (Vd2 / Vd3).

In the temperature region near the body temperature, when the temperature rises, the peak in the characteristic curve of spectral radiation divergence shown in FIG. 5 shifts to the long wavelength side. Thereby, (Mλ ₁ / Mλ ₂ ) becomes smaller as the temperature T is higher.

  Temperature measurement based on the principle of such a two-color thermometer is not easily affected by the emissivity of the subject, so the temperature of an object with unknown emissivity can be measured, and the medium (gas, moisture, etc.) between the subject and the sensor can be measured. Excellent in that it is relatively unaffected.

  Based on the ethyl alcohol content A detected by the ethyl alcohol detection unit 40 and the temperature T of the driver 18 detected by the temperature detection unit 42, the determination unit 44 determines whether or not the alcohol is drunk.

The determination by the determination unit 44 includes, for example, the following two methods.
(1) A threshold correction determination method for determining a threshold Vth corresponding to a predetermined reference temperature To by correcting the temperature to the threshold Vth based on the detected temperature T.
(2) A content correction determination method in which the ethyl alcohol content A of the detected temperature T is determined by correcting the temperature so as to correspond to the case of the predetermined reference temperature To.

  Regardless of the determination method, the temperature correction coefficient K obtained from the determination threshold line 100 in the graph of FIG. 8 is used.

  FIG. 10A is a graph showing the content correction determination method. Here, for example, To = 33 ° C. is set as the reference temperature To, and in this case, Vtho = 0.07 (volts) is obtained from the determination threshold line 100 of FIG. 8 as the reference threshold Vtho at the reference temperature To. The reference threshold value is stored in advance in the memory 36 together with the temperature correction coefficient K as a constant.

Now, assuming that the ethyl alcohol content A = ΔVd and the detection temperature T indicated by the measurement point a are obtained by the ethyl alcohol detection unit 40, the ethyl alcohol detection unit 40 subsequently calculates the ethyl alcohol content A = ΔVd by the following formula. Accordingly, the temperature is corrected to the ethyl alcohol content ΔVdo corresponding to the measurement point b of the reference temperature To.
ΔVdo = ΔVd + K (To−T) (2)

When the ethyl alcohol content ΔVdo whose temperature is corrected in correspondence with the reference temperature To is obtained in this way, it is compared with the reference threshold value Vtho, and when it is equal to or less than the reference threshold value Vtho, that is, ΔVdo ≦ Vtho
If the condition is satisfied, it is determined (judged) that it is drunk, and a warning display that prompts not to drive drunk is output and displayed, or the control unit 54 prohibits the engine from starting even if the ignition key is turned to the start position. For example, to avoid driving drunk.

  Regardless of the equation (2), the value of the ethyl alcohol content ΔVdo whose temperature is corrected to correspond to the reference temperature To with respect to the combination of the value of the ethyl alcohol content A = ΔVd before the correction and the value of the detected temperature T. May be used in advance.

  Further, although the temperature correction approximation by the linear expression (determination threshold line 100) is performed in the expression (2), the correction by a multi-order expression (determination threshold curve) may be performed instead.

  FIG. 10B is a graph showing a threshold correction determination method which is another determination method. Here, for example, To = 33 ° C. is set as the reference temperature To, and Vtho = 0.07 (volts) is obtained from the determination threshold line 100 of FIG. 8 as the reference threshold Vtho at the reference temperature To. The threshold value is stored in advance in the memory 36 together with the temperature correction coefficient K as a constant.

Now, assuming that the ethyl alcohol content A = ΔVd and the detection temperature T indicated by the measurement point a are obtained by the ethyl alcohol detection unit 40, the ethyl alcohol detection unit 40 subsequently obtains the reference threshold value Vtho at the reference temperature To by the following equation: Accordingly, the temperature is corrected to the threshold value Vth at the measurement point a of the detected temperature T.
Vth = Vthho + K (T-To) (3)

When the ethyl alcohol detection unit 40 obtains the threshold value Vth corrected for the temperature corresponding to the detected temperature T in this way, the ethyl alcohol detection unit 40 compares it with the ethyl alcohol content A = ΔVd.
If it is established, it is determined that it is drunken, and a warning display that encourages not to drip is output, or the control unit 54 prohibits the engine from starting even if the ignition key is turned to the start position, etc. Avoid drunk driving.

  In this case as well, a memory table in which the threshold value Vth, which is temperature-corrected from the reference temperature To, is allocated and stored in advance for each detected temperature T value may be used regardless of the equation (3). good.

  FIG. 11 is a flowchart illustrating an example of a detection process of drunkness in the embodiment of FIG. In FIG. 1, when the driver 18 sits on the seat and operates the ignition key to the on position to supply power to the ethyl alcohol detection processing unit 10 and its peripheral devices, initialization, self-diagnosis, If various settings are read and there is no abnormality, the process proceeds to step S2 to determine whether or not there is an ethyl alcohol detection request. For example, when the driver turns the ignition key to the ON position, that is, for example, at a predetermined timing after the power is turned on, a detection request signal is output to the ethyl alcohol detection processing unit 10 and is detected by the imaging control unit 38. The detection process is started.

  In the drunkenness detection process, the λ1 filter 20-1 is set in the incident system of the infrared camera 12 in step S3, the imaging operation is performed, and the λ1 image 46-1 is stored in the memory 36. The imaging system is set in the incident system of the camera 12 and the imaging operation is performed by the infrared camera 12, and the λ2 image 46-2 is stored in the memory 36. Subsequently, the λ3 filter 20-3 is set in the incident system of the infrared camera 12 and the imaging operation is performed. Then, the λ3 image 46-3 is stored in the memory 36. In step S3, the λ1, λ2, and λ3 images may be captured and stored in memory once, or may be captured and stored continuously n times as necessary.

  Subsequently, in step S4, as shown in FIG. 6, for example, any one of the feature extraction regions 50-1 to 50-3 is extracted from the λ2 image 46-2.

  In step S5, the received light amount Vd1 is calculated from the λ1 image, the received light amount Vd2 is calculated from the λ2 image, and the received light amount Vd3 is calculated from the λ3 image. To do.

  Next, in step S6, the ethyl alcohol content A = ΔVd, which is the difference between the received light amount Vd1 of the λ1 image and the received light amount Vd2 of the λ2 image, is calculated by the equation (1). Subsequently, in step S7, the temperature T of the driver 18 is calculated (detected) according to the principle of the two-color thermometer based on the ratio (Vd1 / Vd2) of the received light amount Vd2 of the λ2 image and the received light amount Vd3 of the λ3 image.

  If each λ1, λ2, λ3 image is captured a plurality of times in step S3, after processing such as averaging of each image data is performed, step S4 is performed based on the data after the processing. The subsequent processing may be performed.

  Subsequently, temperature correction processing is performed in step S8. This temperature correction processing is performed according to either the content temperature correction method shown in FIG. 10A or FIG. 10B. For example, when the method shown in FIG. Based on the temperature T calculated in step S7, the ethyl alcohol content A = ΔVd is corrected to the ethyl alcohol content ΔVdo at the reference temperature To according to the equation (2), and whether or not it is drunk in step S9. Determine whether. In this case, it is determined whether or not the ethyl alcohol content ΔVdo corresponding to the reference temperature To obtained in the temperature correction process in step S8 is equal to or less than the determination threshold value Vtho at the preset reference temperature To.

  In step S9, if the temperature-corrected ethyl alcohol content ΔVdo is equal to or less than the threshold value Vtho, it is determined that the state is drunk, the process proceeds to step S10, and a corresponding process is executed. Specifically, a warning display that prompts the driver to not perform drunk driving is displayed on the display unit 52, or start prohibition control is performed on the engine starting device by the control unit 54 so that the drunk driving is not performed. To.

  On the other hand, if the ethyl alcohol content ΔVdo whose temperature has been corrected in step S9 exceeds the threshold value Vtho, it is determined that the alcohol is not drunk. At this time, the engine start prohibition control is not performed. It is started. Alternatively, if it is determined in step S9 that the person is not drunk, the processes in steps S1 to S9 may be repeated again, and the engine may be started when it is still determined that the person is not drunk. In addition, steps S1 to S9 are repeated a predetermined number of times, and when the number of times determined to be drunk is equal to or greater than a predetermined ratio of the total number of times, the corresponding process (engine start prohibition control) in step S10 is performed. You can also

  Of course, the temperature correction processing in step S8 may be processing according to the threshold temperature correction method shown in FIG. 10B, for example.

  FIG. 12 is an explanatory diagram showing an example in which a wavelength tunable filter is used as a component of the wavelength extracting means used in this embodiment. In FIG. 12, a wavelength tunable filter 25 is provided between the objective lens 22 a and the imaging lens 22 b of the infrared camera 12, and the transmission wavelength of the wavelength tunable filter 25 is controlled by the imaging control unit 38 and is a wavelength tunable filter controller. 48. In this case, instead of the filter switching unit 14 and the drive unit 16 shown in FIG. An imaging device 24 is disposed in the infrared camera 12, and infrared light in a wavelength band that has passed through the wavelength tunable filter 25 is imaged by the imaging lens 22 b and captured as an image. As such a wavelength tunable filter 25, for example, one disclosed in JP-A-8-285688 can be used.

  FIG. 13 is a principal block diagram illustrating another embodiment of the ethyl alcohol detector according to the present invention. In this embodiment, two wavelength bands are used (two-wavelength type), and the subject's The temperature is detected based on the principle of a one-color thermometer.

  In FIG. 13, an infrared camera 12 and a filter switching unit 14 are provided for the ethyl alcohol detection processing unit 10, and the filter switching unit 14 is basically the same as the structure shown in FIG. The first transmission window that selectively transmits the first wavelength band including the absorption wavelength λ1 = 9.5 μm of ethyl alcohol is formed as an optical filter having different transmission bands, for example, at two places on the rotating disk disposed in front of A λ1 filter 20-1 and a λ2 filter 20-2 that forms a second transmission window that selectively transmits a second wavelength band including a wavelength λ2 = 9.0 μm in the vicinity of the wavelength λ1, which has a low absorption rate due to ethyl alcohol. The λ3 filter 20-3 that is attached and forms the third transmission window used in the embodiment of FIG. 1 is omitted.

  In the present embodiment, the wavelength / side filter 25 and the wavelength variable controller 48 shown in FIG. 12 are provided in place of the filter switching unit 14 and the control unit 16 to extract the wavelengths λ1 and λ2. I can do it.

  The ethyl alcohol detection processing unit 10 is provided with a CPU 26, and an AD converter 30, output interfaces 32, 34, 35 and a memory 36 are connected to the bus 28 of the CPU 26, and the CPU 26 is realized by executing a program. As functions, an imaging control unit 38, an ethyl alcohol detection unit 40, a temperature detection unit 42, and a determination unit 44 are provided. These configurations and functions are such that the imaging control unit 38 captures and stores only two images excluding the λ3 image 46-3, that is, the λ1 image 46-1 and the λ2 image 46-2, and the temperature detection unit 42. This embodiment is basically the same as the embodiment of FIG. 1 except that the temperature is calculated based on the principle of the color thermometer.

  The ethyl alcohol detection unit 40 is given by the equation (1) corresponding to the ethyl alcohol concentration based on Vd2 based on the received light amount Vd1 obtained from the λ1 image 46-1 and the λ2 image 46-2 stored in the memory 36. The ethyl alcohol content A = ΔVd is calculated.

  The temperature detection unit 42 calculates the temperature of the driver 18 based on the λ2 image 46-2 stored in the memory 36. Since the temperature detection based on the principle of the two-color thermometer in the embodiment of FIG. 1 is not easily affected by the emissivity of the subject (subject), the temperature of an object with an unknown emissivity can be detected, and the subject (subject) Is superior in that it is relatively less susceptible to the influence of the medium (gas, moisture, etc.) between the sensor and the sensor, but if it is not so affected, the principle of a one-color thermometer with a simpler configuration Temperature detection is possible.

  That is, by calculating the infrared light reception amount Vd2 in one wavelength band, for example, the second wavelength band including the wavelength λ2 = 9.0 μm having a small absorption rate due to ethyl alcohol, the operation as the subject (subject) is performed based on Planck's law. The temperature of the person 18 can be obtained.

In this case, the following preconditions are required.
(A) The emissivity of the subject is assumed to be a standard value of the human body (for example, 0.95).
(B) Assume that there is a standard atmosphere between the subject and the sensor.
(C) The entire field of view of the infrared sensor is covered by the subject. That is, infrared rays other than the body temperature of the subject do not enter the sensor (this item applies to the two-color thermometer).

Here the temperature T is specifically calculated by substituting the received light amount Vd2 obtained from λ2 image 46-2 of the memory 36 as m [lambda ₂ in the following equation.

  FIG. 14 is a flowchart showing an example of the detection process of drunkness according to the embodiment of FIG. 13. In step S13, the λ1 filter 20-1 is set in the incident system of the infrared camera 12 to perform an imaging operation, and a λ1 image 46- 1 is stored in the memory 36, then the λ2 filter 20-2 is set in the incident system of the infrared camera 12, the imaging operation is performed by the infrared camera 12, and the λ2 image 46-2 is stored in the memory 36, and step S15. In step S17, the received light amount Vd1 is calculated from the λ1 image, the received light amount Vd2 is calculated from the λ2 image, and the temperature T of the subject is calculated from the received light amount Vd2 based on the principle of the one-color thermometer in step S17. This is the same as the detection process according to the embodiment of FIG. 1 shown in FIG.

  FIG. 15 is a block diagram of a main part illustrating another embodiment of the ethyl alcohol detection device according to the present invention. In this embodiment, an infrared sensor having an infrared light receiving element is used in place of the infrared imaging element. It was made to do.

  That is, in FIG. 15, the infrared camera 12 provided for the ethyl alcohol detection processing unit 10 is provided with an infrared sensor 56 instead of the image sensor 24 of FIG.

  FIG. 16 shows an example of the infrared sensor 56 of FIG. The infrared sensor 56 has a window 64 such as a translucent glass of a case 62, and an infrared detection element 65 is provided behind the window 64 as shown in a transparent state in the figure. Connected to the lead 66. As the infrared detection element 65, an uncooled element such as a pyroelectric element, a thermopile, a thermistor, or a bolometer can be used. A cooling element such as MCT or Insb may be used.

  In the embodiment of FIG. 15, the configuration is basically the same as that of the embodiment of FIG. 1 except that an infrared sensor 56 is provided instead of the image sensor 24.

  On the other hand, the CPU 26 provided in the ethyl alcohol detection processing unit 10 of the present embodiment is provided with the function of the light reception control unit 60 corresponding to the infrared sensor 56 instead of the imaging control unit 38 of FIG. The light reception control unit 60 controls the filter switching unit 14 as in the embodiment of FIG. Then, the λ1 received light amount Vd1, which is the first received light signal from the subject that is transmitted through the λ1 filter 20-1 by the infrared sensor 56, is stored in the memory 36, and is transmitted through the λ2 filter 20-2 and received. The λ2 received light amount Vd2 that is the second received light signal from the subject is stored in the memory 36, and further the λ3 received light amount Vd3 that is the third received light signal from the subject that has been transmitted through a λ3 filter (not shown) is received. It is stored in the memory 36.

  The ethyl alcohol detector 40 calculates the ethyl alcohol content ΔVd from the λ1 received light amount Vd1 and the λ2 received light amount Vd2 stored in the memory 36 by the equation (1), and the temperature detector 42 is stored in the memory 36. The temperature T of the driver 18 is detected from the λ2 received light amount Vd2 and the λ3 received light amount Vd3 based on the principle of the two-color thermometer, and the determination unit 44 performs the content temperature correction method shown in FIG. After performing temperature correction by the threshold temperature correction method of (B), it is determined whether or not it is in an alcoholic state by comparing with the threshold value, and when it is determined that it is in an alcoholic state, the other embodiment of FIG. Corresponding processing is executed in the same manner.

  FIG. 17 is a flowchart showing an example of ethyl alcohol detection processing according to the embodiment of FIG. In FIG. 17, when power supply to the ethyl alcohol detection processing unit 10 and its peripheral devices is started, initialization, self-diagnosis, reading of various settings, etc. are executed in step S21. If there is no abnormality, the process proceeds to step S22. Similar to the processing in step S2 of FIG. 11, it is determined whether or not there is an ethyl alcohol detection request.

  If it is determined in step S22 that there is a detection request, the λ1 filter 20-1 is set in the incident system of the infrared camera 12 in step S23, and the λ1 received light amount Vd1 detected by the infrared sensor 56 is stored in the memory 36. The λ2 filter 20-2 is set in the incident system of the infrared camera 12, the λ2 received light amount Vd2 detected by the infrared sensor 56 is stored in the memory 36, and the λ3 filter 20-3 is set in the incident system of the infrared camera 12. The λ3 received light amount Vd3 detected by the infrared sensor 56 is stored in the memory 36. In step S23, the λ1 received light amount Vd1, the λ2 received light amount Vd2, and the λ3 received light amount Vd3 may be stored once, or may be detected and stored continuously n times as necessary. Good. In addition, when it detects and preserve | saves several times, the sum total or an average can be made into the light reception amount Vd1, Vd2, Vd3.

  Subsequently, in step S24, the ethyl alcohol content A = ΔVd that is the difference between the λ1 received light amount Vd1 and the λ2 received light amount Vd2 is calculated according to the equation (1).

  Subsequently, in step S25, the temperature T of the driver 18 is calculated according to the principle of the two-color thermometer based on the ratio (Vd2 / Vd3) of the λ2 received light amount Vd2 and the λ3 received light amount Vd3. Subsequently, using this, a temperature correction process is performed in step S26. This temperature correction process is performed, for example, according to the content temperature correction method of FIG. 10A or the threshold temperature correction method of FIG.

  Subsequently, in step S27, it is determined whether or not the person is in an alcoholic state by comparing with a threshold value. If it is determined that the person is in an alcoholic state, the process proceeds to step S28, and the corresponding process is performed as in the other embodiments in FIG. Run.

  FIG. 18 is a block diagram of the main part illustrating another embodiment of the two-wavelength type ethyl alcohol detection device according to the present invention as shown in FIG. One feature is that the temperature is detected based on the principle of a one-color thermometer. And in this embodiment, it replaces with the image pick-up element 24 and the imaging control part 38, and the point provided with the infrared sensor 56 and the light reception control part 60 differs from the thing of FIG.

  In FIG. 18, an infrared camera 12 and a filter switching unit 14 are provided for the ethyl alcohol detection processing unit 10, and the filter switching unit 14 has a first wavelength band including an absorption wavelength λ1 of 9.5 μm of ethyl alcohol. Λ1 filter 20-1 that forms a first transmission window that selectively transmits light, and a second wavelength band in the vicinity of λ1 that includes a wavelength λ2 = 9.0 μm that has a small absorption rate by ethyl alcohol. Two types of λ2 filter 20-2 that forms two transmission windows are switched.

  The ethyl alcohol detection processing unit 10 is provided with a CPU 26, and an AD converter 30, output interfaces 32, 34, 35 and a memory 36 are connected to the bus 28 of the CPU 26, and the CPU 26 is realized by executing a program. As functions, a light reception control unit 60, an ethyl alcohol detection unit 40, a temperature detection unit 42, and a determination unit 44 are provided. These configurations and functions are controlled by the light receiving control unit 60, and the infrared sensor 56 receives infrared light from the driver 18 as a subject, and obtains the λ1 received light amount Vd1 and the λ2 received light amount Vd2 regardless of image processing. This is basically the same as the embodiment of FIG. 13 except that the data is stored in the memory 36.

  FIG. 19 is a flowchart showing the ethyl alcohol detection process according to the embodiment of FIG. 18. In step S33, the λ1 received light amount Vd1 received by the infrared sensor 56 with the λ1 filter 20-1 set in the incident system of the infrared camera 12 is shown. Is stored in the memory 36, and then the λ2 filter 20-2 is set in the incident system of the infrared camera 12 and the λ2 received light amount Vd2 received by the infrared sensor 56 is stored in the memory 36, as shown in FIG. This is basically the same as the detection process according to the embodiment of FIG.

  FIG. 20 is an explanatory view illustrating another embodiment of an infrared sensor used in the ethyl alcohol detection device of FIG. 15 or FIG. 18, for example, corresponding to the increase in the number of elements provided with a plurality of infrared light receiving elements in the infrared sensor. As a result, the number of signal output lead wires 66 has increased. The other configuration is basically the same as that of the infrared sensor 56 of the embodiment shown in FIG.

  In this embodiment, four infrared detecting elements 65-1 to 65-4 are arranged. For this reason, when an image of the subject as the driver is formed on the infrared sensor 68, the infrared detection elements 65-1 to 65- are divided into four areas for the subject image, that is, the driver's face image. The amount of received light corresponding to 4 is obtained. Based on the amount of received light obtained from each of the four infrared detection elements 65-1 to 65-4, the sum or average value is calculated, so that when applied to the detection device of FIG. The amounts Vd1, λ2 received light amount Vd2, and λ3 received light amount Vd3 are obtained, and when applied to the detection apparatus of FIG. 18, the λ1 received light amount Vd1 and the λ2 received light amount Vd2 are obtained.

  Of course, the same processing may be performed based on any one or a plurality of received light amounts without depending on all the received light amounts of the infrared selecting elements 65-1 to 65-4. In this case, as described with reference to FIG. 6, for example, the amount of infrared light received from the region suitable for the detection processing of the present invention is selected from the region of the subject corresponding to each of the four light receiving elements and processed. You can also.

  FIG. 21 is an explanatory view showing still another embodiment of the infrared sensor used in the ethyl alcohol detection device shown in the embodiment of FIG. 15 or FIG. 18, for example. In this embodiment, the infrared sensor 56 is used. Alternatively, an infrared sensor 72 that can be applied in place of the infrared sensor 68 is shown.

  In FIG. 21, the infrared sensor 72 shows the internal structure in a transparent state. For example, three infrared light receiving elements 65-1 to 65-3 are arranged in a case 62 having a window 64 on the light receiving side. A λ1 filter 74-1, a λ2 filter 74-2, and a λ3 filter 74-3 are arranged in front of each other.

  The λ1 filter 74-1 is a filter that selectively transmits an absorption wavelength λ1 = 9.5 μm of ethyl alcohol. The λ2 filter 74-2 is a filter that selectively transmits a wavelength λ2 = 9.0 μm that is not affected by the absorption of ethyl alcohol in the vicinity of the absorption wavelength of ethyl alcohol. The λ3 filter 74-3 is a filter that selectively transmits a wavelength λ2 = 8.3 μm that is not affected by the presence or absence of ethyl alcohol in the vicinity of the absorption wavelength of ethyl alcohol.

  Here, it is assumed that three wavelengths can be selectively received, but an infrared sensor provided with two elements and a filter that selectively transmits two different wavelengths (λ1, λ2) corresponding to the two elements may be used. When such an infrared sensor 72 is used, the filter switching unit 14 and the driving unit 16 thereof, and the wavelength tunable filter 25 and the wavelength tunable filter controller 48 serving as the control unit thereof can be omitted.

  In this way, the infrared sensor 72 itself can directly detect the received light amount corresponding to the wavelengths λ1, λ2, λ3 or the wavelengths λ1, λ2, and the apparatus configuration can be simplified, and the processing by the CPU 26 is simplified. The processing load can be reduced.

  In addition, including all the above-mentioned embodiments, λ2 and λ3 can be arbitrarily selected as wavelengths that are not affected by the absorption of ethyl alcohol, within a range that is compatible with part or all of the object of the present invention. For example, in the embodiment using three wavelengths of λ1, λ2, and λ3, λ2 may be 8.3 μm and λ3 may be 9.0 μm, and in the embodiment using two wavelengths of λ1 and λ2, λ2 may be 9.0 μm. good.

  As for the spectral absorption wavelength λ1, it is also possible to select another wavelength according to the light reception spectrum of the infrared imaging element or infrared sensor to be used. For example, even when λ1 = 2.77 μm or 3.37 μm used in Japanese Patent Application Laid-Open No. 2009-148401 is used, setting λ2 and λ3 in the vicinity thereof does not affect the temperature of the subject and has high accuracy. Judgment can be made.

  Further, in the above embodiment, mechanical filter switching by the filter switching unit and filter switching by the wavelength tunable filter are taken as examples. However, in addition to this, a spectrometer using a diffraction grating or the like Thus, an image in the target wavelength band or the amount of received light may be measured.

  Alternatively, an arbitrary part of each wavelength may be imaged and processed by an image sensor, and other wavelengths may be received and processed using a light receiving element.

  Further, in the above embodiment, the rotating disk provided in the filter switching unit 14 is provided with one filter for selectively transmitting each wavelength, but a plurality of filters may be provided, or a filter corresponding to each wavelength may be provided. The number of sheets may not be the same.

  Moreover, although the said embodiment demonstrated as an ethyl alcohol detection apparatus used for a vehicle-mounted use, it is equipped with a battery power supply and another exclusive power supply, is portable, and can be utilized also as an apparatus which test | inspects a liquor and a drinking state. Or, in addition to or instead of the determination based on the threshold value and the process accompanying it, a function for displaying the ethyl alcohol content (concentration) is provided, and the ethyl alcohol content (concentration) detection other than the detection of alcohol and alcohol consumption It can also be used as a device. In such a case, it is needless to say that the subject does not necessarily need to be a human body and is a subject according to the purpose.

  In addition, the processor shown in the above embodiment can replace some or all of its functions with other means such as wired logic. Other electrical and functional configurations including the processor can be appropriately integrated and abolished.

  In addition, the flowchart of the detection process in the above embodiment describes a schematic example of the process. In addition, other processes can be added or inserted as necessary.

  Further, the present invention includes appropriate modifications that do not impair the object and advantages thereof, and is not limited by the numerical values shown in the above embodiments.

  Here, the features of the present invention are enumerated as follows.
(Feature 1)
  An image sensor having sensitivity in the infrared wavelength band;
An optical system for forming an image of a subject on the image sensor;
A first transmission window that selectively transmits infrared light in a first wavelength band including the absorption wavelength of ethyl alcohol from the subject;
A second transmission window that selectively transmits infrared light in a second wavelength band including a wavelength having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject;
A third transmission window that selectively transmits infrared light in a third wavelength band different from the second wavelength band including a wavelength having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject; ,
The first subject image formed through the first transmission window, the second subject image formed through the second transmission window, and the second subject image formed through the third transmission window An imaging control unit that captures a third subject image by the image sensor and stores the third subject image in a memory;
An ethyl alcohol detector that calculates an ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first subject image and the second subject image stored in the memory;
A temperature detector that calculates the temperature of the subject based on the second subject image and the third subject image stored in the memory;
A determination unit that determines the detection and non-detection of the ethyl alcohol based on the ethyl alcohol content and the detection temperature of the subject,
An ethyl alcohol detector characterized by comprising: (Claim 1)

  (Feature 2)
  In the ethyl alcohol detection device according to Feature 1,
The first transmission window selectively transmits infrared light in a wavelength band including 9.5 μm as a first wavelength band,
The ethyl alcohol detection device, wherein the second transmission window and the third transmission window selectively transmit infrared light in a second wavelength band and a third wavelength band not including the first wavelength band.

  (Feature 3)
  In the ethyl alcohol detection device according to Feature 2,
The second transmission window selectively transmits infrared light in a wavelength band including 9.0 μm as a second wavelength band,
The third transmission window selectively transmits infrared light in a wavelength band including 8.3 μm as a third wavelength band.

  (Feature 4)
  In the ethyl alcohol detection device according to Feature 1,
The ethyl alcohol detection unit calculates the ethyl alcohol content corresponding to the ethyl alcohol concentration as a sum of correlation values or a difference value of average values between pixels at the same position in the first subject image and the second subject image. A characteristic ethyl alcohol detector.

  (Feature 5)
  In the ethyl alcohol detection device according to Feature 1,
The temperature detection unit calculates the temperature of the subject from the sum or average value of correlation values between pixels at the same position in the second subject image and the third subject image.

  (Feature 6)
  In the ethyl alcohol detection device according to Feature 1,
The determination unit, based on a predetermined temperature correction coefficient, temperature-corrects a predetermined threshold set at a predetermined reference temperature to a threshold at the detected temperature of the subject, the ethyl alcohol content is less than the temperature-corrected threshold In this case, the detection of the ethyl alcohol is determined, and the non-detection of the ethyl alcohol is determined when the ethyl alcohol content exceeds the temperature-corrected threshold value.

  (Feature 7)
  In the ethyl alcohol detection device according to Feature 1,
The determination unit corrects the ethyl alcohol content at the detected temperature of the subject to a ethyl alcohol content at a reference temperature set with a predetermined threshold based on a predetermined temperature correction coefficient, and the temperature-corrected ethyl alcohol Ethyl alcohol is detected when the content is less than or equal to the threshold, and non-detection of the ethyl alcohol is determined when the temperature-corrected ethyl alcohol content exceeds the threshold Detection device.

  (Feature 8)
  2. The ethyl alcohol detection device according to claim 1, further comprising a cooling mechanism for cooling the imaging device, the optical system, the first transmission window, the second transmission window, and the third transmission window. .

  (Feature 9)
  An image sensor having sensitivity in the infrared wavelength band;
An optical system for forming an image of a subject on the image sensor;
A first transmission window that selectively transmits infrared light in a first wavelength band including the absorption wavelength of ethyl alcohol from the subject;
A second transmission window that selectively transmits infrared light in a second wavelength band including a wavelength having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject;
A first subject image formed through the first transmission window and a second subject image formed through the second transmission image formed through the second transmission window; An imaging control unit that captures an image with an image sensor and stores the image in a memory;
An ethyl alcohol detector that calculates an ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first subject image and the second subject image stored in the memory;
A temperature detector that calculates the temperature of the subject based on the second subject image stored in the memory;
  A determination unit that determines the detection and non-detection of the ethyl alcohol based on the ethyl alcohol content and the detection temperature of the subject,
An ethyl alcohol detector characterized by comprising: (Claim 2)

  (Feature 10)
  In the ethyl alcohol detector according to Feature 9,
The first transmission window selectively transmits infrared light in a wavelength band including 9.5 μm as a first wavelength band,
The ethyl alcohol detection device, wherein the second transmission window selectively transmits infrared light in a second wavelength band not including the first wavelength band.

  (Feature 11)
  In the ethyl alcohol detector according to feature 10,
The second transmission window selectively transmits infrared light in a wavelength band including 9.0 μm or 8.3 μm as a second wavelength band.

  (Feature 12)
  In the ethyl alcohol detector according to Feature 9,
The ethyl alcohol detection unit calculates the ethyl alcohol content corresponding to the ethyl alcohol concentration as a sum of correlation values or a difference value of average values between pixels at the same position in the first subject image and the second subject image. A characteristic ethyl alcohol detector.

  (Feature 13)
  In the ethyl alcohol detector according to Feature 9,
The temperature detector is configured to calculate the temperature of the subject from a sum or an average value of correlation values between pixels at the same position as the first subject image in the second subject image.

  (Feature 14)
  In the ethyl alcohol detector according to Feature 9,
The determination unit, based on a predetermined temperature correction coefficient, temperature-corrects a predetermined threshold set at a predetermined reference temperature to a threshold at the detected temperature of the subject, the ethyl alcohol content is less than the temperature-corrected threshold In this case, the detection of the ethyl alcohol is determined, and the non-detection of the ethyl alcohol is determined when the ethyl alcohol content exceeds the temperature-corrected threshold value.

  (Feature 15)
  In the ethyl alcohol detector according to Feature 9,
The determination unit corrects the ethyl alcohol content at the detected temperature of the subject to a ethyl alcohol content at a reference temperature set with a predetermined threshold based on a predetermined temperature correction coefficient, and the temperature-corrected ethyl alcohol Ethyl alcohol is detected when the content is less than or equal to the threshold, and non-detection of the ethyl alcohol is determined when the temperature-corrected ethyl alcohol content exceeds the threshold Detection device.

  (Feature 16)
  10. The ethyl alcohol detection device according to claim 9, further comprising a cooling mechanism for cooling the imaging element, the optical system, the first transmission window, and the second transmission window.

  (Feature 17)
  An infrared sensor comprising one or more infrared light receiving elements;
An optical system for forming an image of a subject on the infrared sensor;
A first transmission window that selectively transmits infrared light in a first wavelength band including the absorption wavelength of ethyl alcohol from the subject;
A second transmission window that selectively transmits infrared light in a second wavelength band including a wavelength having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject;
A third transmission window that selectively transmits infrared light in a third wavelength band different from the second wavelength band including a wavelength having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject; ,
The infrared sensor transmits the first light receiving signal received through the first transmission window, the second light reception signal received through the second transmission window, and the light received through the third transmission window. A light reception control unit that detects the received third light reception signal and stores it in a memory;
An ethyl alcohol detector that calculates an ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first light receiving signal and the second light receiving signal stored in the memory;
A temperature detector that calculates the temperature of the subject based on the second received light signal and the third received light signal stored in the memory;
A determination unit that determines the detection and non-detection of the ethyl alcohol based on the ethyl alcohol content and the detection temperature of the subject,
An ethyl alcohol detector characterized by comprising: (Claim 3)

  (Feature 18)
  In the ethyl alcohol detection device according to Feature 17,
The first transmission window selectively transmits infrared light in a wavelength band including 9.5 μm as a first wavelength band,
The ethyl alcohol detection device, wherein the second transmission window and the third transmission window selectively transmit infrared light in the second wavelength band and the third wavelength band not including the first wavelength band. (Claim 4)

  (Feature 19)
  In the ethyl alcohol detector according to feature 18,
The second transmission window selectively transmits infrared light in a wavelength band including 9.0 μm as a second wavelength band,
The third transmission window selectively transmits infrared light in a wavelength band including 8.3 μm as a third wavelength band. (Claim 5)

(Feature 20)
  In the ethyl alcohol detection device according to Feature 17,
The ethyl alcohol detection unit calculates an ethyl alcohol content corresponding to an ethyl alcohol concentration as a difference value between the first light reception signal and the second light reception signal. (Claim 6)

  (Feature 21)
  In the ethyl alcohol detection device according to Feature 17,
The temperature detection unit calculates the temperature of the subject based on a ratio between the second light reception signal and the third light reception signal. (Claim 7)

  (Feature 22)
  In the ethyl alcohol detection device according to Feature 17,
The determination unit, based on a predetermined temperature correction coefficient, temperature-corrects a predetermined threshold set at a predetermined reference temperature to a threshold at the detected temperature of the subject, the ethyl alcohol content is less than the temperature-corrected threshold In this case, the detection of the ethyl alcohol is determined, and the non-detection of the ethyl alcohol is determined when the ethyl alcohol content exceeds the temperature-corrected threshold value. (Claim 8)

  (Feature 23)
  In the ethyl alcohol detection device according to Feature 17,
  The determination unit corrects the ethyl alcohol content at the detected temperature of the subject to a ethyl alcohol content at a reference temperature set with a predetermined threshold based on a predetermined temperature correction coefficient, and the temperature-corrected ethyl alcohol Ethyl alcohol is detected when the content is less than or equal to the threshold, and non-detection of the ethyl alcohol is determined when the temperature-corrected ethyl alcohol content exceeds the threshold Detection device. (Claim 9)

  (Feature 24)
  18. The ethyl alcohol detection device according to claim 17, further comprising a cooling mechanism for cooling the infrared sensor, the optical system, the first transmission window, the second transmission window, and the third transmission window. .

  (Feature 25)
  An infrared sensor comprising one or more infrared light receiving elements;
An optical system for forming an image of a subject on the infrared sensor;
A first transmission window that selectively transmits infrared light in a first wavelength band including the absorption wavelength of ethyl alcohol from the subject;
A second transmission window that selectively transmits infrared light in a second wavelength band including a wavelength having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject;
A light receiving control unit for detecting a first light receiving signal received through the first transmission window and a second light receiving signal received through the second transmission window by the infrared sensor, and storing them in a memory; ,
An ethyl alcohol detector that calculates an ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first light receiving signal and the second light receiving signal stored in the memory;
A temperature detection unit that calculates the temperature of the subject based on the second received light signal stored in the memory;
A determination unit that determines the detection and non-detection of the ethyl alcohol based on the ethyl alcohol content and the detection temperature of the subject,
An ethyl alcohol detector characterized by comprising: (Claim 10)

  (Feature 26)
  In the ethyl alcohol detector according to feature 25,
  The first transmission window selectively transmits infrared light in a wavelength band including 9.5 μm as a first wavelength band,
The ethyl alcohol detection device, wherein the second transmission window selectively transmits infrared light in a second wavelength band not including the first wavelength band. (Claim 11)

  (Feature 27)
  In the ethyl alcohol detector according to Feature 26,
The second transmission window selectively transmits infrared light in a wavelength band including 9.0 μm or 8.3 μm as a second wavelength band. (Claim 12)

  (Feature 28)
  In the ethyl alcohol detector according to feature 25,
The ethyl alcohol detection unit calculates an ethyl alcohol content corresponding to an ethyl alcohol concentration as a difference value between the first light reception signal and the second light reception signal. (Claim 13)

  (Feature 29)
  In the ethyl alcohol detector according to feature 25,
The determination unit, based on a predetermined temperature correction coefficient, temperature-corrects a predetermined threshold set at a predetermined reference temperature to a threshold at the detected temperature of the subject, the ethyl alcohol content is less than the temperature-corrected threshold In this case, the detection of the ethyl alcohol is determined, and the non-detection of the ethyl alcohol is determined when the ethyl alcohol content exceeds the temperature-corrected threshold value. (Claim 14)

  (Feature 30)
  In the ethyl alcohol detector according to feature 25,
The determination unit corrects the ethyl alcohol content at the detected temperature of the subject to a ethyl alcohol content at a reference temperature set with a predetermined threshold based on a predetermined temperature correction coefficient, and the temperature-corrected ethyl alcohol Ethyl alcohol is detected when the content is less than or equal to the threshold, and non-detection of the ethyl alcohol is determined when the temperature-corrected ethyl alcohol content exceeds the threshold Detection device. (Claim 15)

  (Feature 31)
  26. The ethyl alcohol detection device according to claim 25, further comprising a cooling mechanism for cooling at least the infrared sensor, the optical system, the first transmission window, and the second transmission window. (Claim 16)

  (Feature 32)
  First subject imaged by imaging infrared light in a first wavelength band including the absorption wavelength of ethyl alcohol from the subject through an image sensor that is selectively transmitted through the first transmission window and has sensitivity in the infrared wavelength band. Store the image in memory,
Infrared light in a second wavelength band including a wavelength with a low absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject is selectively transmitted through the second transmission window and is connected to the imaging element. Storing a second subject image captured in an image in a memory;
Infrared light in a third wavelength band different from the second wavelength band including the wavelength having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject is selectively transmitted through the third transmission window. And storing the third subject image imaged and imaged on the image sensor in a memory,
Calculate the ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first subject image and the second subject image stored in the memory,
Calculating the temperature of the subject based on the second subject image and the third subject image stored in the memory;
Determine the detection and non-detection of the ethyl alcohol based on the ethyl alcohol content and the subject's detection temperature,
A method for detecting ethyl alcohol.

  (Feature 33)
  In the ethyl alcohol detection method according to Feature 32,
The first transmission window selectively transmits infrared light in a wavelength band including 9.5 μm as a first wavelength band,
The method for detecting ethyl alcohol, wherein the second transmission window and the third transmission window selectively transmit infrared light in a second wavelength band and a third wavelength band not including the first wavelength band.

  (Feature 34)
  In the ethyl alcohol detection method according to Feature 33,
The second transmission window selectively transmits infrared light in a wavelength band including 9.0 μm as a second wavelength band,
The method for detecting ethyl alcohol, wherein the third transmission window selectively transmits infrared light in a wavelength band including 8.3 μm as the second wavelength band.

  (Feature 35)
  In the ethyl alcohol detection method according to Feature 32,
The ethyl alcohol detection unit calculates the ethyl alcohol content corresponding to the ethyl alcohol concentration as a sum of correlation values or a difference value of average values between pixels at the same position in the first subject image and the second subject image. A characteristic ethyl alcohol detection method.

  (Feature 36)
  In the ethyl alcohol detection method according to Feature 32,
The temperature detection unit calculates the temperature of the subject from the sum or average value of correlation values between pixels at the same position in the second subject image and the third subject image.

  (Feature 37)
  In the ethyl alcohol detection method according to Feature 32,
The determination unit, based on a predetermined temperature correction coefficient, temperature-corrects a predetermined threshold set at a predetermined reference temperature to a threshold at the detected temperature of the subject, the ethyl alcohol content is less than the temperature-corrected threshold In this case, the detection of the ethyl alcohol is determined, and the non-detection of the ethyl alcohol is determined when the ethyl alcohol content exceeds the temperature-corrected threshold value.

  (Feature 38)
  In the ethyl alcohol detection method according to Feature 32,
  The determination unit corrects the ethyl alcohol content at the detected temperature of the subject to a ethyl alcohol content at a reference temperature set with a predetermined threshold based on a predetermined temperature correction coefficient, and the temperature-corrected ethyl alcohol Ethyl alcohol is detected when the content is less than or equal to the threshold, and non-detection of the ethyl alcohol is determined when the temperature-corrected ethyl alcohol content exceeds the threshold Detection method.

  (Feature 39)
  33. The ethyl alcohol detection method according to claim 32, wherein the imaging device, the optical system, the first transmission window, the second transmission window, and the third transmission window are cooled.

  (Feature 40)
  First subject imaged by imaging infrared light in a first wavelength band including the absorption wavelength of ethyl alcohol from the subject through an image sensor that is selectively transmitted through the first transmission window and has sensitivity in the infrared wavelength band. Store the image in memory,
Infrared light in a second wavelength band including a wavelength with a low absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject is selectively transmitted through the second transmission window and is connected to the imaging element. Storing a second subject image captured in an image in a memory;
Calculate the ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first subject image and the second subject image stored in the memory,
Calculating the temperature of the subject based on the second subject image stored in the memory;
Determine the detection and non-detection of the ethyl alcohol based on the ethyl alcohol content and the subject's detection temperature,
A method for detecting ethyl alcohol.

  (Feature 41)
  In the ethyl alcohol detection method according to Feature 40,
The first transmission window selectively transmits infrared light in a wavelength band including 9.5 μm as a first wavelength band,
The method for detecting ethyl alcohol, wherein the second transmission window selectively transmits infrared light in a second wavelength band not including the first wavelength band.

  (Feature 42)
  In the ethyl alcohol detection method according to Feature 41,
The method of detecting ethyl alcohol, wherein the second transmission window selectively transmits infrared light in a wavelength band including 9.0 μm or 8.3 μm as the second wavelength band.

  (Feature 43)
  In the ethyl alcohol detection method according to Feature 40,
The ethyl alcohol detection unit calculates the ethyl alcohol content corresponding to the ethyl alcohol concentration as a sum of correlation values or a difference value of average values between pixels at the same position in the first subject image and the second subject image. A characteristic ethyl alcohol detection method.

  (Feature 44)
  In the ethyl alcohol detection method according to Feature 40,
The temperature detection unit calculates the temperature of the subject from the sum or average value of correlation values between pixels at the same position in the second subject image and the third subject image.

  (Feature 45)
  In the ethyl alcohol detection method according to Feature 40,
The determination unit, based on a predetermined temperature correction coefficient, temperature-corrects a predetermined threshold set at a predetermined reference temperature to a threshold at the detected temperature of the subject, the ethyl alcohol content is less than the temperature-corrected threshold In this case, the detection of the ethyl alcohol is determined, and the non-detection of the ethyl alcohol is determined when the ethyl alcohol content exceeds the temperature-corrected threshold value.

  (Feature 46)
  In the ethyl alcohol detection method according to Feature 40,
The determination unit corrects the ethyl alcohol content at the detected temperature of the subject to a ethyl alcohol content at a reference temperature set with a predetermined threshold based on a predetermined temperature correction coefficient, and the temperature-corrected ethyl alcohol Ethyl alcohol is detected when the content is less than or equal to the threshold, and non-detection of the ethyl alcohol is determined when the temperature-corrected ethyl alcohol content exceeds the threshold Detection method.

  (Feature 47)
  41. The ethyl alcohol detection method according to claim 40, wherein the imaging device, the optical system, the first transmission window, and the second transmission window are cooled.

  (Feature 48)
  Infrared light in the first wavelength band including the absorption wavelength of ethyl alcohol from the subject is selectively transmitted through the first transmission window and imaged and received on an infrared sensor including one or more infrared light receiving elements. Storing the first received light signal in the memory;
Infrared light in a second wavelength band including a wavelength with a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject is selectively transmitted through the second transmission window and is coupled to the infrared sensor. The second received light signal received by imaging is stored in the memory,
Infrared light in a third wavelength band different from the second wavelength band including the wavelength having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject is selectively transmitted through the third transmission window. And storing the third light receiving signal formed on the infrared sensor and received in the memory,
Calculating the ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first light receiving signal and the second light receiving signal stored in the memory;
Calculating the temperature of the subject based on the second received light signal and the third received light signal stored in the memory;
Determine the detection and non-detection of the ethyl alcohol based on the ethyl alcohol content and the subject's detection temperature,
A method for detecting ethyl alcohol.

  (Feature 49)
  In the ethyl alcohol detection method according to Feature 48,
The first transmission window selectively transmits infrared light in a wavelength band including 9.5 μm as a first wavelength band,
The method for detecting ethyl alcohol, wherein the second transmission window and the third transmission window selectively transmit infrared light in a second wavelength band and a third wavelength band not including the first wavelength band.

  (Feature 50)
  In the ethyl alcohol detection method according to Feature 49,
The second transmission window selectively transmits infrared light in a wavelength band including 9.0 μm as a second wavelength band,
The method for detecting ethyl alcohol, wherein the third transmission window selectively transmits infrared light in a wavelength band including 8.3 μm as a third wavelength band.

  (Feature 51)
  In the ethyl alcohol detection method according to Feature 48,
The ethyl alcohol detection unit calculates an ethyl alcohol content corresponding to an ethyl alcohol concentration as a difference value between the first light reception signal and the second light reception signal.

  (Feature 52)
  In the ethyl alcohol detection method according to Feature 48,
The temperature detection unit calculates the temperature of the subject based on a ratio between the second light reception signal and the third light reception signal.

  (Feature 53)
  In the ethyl alcohol detection method according to Feature 48,
  The determination unit, based on a predetermined temperature correction coefficient, temperature-corrects a predetermined threshold set at a predetermined reference temperature to a threshold at the detected temperature of the subject, the ethyl alcohol content is less than the temperature-corrected threshold In this case, the detection of the ethyl alcohol is determined, and the non-detection of the ethyl alcohol is determined when the ethyl alcohol content exceeds the temperature-corrected threshold value.

  (Feature 54)
  In the ethyl alcohol detection method according to Feature 48,
  The determination unit corrects the ethyl alcohol content at the detected temperature of the subject to a ethyl alcohol content at a reference temperature set with a predetermined threshold based on a predetermined temperature correction coefficient, and the temperature-corrected ethyl alcohol Ethyl alcohol is detected when the content is less than or equal to the threshold, and non-detection of the ethyl alcohol is determined when the temperature-corrected ethyl alcohol content exceeds the threshold Detection method.

  (Feature 55)
  49. The ethyl alcohol detection method according to claim 48, wherein the infrared sensor, the optical system, the first transmission window, the second transmission window, and the third transmission window are cooled.

  (Feature 56)
  Infrared light in the first wavelength band including the absorption wavelength of ethyl alcohol from the subject is selectively transmitted through the first transmission window and imaged and received on an infrared sensor including one or more infrared light receiving elements. Storing the first received light signal in the memory;
Infrared light in a second wavelength band including a wavelength with a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject is selectively transmitted through the second transmission window and is coupled to the infrared sensor. The second received light signal received by imaging is stored in the memory,
Calculating the ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first light receiving signal and the second light receiving signal stored in the memory;
Calculating the temperature of the subject based on the second received light signal stored in the memory;
Determine the detection and non-detection of the ethyl alcohol based on the ethyl alcohol content and the subject's detection temperature,
A method for detecting ethyl alcohol.

  (Feature 57)
  In the ethyl alcohol detection method according to Feature 56,
The first transmission window selectively transmits infrared light in a wavelength band including 9.5 μm as a first wavelength band,
  The method for detecting ethyl alcohol, wherein the second transmission window selectively transmits infrared light in a second wavelength band not including the first wavelength band.

  (Feature 58)
  In the ethyl alcohol detection method according to feature 57,
The method of detecting ethyl alcohol, wherein the second transmission window selectively transmits infrared light in a wavelength band including 9.0 μm or 8.3 μm as the second wavelength band.

  (Feature 59)
  In the ethyl alcohol detection method according to Feature 56,
The ethyl alcohol detection unit calculates an ethyl alcohol content corresponding to an ethyl alcohol concentration as a difference value between the first light reception signal and the second light reception signal.

  (Feature 60)
  In the ethyl alcohol detection method according to Feature 56,
The determination unit, based on a predetermined temperature correction coefficient, temperature-corrects a predetermined threshold set at a predetermined reference temperature to a threshold at the detected temperature of the subject, the ethyl alcohol content is less than the temperature-corrected threshold In this case, the detection of the ethyl alcohol is determined, and the non-detection of the ethyl alcohol is determined when the ethyl alcohol content exceeds the temperature-corrected threshold value.

  (Feature 61)
  In the ethyl alcohol detection method according to Feature 56,
The determination unit corrects the ethyl alcohol content at the detected temperature of the subject to a ethyl alcohol content at a reference temperature set with a predetermined threshold based on a predetermined temperature correction coefficient, and the temperature-corrected ethyl alcohol Ethyl alcohol is detected when the content is less than or equal to the threshold, and non-detection of the ethyl alcohol is determined when the temperature-corrected ethyl alcohol content exceeds the threshold Detection method.

  (Feature 62)
  57. The ethyl alcohol detection method according to claim 56, wherein the infrared sensor, the optical system, the first transmission window, and the second transmission window are cooled.

10: ethyl alcohol detection processing unit 12: infrared camera 14: filter switching unit 16: drive unit 18: subject 20-1: λ1 filter 20-2: λ2 filter 20-3: λ3 filter 22: optical system 22a: objective lens 22b : Imaging lens 24: Image sensor 25: Wavelength variable filter 26: CPU
28: Bus 30: AD converters 32, 34, 35: Output IF
36: Memory 38: Imaging control unit 40: Ethyl alcohol detection unit 42: Temperature detection unit 44: Determination unit 46: Image 46-1: λ1 image 46-2: λ2 image 46-3: λ3 image 48: Wavelength variable filter controller 50-1 to 50-3: Feature extraction area 52: Display unit 54: Control unit 56, 68: Infrared sensor 60: Light reception control unit 62: Case 64: Window 65, 65-1 to 65-3: Infrared detection element 66 : Lead 72: Multi-infrared sensor 74-1: λ1 filter 74-2: λ2 filter 74-3: λ3 filter

Claims (16)

An image sensor having sensitivity in the infrared wavelength band;
An optical system for forming an image of a subject on the image sensor;
A first transmission window that selectively transmits infrared light in a first wavelength band including the absorption wavelength of ethyl alcohol from the subject;
A second transmission window that selectively transmits infrared light in a second wavelength band including a wavelength having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject;
A third transmission window that selectively transmits infrared light in a third wavelength band different from the second wavelength band including a wavelength having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject; ,
The first subject image formed through the first transmission window, the second subject image formed through the second transmission window, and the second subject image formed through the third transmission window An imaging control unit that captures a third subject image by the image sensor and stores the third subject image in a memory;
An ethyl alcohol detector that calculates an ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first subject image and the second subject image stored in the memory;
A temperature detector that calculates the temperature of the subject based on the second subject image and the third subject image stored in the memory;
A determination unit that determines the detection and non-detection of the ethyl alcohol based on the ethyl alcohol content and the detection temperature of the subject,
An ethyl alcohol detector characterized by comprising:
An image sensor having sensitivity in the infrared wavelength band;
An optical system for forming an image of a subject on the image sensor;
A first transmission window that selectively transmits infrared light in a first wavelength band including the absorption wavelength of ethyl alcohol from the subject;
A second transmission window that selectively transmits infrared light in a second wavelength band including a wavelength having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject;
A first subject image formed through the first transmission window and a second subject image formed through the second transmission image formed through the second transmission window; An imaging control unit that captures an image with an image sensor and stores the image in a memory;
An ethyl alcohol detector that calculates an ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first subject image and the second subject image stored in the memory;
A temperature detector that calculates the temperature of the subject based on the second subject image stored in the memory;
A determination unit that determines the detection and non-detection of the ethyl alcohol based on the ethyl alcohol content and the detection temperature of the subject,
An ethyl alcohol detector characterized by comprising:
An infrared sensor comprising one or more infrared light receiving elements;
An optical system for forming an image of a subject on the infrared sensor;
A first transmission window that selectively transmits infrared light in a first wavelength band including the absorption wavelength of ethyl alcohol from the subject;
A second transmission window that selectively transmits infrared light in a second wavelength band including a wavelength having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject;
A third transmission window that selectively transmits infrared light in a third wavelength band different from the second wavelength band including a wavelength having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject; ,
The infrared sensor transmits the first light receiving signal received through the first transmission window, the second light reception signal received through the second transmission window, and the light received through the third transmission window. A light reception control unit that detects the received third light reception signal and stores it in a memory;
An ethyl alcohol detector that calculates an ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first light receiving signal and the second light receiving signal stored in the memory;
A temperature detector that calculates the temperature of the subject based on the second received light signal and the third received light signal stored in the memory;
A determination unit that determines the detection and non-detection of the ethyl alcohol based on the ethyl alcohol content and the detection temperature of the subject,
An ethyl alcohol detector characterized by comprising:
In the ethyl alcohol detection device according to claim 3 ,
The first transmission window selectively transmits infrared light in a wavelength band including 9.5 μm as a first wavelength band,
The ethyl alcohol detection device, wherein the second transmission window and the third transmission window selectively transmit infrared light in the second wavelength band and the third wavelength band not including the first wavelength band.
In the ethyl alcohol detection device according to claim 3 ,
The second transmission window selectively transmits infrared light in a wavelength band including 9.0 μm as a second wavelength band,
The third transmission window selectively transmits infrared light in a wavelength band including 8.3 μm as a third wavelength band.
In the ethyl alcohol detection device according to claim 3 ,
The ethyl alcohol detection unit calculates an ethyl alcohol content corresponding to an ethyl alcohol concentration as a difference value between the first light reception signal and the second light reception signal.
In the ethyl alcohol detection device according to claim 3,
The temperature detection unit calculates the temperature of the subject based on a ratio between the second light reception signal and the third light reception signal.
In the ethyl alcohol detection device according to claim 3 ,
The determination unit, based on a predetermined temperature correction coefficient, temperature-corrects a predetermined threshold set at a predetermined reference temperature to a threshold at the detected temperature of the subject, the ethyl alcohol content is less than the temperature-corrected threshold In this case, the detection of the ethyl alcohol is determined, and the non-detection of the ethyl alcohol is determined when the ethyl alcohol content exceeds the temperature-corrected threshold value.
In the ethyl alcohol detection device according to claim 3 ,
The determination unit corrects the ethyl alcohol content at the detected temperature of the subject to a ethyl alcohol content at a reference temperature set with a predetermined threshold based on a predetermined temperature correction coefficient, and the temperature-corrected ethyl alcohol Ethyl alcohol is detected when the content is less than or equal to the threshold, and non-detection of the ethyl alcohol is determined when the temperature-corrected ethyl alcohol content exceeds the threshold Detection device.
An infrared sensor comprising one or more infrared light receiving elements;
An optical system for forming an image of a subject on the infrared sensor;
A first transmission window that selectively transmits infrared light in a first wavelength band including the absorption wavelength of ethyl alcohol from the subject;
A second transmission window that selectively transmits infrared light in a second wavelength band including a wavelength having a small absorption rate by the ethyl alcohol in the vicinity of the first wavelength band from the subject;
A light receiving control unit for detecting a first light receiving signal received through the first transmission window and a second light receiving signal received through the second transmission window by the infrared sensor, and storing them in a memory; ,
An ethyl alcohol detector that calculates an ethyl alcohol content corresponding to the ethyl alcohol concentration based on the first light receiving signal and the second light receiving signal stored in the memory;
A temperature detection unit that calculates the temperature of the subject based on the second received light signal stored in the memory;
A determination unit that determines the detection and non-detection of the ethyl alcohol based on the ethyl alcohol content and the detection temperature of the subject,
An ethyl alcohol detector characterized by comprising:
In the ethyl alcohol detection device according to claim 10 ,
The first transmission window selectively transmits infrared light in a wavelength band including 9.5 μm as a first wavelength band,
The ethyl alcohol detection device, wherein the second transmission window selectively transmits infrared light in a second wavelength band not including the first wavelength band.
In the ethyl alcohol detection device according to claim 10 ,
The second transmission window selectively transmits infrared light in a wavelength band including 9.0 μm or 8.3 μm as a second wavelength band.
In the ethyl alcohol detection device according to claim 10 ,
The ethyl alcohol detection unit calculates an ethyl alcohol content corresponding to an ethyl alcohol concentration as a difference value between the first light reception signal and the second light reception signal.
In the ethyl alcohol detection device according to claim 10 ,
The determination unit, based on a predetermined temperature correction coefficient, temperature-corrects a predetermined threshold set at a predetermined reference temperature to a threshold at the detected temperature of the subject, the ethyl alcohol content is less than the temperature-corrected threshold In this case, the detection of the ethyl alcohol is determined, and the non-detection of the ethyl alcohol is determined when the ethyl alcohol content exceeds the temperature-corrected threshold value.
In the ethyl alcohol detection device according to claim 10 ,
The determination unit corrects the ethyl alcohol content at the detected temperature of the subject to a ethyl alcohol content at a reference temperature set with a predetermined threshold based on a predetermined temperature correction coefficient, and the temperature-corrected ethyl alcohol Ethyl alcohol is detected when the content is less than or equal to the threshold, and non-detection of the ethyl alcohol is determined when the temperature-corrected ethyl alcohol content exceeds the threshold Detection device.
11. The ethyl alcohol detection device according to claim 3 , further comprising a cooling mechanism for cooling at least the infrared sensor, the optical system, the first transmission window, and the second transmission window.