DETECTION APPARATUS AND DETECTION METHOD

Abstract

This detection device comprises: an imaging unit having an infrared sensor which includes at least one infrared detection element that receives light in the infrared region wavelength range in order to clearly detect a trace of something which has adhered to an object and which derives from a human body; and a temperature setting unit that heats the object from which a trace of something deriving from a human body is to be detected.

Description

[Technical field]

[0001] The present disclosure relates to a detection device and the like used for detecting traces originating from the human body. [Background technology]

[0002] Any object that the human body touches leaves traces of the human body. For example, when a person touches an object with their fingertips or hands, that person's fingerprints, palm prints, or other residues remain on the object. Residues such as fingerprints that remain on objects are difficult to see, making them difficult to preserve as evidence.

[0003] When residual fingerprints are preserved as evidence at crime scenes, they are processed using methods such as the aluminum powder method and the ninhydrin method so that they become clear when photographed with a camera. With the aluminum powder method, fine aluminum powder mixed with silica, talc, kaolin, etc. is sprinkled on the target to detect fingerprints. With the ninhydrin method, fingerprints are detected by spraying a chemical made by dissolving ninhydrin reagent in acetone, etc. onto the fingerprint, where the amino acids in the fingerprint react with ninhydrin to turn it reddish purple, a chemical reaction that is used to detect fingerprints.

[0004] Methods of applying powder or liquid to fingerprints, such as the aluminum powder method and the ninhydrin method, have some problems. For example, in the aluminum powder method, fine powder is applied to the target object, which stains the target object and its surroundings. For example, in the ninhydrin method, the fingerprint itself and the target object on which the fingerprint is attached are easily damaged. Therefore, a technology is required to detect a fingerprint attached to an object without destroying the target object or the fingerprint. Patent Documents 1 and 2 disclose a fingerprint detection method for detecting a fingerprint without directly touching the specimen and without contacting the fingerprint.

[0005] In the method of Patent Document 1, a measurement light having a wavelength absorbed by organic substances contained in the fingerprint components and a comparison light whose absorption characteristics do not change depending on the amount of organic substances are projected onto the specimen. The method of Patent Document 1 calculates the ratio of the amount of reflected light of the measurement light and the comparison light reflected from the specimen, and displays the image obtained as a result of the calculation to identify the location of the fingerprint.

[0006] The method of Patent Document 2 captures thermal image information of the surface of a specimen after projecting light of a wavelength in a range in which the absorption characteristics change depending on the amount of organic matter contained in the fingerprint components for a certain period of time. The method of Patent Document 2 calculates the difference in two-dimensional temperature distribution of the thermal image information before and after irradiation with the projected light, and identifies the location of fingerprint ridges by displaying the image obtained as a result of the calculation. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 5-220131 [Patent Document 2] Japanese Patent Application Publication No. 5-168610 Summary of the Invention [Problem to be solved by the invention]

[0008] According to the technique of Patent Document 1, the location of a fingerprint attached to a specimen can be identified from an image based on the ratio of the amount of reflected light of measurement light and comparison light. According to the technique of Patent Document 2, the location of a fingerprint can be identified from an image based on the difference in two-dimensional temperature distribution of thermal image information before and after projection of light of a wavelength in a range where the absorption characteristics change depending on the fingerprint components. However, even if infrared light reflection is used as in Patent Documents 1 and 2, there were cases where a clear fingerprint could not be detected.

[0009] An object of the present disclosure is to provide a detection device etc. that can clearly detect traces originating from the human body attached to an object. [Means for solving the problem]

[0010] A detection device of one embodiment of the present disclosure includes an imaging unit having an infrared sensor having at least one infrared detection element that receives light in the infrared wavelength band, and a heating unit that heats an object on which traces originating from the human body are to be detected.

[0011] In one embodiment of the detection method of the present disclosure, a heating unit is controlled to heat an object that is to be detected for traces originating from the human body, and an imaging means having an infrared sensor with at least one infrared detection element that receives light in the infrared wavelength range is controlled to image the object heated by the heating unit and detect any traces remaining on the object. Effect of the Invention

[0012] According to the present disclosure, it is possible to provide a detection device etc. that can clearly detect traces originating from the human body attached to an object. [Brief description of the drawings]

[0013] [Figure 1] 1 is a block diagram showing an example of a configuration of a detection device according to a first embodiment. [Diagram 2] 1 is a conceptual diagram showing an example of the configuration of a detection device according to a first embodiment. [Diagram 3] 4 is a conceptual diagram showing an example of how a clear fingerprint is captured by heating an object using the detection device according to the first embodiment. FIG. [Figure 4] FIG. 2 is a conceptual diagram conceptualizing an example of an image including a fingerprint captured by the detection device according to the first embodiment at a set temperature range of 30 to 100 degrees Celsius. [Diagram 5] 1 is a graph showing an example of temperature change in an index representing the clarity of a fingerprint in a fingerprint image including a fingerprint attached to an object, the index being captured at a set temperature range of 30 to 100 degrees Celsius by the imaging section of the detection device according to the first embodiment. [Figure 6] FIG. 2 is a conceptual diagram showing an example of a configuration of a detection device according to a first modified example of the first embodiment. [Figure 7] FIG. 11 is a conceptual diagram showing an example of the configuration of a detection device according to a second modified example of the first embodiment. [Figure 8] FIG. 11 is a conceptual diagram showing an example of the configuration of a detection device according to a third modified example of the first embodiment. [Figure 9] FIG. 11 is a block diagram showing an example of the configuration of a detection device according to a second embodiment. [Figure 10] FIG. 11 is a conceptual diagram showing an example of the configuration of a detection device according to a second embodiment. [Figure 11] FIG. 13 is a conceptual diagram showing an example of the configuration of a detection device according to a modified example of the second embodiment. [Figure 12] FIG. 11 is a block diagram showing an example of the configuration of a detection device according to a third embodiment. [Figure 13] FIG. 13 is a conceptual diagram showing an example of the configuration of a detection device according to a third embodiment. [Figure 14] FIG. 13 is a block diagram showing an example of the configuration of a detection unit of a detection device according to a third embodiment. [Figure 15] FIG. 13 is a conceptual diagram showing an example in which a detection result of the detection device according to the third embodiment is displayed on a display device. [Figure 16] 13 is a flowchart showing an example of the operation of the detection device according to the third embodiment. [Figure 17] FIG. 13 is a block diagram showing an example of the configuration of a detection device according to a fourth embodiment. [Figure 18] FIG. 13 is a conceptual diagram showing an example of the configuration of a detection device according to a fourth embodiment. [Figure 19] FIG. 13 is a block diagram showing an example of the configuration of a matching unit of a detection device according to a fourth embodiment. [Figure 20] FIG. 13 is a conceptual diagram showing an example in which a collation result of the detection device according to the fourth embodiment is displayed on a display device. [Figure 21] 13 is a flowchart showing an example of the operation of the detection device according to the fourth embodiment. [Figure 22] FIG. 13 is a block diagram showing an example of the configuration of a detection device according to a fifth embodiment. [Diagram 23] FIG. 2 is a block diagram showing an example of a hardware configuration for implementing the detection device according to each embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, the embodiments for carrying out the present invention will be described with reference to the drawings. However, the embodiments described below are limited in a manner that is technically preferable for carrying out the present invention, but the scope of the invention is not limited to the following. In addition, in all the drawings used to explain the following embodiments, the same reference numerals are used for similar parts unless otherwise specified. In addition, in the following embodiments, repeated explanations of similar configurations and operations may be omitted.

[0015] (First embodiment) First, the detection device of the first embodiment will be described with reference to the drawings. The detection device of this embodiment captures an image for detecting traces of residues (also called attachments) originating from the human body. The image captured by the detection device of this embodiment is used to detect traces of residues originating from the human body. Hereinafter, traces of residues originating from the human body will be referred to as "traces originating from the human body" or simply as "traces". In this embodiment, an object on which traces originating from the human body remain is heated to increase the difference in emissivity caused by the presence or absence of the traces, so that the traces become clear. In the following, a flat object is exemplified, but the object does not have to be flat. For example, the object may have a curved surface, such as a cylinder or a sphere.

[0016] In the following, a fingerprint will be taken as an example of a trace originating from a human body. For example, the trace originating from a human body may be other than a fingerprint, such as a palm print, a mid-knuckle print, a proximal knuckle print, a foot print (sole print), a toe print, an ear print, a nose print, a lip print, a forehead print, or a chin print. Hereinafter, the pattern of a trace originating from a human body, such as a fingerprint, a palm print, a mid-knuckle print, a proximal knuckle print, a foot print (sole print), a toe print, an ear print, a nose print, a lip print, a forehead print, or a chin print, is also called a pattern. Note that the detection target in this embodiment is not limited to a fingerprint, a palm print, a foot print (sole print), a toe print, an ear print, a nose print, a lip print, a forehead print, or a chin print. For example, the detection target based on an image captured by the detection device of this embodiment may be other than a trace originating from contact of a human body, as long as it can be detected by controlling the wavelength of infrared light or the like.

[0017] (composition) Fig. 1 is a block diagram showing an example of the configuration of a detection device 10 of this embodiment. Fig. 2 is a conceptual diagram showing an example of capturing an image of a fingerprint 110 attached to an object 100. The detection device 10 includes an imaging unit 11 and a heating unit 12. The imaging unit 11 includes an infrared sensor 111, a lens 112, a cooler 113, and a control unit 114. For example, the fingerprint 110 is a residue derived from a human body, such as a fingerprint, attached to the object 100. For example, the fingerprint 110 may be a degenerated portion of the object 100 where a fingerprint or the like was attached.

[0018] The infrared sensor 111 is a sensor having at least one infrared detection element that detects light in the infrared wavelength band. The infrared sensor 111 includes at least one infrared detection element that receives light in the same infrared wavelength band. The infrared sensor 111 may be provided with one infrared detection element or may be provided with multiple infrared detection elements. In the case of the infrared sensor 111 having one infrared detection element or infrared detection elements arranged in one dimension, a two-dimensional image can be obtained by moving the infrared sensor 111 or using a MEMS mirror. In addition, in the case of the infrared sensor 111 having two or more infrared detection elements, the presence or absence of a trace can be detected according to the presence or absence of light reception in different infrared detection elements. In addition, in the case where the infrared detection elements are formed in a matrix shape, the trace can be detected as an image. The infrared sensor 111 receives light in the infrared wavelength band incident through the lens 112 and converts it into an electrical signal. The infrared sensor 111 outputs the converted electrical signal to the control unit 114.

[0019] For example, the infrared sensor 111 is configured as a one-dimensional or two-dimensional sensor in which multiple infrared detection elements are arranged. When the pattern of the fingerprint 110 is to be detected, it is preferable to configure the infrared sensor 111 as a two-dimensional sensor in order to detect the pattern as an image. When detecting the pattern using a one-dimensional sensor, it is sufficient to scan in a direction perpendicular to the arrangement direction of the multiple infrared detection elements.

[0020] For example, the infrared sensor 111 is vacuum-sealed by a sealing member having a window that transmits light in the infrared wavelength band. For example, the window provided in the sealing member can be made of a material that easily transmits infrared light in the wavelength band used for detection, similar to the lens 112 described later.

[0021] The infrared detection element constituting the infrared sensor 111 is preferably sensitive to a wavelength band suitable for detecting the fingerprint 110 remaining on the object 100. For example, the infrared detection element constituting the infrared sensor 111 is realized by an element sensitive to the wavelength bands of near infrared (0.7 to 1.4 micrometers), short wavelength infrared (1.4 to 3 micrometers), and mid wavelength infrared (3 to 8 micrometers). The infrared detection element constituting the infrared sensor 111 may be realized by an element sensitive to the wavelength band of far infrared (8 to 15 micrometers), although this may become saturated depending on the temperature of the object.

[0022] For example, the infrared sensor 111 is realized by a sensor having a cooled (quantum) infrared detection element. For example, the infrared sensor 111 has an infrared detection element including a sensor material such as mercury cadmium telluride (HgCdTe), indium antimonide (InSb), gallium arsenide (GaAs), or aluminum gallium arsenide (AlGaAs). For example, the infrared sensor 111 has a quantum well type infrared detection element including a type-II superlattice in which indium arsenide (InAs) and gallium antimonide (GaSb) are stacked. For example, the infrared sensor 111 has an infrared detection element including a sensor material such as platinum silicon (PtSi) or germanium silicon (GeSi). Note that the infrared sensor 111 may be a sensor having a non-cooled infrared detection element as long as it can detect traces originating from the human body, such as fingerprints.

[0023] For example, human body residues such as fingerprints are a mixture of moisture, fat, dust, and the like. The main component of fat (sebum) is a fatty acid ester compound. Fatty acid ester compounds have infrared absorption characteristics in a wavelength band including 3.5 micrometers. Therefore, when detecting human body residues such as fingerprints, it is preferable to use an infrared sensor 111 including an infrared detection element that is sensitive to a wavelength band including 3.5 micrometers.

[0024] For example, when detecting a pattern of a trace from a human body, it is preferable that the infrared sensor 111 has a pixel count capable of identifying such a pattern. For example, when detecting a fingerprint, it is preferable that the infrared sensor 111 is configured as a two-dimensional sensor having a pixel count of at least 320×256 pixels. Furthermore, it is more preferable that the resolution of the infrared sensor 111 is 640×480 pixels or more. It is preferable that the resolution of the infrared sensor 111 is determined according to the size, shape, state, etc. of the detection target.

[0025] The lens 112 is a lens capable of focusing infrared rays in a wavelength band to be detected. The lens 112 focuses infrared rays in a wavelength band to be detected on a light receiving surface of the infrared sensor 111. For example, the lens 112 may be a lens made of a material such as germanium (Ge), silicon (Si), zinc sulfide (ZnS), zinc selenide (ZnSe), or sapphire (Al2O3). For example, the lens 112 may be a lens made of a material such as barium fluoride (BaF2), calcium fluoride (CaF2), lithium fluoride (LiF), or chalcogenide glass. The lens 112 may be one capable of focusing infrared rays in a wavelength band to be detected. For example, the lens 112 is preferably equipped with an autofocus function.

[0026] The cooler 113 is a device that cools the infrared sensor 111. In FIG. 2, the infrared sensor 111 and the cooler 113 are in contact with each other. In a quantum type infrared sensor, the cooler 113 is necessary to eliminate the influence of noise due to dark current or the like. For example, the cooler 113 cools the infrared sensor 111 so that the temperature is within a temperature range of about 60 to 250 Kelvin. For example, a cooler having a Stirling mechanism or an electronic cooling element using the Peltier effect is used as the cooler 113. Note that if it is not necessary to cool the infrared sensor 111, the cooler 113 may be omitted. Also, a filter that selectively transmits infrared rays in a wavelength band originating from the fingerprint 110 may be added to make it easier to detect the fingerprint 110.

[0027] The control unit 114 converts the electrical signal output by the infrared sensor 111 into image data. The control unit 114 outputs the converted image data. The image data output from the control unit 114 can be converted into an image for detecting traces originating from a human body in a detection device (not shown), an external system, an external device, etc., and displayed on a display device, etc. For example, an image based on the electrical signal output by the infrared sensor 111 is used for detecting and matching patterns such as fingerprints. For example, the control unit 114 is realized by a microcomputer. For example, in preparation for the object 100 having a curved surface portion, a function for correcting the curved surface portion to a flat surface on the image may be added to the imaging unit 11. In addition, in preparation for the object 100 having an uneven surface, a function for measuring the distance to the object 100 and flattening the unevenness of the surface of the object 100 on the image according to the measured distance may be added to the imaging unit 11.

[0028] The heating unit 12 (also called a temperature setting unit) is a device for heating the object 100 to a desired temperature (also called a detection temperature). The detection temperature is a temperature of the object suitable for detecting a fingerprint 110 such as a fingerprint attached to the object 100. The heating unit 12 is set to a set temperature in order to set the object 100 to the detection temperature. The object 100 is set to the detection temperature according to the set temperature set in the heating unit 12. As described later, the set temperature is preferably 50 degrees Celsius or higher. The object 100, which is the heating target of the heating unit 12, is heated to a temperature close to the set temperature, but the temperature does not necessarily match the set temperature. For example, if a temperature sensor is installed in the object 100 and the set temperature is controlled based on the temperature measured by the temperature sensor, the object temperature can be brought close to the detection temperature. The temperature of the object 100 heated by the heating unit 12 varies depending on the heating conditions and heating time. Therefore, it is preferable that the heating of the object 100 by the heating unit 12 is maintained for a certain period of time so that the temperature of the object 100 reaches the detection temperature.

[0029] For example, the heating unit 12 is realized by an appliance such as a hot plate that heats the object 100 placed on a plate. For example, the heating unit 12 is realized by an appliance such as an oven that heats the object 100 stored inside. For example, the heating unit 12 is realized by a hot air blower that blows hot air onto the object. It is sufficient for the heating unit 12 to be able to heat the object 100 to an appropriate temperature. The heating unit 12 may also have a function of cooling the object 100 in order to stabilize the temperature of the object 100.

[0030] According to Kirchhoff's law, the emissivity of thermal radiation depends on the reflectivity of the object's surface. The surface of an object with high reflectivity, such as metal, has a low emissivity of thermal radiation. On the other hand, the surface of a black body with low reflectivity, such as carbon, has a high emissivity of thermal radiation. For example, when human body residues such as fingerprints adhere to a metal surface, the reflectivity differs between the part with the residue and the part without the residue. Therefore, the presence or absence of residues such as fingerprints on a metal surface can be detected by the difference in emissivity of thermal radiation.

[0031] Thermal radiation occurs from an object according to its temperature. Generally, the Stefan-Boltzmann law shown in the following equation 1 holds true for thermal radiation from a black body. I=σT 4 (1) In the above equation, I is the amount of radiation, σ is the Stephan-Boltzmann constant, and T is temperature (Kelvin). The Stephan-Boltzmann law applies to black bodies, but it can also be qualitatively applied to general objects.

[0032] As shown in formula 1 above, the higher the temperature, the greater the amount of heat emitted from the object. In other words, it is easier to detect differences in emissivity when the temperature of the object 100 is heated to a temperature higher than room temperature. For example, when the temperature of the object 100 is set to 50 degrees Celsius or higher, it becomes easier to detect small differences in emissivity than at room temperature, and a clearer image can be captured. For example, when the temperature of the object 100 is set to about 100 degrees Celsius, it becomes easier to detect small differences in emissivity than at 50 degrees Celsius, and a clearer image can be captured.

[0033] 3 is a conceptual diagram showing how heating the object 100 increases the difference in emissivity between a portion where the fingerprint 110 is attached and a portion where the fingerprint 110 is not attached, resulting in a clear image of the fingerprint 110. For example, the set temperature is set to 100 degrees Celsius. At room temperature, the difference in emissivity between a portion where the fingerprint 110 is attached and a portion where the fingerprint 110 is not attached is not large enough, so the fingerprint 110 is unclear. If the set temperature is set to 50 degrees Celsius or higher, the difference in emissivity between a portion where the fingerprint 110 is attached and a portion where the fingerprint 110 is not attached becomes large enough, so the fingerprint 110 becomes clear.

[0034] 4 is a conceptual diagram conceptualizing an example of an image including a fingerprint (also called a fingerprint image) captured at each set temperature of the heating unit 12 set to 30, 50, 70, 90, and 100 degrees Celsius. In reality, an object 100 with a fingerprint 110 attached thereto was heated by the heating unit 12 set to each set temperature, and a fingerprint image was captured using the imaging unit 11, but from the viewpoint of privacy, the fingerprint image is not used as is, and instead a conceptual diagram showing the change in the fingerprint image with temperature is shown. As shown in FIG. 4, as the set temperature increases, the fingerprint 110 attached to the object 100 becomes clearer.

[0035] FIG. 5 is a graph showing an example of a temperature change of an index representing the clarity of a fingerprint in a fingerprint image including a fingerprint 110 attached to an object 100. In FIG. 5, a plurality of linearly continuous pixels (here, 13 pixels) were extracted from the same location of a fingerprint image taken at a set temperature in the temperature range of 30 to 100 degrees Celsius. Then, the signal intensity ratio of the extracted plurality of pixels was used as an index representing the clarity of the fingerprint. The signal intensity ratio corresponds to a value obtained by dividing the signal intensity of the brightest pixel among the extracted plurality of pixels by the signal intensity of the darkest pixel. For example, the signal intensity corresponds to the number of electrons stored in the capacitor of each pixel, and is uniquely determined depending on the optical system, the integration time, the temperature of the subject, the emissivity of the subject, and the like. The larger the signal intensity ratio, the clearer the fingerprint. As shown in FIG. 5, when the signal intensity ratio at each set temperature (30, 50, 70, 90, 100 degrees Celsius) is plotted against the set temperature, the signal intensity ratio increases with increasing temperature. That is, under the measurement conditions of FIG. 5, when the set temperature was the maximum of 100 degrees Celsius, the fingerprint 110 was most clear.

[0036] The optimum set temperature depends on the object 100, the fingerprint 110 attached to the object 100, and a combination thereof. If it is desired to prevent deterioration of the object 100, it is preferable to set the temperature at which the object 100 does not deteriorate. Also, if it is desired to prevent deterioration of the fingerprint 110 attached to the object 100, it is preferable to set the temperature at which the fingerprint 110 does not deteriorate. For example, if the fingerprint 110 attached to the object 100 is to be deteriorated or the portion where the fingerprint 110 is attached is to be deteriorated before inspection, it is sufficient to carry out a pretreatment such as a heat treatment on the fingerprint 110 or the portion where the fingerprint 110 is attached to cause the deterioration.

[0037] [Modifications] Here, a description will be given of some examples of modified examples of the detection device 10. Figures 6 to 8 are conceptual diagrams of examples of modified examples of the detection device 10.

[0038] FIG. 6 shows an example (variation 1) in which the heating unit 12 on which the object 100 with the fingerprint 110 is placed is placed inside a sealed measurement tank 18 to detect the fingerprint 110. For example, the measurement tank 18 is realized by a container or enclosure that can seal the inside. A window material 180 that transmits infrared rays in a wavelength band that the imaging unit 11 can detect is provided in a part of the measurement tank 18. For example, silicon or sapphire can be used as the material of the window material 180. The imaging unit 11 analyzes the surface of the object 100, which is set to the object temperature, through the window material 180. In the example of FIG. 6, the atmosphere inside the measurement tank 18 can be selected arbitrarily. For example, if it is not desired to oxidize the object 100 or the fingerprint 110, the atmosphere inside the measurement tank 18 can be filled with an inert gas, nitrogen, or the like. Also, the measurement tank 18 may be configured to circulate an atmosphere of an inert gas, nitrogen, or the like without sealing the inside of the measurement tank 18. If the heating unit 12 on which the object 100 is placed is placed inside the sealed measurement tank 18 for measurement, the temperature distribution of the object 100 tends to be uniform, and the fingerprint 110 tends to be detected more clearly. For example, even if the inside is not sealed like the measurement tank 18, but the object 100 is simply surrounded by a fence, the temperature distribution of the object 100 can be reduced if the effects of disturbances such as light and wind can be reduced.

[0039] FIG. 7 shows an example (modification 2) in which the object 100 with the fingerprint 110 attached thereto is placed inside a sealed oven 19, the inside of the oven 19 is set to a set temperature, and the fingerprint 110 is detected. For example, the oven 19 is realized by a thermostatic bath capable of uniformly heating the inside temperature. A window material 190 that transmits infrared rays in a wavelength band detectable by the imaging unit 11 is provided in a part of the oven 19. For example, silicon or sapphire can be used as the material of the window material 190. The imaging unit 11 analyzes the surface of the object 100 set to a set temperature through the window material 190. In the example of FIG. 7, the atmosphere inside the oven 19 can be selected arbitrarily. For example, if it is not desired to oxidize the object 100 or the fingerprint 110, the atmosphere inside the oven 19 can be filled with an inert gas, nitrogen, or the like. Also, the oven 19 may be configured to circulate an atmosphere of an inert gas, nitrogen, or the like inside the oven 19. If the heating unit 12 on which the object 100 is placed is placed inside a sealed oven 19 for measurement, it becomes easier to control the temperature distribution of the object 100 more uniformly, so that the fingerprint 110 can be detected more clearly.

[0040] FIG. 8 shows an example (Modification 3) in which the temperature of the object 100 on which the fingerprint 110 is attached is set to an appropriate temperature by hot air blown from the heating unit 12-3 set to a set temperature, and the fingerprint 110 is detected. For example, the heating unit 12-3 is realized by a hot air tool that blows out uniform hot air. It is preferable that the hot air blown out from the heating unit 12-3 is adjusted so that the temperature is uniform at the position of the surface of the object 100. The imaging unit 11 images the surface of the object 100, which has been set to an appropriate temperature by the hot air blown out from the heating unit 12-3. In the example of FIG. 8, the gas blown out from the heating unit 12-3 can be selected arbitrarily. For example, if it is not desired to oxidize the object 100 or the fingerprint 110, hot air of an inert gas, nitrogen, or the like may be blown out from the heating unit 12-3. Even if the object 100 cannot be placed inside the measurement tank 18 or the oven 19, the object 100 can be set to an appropriate temperature by the heating unit 12-3, so that the fingerprint 110 can be more clearly detected.

[0041] As described above, the detection device of this embodiment includes an imaging unit having an infrared sensor having at least one infrared detection element that receives light in the infrared wavelength band, and a heating unit (temperature setting unit) that heats an object that is a detection target for traces originating from a human body. According to this embodiment, the temperature of the object is set to an appropriate temperature at which traces originating from a human body are easily detected, so that traces originating from a human body attached to the object can be clearly detected.

[0042] For example, the trace is derived from at least one of a fingerprint, a palm print, a metacarpal print, a proximal print, a sole print, a toe print, an ear print, a nose print, a lip print, a forehead print, and a chin print. For example, the imaging unit has an infrared detection element sensitive to light in a wavelength band included in 0.7 to 8 micrometers.

[0043] For example, when a person touches an object with a fingertip, the main component of the residue remaining on the object as a fingerprint is water. The residue remaining on the object as a fingerprint includes sodium, potassium, magnesium, amino acids, urea, lactic acid, fat, and the like in addition to water. For example, when the object is metal, the area where the fingerprint is attached is placed in an environment where it is more likely to deteriorate than other areas due to the influence of salts such as sodium contained in the fingerprint components. Therefore, the area where the residue originating from the human body is attached is more likely to deteriorate, such as corroded, than other areas. In this embodiment, the detection target also includes traces formed by the deterioration of the area where the residue originating from the human body is attached to the object. Note that, according to the method of this embodiment, it may be easier to detect the residue originating from the human body attached to the surface of the deteriorated object.

[0044] Not only on metal surfaces, but also in areas where fingerprints are present, the infrared absorption rate and thermal radiation emissivity are different between areas where fingerprints are not present. For example, even on wood or paper, the thermal radiation emissivity is different between areas where fingerprints are present and areas where fingerprints are not present. For example, with some ingenuity, it may be possible to detect fingerprints from human body marks on wood, paper, cloth, plastic, polymers, etc. in the same way as metal. For example, if it is possible to detect human body marks on cloth, it may be possible to detect fingerprints on clothing.

[0045] Second embodiment Next, a detection device according to a second embodiment will be described with reference to the drawings. The detection device of this embodiment includes an illumination unit for facilitating detection of traces originating from the human body, such as fingerprints. The detection device of this embodiment includes an illumination unit that irradiates infrared rays in a wavelength band that is easily absorbed / reflected by the target object or traces originating from a person attached to the target object.

[0046] FIG. 9 is a block diagram showing an example of the configuration of the detection device 20 of this embodiment. The detection device 20 includes an imaging unit 21, a heating unit 22, and an illumination unit 23. FIG. 10 is a conceptual diagram showing an example of detecting a fingerprint 210 attached to an object 200 placed on the heating unit 22. The imaging unit 21 includes an infrared sensor 211, a lens 212, a cooler 213, and a control unit 214. The illumination unit 23 includes a light source 230. For example, the fingerprint 210 is a residue derived from a human body such as a fingerprint attached to the object 200. For example, the fingerprint 210 is a part where a part of a residue such as a fingerprint attached to the object 200 has changed in quality. The imaging unit 21 is the same as the imaging unit 11 of the first embodiment. Note that if it is not necessary to cool the infrared sensor 211, the cooler 213 may be omitted. In addition, a filter that selectively transmits infrared rays in a wavelength band derived from the fingerprint 210 may be added to make it easier to detect the fingerprint 210. The heating unit 22 (also referred to as a temperature setting unit) is similar to the heating unit 12 in the first embodiment. Therefore, in the following, the description of the imaging unit 21 and the heating unit 22 will be simplified, and the description will focus on the illumination unit 23.

[0047] The light source 230 of the illumination unit 23 is an illumination for facilitating detection of the fingerprint 210 derived from the human body. For example, the light source 230 emits infrared rays (near infrared to mid-infrared) in a wavelength range including 1 to 5 micrometers. For example, the light source 230 can use a filament of an incandescent light bulb that operates at a low temperature range of 100 to 1000 degrees Celsius, such as silicon carbide (SiC) or nichrome (NiCr). For example, if such a filament is operated at about 1000 degrees Celsius, it can emit infrared rays in a wavelength range including 1 to 5 micrometers with a watt-level output. Note that the filament used for the light source 230 is not limited to silicon carbide (SiC) or nichrome (NiCr) as long as it can emit infrared rays in the wavelength band to be detected. For example, if a milliwatt-level output is sufficient, a light-emitting diode may be used as the light source 230.

[0048] [Modifications] Here, a modified example of the detection device 20 of this embodiment will be illustrated. FIG. 11 is a conceptual diagram showing an example of the configuration of the detection device of the modified example. The detection device of the modified example is an example in which the imaging unit 21 and the illumination unit 23 included in the detection device 20 of FIG. 10 are stored inside a single housing 29. In this modified example, the emission axis of the illumination emitted from the illumination unit 23 and the shooting axis of the imaging unit 21 are fixed, so that the direction (shooting direction) in which the reflected light reflected on the surface of the object 200 enters the imaging unit 21 is constant. Therefore, according to this modified example, stable imaging is possible. Also, according to this modified example, the imaging unit 21 and the illumination unit 23 are integrated, making it easy to carry.

[0049] As described above, the detection device of this embodiment includes an imaging unit, a heating unit, and an illumination unit. The illumination unit irradiates light in the infrared region of the detection wavelength band of the infrared detection element. The detection device of this embodiment can illuminate an object on which a trace of the detection target is presumed to remain by the illumination unit. Therefore, according to the detection device of this embodiment, even in a work environment that is easily affected by external light, the trace originating from the human body can be clearly detected nondestructively.

[0050] (Third embodiment) Next, a detection device according to a third embodiment will be described with reference to the drawings. The detection device according to this embodiment includes a detection unit that detects traces originating from the human body, such as fingerprints, using an image captured by an imaging unit. In order to detect traces originating from the human body more clearly, the illumination unit according to the second embodiment may be added to the detection device according to this embodiment.

[0051] FIG. 12 is a block diagram showing an example of the configuration of the detection device 30 of this embodiment. The detection device 30 includes an imaging unit 31, a heating unit 32, and a detection unit 35. FIG. 13 is a conceptual diagram showing an example of detecting a fingerprint 310 attached to an object 300 placed on the heating unit 32. The imaging unit 31 includes an infrared sensor 311, a lens 312, a cooler 313, and a control unit 314. For example, the fingerprint 310 is a residue derived from a human body such as a fingerprint attached to the object 300. For example, the fingerprint 310 is a part where a part of a residue such as a fingerprint attached to the object 300 has been altered. The imaging unit 31 is the same as the imaging unit 11 of the first embodiment. Note that, if it is not necessary to cool the infrared sensor 311, the cooler 313 may be omitted. In addition, a filter that selectively transmits infrared rays in a wavelength band derived from the fingerprint 310 may be added so that the fingerprint 310 can be easily detected. The heating unit 32 (also called a temperature setting unit) is the same as the heating unit 12 of the first embodiment. In the following, the description will be simplified for the imaging unit 31 and the heating unit 32, and will focus on the detection unit 35. Note that the illumination unit 23 of the second embodiment may be added to the detection device 30.

[0052] The detection unit 35 is connected to the imaging unit 31 and the heating unit 32. The detection unit 35 may be connected to the imaging unit 31 and the heating unit 32 by wire or wirelessly. The detection unit 35 may also be connected to the imaging unit 31 and the heating unit 32 via a network (not shown). The detection unit 35 may be configured as a dedicated server device or terminal device, or may be realized by software installed in a general-purpose server device or terminal device.

[0053] The detection unit 35 controls the imaging unit 31 and the heating unit 32. The detection unit 35 controls the imaging unit 31 and causes the imaging unit 31 to capture the imaging target range. The detection unit 35 detects a portion originating from a fingerprint 310 such as a fingerprint from the image of the imaging target range captured by the imaging unit 31. For example, the detection unit 35 extracts a feature from the image of the imaging target range and determines whether the feature originates from a fingerprint 310 such as a fingerprint based on the size and shape of the range from which the feature was extracted, the state and density of lines included in the range, and the like. If no feature originating from the fingerprint 310 is detected, the detection unit 35 controls the set temperature of the heating unit 32 to change the temperature of the object 300.

[0054] For example, when the detection unit 35 detects a feature derived from a fingerprint at a certain set temperature, it generates an image (also called a fingerprint image) for detecting a fingerprint 310 such as a fingerprint, using image data captured at the set temperature. For example, the detection unit 35 extracts a feature from the detection data, and determines whether the feature is derived from a fingerprint based on the size and shape of the range from which the feature is extracted, the state and density of the lines included in the range, and the like. For example, the detection unit 35 determines that a fingerprint has been detected when noise, contrast, and the like included in the detection data meet a preset standard. For example, the detection unit 35 inputs the detection data into an estimation model that outputs a determination result as to whether or not the data is a fingerprint in response to the input of the detection data, and determines whether or not a fingerprint has been detected based on the output determination result. Note that the method of fingerprint detection by the detection unit 35 is not limited to the example given here. Among the functions of the detection unit 35, the function of controlling the heating unit 32 and the function of generating a fingerprint image may be integrated into the main body of the imaging unit 31. For example, the detection unit 35 can be used in a portable manner by integrating it with a system that performs fingerprint matching via a network.

[0055] The detection unit 35 outputs a detection result regarding the detected fingerprint 310. For example, the detection unit 35 outputs a fingerprint image in which the fingerprint 310 is captured most clearly. For example, the detection unit 35 may output a detection result (for example, a fingerprint image) regarding a fingerprint that is clearer than a predetermined standard in association with a set temperature. The fingerprint image is used for fingerprint matching or the like. If the detection unit 35 can identify a fingerprint, it may output an image in which the fingerprint 310 is not captured most clearly as a fingerprint image. For example, the detection unit 35 may output images captured at several set temperatures in association with those temperatures. For example, when a fingerprint is not detected from the detection data, the detection unit 35 may output an image captured at that stage in association with the set temperature. The fingerprint image output from the detection unit 35 may be output to a display device (not shown) or to a system that performs fingerprint matching or the like using the fingerprint image.

[0056] [Detection unit] Next, a detailed configuration of the detection unit 35 will be described with reference to the drawings. Fig. 14 is a block diagram showing an example of a detailed configuration of the detection unit 35. The detection unit 35 has a temperature control unit 351, an imaging control unit 352, an image processing unit 353, and a pattern detection unit 354.

[0057] The temperature control unit 351 controls the heating unit 32 in response to an instruction from the pattern detection unit 354. Under the control of the temperature control unit 351, the heating unit 32 heats the object 300, whereby the temperature of the object 300 is set.

[0058] The imaging control unit 352 controls the imaging unit 31. The imaging control unit 352 outputs image data captured in accordance with the control to the image processing unit 353.

[0059] The image processing unit 353 acquires image data from the imaging control unit 352. The image processing unit 353 applies image processing to the acquired image data to generate detection data (also called a fingerprint image) for detecting feature amounts. For example, the image processing unit 353 performs image processing on the image data, such as dark current correction, interpolation calculation, color space conversion, gamma correction, aberration correction, noise reduction, and image compression. Note that the image processing by the image processing unit 353 is not limited to those listed here. Furthermore, if image processing is not necessary, the image processing unit 353 may be omitted. The image processing unit 353 outputs the generated detection data to the pattern detection unit 354.

[0060] Pattern detection unit 354 acquires detection data from image processing unit 353. Pattern detection unit 354 detects a fingerprint from the acquired detection data. Pattern detection unit 354 outputs a detection result related to the detected fingerprint. Pattern detection unit 354 may also output an instruction to temperature control unit 351 to change the temperature of heating unit 32 in order to obtain a clearer image of the fingerprint.

[0061] FIG. 15 is an example in which an image of a fingerprint 310 (fingerprint image) detected by the detection device 30 is displayed on the display device 350. For example, an operator compares the fingerprint image displayed on the display device 350 with a fingerprint image (also called control fingerprint data) stored in a database or the like (not shown) to verify the fingerprints. For example, the display device 350 may display the time, place, and circumstances in which the fingerprint 310 from which the fingerprint image was extracted was detected. For example, the display device 350 may display supplementary information such as the time, place, and circumstances in which the fingerprint 310 from which the fingerprint image was extracted was detected together with the fingerprint image. For example, when investigating a case, if the supplementary information associated with the fingerprint image can be referred to, it becomes easier to identify the person corresponding to the fingerprint 310 from which the fingerprint image was extracted by comparing it with the behavior of a suspect in the case.

[0062] (operation) Next, the operation of the detection unit 35 will be described with reference to the drawings. Fig. 16 is a flow chart for explaining the operation of the detection unit 35. In Fig. 16, the operation will be described with the detection unit 35 as the subject of the operation.

[0063] In FIG. 16, first, the detection unit 35 controls the imaging unit 31 to cause the imaging unit 31 to capture an image of the area in which the fingerprint 310 is presumed to be attached (step S31).

[0064] Next, the detection unit 35 processes the captured image data to generate detection data (step S32).

[0065] Next, the detection unit 35 detects a fingerprint from the detection data (step S33). For example, the detection unit 35 extracts features from the detection data, and determines whether the features are derived from a fingerprint based on the size and shape of the area from which the features are extracted, and the state and density of the lines included in the area. For example, the detection unit 35 determines that a fingerprint has been detected when noise, contrast, and the like included in the detection data meet a preset standard. For example, the detection unit 35 inputs the detection data to an estimation model that outputs a determination result as to whether or not the data is a fingerprint in response to the input of the detection data, and determines whether or not a fingerprint has been detected based on the output determination result. Note that the method of fingerprint detection by the detection unit 35 is not limited to the example given here.

[0066] If a fingerprint is detected from the detection data (Yes in step S33), the detection unit 35 outputs a detection result related to the fingerprint (step S35). For example, the detection unit 35 may output a detection result (e.g., a fingerprint image) related to a fingerprint that is clearer than a predetermined standard, in association with a set temperature. For example, the detection unit 35 may output images captured at several set temperatures in association with those temperatures.

[0067] On the other hand, if a fingerprint is not detected from the detection data (No in step S33), the detection unit 35 controls the heating unit 32 to change the set temperature (step S34). For example, the detection unit 35 controls the heating unit 32 to set the set temperature to a higher temperature in order to increase the difference in emissivity caused by the presence or absence of a fingerprint 310 and improve contrast. After step S34, the process returns to step S31. For example, if a fingerprint is not detected even after controlling the heating unit 32 several times, the process may be configured to end according to the flowchart of FIG. 16. For example, if a fingerprint is not detected from the detection data, the detection unit 35 may output the image captured at that stage in association with the set temperature.

[0068] As described above, the detection device of this embodiment includes a detection unit that controls the set temperature of the heating unit (temperature setting unit) to heat the object and controls the imaging unit to image the object. The detection unit detects traces from the image captured by the imaging unit and outputs a detection result regarding the detected trace. According to the detection device of this embodiment, the set temperature of the heating unit is set according to the detection status of the trace, so that traces originating from the human body can be detected from the image captured by the imaging unit.

[0069] In one aspect of the present embodiment, the detection unit extracts feature points from the image captured by the imaging unit and detects a pattern of a trace based on the extracted feature points. According to this aspect, a pattern of a trace originating from a human body can be detected based on the feature points extracted from the image captured by the imaging unit.

[0070] In one aspect of this embodiment, when no trace is detected from the image captured by the imaging unit, the detection unit controls the heating unit to increase the temperature of the object. According to this aspect, when no trace is detected, the setting temperature of the heating unit is reset to a higher temperature, thereby increasing the difference in emissivity caused by the presence or absence of a trace, and improving the contrast of the trace in the image.

[0071] In the detection method of this embodiment, in one aspect of the detection method of this embodiment, the heating unit (temperature setting unit) is controlled to heat the object that is the detection target for traces originating from the human body. Next, in the detection method of this embodiment, the imaging unit having an infrared sensor having at least one infrared detection element that receives light in the infrared wavelength band is controlled to image the object heated by the heating unit. Then, in the detection method of this embodiment, traces remaining on the object are detected. According to this aspect, the object can be set to an appropriate temperature by setting the heating unit to an appropriate set temperature.

[0072] In the detection method according to one aspect of the present embodiment, the object is pre-heated, and the pre-heated object is heated and set to an appropriate temperature (detection temperature). For example, when the object is set to the detection temperature, the object, fingerprints, etc. may be altered, and traces remaining on the object may not be clearly detected. In such a case, in this aspect, the object is pre-heated at a temperature higher than the detection temperature, so that the object, fingerprints, etc. do not degrade during the inspection. In addition, there may be cases where the traces remaining on the object can be more clearly detected by pre-deteriorating the object, fingerprints, etc. In such a case, in this aspect, the object is pre-heated at a temperature higher than the detection temperature to pre-deteriorate the object, fingerprints, etc., so that the traces remaining on the object can be more clearly detected.

[0073] (Fourth embodiment) Next, a detection device according to a fourth embodiment will be described with reference to the drawings. The detection device according to this embodiment searches a database in which fingerprints of multiple people are stored, and collates fingerprints detected from an image captured by an imaging unit. In order to detect traces originating from the human body more clearly, the illumination unit according to the second embodiment may be added to the detection device according to this embodiment.

[0074] FIG. 17 is a conceptual diagram showing an example of the configuration of the detection device 40 of this embodiment. FIG. 17 also shows a database 470 connected to the detection device 40. The database 470 stores fingerprint data (also called control fingerprint data) of a plurality of people used for fingerprint matching. FIG. 18 is a conceptual diagram showing an example of detecting a fingerprint 410 attached to an object 400 placed on a heating unit 42. The detection device 40 includes an imaging unit 41, a heating unit 42, and a detection unit 45. The imaging unit 41 has an infrared sensor 411, a lens 412, a cooler 413, and a control unit 414. For example, the fingerprint 410 is a residue derived from a human body, such as a fingerprint, attached to the object 400. For example, the fingerprint 410 is a portion where a portion of a fingerprint or other residue attached to the object 400 has been altered. The imaging unit 41 is the same as the imaging unit 11 of the first embodiment. If it is not necessary to cool the infrared sensor 411, the cooler 413 may be omitted. Also, a filter that selectively transmits infrared rays in a wavelength band originating from the fingerprint 410 may be added to make it easier to detect the fingerprint 410. The heating unit 42 (also called a temperature setting unit) is similar to the heating unit 12 in the first embodiment. In the following, the description of the imaging unit 41 and the heating unit 42 will be simplified, and the description will focus on the detection unit 45. The illumination unit 23 in the second embodiment may be added to the detection device 40.

[0075] The detection unit 45 is connected to the imaging unit 41, the heating unit 42, and the database 470. The detection unit 45 may be connected to the imaging unit 41, the heating unit 42, and the database 470 by wire or wirelessly. The detection unit 45 may also be connected to the imaging unit 41, the heating unit 42, and the database 470 via a network (not shown). The detection unit 45 may be configured as a dedicated server device or terminal device, or may be realized by software installed in a general-purpose server device or terminal device.

[0076] Furthermore, the detection unit 45 may be integrated into the imaging unit 41. For example, a usage form can be envisioned in which a function such as control of the heating unit 42 is integrated into the detection unit 45, and functions such as fingerprint matching and image analysis are accessed via the cloud to the database 470. In such a case, the detection unit 45 is realized in the form of a dedicated mobile terminal having an information processing function and a communication function, or in the form of software installed in a general-purpose mobile terminal such as a notebook computer or a smartphone.

[0077] The detection unit 45 controls the imaging unit 41 and the heating unit 42. The detection unit 45 controls the imaging unit 41 and causes the imaging unit 41 to capture the imaging target range. The detection unit 45 detects a portion originating from a fingerprint 410 such as a fingerprint from the image of the imaging target range captured by the imaging unit 41. For example, the detection unit 45 extracts a feature from the image of the imaging target range and determines whether the feature originates from a fingerprint 410 such as a fingerprint based on the size and shape of the range from which the feature is extracted, the state and density of lines included in the range, and the like. If a feature originating from a fingerprint 410 is not detected, the detection unit 45 controls the set temperature of the heating unit 42 to change the temperature of the object 400.

[0078] For example, when the detection unit 45 detects a feature derived from a fingerprint, it generates an image (also called a fingerprint image) for detecting a fingerprint 410 such as a fingerprint, using image data captured at the object temperature. For example, the detection unit 45 extracts a feature from the detection data, and determines whether the feature is derived from a fingerprint based on the size and shape of the range from which the feature is extracted, the state and density of the lines included in the range, and the like. For example, the detection unit 45 determines that a fingerprint has been detected when noise, contrast, and the like included in the detection data meet a preset standard. For example, the detection unit 45 inputs the detection data to an estimation model that outputs a determination result as to whether or not the data is a fingerprint in response to the input of the detection data, and determines whether or not a fingerprint has been detected based on the output determination result. Note that the method of fingerprint detection by the detection unit 45 is not limited to the example given here. Among the functions of the detection unit 45, the function of controlling the heating unit 32 and the function of generating a fingerprint image may be integrated into the main body of the imaging unit 41.

[0079] When the detection unit 45 detects a fingerprint (also called a target fingerprint) from a fingerprint image, it extracts minutiae from the target fingerprint. The detection unit 45 searches the database 470 to detect a control fingerprint having minutiae that closely match the minutiae of the target fingerprint. The detection unit 45 outputs a matching result regarding the target fingerprint. For example, the detection unit 45 can be used in a portable manner by integrating it with a fingerprint matching system via a network.

[0080] [Detection unit] Next, a detailed configuration of the detection unit 45 will be described with reference to the drawings. FIG. 19 is a block diagram showing an example of a detailed configuration of the detection unit 45. The detection unit 45 has a temperature control unit 451, an imaging control unit 452, an image processing unit 453, a pattern detection unit 454, a feature point extraction unit 455, and a matching unit 456. The temperature control unit 451, the imaging control unit 452, the image processing unit 453, and the pattern detection unit 454 are similar to the configurations included in the detection unit 35 of the third embodiment. Therefore, the following description will focus on the feature point extraction unit 455 and the matching unit 456 that are not included in the detection unit 35 of the third embodiment.

[0081] The minutiae extraction unit 455 acquires the fingerprint (also called a target fingerprint) detected by the pattern detection unit 454. The minutiae extraction unit 455 extracts minutiae from the acquired target fingerprint. The minutiae extraction unit 455 outputs the extracted minutiae to the matching unit 456. For example, the minutiae extraction unit 455 extracts positions such as the start point of a ridge, an island-shaped line (island line), an independent short ridge (short ridge), the end point of a ridge, a junction point where ridges are connected, a branch point where a ridge is split, and other points as minutiae.

[0082] The matching unit 456 acquires the feature points extracted by the feature point extraction unit 455. The matching unit 456 searches the database 470 to detect a control fingerprint having feature points that closely match the feature points of the fingerprint to be matched. The matching unit 456 outputs a matching result regarding the fingerprint to be matched. For example, the matching unit 456 outputs, as the matching result, identification information such as an individual's name associated with the control fingerprint detected by matching, or personal information.

[0083] Also, the matching unit 456 may search for candidates for the control fingerprint from the database 470 based on a preset criterion. For example, if there is a candidate for the person of the fingerprint to be matched, the matching unit 456 searches for the control fingerprint of that person as a candidate from the database 470. For example, if a control fingerprint detected in the vicinity of the place where the fingerprint to be matched is detected is registered in the database 470, the matching unit 456 searches for the control fingerprint as a candidate from the database 470. Then, the matching unit 456 may compare the feature points of the searched control fingerprint with the feature points of the fingerprint to be matched, and determine that the fingerprints have been matched if a preset matching criterion is satisfied. For example, the matching unit 456 compares the feature points of the matched fingerprint and the control fingerprint, or compares multiple feature points, and calculates the ratio of matching feature points as the degree of match. For example, the matching unit 456 determines that the fingerprints match if the degree of match exceeds a predetermined criterion. Furthermore, matching unit 456 may perform matching based on the shape of the ridges, the shape and interval / position of sweat pores in the ridges, etc. As a method for fingerprint matching by matching unit 456, a general method can be used.

[0084] Fig. 20 shows an example in which the matching result by the detection device 40 is displayed on the screen of the display device 450. In the example of Fig. 20, the name of the individual (AAA) associated with the control fingerprint detected by matching is displayed as the matching result on the screen of the display device 450. By referring to the matching result displayed on the screen of the display device 450, the worker can recognize the person whose fingerprint is to be matched.

[0085] (operation) Next, the operation of the detection unit 45 will be described with reference to the drawings. Fig. 21 is a flow chart for explaining the operation of the detection unit 45. In Fig. 21, the operation will be described with the detection unit 45 as the subject of the operation.

[0086] In FIG. 21, first, the detection unit 45 controls the detection device 40 to capture an image of the area where the fingerprint 410 is presumed to be attached (step S41).

[0087] Next, the detection unit 45 processes the captured image data to generate detection data (step S42).

[0088] Next, the detection unit 45 detects a fingerprint from the detection data. For example, the detection unit 45 extracts features from the detection data, and determines whether the features are derived from a fingerprint based on the size and shape of the range from which the features are extracted, and the state and density of the lines included in the range. For example, the detection unit 45 determines that a fingerprint has been detected when noise, contrast, and the like included in the detection data meet a preset standard. For example, the detection unit 45 inputs the detection data to an estimation model that outputs a determination result as to whether or not the data is a fingerprint in response to the input of the detection data, and determines whether or not a fingerprint has been detected based on the output determination result. Note that the method of fingerprint detection by the detection unit 45 is not limited to the example given here.

[0089] If a fingerprint is detected from the detection data (Yes in step S43), the detection unit 45 extracts feature points from the fingerprint (step S45). For example, the detection unit 45 may output a detection result (e.g., a fingerprint image) related to a fingerprint that is clearer than a predetermined standard, in association with a set temperature. For example, the detection unit 45 may output fingerprint images captured at several set temperatures in association with those temperatures.

[0090] On the other hand, if a fingerprint is not detected from the detection data (No in step S43), the detection unit 45 controls the heating unit 42 to change the set temperature (step S44). For example, the detection unit 45 controls the heating unit 42 to set the set temperature to a higher temperature in order to increase the difference in emissivity caused by the presence or absence of a fingerprint 410 and improve contrast. After step S44, the process returns to step S41. For example, if a fingerprint is not detected even after controlling the heating unit 42 several times, the process may be configured to end according to the flowchart of FIG. 21. For example, if a fingerprint is not detected from the detection data, the detection unit 45 may output the image captured at that stage in association with the set temperature.

[0091] Following step S45, detection unit 45 searches database 470 and performs fingerprint matching to detect a control fingerprint having minutiae that closely match the minutiae of the fingerprint to be matched (step S46).

[0092] Then, the detection unit 45 outputs the collation result (step S47).

[0093] As described above, the detection device of this embodiment includes an imaging unit, a heating unit, and a detection unit. The detection unit searches a database in which control patterns of multiple people are stored. The detection unit detects a control pattern from the database that has feature points that closely match feature points of the trace pattern. The detection unit outputs information about the detected control pattern. According to the detection device of this embodiment, by searching the database, matching can be performed based on the pattern of the trace originating from the detected human body.

[0094] In the detection method according to one aspect of the present embodiment, a heating unit (temperature setting unit) is controlled to set the temperature of an object to be detected for traces originating from a human body to an appropriate temperature. Next, in the detection method according to the present embodiment, an imaging unit having an infrared sensor having at least one infrared detection element that receives light in a wavelength band of the infrared region is controlled to image the object set to the appropriate temperature. Next, in the detection method according to the present embodiment, feature points are extracted from an image captured by the imaging unit, and a trace pattern is detected based on the extracted feature points. Next, in the detection method according to the present embodiment, a database is searched in which the comparison patterns of a plurality of persons used for matching are stored, and a comparison pattern having feature points that are highly consistent with the feature points of the trace pattern is detected from the database. Then, in the detection method according to the present embodiment, information about the detected comparison pattern is output. In the detection method according to the present embodiment, a trace pattern is detected based on the feature points extracted from an image, and a database is searched, thereby making it possible to identify the person from whom the fingerprint was extracted.

[0095] The matching results of the detection device of this embodiment can be applied to a system that identifies people by fingerprint matching, and also to a service that tracks identified fingerprints.

[0096] Fifth embodiment Next, a detection device according to a fifth embodiment will be described with reference to the drawings. The detection device of this embodiment has a simplified configuration of the detection devices of the first to fourth embodiments.

[0097] 22 is a block diagram showing an example of the configuration of a detection device 50 of this embodiment. The detection device 50 includes an imaging unit 51 and a heating unit 52. The heating unit 52 corresponds to the heating unit of the first to fourth embodiments. The imaging unit 51 has an infrared sensor having at least one infrared detection element that receives light in a wavelength band of the infrared region. The heating unit 52 heats an object that is the target of detection of traces originating from the human body.

[0098] According to the detection device of this embodiment, the temperature of the object is set to a temperature at which traces originating from the human body are easily detected, so that traces originating from the human body attached to the object can be clearly detected.

[0099] (Hardware) Here, a hardware configuration for executing the processing of the detection device according to each embodiment of the present invention will be described by taking as an example an information processing device 90 in Fig. 23. Note that the information processing device 90 in Fig. 23 is an example of a configuration for executing the processing of the detection device according to each embodiment, and does not limit the scope of the present invention.

[0100] As shown in Fig. 23, an information processing device 90 includes a processor 91, a main storage device 92, an auxiliary storage device 93, an input / output interface 95, and a communication interface 96. In Fig. 23, the interface is abbreviated as I / F (Interface). The processor 91, the main storage device 92, the auxiliary storage device 93, the input / output interface 95, and the communication interface 96 are connected to each other via a bus 98 so as to be able to communicate data with each other. In addition, the processor 91, the main storage device 92, the auxiliary storage device 93, and the input / output interface 95 are connected to a network such as the Internet or an intranet via the communication interface 96.

[0101] The processor 91 loads a program stored in the auxiliary storage device 93 or the like into the main storage device 92 and executes the loaded program. In this embodiment, a software program installed in the information processing device 90 may be used. The processor 91 executes processing by the detection device according to this embodiment.

[0102] The main storage device 92 has an area in which a program is loaded. The main storage device 92 may be a volatile memory such as a dynamic random access memory (DRAM). A non-volatile memory such as a magnetoresistive random access memory (MRAM) may also be configured or added as the main storage device 92.

[0103] The auxiliary storage device 93 stores various data. The auxiliary storage device 93 is configured with a local disk such as a hard disk or a flash memory. Note that it is also possible to configure the main storage device 92 to store various data, and omit the auxiliary storage device 93.

[0104] The input / output interface 95 is an interface for connecting the information processing device 90 to peripheral devices. The communication interface 96 is an interface for connecting to an external system or device through a network such as the Internet or an intranet based on standards and specifications. The input / output interface 95 and the communication interface 96 may be a common interface for connecting to an external device.

[0105] The information processing device 90 may be configured to be connected to input devices such as a keyboard, a mouse, and a touch panel, as necessary. These input devices are used to input information and settings. When a touch panel is used as the input device, the display screen of the display device may be configured to also function as an interface for the input device. Data communication between the processor 91 and the input devices may be mediated by an input / output interface 95.

[0106] The information processing device 90 may be equipped with a display device for displaying information. When the display device is equipped, the information processing device 90 is preferably equipped with a display control device (not shown) for controlling the display of the display device. The display device may be connected to the information processing device 90 via the input / output interface 95.

[0107] The above is an example of a hardware configuration for enabling the detection device according to each embodiment of the present invention. The hardware configuration in FIG. 23 is an example of a hardware configuration for executing the arithmetic processing of the detection device according to each embodiment, and does not limit the scope of the present invention. In addition, a program for causing a computer to execute processing related to the detection device according to each embodiment is also included in the scope of the present invention. Furthermore, a recording medium on which the program according to each embodiment is recorded is also included in the scope of the present invention. The recording medium can be realized, for example, by an optical recording medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disc). In addition, the recording medium may be realized by a semiconductor recording medium such as a USB (Universal Serial Bus) memory or an SD (Secure Digital) card, a magnetic recording medium such as a flexible disk, or other recording medium. When the program executed by the processor is recorded on a recording medium, the recording medium corresponds to a program recording medium.

[0108] The components of the detection device of each embodiment can be combined in any manner, and the components of the detection device of each embodiment may be realized by software or a circuit.

[0109] Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above-mentioned embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

[0110] This application claims priority based on Japanese Patent Application No. 2020-159315, filed on September 24, 2020, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0111] 10, 20, 30, 40, 50 Detection device 11, 21, 31, 41, 51 Imaging unit 12, 22, 32, 42, 52 heating section 18 Measuring tank 19 Oven 23 Lighting Department 29 Case 35, 45 Detector 111, 211, 311, 411 Infrared Sensor 112, 212, 312, 412 Lenses 113, 213, 313, 413 cooler 114, 214, 314, 414 Control unit 180, 190 Window material 230 light source 350, 450 display device 351, 451 Temperature control unit 352, 452 Imaging control unit 353, 453 Image processing unit 354, 454 Pattern detection unit 455 Feature Point Extraction Unit 456 Matching Department 470 Database

Claims

1. An imaging means having an infrared sensor having at least one infrared detection element that receives light in an infrared wavelength band in which a fatty acid ester compound exhibits infrared absorption characteristics; a heating means for controlling heating of an object on which traces originating from a human body are to be detected so as to maintain the object at a detection temperature suitable for fingerprint detection using the infrared sensor.

2. 2. The detection device of claim 1, wherein the trace is derived from at least one of a fingerprint, a palm print, a metacarpal print, a metacarpal print, a sole print, a toe print, an ear print, a nose print, a lip print, a forehead print, and a chin print.

3. 3. The detection apparatus according to claim 1, further comprising an illumination means for irradiating the infrared detection element with light in an infrared region having a detection wavelength band.

4. a detection means for controlling a set temperature of the heating means to heat the object and for controlling the imaging means to capture an image of the object, The detection means includes: Detecting the trace from the image captured by the imaging means; The detection device according to claim 1 , further comprising: a detection unit that outputs a detection result relating to the detected trace.

5. The detection means includes: Extracting feature points from the image captured by the imaging means; The detection device according to claim 4 , wherein the pattern of the trace is detected based on the extracted feature points.

6. The detection means includes: The detection device according to claim 4 or 5, wherein the heating means is controlled so as to increase the temperature of the object when the trace is not detected from the image captured by the imaging means.

7. The detection means includes: Searching a database containing comparison patterns of multiple people; detecting the control pattern from the database, the control pattern having feature points that are highly consistent with feature points of the pattern of the trace; 7. The detection device according to claim 6, further comprising an output section for outputting information relating to the detected control pattern.

8. controlling the heating means to heat the object to be detected for traces originating from the human body so as to maintain the object at a detection temperature suitable for fingerprint detection using light in an infrared wavelength range in which the fatty acid ester compound exhibits infrared absorption characteristics; controlling an imaging means having an infrared sensor having at least one infrared detection element that receives light in an infrared wavelength band in which the fatty acid ester compound exhibits infrared absorption characteristics, to image the object heated by the heating means; A detection method for detecting the trace remaining on the object.

9. Extracting feature points from the image captured by the imaging means; Detecting a pattern of the trace based on the extracted feature points; Searching a database that stores comparison patterns of multiple people to be used for matching; detecting the control pattern from the database, the control pattern having feature points that are highly consistent with feature points of the pattern of the trace; The detection method according to claim 8, further comprising the step of outputting information relating to the detected control pattern.

10. The object is subjected to a heat treatment in advance, 10. The detection method according to claim 8, wherein the object, which has been previously heat-treated, is heated to an appropriate temperature.

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