WO2022005121A1

WO2022005121A1 - Device for improving temperature accuracy of thermal imaging camera for detecting human body

Info

Publication number: WO2022005121A1
Application number: PCT/KR2021/008036
Authority: WO
Inventors: 최규태
Original assignee: 주식회사 웨이브아이알
Priority date: 2020-07-02
Filing date: 2021-06-25
Publication date: 2022-01-06
Also published as: KR102208150B1

Abstract

The present invention relates to a device for improving the temperature accuracy of a thermal imaging camera for detecting a human body, and provides a device for improving the temperature accuracy of a thermal imaging camera for detecting a human body, the device being capable of obtaining an accurate temperature value of a subject by converting the temperature value by using a deviation between a temperature data value of the subject, which is emitted from the subject and input to a temperature controller via a thermal image sensor, and a temperature data value input to the temperature controller via the thermal image sensor from a temperature adjusting device that is set to an arbitrary temperature within a human body temperature range. The technical configuration of the device for improving the temperature accuracy comprises: the thermal image sensor which detects an infrared ray image emitted from the subject and input through a lens, and then outputs the infrared ray image as an electrical signal; a temperature adjusting unit which is arranged on one side of the front surface of the lens and generates heat to a set temperature within the human body temperature range; and the temperature controller which measures the current temperature by using a deviation between the temperature data value of the subject input to the thermal image sensor and the set temperature data value of the temperature controller input to the thermal image sensor.

Description

Temperature accuracy improvement device of thermal imaging camera for human body detection

The present invention relates to an apparatus for improving the temperature accuracy of a thermal imager, and more particularly, the temperature data value detected by the thermal imager changes over time due to the temperature and noise around the camera, even for objects of the same temperature. Therefore, it is measured from the subject using the difference between the temperature data value of the subject emitted from the subject and input through the thermal image sensor and the temperature data value input through the thermal image sensor in the temperature control device that generates heat at an arbitrarily set temperature. The present invention relates to an apparatus for improving temperature accuracy of a thermal imaging camera for human body detection capable of improving temperature accuracy and precision.

In general, a thermal imaging camera is a camera that uses heat to photograph a subject, detects infrared rays emitted from the subject, measures the temperature, and visually displays the measured temperature as a color.

Unlike a general camera that has a structure similar to that of a human eye and captures an image similar to what a human sees, the thermal imaging camera detects the amount of infrared light that varies depending on the temperature generated on the surface of the subject and measures the temperature, It is expressed in different colors according to the measured temperature so that the human eye can see the difference in temperature.

Here, the thermal image is expressed as a color by recognizing the wavelength and the length of the wavelength of infrared rays that vary depending on the intensity of heat.

As described above, in a thermal imaging camera, light passing through an optical lens is converted into an electrical signal by a thermal imaging sensor incorporated in the camera.

In this case, the thermal image sensor is an infrared sensor that responds to infrared rays like a microbolometer, and has a structure that converts infrared energy passing through an optical lens into an electrical signal.

On the other hand, in the case of a general camera, an image sensor is built in instead of a thermal image sensor, so that light passing through an optical lens and an aperture is converted into a digital signal by an image sensor such as a CCD or CMOS sensor in the camera.

FIG. 1 shows that data output from a thermal image sensor changes with time when the temperature of a subject set at 37.5° C. is measured with a thermal imaging camera.

As shown in the figure, even when the same temperature is measured, the temperature data value output by the thermal image sensor changes over time due to environmental influences and characteristics such as ambient temperature and noise, and thus changes In order to accurately convert the temperature data value into a temperature value, a specific algorithm of the manufacturer must be used.

However, the manufacturer's algorithm is complex and at the same time it is difficult to convert data values that change depending on the surrounding environment and characteristics into accurate temperature values.

As such, in the case of the conventional thermal imaging camera, there is a problem in that it is difficult to calculate an accurate temperature value because the temperature data value changes depending on the surrounding temperature and characteristics when the temperature is measured by the thermal imaging sensor.

In addition, in order to improve the temperature accuracy through the conventional thermal imaging camera, it is corrected with Non-Uniformity Correction (NUC), which is an algorithm that basically corrects the deviation between sensor pixels to make it uniform, and then each manufacturer Although the temperature is displayed using the temperature extraction algorithm of

On the other hand, in order to solve the above-mentioned problems, "a device for measuring temperature data of a thermal imaging camera" is presented in Korean Patent Registration No. 10-1690096, an infrared ray that detects infrared rays emitted from a subject and outputs them as electrical signals A configuration in which an infrared blocking unit is installed in the sensor and a temperature sensor unit for measuring a temperature is provided in the blocking unit. The current temperature is calculated using the sensor pixel data value belonging to the first region, the data value of the sensor pixel belonging to the second region, and the value measured by the temperature sensor unit.

According to the configuration as described above, there is an advantage that the current temperature of the sensor pixel belonging to the first region to which infrared rays emitted from the subject are irradiated can be measured immediately without a stabilization time.

However, there is a problem in that accurate temperature measurement is difficult as the error range is large as ±2°C when measuring temperature within a wide temperature range of 0°C to 100°C.

On the other hand, since the first outbreak of Corona 19 (COVID-19), an infectious disease in Wuhan, China in 2019, it has spread all over China and the world, causing many confirmed cases and casualties until recently. Microorganisms, which are pathogens, are transmitted to living things and multiply to cause diseases, and they occur through various routes such as contact with other people.

As a result, the World Health Organization (WHO) declared COVID-19 a pandemic, the highest warning level of an infectious disease, that is, a global pandemic.

Here, Corona 19 is a respiratory infectious disease, and the pathogen is SARS-CoV-2 (SARS-CoV-2), and mainly spread by droplets of an infected person penetrating into the respiratory tract or the mucous membranes of the eyes, nose, and mouth. That is, it is spread by coughing or sneezing, or by touching a material contaminated with the virus and then touching your eyes, nose, and mouth.

Corona 19 is mainly expressed with respiratory symptoms such as fever, cough, sore throat, etc. Due to this, recently, religious organizations including churches, cathedrals, temples, schools, private institutes, kindergartens, daycare centers, libraries, corporate training centers, etc. educational institutions, including highway rest rooms, bus terminals, hotels, museums, resorts, theaters, convention centers, etc. Medical institutions including hospitals, clinics, and pharmacies, government offices including city and county offices, community centers, public health centers, police stations, cultural centers, military bases, and financial institutions including banks and securities companies, etc. A thermal imaging camera is being installed to identify a symptomatic person by measuring the body temperature of the person and checking whether the person has a fever.

As described above, there is a problem in that accurate body temperature measurement is difficult as it has a large error range of ±2°C based on 36.5°C, which is the normal body temperature of the human body, when measuring the body temperature of an occupant through the existing thermal imaging camera. There was a problem that the thermal imaging camera was difficult to perform as a quarantine to cope with COVID-19.

Therefore, compared to the existing thermal imaging camera that measures and detects the temperature within a wide range of 0°C to 100°C, the temperature within the body temperature range is more accurately detected when checking a fever to check whether an infectious disease is present or not. In addition, there is a need for a thermal imaging camera capable of improving the accuracy and precision of body temperature measurement by minimizing the error range.

The present invention was invented to improve the above problems, and a temperature control device that is set to an arbitrary temperature within the temperature range of the subject's temperature data value emitted from the subject and input to the temperature control unit through the thermal image sensor and the human body The purpose of the present invention is to provide an apparatus for improving the temperature accuracy of a thermal imaging camera for human body detection that can obtain an accurate temperature value of a subject by converting the temperature value using the deviation of the temperature data value input to the temperature controller through the thermal imaging sensor. .

In addition, the present invention provides an object that irregularly changes over time due to ambient temperature and noise using data input from the subject to the thermal image sensor and temperature data input to the thermal image sensor through the temperature control device. It is possible to improve the accuracy and precision of temperature measurement by correcting the temperature data value of It provides a device for improving the temperature accuracy of a thermal imaging camera for human body detection that enables immediate operation without stabilization time of the thermal imaging camera and can dramatically reduce mass production time by detecting only a specific temperature within the body temperature range. aim to

In addition, the technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned are clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. it could be

In order to achieve the above object, the present invention provides a thermal image sensor that detects an infrared image emitted from a subject and input through a lens and outputs an electrical signal; Doedoe disposed on the front side of the lens, a temperature control unit that generates heat to a temperature set within the body temperature range; and a temperature controller configured to measure a current temperature using a difference between a temperature data value of the subject input to the thermal image sensor and a temperature data value set by the temperature controller input to the thermal image sensor. It is characterized in that it includes.

Here, the temperature control unit is disposed to cover a predetermined area of the edge of the front part of the lens, and the temperature of the heating plate that generates heat at a temperature set by the temperature control unit and the heating plate that generates heat at the temperature set by the temperature control unit is constant. Includes thermostat.

In addition, the temperature control unit further includes a temperature sensor for detecting whether heat is constantly generated at a temperature set by the temperature control unit, the temperature sensor being provided at one side of the heating plate at least one or more to sense the temperature of the heating plate.

Preferably, the temperature controller includes first data, which is a temperature data value emitted from the subject and input to the thermal image sensor, and a first data value, which is a temperature data value input to the thermal image sensor from the temperature controller that generates heat to a temperature set within a temperature range of the human body. 2 Calculate the current temperature value by converting it to the conversion temperature using the deviation of the data.

Here, the formula for calculating the conversion temperature is as follows,

Conversion temperature = f(x) + thermostat temperature

The transformation expression f(x) can be obtained as a linear function or a quadratic function.

And, when the transformation expression f(x) is a linear function,

Conversion temperature = (ax + b) + thermostat temperature

x is the deviation of the first data and the second data,

a is a proportional coefficient for converting a deviation value into a temperature, indicating a slope, and may vary depending on the characteristics of the thermal image sensor, and b is a constant value, which may vary depending on the characteristics of the lens.

In addition, when the transformation expression f(x) is a quadratic function,

Conversion temperature = (ax ² + bx + c) + thermostat temperature

x is the deviation of the first data and the second data,

a, b, and c may vary depending on the characteristics of the thermal image sensor and the characteristics of the lens.

As described above, the present invention having the above configuration can improve the accuracy and precision of temperature measurement by correcting irregularly changing temperature data values to minimize the error range during temperature measurement through a thermal imaging camera, Temperature measurement by correcting the temperature data value that changes over time due to environmental factors such as ambient temperature and noise, and minimizing the error range of about ±2℃ to about ±0.5℃ It can have the effect of improving the accuracy and precision of viewing.

In addition, the present invention enables more accurate detection of temperature within the range of body temperature, and is used for measuring body temperature of various visitors who use and enter multi-use facilities including schools, service areas, churches, stores, and government offices. It is suitable, it can measure body temperature in a non-face-to-face manner and check whether there is a fever to prevent the spread of the virus. It is possible to measure temperature, so it is not mechanically complicated, manufacturing cost is low, it can be operated immediately without stabilization time, and it has the effect of drastically reducing mass production time by detecting only the temperature within the body temperature range. can reap

1 is a view showing the change in the temperature data value over time when measuring the temperature of a subject set at 37.5 ° C with a thermal imaging camera;

2 is a configuration diagram schematically showing an apparatus for improving temperature accuracy of a thermal imaging camera according to the present invention;

3 is a configuration diagram schematically showing a temperature control unit of the apparatus for improving temperature accuracy of a thermal imaging camera according to the present invention;

4 is a configuration diagram schematically showing the operation process of the apparatus for improving temperature accuracy of a thermal imaging camera according to the present invention;

5 is a front view schematically showing a state in which a heating plate is installed in the thermal image sensor of the device for improving temperature accuracy of a thermal imaging camera according to the present invention;

6 is a first data value that is a temperature data value input to a thermal image sensor from a subject set to 37.5°C through the temperature accuracy improving device of a thermal imaging camera according to the present invention, and a temperature controller set to 36.5°C input to the thermal image sensor A diagram showing a state in which a second data value, which is a temperature data value, changes as time elapses.

1: Temperature accuracy improvement device for thermal imaging camera for human body detection;

10: lens, 30: thermal image sensor,

50: temperature control unit, 51: heating plate,

53: temperature controller, 55: temperature sensor,

70: temperature control unit, 71: setting unit,

73: execution unit, 75: operation unit,

77: storage.

a thermal image sensor that detects an infrared image emitted from a subject and input through a lens and outputs an electrical signal; a temperature control unit disposed on one side of the front surface of the lens and generating heat to a temperature set within a body temperature range; and a temperature controller configured to measure a current temperature using a difference between a temperature data value of a subject input to the thermal image sensor and a temperature data value set by the temperature controller input to the thermal image sensor. It provides an apparatus for improving the temperature accuracy of a thermal imaging camera for human body detection comprising a.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement them. However, the present invention may be embodied in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is "connected" with another part, this includes not only the case of being "directly connected" but also the case of being "electrically connected" with another element interposed therebetween. . In addition, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated, and one or more other features However, it is to be understood that the existence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded in advance.

The terms "about", "substantially", etc. to the extent used throughout the specification are used in or close to the numerical value when manufacturing and material tolerances inherent in the stated meaning are presented, and are intended to enhance the understanding of the present invention. To help, precise or absolute figures are used to prevent unfair use by unconscionable infringers of the stated disclosure. As used throughout the specification of the present invention, the term "step of (to)" or "step of" does not mean "step for".

In this specification, a "part" includes a unit realized by hardware, a unit realized by software, and a unit realized using both. In addition, one unit may be implemented using two or more hardware, and two or more units may be implemented by one hardware.

Some of the operations or functions described as being performed by the terminal, apparatus, or device in the present specification may be performed instead of by a server connected to the terminal, apparatus, or device. Similarly, some of the operations or functions described as being performed by the server may also be performed in a terminal, apparatus, or device connected to the server.

In this specification, some of the operations or functions described as mapping or matching with the terminal means mapping or matching the terminal's unique number or personal identification information, which is the identification data of the terminal. can be interpreted as

In the present specification, the word “at least one” is defined as a term that can refer to a singular and a plural. Also, the term “at least one” may be used but may be omitted, and its meaning is the same as described above.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. 2 is a configuration diagram schematically showing an apparatus for improving temperature accuracy of a thermal imaging camera according to the present invention, and FIG. 3 is a configuration diagram schematically showing a temperature control unit of an apparatus for improving temperature accuracy of a thermal imaging camera according to the present invention, FIG. 4 is a configuration diagram schematically showing the operation process of the device for improving the temperature accuracy of a thermal imaging camera according to the present invention, and FIG. It is a schematic front view, and FIG. 6 is a first data value that is a temperature data value input to a thermal image sensor from a subject set to 37.5°C through the device for improving temperature accuracy of a thermal imaging camera according to the present invention, and a temperature controller set to 36.5°C It is a diagram illustrating a state in which a second data value, which is a temperature data value input to a thermal image sensor, changes as time elapses.

As shown in the drawing, the apparatus 1 for improving temperature accuracy of a thermal imaging camera for human body detection according to the present invention includes a thermal image sensor 30 , a temperature control unit 50 , and a temperature control unit 70 . do.

The thermal image sensor 30 detects an infrared image through the lens 10 to which infrared radiation emitted from a subject is input and outputs an electric signal.

The temperature control unit 50 is disposed on one side of the front surface of the lens 10 to generate heat at a set temperature within the body temperature range.

At this time, since the normal body temperature of the human body is 36.5°C, the temperature control unit 50 of the temperature accuracy improving device 1 of the thermal imaging camera for human detection according to the present invention generates heat only within a temperature range of 30°C to 40°C. It is preferable to do so, but it is not limited thereto.

Here, the temperature control unit 50 is controllably connected to the temperature control unit 70 and is set to a specific temperature within the temperature range of the human body by the temperature control unit 70, heats up at a set temperature, and returns to the set temperature. controlled to remain constant.

To this end, the temperature control unit 50 is configured to include a heating plate 51 and a temperature control device (53).

The heating plate 51 is disposed on one side of the front part of the lens 10 , is disposed to cover a predetermined area of the edge of the lens 10 , and is heated to a temperature set by the temperature control unit 70 , the temperature control unit By applying a voltage through 70, it is heated to a set temperature within the human body range.

Here, the heating plate 51 is formed of a plate body, is made of a Peltier material, is made to be set to a specific temperature by application of a voltage, and is preferably made of a substantially rectangular plate body in order to cover a predetermined area of the lens 10. , but not limited thereto.

On the other hand, the heating plate 51 is installed on any one edge or two or more edges of the lower portion, upper portion, left portion, or right portion of the front surface of the lens 10 and is preferably disposed to cover a predetermined area of the lens 10 . , but not limited thereto.

In this case, when the lens 10 is disposed in a predetermined area on the front surface of the lens 10 through the heating plate 51 , the interference range that covers the lens 10 can be variously changed according to the characteristics and environment of the product.

In addition, the heating plate 51 is configured to be disposed to be in contact with the front surface of the lens 10 or to be disposed to be spaced apart from the front surface of the lens 10 by a predetermined interval.

The temperature control device 53 constantly adjusts the temperature of the heating plate 51 that generates heat to a temperature set within the temperature range of the human body through the temperature control unit 70 .

That is, the temperature controller 53 controls the temperature of the heating plate 51 so that the heating plate 51 that is set to a specific temperature within the temperature range of the human body through the temperature control unit 70 constantly heats at the set temperature. Regulate and control.

In this way, when the temperature controller 53 sets the heating plate 51 to heat to a specific temperature selected within the body temperature range through the temperature control unit 70, the heating plate ( 51) to regulate and control the temperature.

In an embodiment of the present invention, the temperature control device 53 is configured to adjust and control the temperature of the heating plate 51 that generates heat to a temperature set by the temperature control unit 70 to be kept constant, but the temperature control device ( 53 , it is also possible to adjust and control the temperature of the heating plate 51 to be kept constant and to feed back the temperature value of the heating plate 51 to the temperature controller 70 .

Meanwhile, the heating plate 51 of the temperature controller 50 further includes a temperature sensor 55 to detect whether the heating plate 51 is heating at a temperature set by the temperature controller 70 .

That is, at least one temperature sensor 55 is provided on one side of the heating plate 51 , and the temperature sensor 55 determines whether the heating plate 51 is generating heat at a temperature set through the temperature control unit 70 . Sensing is performed in real time, and the sensed value is fed back to the temperature controller 70 in real time.

As described above, the heating plate 51 is provided with a temperature sensor 55 to detect whether the heating plate 51 generates heat at a temperature set through the temperature control unit 70, and according to the detected value, When the temperature is different from the temperature set by the temperature control unit 70, the temperature control unit 70 adjusts the voltage applied to the heating plate 51 to uniformly and constant the temperature of the heating plate 51 to the initially set temperature. made to be controlled.

Meanwhile, the apparatus 1 for improving temperature accuracy of a thermal imaging camera for human body detection according to the present invention may further include a non-uniformity correcting unit (not shown).

The non-uniformity corrector removes noise from the infrared image to improve the image quality, but improves the image quality by non-uniformity correction (NUC) on the image signal output from the thermal image sensor 30 . Since it is a general function to improve, a detailed description will be omitted below.

The temperature controller 70 corrects a temperature value through a difference between a temperature data value input from the subject to the thermal image sensor 30 and a temperature data value input from the temperature controller 50 to the thermal image sensor 30 . to output the thermal image and temperature data.

And, the temperature control unit 70 sets the temperature on the heating plate 51 of the temperature control unit 50, but is configured to set within the temperature range of the human body, and the temperature control unit 53 and the temperature sensor 55 ) through which the set temperature value of the heating plate 51 is fed back.

To this end, the temperature control unit 70 includes a setting unit 71 , an execution unit 73 , an operation unit 75 , and a storage unit 77 .

The setting unit 71 sets the temperature of the heating plate 51 . At this time, the setting unit 71 is preferably configured to be set within the temperature range of the human body, but more preferably, the setting unit 71 sets the heating plate 51 within a temperature range of 30°C to 40°C. made to do

The execution unit 73 applies a voltage to the heating plate 51 to generate heat at a temperature set through the setting unit 71 .

The calculating unit 75 includes a temperature data value through a pixel data value of the sensor input through the thermal image sensor 30 and a thermal image sensor ( 30) calculates and calculates the exact temperature value of the subject by using the deviation of the temperature data value through the pixel data value of the sensor input through .

The storage unit 77 stores the temperature data value and the temperature value calculated and calculated through the operation unit 75 , and the temperature data value input through the thermal image sensor 30 and the temperature control unit 50 . The temperature data value input through the thermal image sensor 30 is stored, and the set temperature of the heating plate 51 is stored.

Here, the storage unit 77 is a storage module that can input/output information such as a flash memory, a compact flash card (CF card), and a secure digital card (SD card), and is provided inside the thermal imaging camera. may be provided, or may be provided in a separate device.

Religious organizations including churches, cathedrals, temples, etc., schools, private institutes, kindergartens, daycare centers, libraries, corporate training centers, etc. Educational institutions, including highway rest rooms, bus terminals, hotels, museums, resorts, theaters, convention centers, etc. Medical institutions including hospitals, clinics, and pharmacies; public offices including city and county offices, community centers, public health centers, police stations, cultural centers, military bases, etc.; and financial institutions including banks and securities companies. After installation, check whether the occupant or mover has a fever.

At this time, the temperature data value of the infrared image emitted from the subject and input through the lens 10 is input to the thermal image sensor 30, and the temperature is set through the temperature control unit 70 through the temperature control unit 50 The temperature data value of the input infrared image is input to the lens 10 and the thermal image sensor 30 , and the temperature controller adjusts the difference between the temperature data value input from the subject and the temperature data value input from the temperature controller 50 . Calculate the converted temperature in addition to the temperature set in (50).

An example will be described in more detail with reference to FIGS. 4 to 6 , and the subject will be limited to a person.

Although the normal body temperature of the human body is 36.5°C, fever symptoms are mainly expressed in cases of suspected or infected persons suspected of being infected with respiratory infectious disease symptoms.

If a suspected symptom or infected person whose body temperature exceeds the normal body temperature range of 37.5°C is photographed, the temperature data value of the suspected symptom or infected person is input to the thermal imaging sensor 30 through the lens 10 and then the temperature controller A thermal image and a temperature value of 37.5 ° C should be output through 70, but the temperature value is the same as time passes due to ambient temperature or environmental influences, whereas the thermal image sensor 30 through the lens 10 The temperature data value of the subject input as ' is irregularly changed, so that the temperature controller 70 has an actual temperature value of 37.5°C, not a temperature data value having a temperature value of 37.5°C, 36.5°C or 38.5°C It is recognized as a temperature data value having a different temperature value such as °C, and when checking a fever, a thermal image can be displayed at a different temperature value such as 36.5 °C or 38.5 °C, or other temperature values such as 36.5 °C or 38.5 °C can be output.

Therefore, when detecting the body temperature of a subject through the temperature accuracy improving device 1 of the thermal imaging camera for detecting a human body according to the present invention, first, the temperature control unit ( 50), the temperature of the heating plate 51 is set to 36.5 ℃, and then the shooting proceeds.

In this way, when the temperature of the heating plate 51 is set to 36.5° C. through the setting unit 71 of the temperature control unit 70 and then the heating plate 51 is heated to 36.5° C. through the execution unit 73, The calculator 75 of the temperature controller 70 includes a first data value that is a temperature data value input from the subject to the thermal image sensor 30 and a second data value that is a temperature data value that is input from the heating plate 51 to the thermal image sensor 30 . After receiving the data value, the first data value and the second data value are non-uniformly corrected (NUC) to correct the deviation between the sensor pixels, and after correcting the lens deviation, the deviation of the first data value and the second data value An accurate temperature value of the subject may be obtained by converting the temperature of the subject compared to the temperature controller 50 using the value.

That is, when photographing a suspected or infected person whose body temperature exceeds the normal body temperature range of 37.5°C, the temperature data value of the suspected or infected person is input to the thermal imaging sensor 30 through the lens 10. The first data value, which is the temperature data value, and the second data value, which is the temperature data value of 36.5° C. input from the heating plate 51 that generates heat at a set temperature, to the lens 10 and the thermal image sensor 30, are compensated for non-uniformity (NUC) by the sensor After correcting the deviation between the pixels and correcting the lens deviation, the first data value that is the temperature data value according to 37.5° C. of the subject and the temperature data value according to 36.5° C. of the heating plate 51 of the temperature controller 50 are The deviation of the second data value is calculated, and the converted temperature of the object is calculated through the calculated deviation value of the object and the temperature controller 50 .

Conversion temperature = f(x) + temperature of thermostat (°C)

Here, the conversion equation f(x) represents a deviation value between a first data value input from the subject to the thermal image sensor 30 and a second data value input from the temperature controller 50 to the thermal image sensor 30 . .

For example, first, the temperature range to be corrected is set according to the difference between the temperature data value input from the subject to the thermal image sensor 30 and the temperature data value input from the temperature controller 50 to the thermal image sensor 30 . Then, the conversion temperature is calculated using the temperature value according to the deviation of the data value as the correction temperature value.

That is, the temperature value according to the deviation of the first data value and the second data value is first set, and a correction value of 1°C is set for every 10 deviations of the first data value and the second data value, and the thermal image from the subject is set. The first data value, which is a temperature data value of 37.5° C. input to the sensor 30, is 60, and the second data value, which is a temperature data value of 36.5° C. input from the temperature controller 50 to the thermal image sensor 30, is 50 days. case,

Conversion temperature = f(x) + temperature of thermostat (°C)

= (60 - 50) + temperature of the temperature control unit (℃)

Deviation value = first data - second data

= 60 - 50 = 10

Here, when the deviation value is 10, if it is set as a correction value of 1℃,

= 1℃ + 36.5℃

= 37.5℃

can be calculated, and therefore it can be seen that the temperature value according to the temperature data value input from the subject to the thermal image sensor 30 is accurate to 37.5°C.

On the other hand, a correction value of 1°C per 10 deviations of the first data value and the second data value is set, and the first data value, which is a temperature data value of 37.5°C input from the subject to the thermal image sensor 30, is 70, , when the second data value, which is a temperature data value of 36.5° C. input from the temperature controller 50 to the thermal image sensor 30, is 50,

Conversion temperature = f(x) + temperature of thermostat (°C)

= (70 - 50) + temperature of the temperature control unit (℃)

Deviation value = first data - second data

= 70 - 50 = 20

Here, when the deviation value is 20, if it is set as a correction value of 2℃,

= 2℃ + 36.5℃

= 38.5°C

can be calculated, and therefore it can be calculated that the temperature value according to the temperature data value input from the subject to the thermal image sensor 30 is actually 38.5°C instead of 37.5°C.

At this time, since the first data value that is the temperature data value of the subject and the second data value that is the temperature data value of the temperature controller 50 are both under the same characteristics and environment, the first data value and the second data value that change over time The data value changes as shown in FIG. 5 , and in this case, the first data value and the second data value do not change in the same way, but the deviation between the first data value and the second data value is almost constant under the same condition. changes, and through this, the temperature of the subject can be converted to improve the accuracy of the temperature.

Such correction of the temperature value is performed after correcting the non-uniformity correction (NUC) and the lens deviation.

Meanwhile, the above-described transformation expression f(x) may be calculated as a first-order function, a second-order function, or a function of higher order. That is, various variables may occur when measuring the subject's temperature due to environmental factors such as the ambient temperature of the subject being photographed, and product characteristics such as lens distortion. It can be calculated as a function.

Here, when the transformation expression f(x) is expressed as a linear function,

It can be expressed as f(x) = ax + b,

Conversion temperature = (ax + b) + temperature of thermostat (°C)

can be expressed as

where x is the deviation between the first data and the second data,

a is the proportionality coefficient for converting the deviation value into temperature, representing the slope,

b is a constant value.

In this case, a varies according to the characteristics of the thermal image sensor, and b varies according to hardware characteristics such as lens characteristics according to distortion and smoothing of the lens.

Deviation value = first data - second data

= 60 - 50 = 10

Conversion temperature = (ax + b) + temperature of thermostat (°C)

In this case, it is assumed that the slope is 1, and the first data value input from the subject to the thermal image sensor 30 and the second data value input from the temperature controller 50 to the thermal image sensor 30 are under the same condition. So, when calculating with b = 0,

Conversion temperature = {gradient × (first data value - second data value)} + temperature of temperature controller (°C)

= (1 × 1℃) + 36.5℃

= 37.5℃

On the other hand, a correction value of 1°C per 10 deviations of the first data value and the second data value is set, and the first data value, which is a temperature data value of 37.5°C input from the subject to the thermal image sensor 30, is 70, , the second data value, which is a temperature data value of 36.5° C. input from the temperature controller 50 to the thermal image sensor 30 , is 50, in this case, the slope is 1, and the first inputted from the subject to the thermal image sensor 30 . Assuming that the data value and the second data value input from the temperature controller 50 to the thermal image sensor 30 are under the same condition, b = 0,

Conversion temperature = (ax + b) + temperature of thermostat (°C)

= {1 × (70 - 50) + 36.5°C}

Deviation value = first data - second data

= 70 - 50 = 20

= (1 × 20) + 36.5℃

= (1 × 2℃) + 36.5℃

= 38.5°C

On the other hand, when the transformation expression f(x) is expressed as a quadratic function,

It can be written as f(x) = ax ² + bx + c,

Conversion temperature = (ax ² + bx + c) + temperature of thermostat (°C)

can be expressed as

where x is the deviation between the first data and the second data,

a, b, and c vary depending on the characteristics of the hardware, such as the characteristics of the thermal image sensor and lens. That is, when the temperature data value that changes within the temperature range of the human body, for example, within the range of 30°C to 40°C, appears in the form of a quadratic function, according to the characteristics of the hardware including the characteristics of the thermal image sensor and the characteristics of the lens. The values of a, b and c can be determined.

As mentioned above, although the present invention has been shown and described in relation to specific embodiments, it is common knowledge in the art that various modifications and changes are possible without departing from the spirit and scope of the invention as set forth in the appended claims. Anyone who has it will know it easily.

According to the present invention, the temperature of the subject that changes irregularly over time due to ambient temperature and noise using data input from the subject to the thermal image sensor and the temperature data value input to the thermal image sensor through the temperature controller By correcting the data value, it is possible to improve the accuracy and precision of temperature measurement by minimizing the error range when measuring the temperature of the human body through a thermal imaging camera. Immediate operation is possible without the stabilization time of the thermal imaging camera, and by detecting only a specific temperature within the body temperature range, the mass production time can be drastically reduced. This is an optimal invention that can obtain an accurate temperature value of a subject by using the deviation of the temperature data input to the temperature controller.

Claims

a thermal image sensor that detects an infrared image emitted from a subject and input through a lens and outputs an electrical signal;

a temperature control unit disposed on one side of the front surface of the lens and generating heat to a temperature set within a body temperature range; and

a temperature controller configured to measure a current temperature using a difference between a temperature data value of a subject input to the thermal image sensor and a temperature data value set by the temperature controller input to the thermal image sensor;

Temperature accuracy improvement device of a thermal imaging camera for human body detection, characterized in that it comprises a.
The method according to claim 1,

The temperature control unit,

A temperature control device arranged to cover a predetermined area of the edge of the front part of the lens, and controlling the temperature of the heating plate heating to a temperature set by the temperature control unit and the heating plate heating to a temperature set by the temperature control unit to be constant Temperature accuracy improvement device of a thermal imaging camera for human body detection, characterized in that it comprises a.
3. The method according to claim 2,

The temperature control unit,

A temperature sensor for detecting whether heat is constantly generated at a temperature set by the temperature controller is further included, wherein at least one temperature sensor is provided on one side of the heating plate to sense the temperature of the heating plate A device for improving the temperature accuracy of a thermal imaging camera for human body detection.
The method according to claim 1,

The temperature control unit,

Conversion using the difference between the first data, which is the temperature data value emitted from the subject and input to the thermal image sensor, and the second data, which is the temperature data value input to the thermal image sensor from the temperature controller that generates heat at a set temperature within the body temperature range A device for improving the temperature accuracy of a thermal imaging camera for human body detection, characterized in that the current temperature value is calculated by converting the temperature.
5. The method according to claim 4,

The formula for calculating the conversion temperature is as follows,

Conversion temperature = f(x) + thermostat temperature

The conversion formula f(x) is an apparatus for improving temperature accuracy of a thermal imaging camera for human body detection, characterized in that it can be obtained as a first-order function or a second-order function.
6. The method of claim 5,

When the above conversion expression f(x) is a linear function,

Conversion temperature = (ax + b) + thermostat temperature

Where x is the deviation of the first data and the second data,

Where a is a proportional coefficient for converting a deviation value into a temperature, indicating a slope, and may vary depending on the characteristics of the thermal image sensor,

Wherein b is a constant value, the apparatus for improving temperature accuracy of a thermal imaging camera for human body detection, characterized in that it may vary depending on the characteristics of the lens.
6. The method of claim 5,

When the transformation expression f(x) is a quadratic function,

Conversion temperature = (ax 2 + bx + c) + thermostat temperature

Where x is the deviation of the first data and the second data,

wherein a, b, and c may vary depending on the characteristics of the thermal image sensor and the characteristics of the lens.