• Korean Journal of Optics and Photonics
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• v.28 no.5
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• pp.241-249
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• 2017

This paper presents the design and evaluation of the optical system for an uncooled thermal-imaging camera. The operating wavelength range of this system is from $7.7{\mu}m$ to $12.8{\mu}m$. Through optimization, we have obtained a LWIR (Long Wave Infrared) optical system with a focal length of 5.44 mm, which consists of four aspheric surfaces and two diffractive surfaces. The f-number of the optical system is F/1.2, and its field of view is $90^{\circ}{\times}67.5^{\circ}$. The hybrid lens was used to balance the higher-order aberrations, and its diffraction properties were evaluated by scalar diffraction theory. We calculated the polychromatic integrated diffraction efficiency, and the MTF drop generated by background noise. We have evaluated the thermal compensation of a LWIR fixed optical system, which is optically passively athermalized to maintain MTF performance in the focal depth. In conclusion, these design results are useful for an uncooled thermal-imaging camera.

• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.904-910
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• 2017

This paper presents temperature measurement of solar photovoltaic modules using the custom-made system composed of an infrared temperature sensor and a microcontroller. The obtained measurement results are processed, displayed and stored on a PC using the custom-made virtual instrument. The proposed system overcomes some of the problems related to the contact sensor application, and at the same time offers accurate readings and better flexibility. The proposed system is especially suitable for applications where the cost is a limiting factor in the choice of measuring system. The conducted analysis and the obtained results have shown an excellent accuracy of the proposed system in comparison to a high quality thermal imaging camera used as the reference instrument.

• Korean Journal of Optics and Photonics
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• v.5 no.2
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• pp.212-216
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• 1994

We have designed and constructed a scanner optics for thermal imaging system operating in 8 - 12 /lfll band. The scanner consists of rotating polygon and oscillating mirror for serial-parallel scan using 5 elements SPRITE HgCdTe. A spherical mirror is used for scan relay mirror to minimize size of the scan mirrors and pupil aberration. The scanner has $40^{\circ}\times26.67^{\circ}$ wide scan field of view and the calculated diffraction MTF shows diffraction limited performance. As a result we have obtained high resolution thermal image. image.

• Journal of Acupuncture Research
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• v.15 no.2
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• pp.301-310
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• 1998

Infrared thermographic imaging visualizes noninvasively various abnormal condition by detecting the skin temperature. As the imaging represents the objective condition by the changes in blood flow under the control of autonomic nervous system, it is used to diagnosis and monitor the lumboscral radiculopathy. And asymmetry is important in the diagnosis of disc herniation. The most common type of disc herniation occurs psoterolaterally. This frequently causes nerve root compression leading to a radiculopathy in the distribution of the involved nerve root, most of which also provoke the asymmetric changes in thermography. Central disc herniation, which accounts for 5% to 35% of disc herniation, is typically associated with low back pain. But radiculopathy is usually abscent unless central disc heriniaton is large enough to cause compression of the cauda equina. To evalute the diagnostic value of the thermographic imaging in the diagnosis of central disc herniation, the imaging of 15 normal subjects and 48 patients with central disc herniation documented by CT scan were analyzed. The patients had either bilateral radiculophathy or no radiculopathy. The imaging of patient group with non rediculopathy did not show any significant thermal difference to control. While bilateral radiculopathy group reveled hypothermic pattern compared twith control. Thermal difference between left and right side did not present any significance in non radiculopathy group but hypothermia in bilateral radiculopathy group. Large herniation group demonstrated hyperthemic pattern while the others showed no significant change. Cranial caudal thermal difference did not show any difference between experiment groups. These results shows that infrared thermographic imaging can be used central disc herniation with bilateral radiculopathy, while it seems to little useful on the diagnosis of non radiculopathic disc herniation.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_2
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• pp.707-713
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• 2021

Symptoms of foot-and-mouth disease include fever and drooling a lot around the hoof, blisters in the mouth, poor appetite, blisters around the hoof, and blisters around the hoof. Research is underway on smart barns that remotely manage these symptoms through cameras. Visible light cameras can measure the condition of livestock such as blisters, but cannot measure body temperature. On the other hand, infrared thermal imaging cameras can measure body temperature, but it is difficult to measure the condition of livestock. In this paper, we propose an object detection system using deep learning-based livestock detection using visible and infrared thermal imaging composite camera modules for preemptive response

• Proceedings of the Optical Society of Korea Conference
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• 2001.08a
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• pp.208-209
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• 2001

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.5 s.347
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• pp.182-188
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• 2006

In this study, we have designed the millimeter-wave passive imaging system which records energy that is reflected or emitted from the source and produces image. The lens and front-end of receiver appeared to be important in the system to detect input thermal noise signal. The lens for signal focusing has been designed by optical transfer function. Amplifier of the imaging systemhas been set up with 40dB in maximum gain, 5 dB in maximum noise figure, and 10GHz in bandwidth to enhance sensitivity for thermal noise and to receive it in wide-band width as well. The SBD MSS-20 141B10D diode has been used for the detector circuit to convert amplified millimeter-wave signals to DC output.

• Current Optics and Photonics
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• v.6 no.1
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• pp.69-78
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• 2022

A high-resolution camera is a precise optical system. Its vibrations during transportation and launch, together with changes in temperature and gravity field in orbit, lead to different degrees of defocus of the camera. Thermal refocusing is one of the solutions to the problems related to in-orbit defocusing, but there are few relevant thermal refocusing mathematical models for systematic analysis and research. Therefore, to further research thermal refocusing systems by using the development of a high-resolution micro-nano satellite (CX6-02) super-resolution camera as an example, we established a thermal refocusing mathematical model based on the thermal elasticity theory on the basis of the secondary mirror position. The detailed design of the thermal refocusing system was carried out under the guidance of the mathematical model. Through optical-mechanical-thermal integration analysis and Zernike polynomial calculation, we found that the data error obtained was about 1%, and deformation in the secondary mirror surface conformed to the optical index, indicating the accuracy and reliability of the thermal refocusing mathematical model. In the final ground test, the thermal vacuum experimental verification data and in-orbit imaging results showed that the thermal refocusing system is consistent with the experimental data, and the performance is stable, which provides theoretical and technical support for the future development of a thermal refocusing space camera.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.4
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• pp.90-96
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• 2006

Computer simulation was carried out to develop the tracer composition of a high performance to be able to be observed by not only the naked eye but also the thermal imaging system attached to the weapon system. The results of computer simulation show that the optimum Mg content among the trace compositions is about 40% and the formulation consisted of Viton A has a higher flame temperature compared with that of chloride compound. But the only use of Viton A radiates a yellow light and the composition adding a chloride compound radiates the red light. The light intensity of the tracer composition involving Viton A is higher than that of chloride compound. The tracer composition involving Viton A shows more clear images in case of all tests.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1043-1044
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• 2008

In this study, a novel algorithm of the improvement residual non-uniformity (RNU) in thermal imaging system is proposed using correlated double sample signal processing. The proposed method attempts to eliminate offset variation of ROIC in IR detector causing the variation of FPA (focal plane array) temperature and suppling power. Experimental results show that the proposed method confirmed a better performance than the existing RNU system.