• Journal of Sensor Science and Technology
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• v.20 no.2
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• pp.114-117
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• 2011

A thick 25 ${\mu}m$ thickness poled P(VDF/TrFE) film pyroelectric infrared ray sensor has been fabricated and then thin 1.6 ${\mu}m$ thickness P(VDF/TrFE) film pyroelectric infrared ray sensor has been fabricated also. These thick and thin P(VDF/TrFE) film pyroelectric infrared ray sensor was mounted in TO-5 housing to detect infrared light of 5.5 ~ 14 ${\mu}m$ wavelength for human body detecting with each other. The noise output voltage of the thick P(VDF/TrFE) film pyroelectric infrared ray sensor were 380 mV and NEP(noise equivalent power) is $3.95{\times}10^{-7}$ W which is the similar value with the commercial pyroelectric infrared ray sensor using ceramic materials as a sensing material. The NEP and specific detectivity $D^*$ of the thin P(VDF/TrFE) film pyroelectric infrared ray sensor were $2.13{\times}10^{-8}$ W and $9.37{\times}106$ cm/W under emission energy of 13 ${\mu}W/cm^2$ respectively. These result caused by lower thermal diffusion coefficient of a thin 1.6 ${\mu}m$ thickness PVDF/TrFE film than the thick 25 ${\mu}m$ thickness poled P(VDF/TrFE) film pyroelectric infrared ray sensor.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_2
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• pp.1073-1082
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• 2023

Thermal sensors, also called thermal infrared wavelength sensors, measure temperature based on the intensity of infrared signals that reach the sensor. The infrared signals recognized by the sensor include infrared wavelength(0.7~3.0㎛) and radiant infrared wavelength(3.0~100㎛). Infrared(IR) wavelengths are divided into five bands: near infrared(NIR), shortwave infrared(SWIR), midwave infrared(MWIR), longwave infrared(LWIR), and far infrared(FIR). Most thermal sensors use the LWIR to capture images. Thermal sensors measure the temperature of the target in a non-contact manner, and the data can be affected by the sensor's viewing angle between the target and the sensor, the amount of atmospheric water vapor (humidity), air temperature, and ground conditions. In this study, the characteristics of three thermal imaging sensor models that are widely used for observation using unmanned aerial vehicles were evaluated, and the optimal application field was determined.

• Journal of Sensor Science and Technology
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• v.27 no.1
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• pp.47-54
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• 2018

In this paper, we describe the thermal characteristics of the output voltages of ethanol gas sensor according to the amount of radiation incident on the infrared sensors located at each focal point of two elliptical waveguides. In order to verify the output characteristics of the gas sensor according to the amount of incident light on the infrared sensor, two combinations of sensor modules were fabricated. Hydrophobic thin film is deposited on one of the reflectors of sensor modules and one of the two infrared sensors was equipped with a hollow disk (10 Ø), and the temperature characteristics of the infrared sensor equipped with the hollow disk (10 Ø) and the infrared sensor without the disk were tested. The temperature was varied from 253 K to 333 K at 10 K intervals based on 298 K. The properties of ethanol gas sensor have been identified with respect to varying temperature for a range of ethanol concentration from 0 ppm to 500 ppm. In the case of an infrared sensor equipped with a hollow disk (10 Ø), the output voltage of the sensor decreased by 0.8 mV and 1 mV, respectively, as the temperature increased. Conversely, the output voltage of the diskless infrared sensor showed an average increase of 67 mV and 57 mV as the temperature increased. The ethanol concentrations estimated on the basis of results show an error of more than 10 % for less than 100 ppm concentration. However, if the ethanol concentration exceeds 100 ppm, the gas concentration can be estimated within the range of ${\pm}10%$.

• Journal of IKEEE
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• v.22 no.4
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• pp.907-915
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• 2018

This paper proposes a method to improve the performance of low cost infrared distance sensor. Infrared distance sensor measures the intensity of reflected light and converts it into distance. The proposed method improves the sensing distance of the sensor and makes it operate robustly in various lighting environments. This is achieved by extracting the characteristic curves of the sensor and applying the HDR (High Dynamic Range) technique. The output value of the sensor was obtained by varying the intensity of the infrared input and the exposure time, and the characteristic curve of the sensor was extracted from it.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.423-423
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• 2000

This paper proposes an effective algorithm for following a wall by an autonomous mobile robot with sonar sensors and infrared sensors in an indoor environment. The proposed method uses deadreckoning to estimate the current position and orientation of a mobile robot. Sonar sensor data are used to estimate shape and position of wall using proposed algorithm. Infrared sensor data are used as assistant when sonar sensor data is uncertain. Simulation results using mobile robot show that the proposed algorithm is proper for the following wall.

• Journal of Sensor Science and Technology
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• v.16 no.5
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• pp.331-336
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• 2007

In this study, we have fabricated an infrared optical fiber based sensor which can monitor the respiration of a patient. The design of a chalcogenide optical fiber based sensor is suitable for insertion into a high electro-magnetic field environment because the sensor consists of low cost and compact mid-infrared components such as an infrared light source, a chalcogenide optical fiber and a thermopile sensor. A fiber-optic respiration sensor is capable of detecting carbon dioxide ($CO_{2}$) in exhalation of a patient using the infrared absorption characteristics of carbon gases. The modulated infrared radiation due to the presence of carbon dioxide is guided to the thermopile sensor via a chalcogenide receiving fiber. It is expected that a mid-infrared fiber-optic respiration sensor which can be developed based on the results of this study would be highly suitable for respiration measurements of a patient during the procedure of an MRI.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.464-467
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• 2004

An uncooled infrared sensor has been prepared with sputtering, plasma ash, ICP, and PECVD on a Si wafer In order to analyze the resistance characteristics with the bridge length in the infrared sensor, three samples were prepared with lengths of 0 (no bridge), 15 (short bridge), and 29 urn (long bridge), respectively. I-V curves were measured for their resistance characteristics and EPMA for the dopping concentration of the amorphous Si. The phosphorus concentration was about 4 % and the resistance was increased with the bridge length. The bridge length of cantilever is very important factor for improvement of the efficiency in an infrared sensor.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.8
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• pp.1461-1465
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• 2007

A micromachined sensor part for an infrared focal plane array has been designed and fabricated. Amorphous silicon was adapted as a sensing material, and silicon nitride was used as a membrane material. To get a good efficiency of infrared absorption, the sensor was made as a ${\lambda}/4$ cavity structure. All the processes were done in $0.5\;{\mu}m$ iMEMS fab. in the Electronics and Telecommunication Research Institute (ETRI). The processed MEMS sensor structure had a small membrane deflection less than $0.3\;{\mu}m$. This excellent deflection property can be attributed to the rigorous balancing of the stresses of individual layers. The efficiency of infrared absorption was more than 75% in the wavelength range $8\;-\;14\;{\mu}m$.

• Journal of Sensor Science and Technology
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• v.30 no.1
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• pp.36-41
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• 2021

The motivation of this paper is to easily analyze the properties of nondispersive infrared gas sensor that has more than two different optical path length and to suggest the criterion and definition of infrared light absorbance in order to minimize the measurement errors. With the output voltage ratios and the normalized derivatives of infrared ray (IR) absorbance, when the normalized derivatives of IR absorbance decreases from 0.28 to 0.10, the lower and higher limits of errors were decreased from -5.62% and 2.39% to -4.27% and 2.78%. When the normalized derivatives of IR absorbance were 0.10, the output voltage could be partitioned into two regions with one exponential equation and the temperature compensation error was less than 5%.

• Journal of Industrial Technology
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• v.29 no.A
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• pp.77-82
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• 2009

In this paper, we implement a virtual keyboard using infrared distance sensor. A virtual keyboard allows a user to enter characters by selecting keyboard layouts with sensing areas. By projecting infrared light on any flat surface and detection devices we can sense the user's input characters. Unlike a conventional physical keyboard, the virtual keyboard provides convenience in terms of mobility, portability, and space savings.