Low-cost thermo-electric infrared FPAs and their automotive applications

Masaki Hirota, Yoshimi Ohta, Yasuhiro Fukuyama

Research output: Chapter in Book/Report/Conference proceedingConference contribution

11 Citations (Scopus)

Abstract

This paper describes three low-cost infrared focal plane arrays (FPAs) having a 1,536, 2,304, and 10,800 elements and experimental vehicle systems. They have a low-cost potential because each element consists of p-n polysilicon thermocouples, which allows the use of low-cost ultra-fine micro-fabrication technology commonly employed in the conventional semiconductor manufacturing processes. To increase the responsivity of FPA, we have developed a precisely patterned Au-black absorber that has high infrared absorptivity of more than 90%. The FPA having a 2,304 elements achieved high resposivity of 4,300 V/W. In order to reduce package cost, we developed a vacuum-sealed package integrated with a molded ZnS lens. The camera aiming the temperature measurement of a passenger cabin is compact and light weight devices that measures 45 × 45 × 30 mm and weighs 190 g. The camera achieves a noise equivalent temperature deviation (NETD) of less than 0.7°C from 0 to 40°C. In this paper, we also present a several experimental systems that use infrared cameras. One experimental system is a blind spot pedestrian warning system that employs four infrared cameras. It can detect the infrared radiation emitted from a human body and alerts the driver when a pedestrian is in a blind spot. The system can also prevent the vehicle from moving in the direction of the pedestrian. Another system uses a visible-light camera and infrared sensors to detect the presence of a pedestrian in a rear blind spot and alerts the driver. The third system is a new type of human-machine interface system that enables the driver to control the car's audio system without letting go of the steering wheel. Uncooled infrared cameras are still costly, which limits their automotive use to high-end luxury cars at present. To promote widespread use of IR imaging sensors on vehicles, we need to reduce their cost further.

Original languageEnglish
Title of host publicationInfrared Technology and Applications XXXIV
DOIs
Publication statusPublished - Jun 30 2008
Externally publishedYes
EventInfrared Technology and Applications XXXIV - Orlando, FL, United States
Duration: Mar 17 2008Mar 20 2008

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume6940
ISSN (Print)0277-786X

Other

OtherInfrared Technology and Applications XXXIV
CountryUnited States
CityOrlando, FL
Period3/17/083/20/08

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All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Cite this

Hirota, M., Ohta, Y., & Fukuyama, Y. (2008). Low-cost thermo-electric infrared FPAs and their automotive applications. In Infrared Technology and Applications XXXIV [694032] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 6940). https://doi.org/10.1117/12.780725