Development of a micro-optical distance sensor

Sensors and Actuators A 102 (2003) 261–267

Development of a micro-optical distance sensor Toru Okaa,*, Hajime Nakajimab, Masahiro Tsugaia, Uwe Hollenbachc, Ulrike Wallrabec, Ju¨rgen Mohrc a

Mitsubishi Electric Corporation, Advanced Technology R&D Center, 8-1-1 Tsukaguchi-Honmachi, Amagasaki, Hyogo 661-8661, Japan b Mitsubishi Electric Corporation, Nagoya Works, 1-14 Yada-Minami 5-Chome, Higashi-ku, Nagoya, Aichi 461-8670, Japan c Forschungszentrum Karlsruhe GmbH, Institute for Microstructure Technology, P.O. Box 3640, D-76021 Karlsruhe, Germany Accepted 25 April 2002

Abstract A micro-optical distance sensor has been developed by a combination of LIGA technology and Si micromachining in order to meet industrial demands for miniaturization and low cost. The function of the distance sensor is based on the triangulation principle. This sensor consists of optical components made by the LIGA process, i.e. a free space micro-optical system and micro-cylindrical lenses, and an electrical base with opto-electrical devices. In this paper, one of prototype sensors will be described, which has a measurement range of 1 mm and repeatability error of