'Micro Optical Distance Sensor' Fabricated by Micromachining Technology

摘要

Micromachining technologies, i.e. a LIGA technology and a Si micro machining, are used to fabricate a "micro optical distance sensor" in order to meet industrial demands for miniaturization and low cost. The function of the distance sensor is based on the triangulation principle. Our sensor consists of optical components made by the LIGA process, i.e. a free space micro-optical system, and an electrical base with opto-electrical devices. In this paper, one of proposed prototype sensors will be described, which has a measurement range of 1 mm. A laser diode is driven with a high frequency overlay of 350 MHz in order to suppress the influence of speckle pattern and backreflection to the laser diode. Dimensions of the sensor chip are 7 mm (W) x 7 mm (L) x3 mm (H).