格子ピッチの異なるリニア格子を用いた高分解能な変位計測装置の開発

概要

論文の詳細を見る
This paper discusses an apparatus for optically detecting dimension or displacement. In particular, the optical unit with compact in size and simpler in construction, and signal processing unit with resolution to be better than 0. 1μm are described. The key device of the optical unit is linear scale. The scale consists of one moving and two stationary gratings, and these two types of grating have different grating pitch lengths. These two pitches are set to odd integer multiples. For example, moving and stationary gratings set to 5Oμm and lOμm, respectively. The scale is directly irradiated by a divergent light emitted from a laser diode, and generates two sinusoidal-like signals with lOμm period. By using the divergent light, the need for a collimating lens is eliminated. This reduces the overall size of the optical unit. The signal processing unit operates on the two signals for detecting the signal phase at the stop position of the moving grating. The basis of the phase detection is a linear operation. By using the linear operation system, high resolution detection of the signal phase is accomplished by segmenting the one cycle period into more than 300 parts.
社団法人精密工学会の論文
2003-03-05