首页>
外国专利>
Multiple wavelength configuration for an optical encoder readhead including dual optical path region with an optical path length difference
Multiple wavelength configuration for an optical encoder readhead including dual optical path region with an optical path length difference
展开▼
机译:用于光学编码器读头的多波长配置,包括具有光程长度差的双光路区域
展开▼
页面导航
摘要
著录项
相似文献
摘要
A readhead and scale arrangement comprises: a readhead comprising a light source configured to output diverging source light comprising a plurality of individually detected wavelengths and at least a first optical signal receiver channel configured to provide a first set of position signals; and a scale track extending along the measuring axis direction on a scale member comprising a scale grating, the scale track configured to diffract the first diverging source light to provide first and second diffracted scale light portions of each of the individually detected wavelengths to the first optical signal receiver channel which provide interference fringes. The readhead comprises an optical path difference element, arranged such that respective wavelengths undergo different phase shifts. Such an encoder is robust to scale track contamination and other signal degradation.
展开▼