Linear Encoder Protects Against Scale Contamination

Heidenhain’s redesigned Lida 400 series exposed linear encoders are designed for coordinate measuring machines (CMMs), linear motion stages, wafer inspection, waterjet cutting and other applications. The line is fully mechanically compatible to the previous Lida 400 family, and scanning units are interchangeable with older graduations. Maintaining a 20-micron graduation and interpolation to 100 times available from the scanning unit, the encoder system can provide a resolution of 50 nm and accuracies ranging to ±1 micron. In addition, the signal quality is improved in this redesign, the says company.

Electronic components make the single-field scanning principle more robust against contamination on the scales, where as much as 4 mm of the graduation can be blocked, while the scanning unit still generates signals within specification. Other new features include a multi-colored status LED on the side of the scanning unit to indicate the signal levels during installation, enabling the operator to quickly check encoder status. This status LED also indicates the reference mark signal quality. For the digital TTL versions with interpolation, the interpolation circuits have been miniaturized to fit inside of the scanning unit housing, providing cost savings.