A new range of linear encoders has been developed by Heidenhain for linear motor and high axis speed applications.
A new range of linear encoders has been developed by Heidenhain for linear motor and high axis speed applications. The encoders are particularly targeted at applications such as high speed placement machines and printed circuit board drilling but are equally suitable for use on co-ordinate measuring machines. The LIDA 400 linear encoder, now available from Heidenhain GB of Burgess Hill in West Sussex, has a compact scanning head and high tolerance to contamination and immunity to electromagnetic noise.

A major advantage is the capability to provide a high quality output signal involving large interpolation factors at traversing speeds up to 480 m/min and measuring steps of 50 nanometers.

The scanning head is only 12 mm high and can be easily mounted in very tight spaces.

However, even with such a small head, because of the configuration of the beam path and the inclusion of an innovative photo detector, the scanning area is large at 14.5 mm2 and therefore enhances the encoder's tolerance to contamination.

In addition, the scanning optics completely eliminate any influence of waviness from the surface of the scale tape.

The AURODUR gold 20 micron grating period lines are produced using photolithogranically on the steel scale tape which guarantees high accuracy and repeatability while maintaining a resolution as precise as 0.1 microns.

And, via opposing parallax effects, compensation is achieved for local expansion and compression of the tape surface.

The low interpolation error of LIDA 400 also accommodates high accuracy over short distances giving improved control characteristics of position and velocity control loops.

The encoders are available with reference marks on the tape scale and also feature integrated magnetic limit switches, which output in parallel through the encoder cable.

The LIDA 400 is available in a number of versions with IVpp and TTL interfaces and measuring lengths up to 30 metres as standard.

For rotating axes, the scale can be used for measuring full circles or circular segments.