Disclosed is an optical measurement scale 14 complementary scale reader 10 for determining displacement between the scale and reader. The scale 14 and reader 10 are adapted for use with a liquid C which provides optical communication between the scale 14 and the reader 10. The liquid C is preferably machine coolant or oil. The scale is preferably a stainless steel strip having periodic markings thereon. The scale reader has a window 16 which may have a hard coating (30 Fig 4) thereon, e.g. diamond-like carbon, to prevent surface damage. The scale and reader may be mutually displaced with a shortage of liquid without undue adverse affects. Rotary mutual displacement between the scale and reader is discussed.
申请公布号
WO0225219(A9)
申请公布日期
2004.05.13
申请号
WO2001GB04161
申请日期
2001.09.18
申请人
RENISHAW PLC;HENSHAW, JAMES, REYNOLDS;HOODLESS, RICHARD, JOHN