Patent Number: 7,421,800

Title: Scale reading apparatus

Abstract: A scale for a scale reading apparatus has a scale track with scale marks which form an incremental scale. The scale also has a set of reference marks. The scale has at least one additional track and different combinations of markers in the at least one additional track have different functions, for example reference mark enablers and right and left limit switches.

Inventors: Howley; Colin Keith (Stonehouse, GB)

Assignee: Renishaw PLC

International Classification: G01B 11/02 (20060101); G01B 7/02 (20060101)

Expiration Date: 2020-09-09 0:00:00