Linear resonance scanning apparatus and method of scanning

An optical measurement apparatus comprising a linear resonance scanning apparatus, the linear resonance scanning apparatus comprising:

• an electromagnetic drive unit comprising a coil wound about a core, the electromagnetic drive unit having a field output end;
• and
• a linear motion bearing assembly configured to carry a permanent magnet, the linear motion bearing assembly having a longitudinal axis of reciprocating motion;
• and
• a biasing element disposed adjacent an end of the linear motion bearing assembly to serve as a buffer for motion along the longitudinal axis of reciprocating motion;
• wherein
• the permanent magnet has a surface located opposite the field output end of the electromagnetic drive unit in spaced relation to the field output end of the electromagnetic drive unit;
• and
• the permanent magnet is laterally offset with respect to the core so that the core substantially does not overlie the permanent magnet when at rest.

A method of scanning a linear motion bearing assembly comprising a permanent magnet, the method comprising:

• disposing a field output end of an electromagnetic drive unit opposite the permanent magnet and in spaced relation to the field output end of the electromagnetic drive unit;
• providing a biasing element adjacent an end of the linear motion bearing assembly to serve as a buffer for motion along a longitudinal axis of the linear motion bearing assembly;
• arranging the permanent magnet so as to be offset from core of the electromagnetic drive unit when in a state of rest;
• reciprocating the linear motion bearing assembly by applying an electrically induced fluctuating magnetic field from the field output end of the electromagnet and extending towards the permanent magnet.