Patent ID: 9243895
Filing Date: 2016-01-26
CPC Classification: G01B,G01D

Claim Text:
1. An optical displacement measuring device, comprising: a first substrate including a first area with a first pattern formed on the first substrate; a second substrate including a second area with a second pattern formed on the second substrate; the first or second substrate including a fixed reference pattern; the second substrate overlying the first substrate whereby the second pattern overlies the first pattern and the first and second patterns generate a pattern of modulated intensity which is compared to the fixed reference pattern for determining relative movement of the first and second substrates with respect to each other; wherein the first substrate is attached to a surface at a first connection point and the second substrate is attached to a surface at a second connection point; and a distance between the first and second connection points define a gauge length, and changes in the gauge length cause a phase shift of the pattern of modulated intensity with respect to the fixed reference pattern.