Patent ID: 9030652
Filing Date: 2015-05-12
Classification: G01P,H01L

Abstract:
1. An apparatus for determining the synchronicity of a rotary platen in a vacuum deposition chamber, said apparatus comprising: a vacuum deposition chamber, a platen supported for rotation about a center axis in said vacuum deposition chamber, said platen configured to emit light signals about a circular swept path centered about said central axis, said platen including an asymmetry feature along said circular swept path, said asymmetry feature having a unique light signature with respect to other light signals emitted from said platen along said circular swept path, a rotary spindle drive, a non-positive coupling operatively connecting said rotary spindle drive to said platen for forcibly rotating said platen about said center axis, detector fixed relative to said rotating platen for measuring light signals emitted from said platen along said circular swept path, said detector configured to generate a unique signal in direct response to said unique light signature emitted by said asymmetry feature.