Patent ID: 8956059
Filing Date: 2015-02-17
Classification: G03B

Abstract:
1. An optical shutter apparatus comprising: a) a shutter blade that is pivotable between a first position and a second position that is spaced apart from the first position, and wherein the shutter blade in the first position blocks at least a portion of a light path; b) a stepper motor that is energizable to pivot the shutter blade to at least the first or second positions; and c) a magnetic shutter blade retention apparatus that has: wherein the at least the first movable member is magnetically attracted to the at least the first stationary member when the stepper motor is de-energized and wherein, when the shutter blade is pivoted to the first position by the stepper motor, a point on the first surface is spaced apart from the at least the first stationary member by a first distance, and wherein, when the shutter blade is pivoted to the second position by the stepper motor, the point on the first surface is spaced apart from the at least the first stationary member by a second distance that is less than the first distance.