Limited rotation device having two degrees of freedom
AssigneeMFE Corporation
InventorEdward F. Burke, Jr.
Life of this patent
Estimating the term…
Abstract
A device for reciprocally rotating an output element such as a scanning mirror by means of an electric motor employs a two-degree-of-freedom suspension in which the motor armature is constrained by a first torsional suspension and the output element is supported from the armature by an independent second suspension. The resonant frequency of the armature and its suspension is substantially equal to the resonant frequency of the output element and its suspension.
Claims9
A two degree of freedom, limited rotation system for reciprocally rotating an output element, said system comprising, in addition to said output element,
- A. a driven element,
- B. a first torsional support for said driven element,
- C. a second torsional support independent of said first support for supporting said output element from said driven element,
- D. said system having two system resonant frequencies, said output element and said second support having an individual resonant frequency f.sub.a that is unequal to either of said two system resonant frequencies, said driven element and said first support having an individual resonant frequency f.sub.b that is unequal to either of said two system resonant frequencies, and
- E. means for driving said driven element at a driving frequency that is substantially equal to the individual resonant frequency f.sub.a of said output element and said second support, whereby said driven element has an essentially zero amplitude of motion while said output element may have a substantial amplitude of motion.
A two degree of freedom, limited rotation system for reciprocally rotating an output element, said system comprising, in addition to said output element,
- A. an electromagnetic motor having a stator and an armature, said motor being of the type in which the armature is subject to magnetic forces tending to tilt it or radially displace it against the stator,
- B. a first torsional support for said armature, said first support having sufficient stiffness to prevent said armature tilting or radial displacement,
- C. a second torsional support independent of said first support for supporting said output element from said armature,
- D. said system having two system resonant frequencies, said output element and said second support having an individual resonant frequency f.sub.a that is unequal to either of said two system resonant frequencies, said armature and said first support having an individual resonant frequency f.sub.b that is unequal to either of said two system resonant frequencies, and
- E. means for energizing said motor so that said armature is driven at a driving frequency that is substantially equal to the individual resonant frequency f.sub.a of said output element and said second support, whereby said armature has an essentially zero amplitude of motion while said output element may have a substantial amplitude of motion.
A two degree of freedom, limited rotation system for reciprocally rotating an output element, said system comprising, in addition to said output element,
- A. a driven element,
- B. a first torsional support for said driven element,
- C. a second torsional support independent of said first support for supporting said output element from said driven element, and
- D. said system having two system resonant frequencies, said output element and said second support being characterized in that they together have an individual resonant frequency f.sub.a that is unequal to either of said two system resonant frequencies, said driven element and said first support being characterized in that together they have an individual resonant frequency f.sub.b that is unequal to either of said two system resonant frequencies but substantially equal to the individual resonant frequency f.sub.a of said output element and said second support.
Dependencies are inferred from the claim text.