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US 4,564,267 AGranted
Variable-focal-length lens
AssigneeCanon Kabushiki Kaisha
InventorYoshifumi Nishimoto
Life of this patent
Estimating the term…
Abstract
Disclosed is a variable-focal-length lens whose focal length can be electrically controlled by applying an electric field of uniform intensity distribution to a compound lens including at least one lens formed of electrooptic crystal and varying the intensity of the applied electric field.
Claims6
A variable-focal-length lens comprising:
- a lens system including at least one set of electrooptic crystals cemented together on curved surfaces thereof so that the directions of their respective axes of rotatory inversion are coincident with each other and so that the directions of their respective two corresponding rotation axes differ from each other;
- means for applying an electric field of uniform intensity distribution to said cemented surfaces of said electrooptic crystals so as to make said cemented surfaces refraction surfaces having a lens action;
- and
- means for varying the intensity of the electric field to be applied, to thereby vary the focal length of said lens system.
1 more element
Dependencies are inferred from the claim text.