U.S. patents available from 1976 to present.
U.S. patent applications available from 2005 to present.

Refractor optical system

Patent 4215919 Issued on August 5, 1980. Estimated Expiration Date: Icon_subject April 7, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Patent References

1265671

1455457

2266797

3498699

Inventor

Assignee

Application

No. 05/894455 filed on 04/07/1978

US Classes:

351/235Having plural disc carrier

Examiners

Primary: Sacher, Paul A.

Attorney, Agent or Firm

International Class

A61B 3/12 (20060101)

Abstract

A refractor optical system having a new series of spherical and cylinder lenses substantially eliminates the irregular occurrence of additive errors when lenses spaced from the reference plane are used or more than two lenses are combined and permits correction for the significant additive errors by non-additive lens selection.

Other References

  • M Lang et al., Am. J. Optom. & Physiol. Optics "Additive Lens Systems in Eye Refractors", vol. 52, pp. 533-540 (Aug. 1975)
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