US 12,681,367 B2 · Focal reducer

Abstract

A focal reducer for use with a camera and a primary lens moves the image formed by the primary lens farther back within the lens/reducer/camera assembly so that the image of an object within the field of view is formed at the image plane of the camera. Relaying the image from the image plane of the primary lens to the image plane of the camera enables the primary lens and the camera, which have the same type of mount, to be used with a focal reducer. Previously, a primary lens and a camera having the same type of mount could not be used with a focal reducer, because the focal reducer interposed between the primary lens and the camera caused the image plane of the primary lens to be located in front of the image plane of the camera, making it impossible for the lens/reducer/camera assembly to achieve infinity focus.

Claims20

Dependent claims

A focal reducer configured for use with a camera and a primary lens, the focal reducer comprising:

a generally tubular cylindrical housing including an entrance end and an exit end;
a lens mount at the entrance end of the housing, the lens mount being a female coupler of a mount type and being configured for coupling with a corresponding male coupler of the mount type on the primary lens;
a camera mount at the exit end of the housing, the camera mount being a male coupler of the mount type and being configured for coupling with a corresponding female coupler of the mount type on the camera;
a field lens contained within the housing and positioned to coincide with an image plane of the primary lens when the focal reducer is coupled with the primary lens;
and
a relay and reducing lens contained within the housing and positioned behind the field lens relative to the entrance end of the housing such that an image plane of the relay and reducing lens coincides with an image plane of the camera when the focal reducer is coupled with the camera.

3 more elements

Dependencies are inferred from the claim text.

Focal reducer

Life of this patent

Focal reducer

Life of this patent

Abstract

Claims20