US Patent Issued to Canon on Sept. 1 for "Rear attachment lens and image pickup optical system using the same" (Japanese Inventor)

ALEXANDRIA, Va., Sept. 1 -- United States Patent no. RE51,021, issued on Sept. 1, was assigned to Canon K.K. (Tokyo).

"Rear attachment lens and image pickup optical system using the same" was invented by Junya Ichimura (Utsunomiya, Japan).

According to the abstract* released by the U.S. Patent & Trademark Office: "A rear attachment lens according to the aspect of the embodiments is configured to vary a focal length of a system by being attached to an image side of a master lens. The rear attachment lens includes a positive lens arranged closest to the image side in which a lens surface on the image side of the positive lens has a shape convex toward the image side. A focal length of the rear attachment lens, a magnification of the rear at...