ALEXANDRIA, Va., June 10 -- United States Patent no. 12,292,552, issued on May 6, was assigned to RICOH COMPANY LTD. (Tokyo).

"Projection lens system and image projection apparatus" was invented by Takashi Kamitakahara (Tokyo), Ken Shirasaki (Tokyo), Mutsumi Tanifuji (Tokyo) and Hayato Yoshida (Tokyo).

According to the abstract* released by the U.S. Patent & Trademark Office: "A projection lens system (G1, G2) includes a front group (G1) disposed on a projection-plane (SC) side, a rear group (G2) disposed on a display-surface (SF) side of an image display element inclined with reference to the projection plane (SC), and an aperture stop (S) disposed on the display-surface (SF) side with reference to the front group (G1). The rear-group op...