US 2019/0250367 A1↗2019Assignee: Ricoh Co., Ltd.Inventors: Minoru MurayamaPENTAX HD D FA* 50mm f/1.4 SDM AW— 15 elements / 9 groups, f = 49.57 mm design
US 2016/0327774 A1↗2016Assignee: Ricoh Imaging Company, Ltd.Inventors: Minoru MurayamaHD PENTAX-D FA 150-450mm f/4.5-5.6 ED DC AW— Marketed 150–450mm f/4.5–5.6, Design f = 153.50–440.00 mm