摘要 |
1,154,639. Opthalmometers. R. RODENSTOCK [trading as OPTISCHE WERKE G. RODENSTOCK]. Oct.6, 1967 [Oct.26, 1966], No.45890/67. Heading G2J. A beam dividing surface for use in an opthalmometer which may be of the kind disclosed in Specification 1,067,652, comprises two transparent portions 23, 24, and two fully reflecting portions 21, 22, two pairs of portions 21, 22 and 23, 24 being arranged symmetrically relative to axis 1 and to a plane normal to axis 1 passing through the optical axis 10. |