| 摘要 |
PURPOSE:To obtain a titled lens which is long in its operating distance and also compact by constituting it of three groups consisting of a group having a positive composite power, a group of a negative lens, and a group of two positive lenses in order from an image side. CONSTITUTION:A titled lens consists of the first group I containing one joint lens and having a positive composite power, the second group II consisting of a negative lens, and the third group III containing two positive lenses in order from an image side. Also, a half mirror M can be incoporated between the second group II and the third group III, and these lens groups are made to satisfy the conditions of an expression I and an expression II. In this regard, in the expressions, e1, e2, f2 and (f) denote a distance between principal points of the first group I and the second group II, a distance between prinicpal points of the second group II and the third group III, a composite focal distance of the second group II, and a focal distance of the whole system, respectively. |
