| 摘要 |
PURPOSE:To cover the overall range of photographic distance with one driving means, by constituting the device so that a camera is focused only in a selected distance range and making the macro-photography possible and allowing said distance range to include a part of the macroregion at least. CONSTITUTION:The closest position and the infinity position from a camera 1 are defined as P1 and P5 respectively, and the length between these positions is divided into four, and the macroclosest position is defined as P0. In case of application to a barrel including the macroregion, a part of the luminous flux is led to light receiving faces of a pair of photoelectric elements 5 and 6 through image forming lenses 3 and 4. Output signals (a) and (b) from arrays are inputted to a processing circut 7 to decide the front focus, the rear focus, or the focus, and an object lens 2 is moved to the focus position through a gear 10 by a motor 9. When the object lens 2 is placed for normally the closest position P1 and each position P2, P3, or P4, it is detected by contacts 13, 14, 15, and 16 and a conductive member 11. The macroposition is detected by a contact 70. |
