Optical viewfinder with rosette scanning

摘要

In an optical viewfinder, rosette scanning is achieved when an annular concave mirror (16), arranged on a rotor (12), and a secondary mirror (18) are respectively tilted by an angle of beta and alpha . The secondary mirror (18) is driven by the rotor (12) via a gear (30) which is arranged behind the secondary mirror (18). A gear part (38), on the drive side, of the gear (30) is connected to the rotor (12) via a hollow shaft (34) extending along the axis (10) of rotation. The secondary mirror (18) is supported on this hollow shaft (34). A non-rotating gear part (40) is obtained by a torsion bar (48) which is mounted on the front face of an optical element (20) held in a non-rotating fashion. <IMAGE>