REAL IMAGE VARIABLE POWER VIEWFINDER AND REAL IMAGE VARIABLE POWER VIEWFINDER CAPABLE OF MAGNIFICATION TRANSITION

摘要

PURPOSE: To provide a real-image variable power viewfinder having a short overall length which is not changed as magnification varies, having a simple mechanism for the displacement of lenses required to vary magnification, and causing no change in visibility with changes in magnification. ;CONSTITUTION: A real-image variable power viewfinder has an objective lens and an ocular both of which have positive refractive power, and the objective lens comprises a first group I having positive refractive power, a second group II having negative refractive power, a third group III having positive refractive power, and a fourth group IV having positive refractive power, the groups I-Iv being arranged in sequence form the side of an object; a rearl image is formed between the fourth group IV and the ocular by the objective lens and is observed via the ocular; magnification is increased by movement of the second group II from the side of the object to the side of the ocular and changes in visibility due to the increase in magnification are corrected by movement of the fourth group IV.;COPYRIGHT: (C)1993,JPO&Japio