Abstract: A variable power finder is proposed, which comprises: an objective system; an inverting system; and an ocular system, in order from object side. The third lens group of the objective system is constituted by one lens prism having at least one reflection surface, and following expressions are satisfied: f3/fw?2.5??(1) ?1.0<(R32+R31)/(R32?R31)<1.0??(2) L1/fw2?0.45 1/mm??(3) L2/fw2?0.03 1/mm??(4) where f3 is a focal distance of in millimeters (mm) third lens group, fw is a focal distance in mm at wide angle end of objective system, R31 is a curvature radius of object side lens surface of lens prism, R32 is a curvature radius of image side lens surface of lens prism, L1 is an air equivalent distance in mm from middle imaging surface to object side lens surface of lens prism, and L2 is a distance in mm from middle imaging surface to image side lens surface of lens prism.

Abstract: A semiconductor device in which a control element is buffered from the effect caused by a power element whose heating value is greater than that of the control element, so as to provide the semiconductor device of multiple-chip configuration and having stable operating characteristics within a guaranteed range.