| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To obtain a finder optical system able to obtain a high quality electronic image in real time for a subject image formed on a focusing plate and able to observe a bright finder image. <P>SOLUTION: The finder optical system comprises: an upright optical system that uses a subject image formed on the focusing plate as an upright image; an eyepiece optical system configured to form a virtual image of the upright image formed by the upright optical system; and an imaging optical system configured to form the subject image, formed on the focusing plate, onto an imaging element via the upright optical system. The imaging optical system and the eyepiece optical system are arranged on the light emission side of the upright optical system such that the face of each light incident side is opposite to the light emission face of the upright optical system. The imaging optical system comprises a diaphragm, a first lens of positive refractive power and a second lens of positive refractive power. An imaging optical axis is inclining with respect to an observing optical axis. An angleθ1 formed between the imaging optical axis and a normal on an intersection with the imaging optical axis on the object side face of the first lens, an angleθ0 formed between the imaging optical axis and the observing optical axis, the focal distance f of the imaging optical system, and the paraxial curvature radius r2 of the object side face of the first lens are each appropriately set. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
