| 摘要 |
PROBLEM TO BE SOLVED: To accurately focus on a part to be observed as to a focus detector, an optical device equipped with the focus detector and a focus detecting method. SOLUTION: The focus detector is provided with an illuminating device for illuminating a subject, an objective lens arranged on the optical path of light reflected by the subject, and a photoelectric conversion element for receiving the light reflected by the subject or light transmitted through the subject and converting the light to an electrical signal. The focus detector is further provided with a filter means arranged on the optical path of the reflected light or the transmitted light so as to transmit only the reflected light or the transmitted light both having a prescribed wavelength. COPYRIGHT: (C)2003,JPO |
