Patent ID: 7692856
Filing Date: 2010-04-06
Classification: G02B

Abstract:
1. A microscope, comprising: a plurality of objective lenses in an observational optical system; a plurality of focus error detecting optical systems each having an optical parameter corresponding to a numerical aperture of the objective lenses respectively; a selecting section which selects the focus error detecting optical system corresponding to the objective lens being in use; a focusing section which brings a focal point of the observational optical system into a focus position by using a focus error signal obtained by the selected focus error detecting optical system, wherein each of the focus error detecting optical systems has the optical parameter which makes a focus lock-in range obtained by the focus error signal upon using the corresponding objective lens substantially be a constant value, and wherein each of the focus error detecting optical systems has the optical parameter which makes the focus lock-in range obtained by the focus error signal upon using the corresponding objective lens be the value capable of detecting a focus on a front surface of a cover glass and a focus on a back surface of the cover glass separately.