| 摘要 |
PURPOSE:To provide a focus detecting device which can always obtain a nearly optimum evaluated value of focusing degree with respect to an observed substance having optical conditions such as the numerical aperture of an image- forming optical system and various power spectrum without drastically changing the constitution of an existing microscope and an optical measuring unit, etc., and which can always detect a focusing condition with high accuracy. CONSTITUTION:An aperture stop 6 to change the numerical aperture of illuminating optical systems 1, 2, 3 and 4, and an aperture stop driving means 17 to drive the aperture stop 6 are provided, and the means 17 is driven and controlled by a CPU 11 based on image information obtained from a photodetector array 10 and/or the optical conditions including the numerical aperture of the image- forming optical systems 8 and 9 from a detecting means 16 so that the nearly optimum evaluated value of the focusing degree may be obtained. |
