Patent ID: 7280274

Claim:
A three-dimensional image observation microscope system comprising: an imaging unit that captures images focused at different object point distances in an optical axis direction; and a display unit that displays a plurality of images that are captured by the imaging unit for overlaid observation along the line of sight of a viewer; wherein the imaging unit includes an objective optical system that obtains an image of an object, a zoom optical system that controls the magnification of the image obtained by the objective optical system, and a plurality of image pickup devices that capture images having a magnification that is controlled by the zoom optical system; and the following conditions are satisfied: fob·NA max≧15 mm NAmin≧0.02 0.25 ≦d·NA /( R ·β)≦2 where fob is the focal length, in mm, of the objective optical system; NAmax is the maximum object-side numerical aperture of the objective optical system of the imaging unit; NAmin is the minimum object-side numerical aperture of the objective optical system of the imaging unit; d is the distance, in mm, between two adjacent image pickup surfaces of the image pickup devices; NA is the object-side numerical aperture of the objective optical system of the imaging unit when the zoom optical system has a magnification β; R is the width, in mm, of a pair of black and white lines when the pair of black and white lines are part of a test chart having evenly-spaced, parallel sets of black and white lines and the test chart is placed in a plane that is conjugate with an image pickup surface of one of the image pickup devices with respect to the objective optical system of the imaging unit so that an image of the pair of black and white lines is captured on the image pickup surface of one of the image pickup devices in such a manner that the black and white lines are displayed on a monitor with a contrast of 10% through a circuit system that processes image signals sent from the image pickup devices; and β is the magnification of the zoom optical system.