Patent ID: 7385758

Claim:
A total internal reflection fluorescence microscope comprising: at least one objective lens which takes light from a specimen; an image pick-up device which picks up an image of the light taken into the objective lens; an observation optical path via which the light taken into the objective lens is condensed onto the image pick-up device; a condenser lens, which is disposed in a position facing the objective lens via the specimen, which has a numerical aperture that makes possible total internal reflection illumination, and which guides a transmitted illuminative light, which is emitted by a light source, into the specimen; a base including an upper portion that holds the condenser lens; a laser oscillation unit which outputs a laser beam; an optical fiber which transmits the laser beam output from the laser oscillation unit; a reflection mirror provided at a lower portion of the base to reflect the laser beam output from the optical fiber along a path substantially parallel to a light path of the transmitted illuminative light from the light source, so as to introduce the laser beam into a vicinity of an outermost side of the condenser lens; a condensing lens which condenses the laser beam output from the optical fiber, such that the laser beam is condensed at a condensing position in a vicinity of a front focal position of the condenser lens; and a mirror moving section which moves the reflection mirror in a translatory manner, with respect to the condensing lens, in a direction that is substantially perpendicular to the light path of the transmitted illuminative light from the light source, such that when the mirror moving section moves the reflection mirror, the path of the laser beam reflected by the reflection mirror remains substantially parallel to the light path of the transmitted illuminative light, wherein when the mirror moving section moves the reflection mirror with respect to the condensing lens, an incidence angle, at a boundary of the specimen, of the laser beam emitted from the condenser lens is changed, thereby changing a leak-out depth of evanescent light that illuminates the specimen.