Biological fluorescence diagnostic apparatus with distinct pickup cameras

Claim 1

A biological fluorescence diagnostic apparatus having a system that irradiates biological tissue with illuminating light from a light source having a wavelength range within which the biological tissue generates fluorescent light upon light irradiation and that transmits an image through an ocular optical system provided in an eyepiece of an endoscope, said apparatus comprising: a television camera unit including an ordinary image pickup television camera for taking an ordinary endoscopic observation image passing through the ocular optical system of the endoscope, and a fluorescence image pickup television camera with an image intensifier for taking a fluorescence observation image passing through the ocular optical system of the endoscope after amplifying a light intensity of said fluorescence observation image, said ordinary image pickup television camera and said fluorescence image pickup television camera being distinct and being integrally mountable to the eyepiece of the endoscope; a path switching optical system including a reflecting surface, said path switching optical system mounted to be selectively inserted into and withdrawn from an optical path of light passing through the ocular optical system; a filter selectively insertable into and movable out of an illuminating light path of the endoscope, said filter transmitting light having a wavelength range within which the biological tissue generates fluorescent light; a control unit; a detector that detects a position of said path switching optical system, said control unit controlling said image intensifier and said filter in response to an output of said detector; and a system that operatively connects said television camera unit to the eyepiece of the endoscope.