ENDOSCOPES HAVING A FOCUS STATE DETECTOR

摘要

An endoscope provided with a focus state detector, wherein light is projected through a light guide (33) to be reflected from an object and received by a light receiving means (11) provided with an optical aperture (15) or locally non-sensitive part of a small diameter or width to detect focusing. When an object to be recorded by a photo-graphic or television camera is low in contrast, such as an internal organ observed with an observing optical system of an endoscope, the depth of focus may be so shallow that it will be difficult to obtain a clear image of the object by fitting and setting the lens system in a well-focussed state. Therefore, embodiments of the present invention provide means for projecting a focus state detecting light-spot of high intensity onto the object (25) through the light-spot guide (33) from an external light source (32), and the intensity of the reflected light from the object (25) adjusted to give a unique value from the light receiving means, which indicates the correct focus setting with high precision.