EP0091805A2 — Endoscope focus state detectors

USPTO Abstract

Endoscope focus state detectors, and automatic lens setting devices and exposure triggering devices provided therewith, for use where a hard or soft endoscope (4) is inserted into a body cavity and illuminating light fed from a light source (60) for observation or diagnosis via an eyepiece 3 and a focus state detection light source (33,67) projects light via an aperture (15) to be transmitted via the endoscope optical system and detect reflected light in order to determine the focus state, with reference to a plane in which an image is to be recorded. The light receiving means (11) for detecting the state of focus includes means for increasing the signal-to-noise ratio by reducing or eliminating any reflected illuminating light that would otherwise be incident upon the light receiving means (11).