In-focus state detection device

摘要

An in-focus state detection device having a light source for emitting a near-infrared light for detecting an in-focus state of an object lens by sensing the light of the light source reflected by an object by a sensor through the object lens is disclosed. The in-focus state of the object lens to a visible light is exactly detected by correcting a relation between the light of the light source transmitted through the object lens and the sensor in accordance with a change in chromatic aberration information of the object lens to the light of the light source.