PURPOSE: To decide the focus in the hard part at the tip of an endoscope and to interlock a focus lens, by detecting the incidence position on a light receiving face of the light, which is emitted from a light source and is reflected from a material to be observed, in the hard part at the tip of the endoscope.
CONSTITUTION: The light which is emitted from a light guide 5 in an endoscope hard part 1 and has a wavelength different from that of the illumination light and has a high directivity is incident to the center of visual fields of materials 8 and 8' to be observed, and the reflected light is focused onto a photodetector array 7 through a filter 9 and a focusing lens 10, and focusing or defocusing is detected on a basis of the position of the incidence. When no force is applied to a wire 13, a driving member 11 is placed in the leftmost position by a spring 12, and a lens 3 is focused to the infinity. When the wire 13 is drawn right, the lens 3 is moved left through the driving member 11 and an interlocking lever 15 and is focused to a near object. Simultaneously, a reflector 6 is turned left, and the photodetector array 7 is turned right, and the focus position is detected.
TAIRA AKIO
NAKABASHI KENICHI
IBA YOUICHI
MIHARA SHINICHI
IMAIZUMI MASAKI