Patent ID: 11860352
Assignee: MACHINE VISION LIGHTING INC.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 5:
6. A lighting optical system to be used in an image observation apparatus which collects an object light from an object to be observed and makes an image of the object to be observed observable, wherein the lighting optical system comprises: a filter member for dividing optical attribute of the illumination light into one or more solid angle regions; an objective lens opposed to the object to be observed; a beam splitter disposed on an opposite side to the object to be observed with respect to the objective lens and in which an illumination optical axis of the lighting optical system and an observation optical axis of the observation optical system are in agreement with each other; the filter member or a relay image of the filter member being disposed on the opposite side to the object to be observed with respect to the objective lens and near a focusing position of the objective lens on the illumination optical axis, thereby at respective points of the object to be observed, same illumination solid angles being formed; and wherein said filter member or the relay image of the filter member is disposed at a position of an aperture stop that determines a numerical aperture of said objective lens.