Abstract: An endoscope pretest capsule has approximately the same shape and weight as a capsule-type endoscope and is brought into the body before applying the capsule-type endoscope, and it includes barium sulfate which is a radiopaque substance (or a microcapsule wrapping a radiopaque substance) in a capsule body formed by a material having main components such as chitosan, and has an enteric coat for dissolving after elapse of a predetermined time provided on the surface side thereof. It is possible, by having the pretest capsule swallowed by an examinee in advance, to grasp passage conditions of the capsule-type endoscope in the body and secure good discharge out of the body because it dissolves in the case of remaining in the body for the predetermined time or longer.

Abstract: An optical lens assembly containing a plural number of lens elements for an optical system to be incorporated into a tip end portion of an endoscopic insertion instrument. Of a plural number of lenses which constitute an optical system, a metal film layer is formed on confronting outer peripheral surface portions of at least two adjacently located lenses, outside respective effective lens areas, and the two adjacently located lenses are assembled and fixedly bonded together by applying solder to the outer peripheral surface portions with a metal film layer.

Abstract: An optical lens assembly containing a plural number of lens elements for an optical system to be incorporated into a tip end portion of an endoscopic insertion instrument. Of a plural number of lenses which constitute an optical system, a metal film layer is formed on confronting outer peripheral surface portions of at least two adjacently located lenses, outside respective effective lens areas, and the two adjacently located lenses are assembled and fixedly bonded together by applying solder to the outer peripheral surface portions with a metal film layer.