| 摘要 |
A magnifying optical system is described which is usable at a determined posture of the head of a user, when at least one of the user's eyes is directed onto an object's field to be magnified, which system comprises an objective, an ocular comprising an eye lens and at least one field lens, and a deflecting system interposed between the objective and the ocular, the optical system being located, at the determined head posture, outside the straight path of rays for free sight between the user's eye and the object's field looked at by the eye; the optical axis of the objective is directed toward the center of the object's field, the optical axis of the eye lens of the ocular is directed toward the center of the user's eye ball, both said optical axes forming an obtuse angle with one another, which optical axis of the objective and the central ray of free sight intersect one another under a flat acute angle at the center of the object's field (whereby the object's field can alternatingly been seen by the user either magnified by the said system or freely past the latter, while the user retains the same head posture.
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