| 释义 |
eyepiece|ˈaɪpiːs|
[f. eye n.1 + piece.]
1. Optics. The lens or combination of lenses, usually two in number, known respectively as the field-glass and eye-glass, at the eye-end of a telescope, or other optical instrument, by which the image, formed by the mirror or object-glass, is viewed and magnified.
The principal kinds of eye-pieces are (a) the Huyghenian, or so-called negative from the fact of its forming the image between the lenses; (b) the Ramsden, or common astronomical, called positive because the image is formed outside the field-glass; (c) the erecting or terrestrial for ordinary telescopes, which presents the object in an erect position.
1790Roy in Phil. Trans. LXXX. 155 The common eye⁓piece with two convex glasses. 1831Brewster Optics xliii. 360 Achromatic eyepieces..may be composed of two or three lenses. 1867J. Hogg Microsc. i. ii. 40 The two [eye-glass and field-glass] when combined are termed the eye-piece. 1878Lockyer Stargazing 111 The Achromaticity of the Huyghenian Eyepiece.
b. attrib. as eyepiece micrometer. (See quot.)
1874Knight Dict. Mech., Eye-piece Micrometer, a graduated slip of glass introduced through slits in the eye-piece tube, so as to occupy the center of the field.
2. Australian.
1880Leeds Mercury 16 Nov. 7 The power of a lazy free⁓selector to pick out the eye-piece of a squatter's run. |