| 摘要 |
A compact indirect ophthalmoscope, adapted to hand-held or mounting support, with a prefocused direct line illumination system, has an observing system including a right dihedral angle, semi-silvered beam-splitting and image erecting mirror interposed symmetrically in and with dihedral edge at 45 DEG angle to the beam axis to intercept and rotate at right angles the cone of rays diverging from the eye, providing by the observation system objective lens arrangement a large erect real aerial image of an extensive fundus area, suitable for binocular and stereoptic observation by an appropriate known form of loupe, if desired, and also affording substantially simultaneous observability of the fundus image, pupil and eye exterior; means being provided to suppress or eliminate from the aerial image corneal and other reflections. A second form utilizes a planar beam-splitting mirror to turn the convergent illuminating rays through a right angle and thence into the eye, emergent rays from the eye passing back through the mirror, the objective lens and then encountering a dihedral mirror erecting and directing the image toward a desired angle of observation.
|
