发明授权
US5485231A Apparatus for visual acuity test having an adjustable mirror 失效
具有可调节镜的视力检测装置

Apparatus for visual acuity test having an adjustable mirror
摘要:
An apparatus for visual acuity test of an examinee's eye comprises test chart presenting device for changing and presenting test chart to the examinee's eye, a switch for designating test chart to be presented by the test chart presenting means, a light delivery optical system for delivering luminous flux of test chart from the test chart presenting means to the examinee's eye, the light delivery optical system comprising a concave mirror for making the luminous flux of test chart optically from 4 m ahead of the examinee to infinit and a first reflection mirror for reflecting the luminous flux reflected the concave mirror to the examinee's eye, and reflecting angle adjusting device for adjusting reflection angle of the reflection mirror so as to fit to a height of the examinee's eye, a housing for internally mounting the test chart presenting means and the light delivery optical system, the housing having an aperture to allow the luminous flux of test chart pass therethrough and the aperture being provided with a filter on which reflection reducing coating is coated.
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