The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 30, 2018
Filed:
Aug. 18, 2015
Crewt Medical Systems, Inc., Tokyo, JP;
CREWT MEDICAL SYSTEMS, INC., Tokyo, JP;
Abstract
When displaying visual targets on a planar display element and performing vision examinations, the size of the visual target visible to the subject changes according to the position at which the visual target is displayed. This vision examination device includes: a planar display element that displays visual targets to a subject of a vision examination; and a display optical system provided upon an optical axis between an eyeball position at which an eyeball of the subject is arranged and a display screen of the planar display element. The display optical system includes an f-θ optical system having a proportional relationship between an image height on the display screen of the planar display element and the angle of incidence θ for the main light rays when the subject views the visual target through the display optical system from the eyeball position.