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:
Jul. 14, 1987
Filed:
May. 20, 1985
Kenji Yamada, Narashino, JP;
Nippon Kogaku K. K., Tokyo, JP;
Abstract
An eye-examining apparatus comprises a first positive lens unit, a negative lens unit, a second positive lens unit, a third positive lens unit and a target mark arranged in the named order from the side of the examined eye. The third positive lens unit is mounted movably along the optical axis. Between the first and second positive lens units there is interposed on astigmatic system rotatable about the optical axis. The negative lens unit, the second positive lens unit and the third positive lens unit are so arranged as to form an image of the mark at a position near the focal point on the target mark side of the first lens unit. The focal point on the examined eye of the composite system composed of the negative lens unit, the second positive lens unit and the third positive lens unit is approximately coincident with the position conjugate with the pupil of the examined eye relative to the first positive lens unit. The diopter of the apparatus is changed by moving the third positive lens unit and the change of the axis and degree of astigmatism are achieved by rotating the astigmatism system.