Retinal camera

Abstract

Abstract PURPOSE: To adjust the focus of retinal camera easily, by reflecting the index image forming luminous flux for focus adjustment by a reflecting member other than the reflecting member for eyeground illuminating luminous flux, and directing the reflected flux into the eye to be examined through the objective system. CONSTITUTION: The luminous flux passing through a slit in a linear slit shielding plate 20 form a light source 17 is separated from the middle by a split prism 21, and is refracted into upper and lower sides to enter the eye to be examined, thereby becoming two luminous fluxes A, A. In order to coincide these two luminous fluxes A, A, the slit shielding plate 20 and split prism 21 are moved in the direction of optical axis to be adjusted properly. With these movements, the movement of an imaging lens 8 cooperates, so that the position of coincidence of the two luminous fluxes and the surface of film 10 are maintained in conjugation, so that the focus of the photographing system consisting of objective lens 6 and imaging lens 8 is adjusted on the eyeground. Hence, the operator can adjust the focus easily while observing the index image for focus adjustment on a Braun tube 16. COPYRIGHT: (C)1979,JPO&Japio

Inventors

• 👤 Yoshi Kobayakawa

Bibliographic Details