FUNDUS CAMERA Russian patent published in 2003 - IPC

FIELD: medical devices and instruments for diagnostication; applicable in capacity of system of visual examination and photographical and digital recording of image of eye fundus. SUBSTANCE: fundus camera consists of objective lens, projection optical system, television image recorder and illuminator, point light source whose power supply circuit has electric pulse generator with generation frequency of 5-30 Hg and filter of spatial frequencies is installed in optical system plane Fourier-conjugated with photo-sensitive layer of television recorder. Said spatial frequency filter is made in form of light absorbing screen with absorption factor of 2-10 located on system optical axis in region of zero spatial frequency. With such design of fundus camera, even prolonged fixation of vision on source with modulated illumination intensity does not induce reflex change of angular position of eyes stemming from physiological features of vision that provides for increase of quality of recorded image. Installation of spatial frequency filter made in form of partially absorbing screen and installed in region of zero component of Fourier spectrum of image of eye fundus increases contrast and quality of image. EFFECT: increased contrast and resolution of image. 2 dwg