Kabushiki Kaisha Topcon

Kazuhiko Ohnuma

Yasufumi Fukuma

Hidetaka Aeba

Hisao Kikuta

Takashi Shioiri

A fundus examination apparatus includes an illumination optical system (), which illuminates a fundus by fundus illumination light, an imaging optical system (), which photographs a fundus image based on a polarization property of reflected illumination light, and a picture signal processing device, which processes a signal output from the imaging optical system; and the imaging optical system includes a phase plate array () that a plurality of unit constitutional plates (U) is arranged in a matrix in a plane; each of the unit constitutional plates comprising four or more micro phase plates (-), a polarizer (), which polarizes the reflected illumination light passing through the phase plate array () into a predetermined polarization direction, and an image pickup device () that a plurality of constitutional units (U) is arranged in a matrix in a plane; each of the constitutional units comprising four or more pixels (G-G).

Fundus examination apparatus

Apparatus for measurement of polarized distribution, polarizing filter for using therein and polarizing filter assembly

A glaucoma diagnosis apparatus for determining thickness of nerve fiber layers. The apparatus includes an illuminating optical system for illuminating the ocular fundus of an eye to be examined with circularly polarized illuminating light and an imaging optical system including a CCD camera for photographing the image of an ocular fundus based on the reflected illuminating light from the ocular fundus and has a polarizing filter provided integrally with the imaging surface of the CCD camera. The filter includes repetitions of a unit platelet having a couple of polarizing microplates which transmit those linearly polarized light components crossing with each other out of the reflected illuminating light and adjacent polarizing microplates which transmit linearly polarized light components in direction crossing with both of the above/mentioned linearly polarized light components of the reflected illuminating light. Evaluation of a phase change of the circularly polarized illuminating light can be used to determine the nerve fiber layer thickness.

Glaucoma diagnosis apparatus

A glaucoma diagnosis apparatus capable of minimizing the difficulty of early glaucoma diagnosis caused by the illumination irregularities of the fundus is provided. For each part of the fundus image FB photographed by a color fundus camera Q, the G-component image data corresponding to the G-component reflected light intensity or the B-component image data corresponding to the B-component reflected light intensity is divided by the sum of the G-component image data, the B-component image data and also the R-component image data corresponding to the R-component reflected light intensity, reflected light intensity ratio data is obtained. Based on this reflected light intensity ratio data, the fundus image is reconstructed for glaucoma diagnosis.

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Sodegaura, Japan

Kazuhiko Ohnuma