Illumination system of ghost elimination eye fundus camera

Abstract

The invention discloses an illumination system of ghost elimination eye fundus camera, which comprises the following steps of: sequentially comprising a beam splitter, a collimating lens, a light collecting system, a field-of-view optical waveguide, a polarization beam splitter, a reflecting mirror, a field mirror, a first polarizing beam splitter and a receiving objective lens from object space to image space, a first light source is arranged on the left side of the beam splitter, and a second light source is arranged on the upper side of the beam splitter; the light emitted by the first light source and the second light source sequentially passes through the beam splitter, the collimating lens and the light collecting system to form primary image on the field-of-view optical waveguide, then the light sequentially passes through the polarization beam splitter, the reflecting mirror, the field mirror, the first polarizing beam splitter and the receiving objective lens to form a field-of-view-optical waveguide-like spot is formed in the eye pupil or crystalline lens. Compared with the lighting system in prior art, the illumination system of ghost elimination eye fundus camera has the advantages of simpler structure, more uniform illumination and better effect of eliminating ghost.

Description

【Technical field】 [0001] The invention relates to a lighting system for a fundus camera for eliminating ghost shadows. 【Background technique】 [0002] Since the fundus itself does not emit light, and the diameter of the pupil generally does not exceed 3mm during the day, it is required that the light from the lighting equipment and the light from the imaging equipment pass through such a small aperture at the same time to achieve uniform illumination and imaging without ghosting. Traditional ring lighting requires The illumination source is a ring or an array surface light source plus a ring diaphragm or directly adopts the optical fiber external lighting and the imaging system does not share the lens. If the two overlap, it is easy to produce lens ghosts, which will lead to small imaging pupils, low light efficiency or uneven illumination. Traditional lighting does not use polarizers to eliminate corneal ghosts, but uses small angles. Imaging the light source on the cornea...

AI Technical Summary

Problems solved by technology

[0002] Since the fundus itself does not emit light, and the diameter of the pupil generally does not exceed 3mm during the day, it is required that the light from the lighting equipment and the light from the imaging equipment pass through such a small aperture at the same time to achieve uniform illumination and imaging without ghosting. Traditional ring lighting requires The illumination source is a ring or an array surface light source plus a ring diaphragm or directly adopts the optical fiber external lighting and the imaging system does not share the lens. If the two overlap, it is easy to produce lens ghosts, which will lead to small imaging pupils, low light efficiency or uneven illumination. Traditional lighting does not use polarizers to eliminate corneal ghosts, but uses small angles. Imaging the light source on the cornea can solve corneal ghosting, but lens ghosting cannot be solved. If the irradiation angle is increased to more than 45°, this method will inevitably produce corneal ghosting or lens ghosting. The optical fiber external illumination is not compatible with imaging The shared lens of the system leads to an uncompact structure, the light center of the illumination light is outside the eyes, the illumination is difficult to be uniform, and it is more likely to produce ghost images than the ring illumination

[0003] The Chinese invention patent application with the application number 201510216416.1 discloses a fundus camera lighting system, see the appendix of the patent application description figure 1 , the lighting method used by the fundus camera lighting system is Kohler lighting, and the light spot is an annular spot. The lighting angle of this method is small, about 30°, which can avoid corneal reflection, but the light spot in the lens is easy to coincide with the exit pupil of the imaging system. It leads to reflection ghosting of the lens. When the illumination angle increases to more than 45°, this method cannot avoid corneal ghosting. At the same time, the annular light spot occupies a large area of ​​the pupil. To avoid lens ghosting, the imaging exit pupil will inevitably become smaller, and the imaging Dimming the brightness is equivalent to enhancing the ghosting effect

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