US 12,133,685 B2
Coaxial non-mydriatic multispectral fundus camera using near-infrared ray illumination source and visible ray illumination source
Han Jo Kwon, Busan (KR)
Assigned to ARK INC., Busan (KR)
Appl. No. 17/045,319
Filed by ARK Inc., Busan (KR)
PCT Filed Apr. 3, 2019, PCT No. PCT/KR2019/003936
§ 371(c)(1), (2) Date Oct. 5, 2020,
PCT Pub. No. WO2019/194570, PCT Pub. Date Oct. 10, 2019.
Claims priority of application No. 10-2018-0039225 (KR), filed on Apr. 4, 2018.
Prior Publication US 2021/0121064 A1, Apr. 29, 2021
Int. Cl. A61B 3/00 (2006.01); A61B 3/15 (2006.01); G02B 27/14 (2006.01)
CPC A61B 3/156 (2013.01) [A61B 3/0008 (2013.01); A61B 3/154 (2013.01); G02B 27/14 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A coaxial non-mydriatic multispectral fundus camera using a near-infrared ray illumination source and a visible ray illumination source, comprising:
an illumination unit configured to emit light;
a diffusion lens configured to diffuse the light incident from the illumination unit;
an illumination lens configured to irradiate the light incident from the diffusion lens at a predetermined emission angle;
a mirror configured to reflect the light incident from the illumination lens;
a polarizing beam splitter configured to transmit P-polarized light of the light incident from the mirror and reflect S-polarized light thereof;
an objective lens configured to image a fundus using the light incident from the polarizing beam splitter and then enlarge a returning image of the fundus;
a short-range eyepiece lens configured to reduce or enlarge the image of the fundus enlarged by the objective lens; and
an imaging device configured to acquire a fundus photograph from the image of the fundus received from the short-range eyepiece lens,
wherein the illumination unit includes:
a near-infrared ray illumination source configured to emit a near-infrared ray;
a visible ray illumination source configured to emit a visible ray; and
a non-polarizing beam splitter located between the near-infrared ray illumination source and the diffusion lens and between the visible ray illumination source and the diffusion lens and configured to allow the near-infrared ray emitted from the near-infrared ray illumination source and the visible ray emitted from the visible ray illumination source to be emitted coaxially, wherein the near-infrared ray illumination source emits the near-infrared ray toward the non-polarizing beam splitter in a first direction and the visible ray illumination source emits the visible ray toward the non-polarizing beam splitter in a second direction perpendicular to the first direction, and
wherein coaxial non-mydriatic multispectral fundus camera further comprises: a central imaging mask located between the diffusion lens and the illumination lens and configured to reduce the light incident on a coaxial center of an illumination axis so as to minimize a corneal reflex and to prevent the light from being incident around an apical convex surface of a central part of a cornea, the central imaging mask including a hollow cylinder, a central mask located inside the hollow cylinder to block the light incident on the coaxial center, and spiders supporting the central mask to the hollow cylinder.