US 12,393,016 B2
Endoscope and endoscope system
Nobuyoshi Asaoka, Ageo (JP); and Kazuaki Tamura, Hachioji (JP)
Assigned to OLYMPUS CORPORATION, Tokyo (JP)
Filed by OLYMPUS CORPORATION, Tokyo (JP)
Filed on Jan. 31, 2022, as Appl. No. 17/588,872.
Application 17/588,872 is a continuation of application No. PCT/JP2019/031644, filed on Aug. 9, 2019.
Prior Publication US 2022/0155580 A1, May 19, 2022
Int. Cl. G02B 23/26 (2006.01); F21V 8/00 (2006.01); F21V 9/40 (2018.01)
CPC G02B 23/26 (2013.01) [F21V 9/40 (2018.02); G02B 6/0008 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An endoscope comprising:
an insertion portion which is long and slender;
an intermediate portion which is provided to a base-end side of the insertion portion;
an operating portion which is provided to a holding portion, the holding portion being provided to a base-end side of the intermediate portion;
an optical converting member which is provided to the insertion portion;
a light source which is provided to the holding portion; and
a light guide which is inserted through the insertion portion,
wherein the light guide has a first light guiding area which is provided on the operating portion side, and which has an incidence end surface on which light from the light source is incident, and a second light guiding area having an exit end surface from which the light emanates,
a diameter of the light guide of the first light guiding area becomes smaller toward the second light guiding area, and
the first light guiding area is provided to the intermediate portion;
light emitted from the light source is incident on the incidence end surface of the light guide, and is irradiated to the optical converting member from the exit end surface of the light guide; and
the following conditional expression is satisfied:

OG Complex Work Unit Math
where,
LEF1 denotes an optical coupling efficiency of the light guide, and is expressed by LEF1=Iout/Iin,
ΔEF denotes a difference in a conversion efficiency of the optical converting member, and is expressed by ΔEF=|EFa−EFb|,
Iout denotes an intensity of light incident on the incidence end surface,
Iin denotes an intensity of light emanating from the exit end surface,
EFa denotes a conversion efficiency when a diameter of the exit end surface is ϕa,
EFb denotes a conversion efficiency when the diameter of the exit end surface is ϕb,
the conversion efficiency is expressed by Q/P,
P denotes an intensity of light irradiated to the optical converting member,
Q denotes an intensity of light radiated from the optical converting member,
ϕa denotes a diameter of the incidence end surface, and
ϕb denotes a diameter of the exit end surface.