US 11,669,006 B2
Light guiding unit, light source apparatus, and projector
Hidefumi Sakata, Tatsuno-machi (JP); and Yuichiro Iwama, Azumino (JP)
Assigned to Seiko Epson Corportation, Tokyo (JP)
Filed by SEIKO EPSON CORPORATION, Tokyo (JP)
Filed on Sep. 1, 2021, as Appl. No. 17/463,634.
Claims priority of application No. JP2020-146820 (JP), filed on Sep. 1, 2020.
Prior Publication US 2022/0066307 A1, Mar. 3, 2022
Int. Cl. G03B 21/20 (2006.01); F21V 8/00 (2006.01)
CPC G03B 21/208 (2013.01) [G02B 6/0006 (2013.01); G02B 6/0008 (2013.01); G03B 21/204 (2013.01); G03B 21/2066 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A light guiding unit comprising:
a light guiding member that light enters; and
an angle converter that the light from the light guiding member enters,
wherein the light guiding member has a side surface and a light exiting end surface which intersects the side surface and via which the light exits,
the angle converter includes
a light incident section on which the light from the light guiding member is incident,
a light exiting section via which the light incident on the angle converter exits, and
a reflection section that reflects the light incident via the light incident section toward the light exiting section,
a refractive index of an interior of the angle converter is greater than a refractive index of air,
a refractive index of an interior of the light guiding member is greater than the refractive index of the interior of the angle converter,
the light exiting end surface and part of the side surface are in contact with the angle converter,
wherein the light guiding member includes a first antireflection film and a second antireflection film,
the first antireflection film is formed on a first portion of the side surface that is a portion not buried in the light incident section, and
the second antireflection film is formed on a second portion of the side surface that is a portion buried in the light incident section and on the light exiting end surface.