US 2026/0211188 A1 · OPTICAL MEMBER

Abstract

An optical member for attachment to an inclined mounting member includes a light guide body made of a light-transmissive material with a specific refractive index. The light guide body has an incidence portion with incident prism portions for receiving external scene light, and an exit surface with exit prism portions for exiting part of the incident light. A reflective portion and a reflective surface direct light within the body, while terminal, upper, and lower surfaces connect the structural elements. The arrangement and inclination of the incidence edge, exit surface, and other surfaces are defined with respect to orthogonal axes. The structure enables guidance of light from a blind spot region, with geometric and optical relationships specified by equations.

An optical member configured to be attached to a mounting member inclined with respect to a vertical direction, the optical member guiding external scene light from a region including a blind spot region caused by the mounting member, the optical member comprising:

a light guide body made of a light-transmissive material having a refractive index n, wherein
the light guide body includes:
an incidence portion including incident prism portions having an incidence surface through which the external scene light enters an interior;
an exit surface having exit prism portions, the exit surface including an exit portion that exits a part of incident light from the incidence surface to an outside;
a reflective portion that reflects another part of the incident light;
a reflective surface that reflects light reflected by the reflective portion toward the exit surface;
a terminal surface connecting an end portion of the reflective surface opposite to the incidence surface and the exit surface;
an upper surface connecting the incidence portion and the exit surface;
and
a lower surface connecting the incidence portion and the exit surface and positioned opposite to the upper surface;
an up-down direction along a vertical direction is a Y-axis direction, a left-right direction orthogonal to the Y-axis direction and connecting the light guide body and the mounting member is an X-axis direction, a front-rear direction orthogonal to both the X-axis direction and the Y-axis direction is a Z-axis direction, a plane formed by the X-axis direction and the Y-axis direction is an XY plane, a plane formed by the Y-axis direction and the Z-axis direction is a YZ plane, and a plane formed by the X-axis direction and the Z-axis direction is an XZ plane, an edge of the incidence portion at an end opposite to the reflective surface is an incidence edge, and an edge of the exit surface at an end on the terminal surface side is a terminal edge,
the light guide body is arranged such that, with respect to the Y-axis direction, the incidence edge is inclined at an angle θx in the YZ plane and at an angle θz in the XY plane,
a straight line connecting a point on the terminal edge and a user's viewpoint position is a virtual line, an angle between the virtual line and the Z-axis direction in the YZ plane is φx, and an angle between the virtual line and the Z-axis direction in the XZ plane is φy, a direction in which the exit prism portions are arranged and which is orthogonal to an extending direction of the exit prism portions is a small-z-direction, an apparent incident angle between the external scene light incident on the incidence portion and the small-z-direction is α, and an angle between the incidence surface and a normal direction to the reflective surface is ψx, and sin φx/sin φy=tan δ,
α
=
sin
-
1
⁢
(
(
sin
2
⁢
(
ϕ
⁢
x
)
+
sin
2
⁢
(
ϕ
⁢
y
)
)
/
(
1
+
1
/
tan
2
⁢
(
δ
+
θ
⁢
z
)
)
)
(
i
)
ω0
=
sin
-
1
⁢
(
sin
⁢
(
θ
⁢
x
+
α
)
/
n
c
⁢
o
⁢
s
⁢
ψ
⁢
x
)
(
ii
)
an angle between the upper surface or the lower surface and the small-z-direction, which is an ideal angle calculated by equation (i) and equation (ii), is ωo, and an angle ω satisfying 0≤ω≤10 is an inclination reference angle, an actual angle between the upper surface and the small-z-direction is ωu, and an actual angle between the lower surface and the small-z-direction is ωd,
the upper surface satisfies ωu≤ω, and the lower surface satisfies ωd≥ω, and
among the light exited from the exit surface, the light having a largest number of round trips between the reflective portion and the reflective surface is maximum round-trip light, and a distance traveled by the maximum round-trip light from the incidence portion to the exit portion in a direction orthogonal to the incidence edge in a plane of the reflective surface is Wd, and Wd satisfies equation (iii)
W
⁢
d
≤
5
⁢
2
×
cos
⁢
ω
cos
⁢
θ
⁢
z
sin
⁡
(
ϕ
⁢
x
+
θ
⁢
x
-
ω
)
.
(
iii
)

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Optical member

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Optical member

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Abstract

Claims6