Device with glazing and associated thermal camera, and optimization methods
A device includes a vehicle glazing, including, in a peripheral zone, a through-hole including an insert and a thermal camera.
1. A device, comprising:
a vehicle glazing of given thickness E1, the vehicle glazing having an outer main face oriented outward and an inner main face on a vehicle interior side, the vehicle glazing comprising, in a peripheral zone, a through-hole between the inner main face and the outer main face, the through-hole being delimited by a side wall of the vehicle glazing,
in said through-hole, an insert made of a material that is transparent in a range A of wavelengths in an infrared spectrum beyond 2.5 μm, ranging at least from 9.5 to 10.5 μm, the insert being of given thickness e, made of a material of refractive index n in the range A, with an input face oriented toward the vehicle interior and an output face, the input face fitting within a rectangle or square of width Wi and height Di with aspect ratio Di/Wi of at least 0.8 and of at most 1.2, with Di at most 35 mm, defining a center O which is an intersection of the diagonals of said rectangle,
a thermal camera, disposed on the inner main face side so as to receive an electromagnetic radiation after passing through said insert, the thermal camera comprising an input pupil, with a height p, and an infrared detection system in a range A and a lens, the camera being defined by:
an optical axis X′ passing through a center C of the pupil, C facing the insert,
a vertical viewing angle θ of at least 10°,
the thermal camera being of given volume defined by a point of contact T capable of touching the vehicle glazing first, or a plate on the inner main face of the vehicle glazing, or the insert, or a piece in a peripheral environment of said vehicle glazing, in position mounted in a vehicle,
an orthogonal reference frame (O, X, Y, Z) is defined in which X is an axis parallel to the optical axis X′, oriented toward the outer main face, Z is an axis normal to the optical axis, the axis Y is normal to X in a plane containing P0 oriented toward a top of the vehicle glazing, Z is normal to P0
T being in a plane P0 passing through O and C or Tv, which is a virtual point of contact, is defined as being a projection of T in said plane P0, w being the distance according to X and algebraic in the plane P0 from T or Tv and h is a distance according to Y in the plane P0 between C and T or Tv, the input main face of the insert having an inclination defined by an angle α with respect to X,
wherein a first straight line Dt1 is defined
y
=
-
tan
(
θ
2
)
x
+
(
cos
α
tan
(
θ
2
)
-
sin
α
)
[
D
i
1
-
1
n
2
cos
2
(
α
-
θ
2
)
-
2
e
n
cos
(
α
-
θ
2
)
]
2
1
-
1
n
2
cos
2
(
α
-
θ
2
)
[
Math
49
]
a second straight line Dt2 is defined
y
=
tan
(
θ
2
)
x
+
D
i
2
[
cos
α
tan
(
θ
2
)
+
sin
α
]
[
Math
50
]
Dt1 and Dt2 are secant at C0 (x C0 , y C0 ) with
x
c
o
=
-
sin
α
[
D
i
1
-
1
n
2
cos
2
(
α
-
θ
2
)
-
e
n
cos
(
α
-
θ
2
)
]
+
e
n
cos
α
tan
(
θ
2
)
cos
(
α
-
θ
2
)
2
tan
(
θ
2
)
1
-
1
n
2
cos
2
(
α
-
θ
2
)
[
Math
51
]
y
C
0
=
tan
(
θ
2
)
x
C
0
+
D
i
2
[
cos
α
tan
(
θ
2
)
+
sin
α
]
[
Math
52
]
a third straight line Dt3 is defined
y =−tan(α)( x+w )− h [Math 53]
Dt1 and Dt3 are secant at E(x E ,y E ),
Dt2 and Dt3 are secant at F(x F ,y F )
x
F
=
-
D
I
cos
α
tan
θ
2
+
D
I
sin
α
+
2
w
tan
α
+
2
h
2
(
tan
α
+
tan
θ
2
)
[
Math
54
]
y
F
=
tan
(
θ
2
)
x
F
+
D
i
2
[
cos
α
tan
(
θ
2
)
+
sin
α
]
[
Math
55
]
x
E
=
-
(
cos
α
tan
(
θ
2
)
-
sin
α
)
[
D
i
1
-
1
n
2
cos
2
(
α
-
θ
2
)
-
2
e
n
cos
(
α
-
θ
2
)
]
2
1
-
1
n
2
cos
2
(
α
-
θ
2
)
+
w
tan
α
+
h
tan
α
-
tan
θ
2
[
Math
56
]
y
E
=
-
tan
(
α
)
(
x
E
+
w
)
-
h
[
Math
57
]
x C being a negative value, y C being a positive value,
wherein
in a case a)
y F >y C0 >y E
C(x C ,y C ) is inside a triangle of vertices C0(x C0 ,y C0 ) F(x F ,y F ) and E(x E ,y E ), at least 50% of the pupil being positioned in said triangle by including E; or
in a case b)
when
| x C0 |<|x F | [Math 58]
then y C <(y C0 +5 mm)
a point K of intersection is then defined between a straight line y=y C0 and Dt3 therefore
x
K
=
w
-
y
C
0
-
h
tan
(
α
)
[
Math
59
]
y
K
=
y
C
0
[
Math
60
]
|
x
K
-
x
C
0
|
<
10
mm
.
[
Math
61
]
2. The device as claimed in claim 1 , wherein, in the case a), at least 70% or 80% or 90% of the pupil is positioned in said triangle C0FE by including E.
3. The device as claimed in claim 1 , wherein, in the case a), −(y C0 −2 mm)<y C <(y C0 −0.5 mm) and (x F −5 mm)<x C <(x F +2 mm).
4. The device as claimed in claim 1 , wherein
y C <10 mm [Math 62]
and/or
| x C |<5 cm. [Math 63]
5. The device as claimed in claim 1 , wherein θ is at least 20°.
6. The device as claimed in claim 1 , wherein Di is at most 20 mm.
7. The device as claimed in claim 1 , wherein X′ forms an angle of at most 20°, 10° with the horizontal and/or at most an angle equal to θ/2±2°.
8. The device as claimed in claim 1 , wherein the material of the insert is germanium, zinc sulfide.
9. The device as claimed in claim 1 , wherein the material of the insert exhibits an infrared optical transmission of at least 50% in said range A and a light transmission of at least 30% at a reference wavelength lying between 500 nm and 600 nm.
10. The device as claimed in claim 1 , wherein the material of the insert is chosen from among:
a compound of zinc comprising selenium and/or sulfur, or
a compound comprising a barium fluoride.
11. The device as claimed in claim 1 , wherein the vehicle glazing forms a laminated glazing, the laminated glazing comprising a first sheet of glass with said inner face and an opposite face and a second sheet of glass or plastic with said outer face on an internal side of the vehicle interior, the first sheet of glass and the second sheet of glass or plastic being linked by an interlayer.
12. A vehicle comprising said device as claimed in claim 1 .
13. An optimization method for forming the device defined as claimed in claim 1 , comprising, for a camera with θ, p, given, determining both a smallest possible insert height D min , satisfying the case a), and the insert height Di≥D min is chosen such that
( y F −y C0 )≥0.5 p/ 2.
14. An optimization method for forming the device defined as claimed in claim 1 , comprising, for a given insert height Di, for a camera with given p, determining a smallest possible θmin, satisfying the case a) and θ≥θmin is chosen such that
( y F −y C0 )≥0.5 p/ 2.
15. An optimization method for forming the device defined as claimed in claim 1 , comprising, for a given insert height Di and for a camera with given θ, p, determining a smallest possible h min that satisfies the case a) and h≥h min is chosen such that
( y F −y C0 )≥0.5 p/ 2.
16. The device as claimed in claim 1 , wherein the vehicle glazing is a motor vehicle or rail car glazing.
17. The device as claimed in claim 1 , wherein the peripheral zone is in an upper part of the glazing.
18. The device as claimed in claim 1 , wherein the infrared spectrum is from 8 to 12 μm.
19. The device as claimed in claim 1 , wherein the insert is circular.
20. The device as claimed in claim 1 , wherein Di>Wi.