Light field display apparatus
A device for optical-field displaying includes: a display screen and a lens unit provided on a light exiting side of the display screen; the lens unit includes a plurality of lenses arranged in an array; the display screen is provided on a focal plane of the plurality of lenses; the display screen includes a first substrate and a second substrate that match; the first substrate is a light-exiting-side substrate, the second substrate includes a plurality of pixel islands arranged in an array; the plurality of pixel islands correspond to the plurality of lenses; a view region formed by light rays emitted by the sub-pixels of the pixel islands and propagated via the corresponding lenses to a human eye is smaller than or equal to a half-pupil region, and light rays of different viewpoints emitted by different sub-pixels of the pixel islands enter different cone cells via the lenses.
1. A device for optical-field displaying, wherein the device comprises: a display screen and a lens unit that is provided on a light exiting side of the display screen;
the lens unit comprises a plurality of lenses that are arranged in an array;
the display screen is provided on a focal plane of the plurality of lenses;
the display screen comprises a first substrate and a second substrate that match;
the first substrate is a light-exiting-side substrate, the second substrate comprises a plurality of pixel islands that are arranged in an array, and each of the pixel islands comprises at least one sub-pixel;
the plurality of pixel islands correspond to the plurality of lenses; and
a view region formed by light rays that are emitted by the sub-pixels of the pixel islands and propagated via the corresponding lenses to a human eye is smaller than or equal to a half-pupil region, and light rays of different viewpoints that are emitted by different sub-pixels of the pixel islands enter different cone cells via the lenses;
wherein the lenses are spherical lenses, and the plurality of lenses are closely arranged; and
an aperture D of the lenses satisfies:
D
≥
2
L
tan
(
N
ε
1
2
0
)
;
wherein L is an actual watching distance, N is a quantity of the viewpoints, N≥2, and ε is a human-eye limiting angle of resolution;
wherein the human-eye limiting angle of resolution ε=2′, and the aperture D of the lenses satisfies:
D
≥
2
L
tan
(
N
6
0
)
°
;
wherein,
a first watching distance L F satisfies:
a
/
2
+
e
/
2
tan
ω
≤
L
F
≤
Φ
f
2
p
;
a focal length f of the lenses satisfies:
f
=
(
a
+
e
)
p
Φtan
ω
+
2
p
s
Φ
;
and
a placement height t of the lenses satisfies:
t=nf;
wherein a is a value of a side length of a longer side of the display screen, e is an interpupillary distance between human eyes, p is a pixel spacing of the display screen, Φ is a pupil diameter of a human eye, ω is a field angle of the lenses, s is a preset movable distance, and n is a refractive index of the lenses.
2. The device for optical-field displaying according to claim 1 , wherein N=2, and a minimum value of the apertures of the lenses
D
min
=
2
L
tan
(
1
3
0
)
°
.
3. The device for optical-field displaying according to claim 1 , wherein a shape of a visible space of the device for optical-field displaying is a circular truncated cone;
the circular truncated cone comprises a top circle and a bottom circle that are opposite, and the bottom circle is closer to the display screen than the top circle;
a diameter of the bottom circle is the interpupillary distance between human eyes, and is less than a diameter d of the top circle; and
the diameter d of the top circle satisfies:
d
=
D
Φ
N
p
;
wherein D is the aperture of the lenses, Φ is the pupil diameter of a human eye, and p is the pixel spacing of the display screen.
4. The device for optical-field displaying according to claim 3 , wherein N=2, and the diameter d of the top circle satisfies:
d=DΦ/ 2 p.
5. The device for optical-field displaying according to claim 1 , wherein a shape of a visible space of the device for optical-field displaying is a first circular truncated cone and a second circular truncated cone that are joined, wherein the first circular truncated cone is closer to the display screen than the second circular truncated cone;
the first circular truncated cone comprises a bottom circle and a joining circle that are opposite, and the second circular truncated cone comprises the joining circle and a top circle that are opposite;
a diameter of the bottom circle is the interpupillary distance e between human eyes, and is less than a diameter d of the top circle and a diameter d 2 of the joining circle;
the diameter d of the top circle satisfies:
d
=
D
Φ
2
p
;
the diameter d 2 of the joining circle satisfies:
d
2
=
a
D
2
f
tan
ω
-
D
;
a height h 1 of the first circular truncated cone satisfies:
h
1
=
a
f
2
f
tan
ω
-
D
-
a
+
e
2
tan
ω
;
and
a height h 2 of the second circular truncated cone satisfies:
h 2= s−h 1;
wherein D is the aperture of the lenses, Φ is a pupil diameter of a human eye, p is a pixel spacing of the display screen, f is the focal length of the lenses, ω is a field angle of the lenses, a is the value of the side length of the longer side of the display screen, and s is a preset movable distance.
6. The device for optical-field displaying according to claim 1 , wherein,
a second watching distance L M satisfies:
e
f
D
≤
L
M
<
a
+
e
2
tan
ω
;
wherein a is the value of the side length of the longer side of the display screen, e is the interpupillary distance between human eyes, D is the aperture of the lenses, f is the focal length of the lenses, and ω is the field angle of the lenses.
7. The device for optical-field displaying according to claim 1 , wherein,
a third watching distance L N satisfies:
L
min
≤
L
N
<
e
f
D
;
wherein D is the aperture of the lenses, e is the interpupillary distance between human eyes, f is the focal length of the lenses, and Lmin is a minimum safe distance.
8. The device for optical-field displaying according to claim 7 , wherein the minimum safe distance Lmin is 12 mm.
9. A device for optical-field displaying, wherein the device comprises: a display screen and a lens unit that is provided on a light exiting side of the display screen;
the lens unit comprises a plurality of lenses that are arranged in an array;
the display screen is provided on a focal plane of the plurality of lenses;
the display screen comprises a first substrate and a second substrate that match;
the first substrate is a light-exiting-side substrate, the second substrate comprises a plurality of pixel islands that are arranged in an array, and each of the pixel islands comprises at least one sub-pixel;
the plurality of pixel islands correspond to the plurality of lenses; and
a view region formed by light rays that are emitted by the sub-pixels of the pixel islands and propagated via the corresponding lenses to a human eye is smaller than or equal to a half-pupil region, and light rays of different viewpoints that are emitted by different sub-pixels of the pixel islands enter different cone cells via the lenses;
wherein a resolution PPD of an optical-field imaging system of the device for optical-field displaying satisfies:
PPD
=
L
D
*
π
180
;
wherein D is an aperture of the lenses, and L is an actual watching distance.
10. The device for optical-field displaying according to claim 1 , wherein the focal lengths of the lenses are equal.
11. A device for optical-field displaying, wherein the device comprises: a display screen and a lens unit that is provided on a light exiting side of the display screen;
the lens unit comprises a plurality of lenses that are arranged in an array;
the display screen is provided on a focal plane of the plurality of lenses;
the display screen comprises a first substrate and a second substrate that match;
the first substrate is a light-exiting-side substrate, the second substrate comprises a plurality of pixel islands that are arranged in an array, and each of the pixel islands comprises at least one sub-pixel;
the plurality of pixel islands correspond to the plurality of lenses; and
a view region formed by light rays that are emitted by the sub-pixels of the pixel islands and propagated via the corresponding lenses to a human eye is smaller than or equal to a half-pupil region, and light rays of different viewpoints that are emitted by different sub-pixels of the pixel islands enter different cone cells via the lenses;
wherein the focal lengths of the lenses progressively increase in a first direction, wherein the first direction refers to a direction from a center position of the lens unit to an edge position of the lens unit.
12. The device for optical-field displaying according to claim 1 , wherein the display screen is a liquid-crystal display screen, the first substrate is a color-film substrate, and the second substrate is an array substrate; or,
the display screen is an OLED display screen, the first substrate is a packaging substrate, and the second substrate is a displaying substrate of an OLED unit.