Collimating structure, method for fabricating the same and display device
A collimating structure, a method for fabricating the same and a display device are provided. The collimating structure includes a plurality of light-shielding layers with light-transmitting parts, and the distances between the respective light-shielding layers are adjusted using light-transmitting layers to thereby achieve a desirable depth-to-width ratio of a column of holes so as to define a light convergence angle of the collimating structure. At least one intermediate light-shielding layer is arranged between the top light-shielding layer and the bottom light-shielding layer, and the distances between the respective light-shielding layers are adjusted using the light-transmitting layers, so that crosstalk between light of the light-transmitting parts can be shielded to thereby improve the accuracy of recognized information about texture.
1. A collimating structure, comprising:
a plurality of light-shielding layers and a plurality of light-transmitting layers stacked, and at least one of the light-shielding layers is arranged between every two of the light-transmitting layers, wherein:
the light-shielding layer comprises a plurality of light-transmitting parts and a plurality of light-shielding parts, and the plurality of light-transmitting parts in each light-shielding layer correspond to the light-transmitting parts in other light-shielding layers in one-to-one manner, and orthographic projections of the light-transmitting parts in each light-shielding layer onto at least one light-transmitting layer overlap with orthographic projections of the light-transmitting parts in other light-shielding layers onto the at least one light-transmitting layer; and
the light-shielding layers comprises: a top light-shielding layer, a bottom light-shielding layer, and at least one intermediate light-shielding layer located between the top light-shielding layer and the bottom light-shielding layer; the top light-shielding layer and the bottom light-shielding layer are configured to define a light convergence angle of the collimating structure; and the intermediate light-shielding layer is configured to shield crosstalk between light of the plurality of the light-transmitting parts;
wherein the light-transmitting parts are light-transmitting holes filled with a light-transmitting material;
wherein the light-transmitting layer comprises: a first light-transmitting material layer, a second light-transmitting material layer located between the first light-transmitting material layer and one of the light-shielding layers adjacent to a side of the first light-transmitting material facing the top light-shielding layer, and a third light-transmitting material layer located between the first light-transmitting material layer and one of the light-shielding layers adjacent to a side of the first light-transmitting material layer facing the bottom light-shielding layer; and the third light-transmitting material layer is partially filled in the light-transmitting holes to form the light-transmitting parts.
2. The collimating structure according to claim 1 , wherein the light-transmitting parts are light-transmitting holes.
3. The collimating structure according to claim 1 , wherein all the light-transmitting layers are located between the top light-shielding layer and the bottom light-shielding layer.
4. The collimating structure according to claim 1 , wherein thicknesses of the plurality of light-transmitting layers are different.
5. The collimating structure according to claim 1 , wherein thicknesses of the plurality of light-shielding layers are the same.
6. The collimating structure according to claim 1 , wherein the light-transmitting parts in the light-shielding layer are arranged periodically, and the smaller the periodicity of the light-transmitting parts is, the larger the number of the light-shielding layers is.
7. The collimating structure according to claim 1 , wherein the smaller the diameter of the light-transmitting parts is, the smaller the thickness of the collimating structure is.
8. The collimating structure according to claim 1 , wherein a thickness of the collimating structure is smaller than or equal to 100 μm.
9. The collimating structure according to claim 1 , wherein the number of intermediate light-shielding layers is more than or equal to two.
10. The collimating structure according to claim 1 , wherein the light-transmitting layers and the light-shielding layers satisfy the equations of:
tan
θ
2
=
d
/
H
;
∑
i
=
1
n
h
i
≤
(
p
-
d
)
+
(
n
-
1
)
p
np
*
(
H
-
h
)
-
(
n
-
1
)
h
;
and
(
N
+
1
)
h
+
∑
i
=
1
N
h
i
=
H
;
wherein θ represents the light convergence angle of the collimating structure; d represents a diameter of each of the light-transmitting parts; p represents a periodicity of the light-transmitting parts; H represents a thickness from an outside surface of the top light-shielding layer to an outside surface of the bottom light-shielding layer; h represents a thickness of each of the light-shielding layers; and h, represents a thickness of the light-transmitting layer, i=1, . . . , N, and the light-transmitting layer with smaller i is closer to the top light-shielding layer.
11. The collimating structure according to claim 1 , wherein the orthographic projections of the plurality of light-transmitting parts in each of the light-shielding layer onto at least one light-transmitting layer fully overlap with the orthographic projections of the plurality of light-transmitting parts in other light-shielding layers onto at least one light-transmitting layer.
12. A display device, comprising the collimating structure according to claim 1 , a display panel, and an optical sensor structure, wherein:
the collimating structure is arranged at a surface of the display panel away from a display surface thereof; and the optical sensor structure is arranged at a surface of the collimating structure away from the display panel.
13. The display panel according to claim 12 , wherein the collimating structure is configured, when a finger touches the display surface of the display panel, to collimate light reflected by the finger through the light-transmitting parts in the light-shielding layers and the light-transmitting layers; and the optical sensor structure is configured to receive the light collimated by the collimating structure to recognize fingerprint.
14. The display panel according to claim 12 , wherein the optical sensor structure comprises a plurality of optical sensors corresponding to the plurality of light-transmitting parts in one-to-one manner.
15. A method for fabricating a collimating structure, comprising:
forming a plurality of light-shielding layers with light-transmitting parts and light-shielding parts and a plurality of light-transmitting layers alternately on a base substrate, wherein at least one of the light-shielding layers is formed between every two of the light-transmitting layers, and forming each of the light-transmitting layers comprises: forming a first light-transmitting material layer and a second light-transmitting material layer sequentially;
forming a third light-transmitting material layer before forming the first light-transmitting material layer.