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.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to Chinese patent application No. 201810113825.2 filed on Feb. 5, 2018, which is incorporated herein by reference in its entirety.

FIELD

The present disclosure relates to the field of display technologies, and particularly to a collimating structure, a method for fabricating the same and a display device.

BACKGROUND

During the acquisition of an optical image, when the distance between an object and an optical sensor structure is too large, the acquired image may be blurred, and there may be crosstalk between light of the object for which the image is acquired, thus failing to acquire a clear image of the object as a result.

SUMMARY

In an aspect, an embodiment of the disclosure provides a collimating structure. The collimating structure includes: a plurality of light-shielding layers and a plurality of light-transmitting layers stacked, and at least one of the light-shielding layer 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.

In some embodiments, in the collimating structure above according to the embodiment of the disclosure, the light-transmitting parts are light-transmitting holes.

In some embodiments, in the collimating structure above according to the embodiment of the disclosure, the light-transmitting parts are light-transmitting holes filled with a light-transmitting material.

In some embodiments, in the collimating structure above according to the embodiment of the disclosure, all the light-transmitting layers are located between the top light-shielding layer and the bottom light-shielding layer.

In some embodiments, in the collimating structure above according to the embodiment of the disclosure, the light-transmitting layer includes: a first light-transmitting material layer, and 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.

In some embodiments, in the collimating structure above according to the embodiment of the disclosure, the first light-transmitting material layer is partially filled in the light-transmitting holes to form the light-transmitting parts.

In some embodiments, in the collimating structure above according to the embodiment of the disclosure, the light-transmitting layer further includes: 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.

In some embodiments, in the collimating structure above according to the embodiment of the disclosure, thicknesses of the plurality of light-transmitting layers are different.

In some embodiments, in the collimating structure above according to the embodiment of the disclosure, thicknesses of the plurality of light-shielding layers are the same.

In some embodiments, in the collimating structure above according to the embodiment of the disclosure, the light-transmitting parts in the light-shielding layers are arranged periodically, and the smaller the periodicity of the light-transmitting parts is, the larger the number of the light-shielding layers is.

In some embodiments, in the collimating structure above according to the embodiment of the disclosure, the smaller the diameter of the light-transmitting parts is, the smaller the thickness of the collimating structure is.

In some embodiments, in the collimating structure above according to the embodiment of the disclosure, a thickness of the collimating structure is smaller than or equal to 100 μm.

In some embodiments, in the collimating structure above according to the embodiment of the disclosure, the number of intermediate light-shielding layers is more than or equal to two.

In some embodiments, in the collimating structure above according to the embodiment of the disclosure, the light-shielding layers and the light-shielding layers satisfy the equations of:

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 hirepresents 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.

In some embodiments, in the collimating structure above according to the embodiment of the disclosure, 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.

In another aspect, an embodiment of the disclosure further provides a display device. The display device includes: the collimating structure above according to the embodiment of the disclosure, a display panel, and an optical sensor structure. 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.

In some embodiments, in the display panel above according to the embodiment of the disclosure, 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.

In some embodiments, in the display panel above according to the embodiment of the disclosure, the optical sensor structure includes a plurality of optical sensors corresponding to the plurality of light-transmitting parts in one-to-one manner.

In another aspect, an embodiment of the disclosure further provides a method for fabricating a collimating structure. The method includes: 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 includes: forming a first light-transmitting material layer and a second light-transmitting material layer sequentially.

In some embodiments, in the fabricating method above according to the embodiment of the disclosure, forming the light-transmitting layer further includes: forming a third light-transmitting material layer before forming the first light-transmitting material layer.

DETAILED DESCRIPTION

During a texture is being recognized optically, when the distance between a finger and a sensor is too large, then light reflected by the finger may be diffused so that an acquired image may be blurred, and thus information about the fingerprint may be recognized inaccurately using the light received by the sensor. In order to acquire information about a valley and a ridge of the texture precisely, a collimating structure is generally added to the sensor in a through-hole filter scheme and a lens plus diaphragm scheme. There may be such a high depth-to-width ratio of the through-hole structure made of a specific material that as illustrated inFIG. 1, there may be such a cornered structure in the related photolithograph process that sidewalls of the through-hole structure may not be exactly perpendicular to a light incidence face, so that there is such a larger light convergence angle that there may be crosstalk between information about light rays of adjacent valleys and ridges, so information about the recognized line may be recognized inaccurately, and thus the acquired image may be blurred. In the lens plus diaphragm scheme, there is a large thickness of the device as a whole. Both of the two structures above suffer from high process difficulty, a large thickness of the device as a whole, etc.

In view of the problems above, embodiments of the disclosure provide a collimating structure, a method for fabricating the same and a display device. In order to make the objects, technical solutions, and advantages of the disclosure more apparent, the disclosure will be described below in further details with reference to the drawings, and apparently the embodiments described below are only a part but not all of the embodiments of the disclosure. Based upon the embodiments here of the disclosure, all the other embodiments which can occur to those ordinarily skilled in the art without any inventive effort shall fall into the scope of the disclosure.

The shapes and sizes of respective components in the drawings are not intended to reflect any real proportion, but only intended to illustrate the content of the disclosure.

An embodiment of the disclosure provides a collimating structure, as illustrated inFIG. 2, the collimating structure includes: a plurality of light-shielding layers10and a plurality of light-transmitting layers20stacked, wherein at least one of the light-shielding layers10is arranged between every two of the light-transmitting layers20.

The light-shielding layer includes a plurality of light-transmitting parts11and a plurality of light-shielding parts, and the light-transmitting parts11in each light-shielding layer10correspond to the light-transmitting parts11in another light-shielding layer in a one-to-one manner, and the orthographic projections of the light-transmitting parts11in each light-shielding layer10onto at least one light-transmitting layer20overlap with the orthographic projections of the light-transmitting parts11in other light-shielding layers10onto the at least one light-transmitting layer20.

The light-shielding layers10includes: a top light-shielding layer10a, a bottom light-shielding layer10b, and at least one intermediate light-shielding layer10clocated between the top light-shielding layer10aand the bottom light-shielding layer10b. The top light-shielding layer10aand the bottom light-shielding layer10bare configured to define a light convergence angle θ of the collimating structure; and the intermediate light-shielding layer10cis configured to shield crosstalk between light of the light-transmitting parts11.

Specifically in the collimating structure above according to the embodiment of the disclosure, the number of the light-transmitting parts11in each light-shielding layers10is same, and the corresponding light-transmitting parts11at the respective light-shielding layer10are located at same positions and correspond to each other in a one-to-one manner. The orthographic projections of the light-transmitting parts11at the same position in the respective light-shielding layers10onto at least one light-transmitting layer20overlap with each other as fully as possible, but there is such an alignment error in a real fabrication process that there may be some offset between the light-transmitting parts11at same position in the respective light-shielding layers10, so the light-transmitting parts11may overlap partially with each other instead of overlapping fully with each other.

The orthographic projections of the light-transmitting parts11at the same position in the respective light-shielding layers10onto the light-transmitting layers20overlap with each other so that the light-transmitting parts constitute a column-of-holes structure for collimating light incident on the position at respective angles so that light in some range of angles (small angles) from the normal to the surface of the collimating structure can be transmitted through the column-of-holes structure, and light at larger angles than the range of angles (large angles) can be shielded. The difference between the smallest and largest angles at which light can be transmitted is the light convergence angle θ.

Specifically in the collimating structure above according to the embodiment of the disclosure, the collimating structure includes the plurality of light-shielding layers10with the light-transmitting parts11, and the distances between the light-shielding layers10are adjusted using the light-transmitting layers20to define the distance between the top light-shielding layer10aand the bottom light-shielding layer10band the diameter of the light-transmitting part11, to thereby achieve a desirable depth-to-width ratio of a column of holes so as to define the light convergence angle θ of the collimating structure for a desirable collimation effect, so that information about a valley and a ridge of a fingerprint can be acquired precisely.

Since a better collimating effect can be achieved by fabricating the plurality of structurally simple light-shielding layers and light-transmitting layers, and the structure of the device is light-weighted and thin, the process difficulty of the device can be lowered. Furthermore the intermediate light-shielding layer10cis arranged, and the distances between the respective light-shielding layers10are adjusted using the light-transmitting layers20, so that there is no interfering stray light, that is, the intermediate light-shielding layer10ccan shield crosstalk between light of the light-transmitting parts11to thereby improve the accuracy of recognized fingerprint information.

In some embodiments of the disclosure, in the collimating structure above, as illustrated inFIG. 2, the light-transmitting parts11are light-transmitting holes.

In some embodiments of the disclosure, in the collimating structure above, as illustrated inFIG. 3, light-transmitting parts11are light-transmitting holes filled with a light-transmitting material. The light-transmitting material can fill into the light-transmitting holes to form the light-transmitting parts11. The light-transmitting parts with filled light-transmitting material can avoid air, water molecules, and other substances from existing in the light-transmitting holes, which would otherwise have resulted in exfoliation of a layer, and also can avoid light from being refracted in the transmitting holes, which would otherwise have resulted in inaccurately recognized information.

In some embodiments of the disclosure, in the collimating structure above, the light-transmitting layers20function to adjust the distances between the respective light-shielding layers10, so in order to make the collimating structure more light-weighted and thinner, all the light-transmitting layers20can be located between the top light-shielding layer10aand the bottom light-shielding layer10bas illustrated inFIG. 2, that is, the top light-shielding layer10aand the bottom light-shielding layer10bare the outermost layers of the collimating structure, so that the number of light-shielding layers10is more than the number of light-transmitting layers20in the collimating structure. Of course, a light-transmitting layer20can alternatively be arranged outside the top light-shielding layer10aand the bottom light-shielding layer10bas needed in reality, although the embodiment of the disclosure will not be limited thereto.

Specifically a light-shielding material of the light-shielding parts of the light-shielding layers10can be a material absorbing a light wave in some wavelength range, e.g., a material absorbing the visible wavelength range; or the material of the light-shielding parts of the light-shielding layers10can be a material absorbing some specific wavelength, e.g., a material absorbing an infrared light wave, although the embodiment of the disclosure will not be limited thereto.

Specifically the materials of the light-transmitting layers20and the light-transmitting parts can be light-transmitting materials with a high transmittivity of a light wave in some wavelength range, e.g., materials with a high transmittivity in the visible wavelength range; or the materials of the light-transmitting layers20and the light-transmitting parts can be materials with a high transmittivity at some specific wavelength, e.g., materials with a high transmittivity of an infrared light wave, although the embodiment of the disclosure will not be limited thereto.

In some embodiments, the materials of the light-transmitting layers20and the light-transmitting parts may be the same material or may be different materials. For example, the light-transmitting layers20are made of transparent PI, and the light-transmitting parts are made of SiO2with a transmittivity up to 99%. Since PI is a flexible material, the fabricated collimating structure can be applicable to a flexible component.

In some embodiments, the light-shielding material of the light-shielding parts of the light-shielding layers10can be a BM, and since the BM can not be exposed on the PI material, the BM may remain thereon, thus hindering light transmissive performance of the light-transmitting parts11. In view of this, optionally in the collimating structure above according to the embodiment of the disclosure, as illustrated inFIG. 4, a light-transmitting layer20can include: a first light-transmitting material layer21, and a second light-transmitting material layer22located between the first light-transmitting material layer21and a light-shielding layer10adjacent to the side thereof facing the top light-shielding layer10a.

In some embodiments, the materials of the first light-transmitting material layer21and the second light-transmitting material layer22are different from each other, the thicknesses of the first light-transmitting material layer21and the second light-transmitting material layer22are different from each other. The second light-transmitting material layer22deposited above the first light-transmitting material layer21can isolate the first light-transmitting material layer21from the light-shielding layer10so that the light-shielding layer10fabricated on the second light-transmitting material layer22can be exposed fully, thus forming the light-transmitting parts11. For example, the first light-transmitting material layer21can be made of transparent PI, and the second light-transmitting material layer22can be made of SiO2on which a BM can be exposed fully.

In some embodiments of the disclosure, in the collimating structure above, as illustrated inFIG. 4, the first light-transmitting material layer21can be partially filled in the light-transmitting holes to form the light-transmitting parts11, that is, the light-transmitting parts11are made of a transparent PI material. Or as illustrated inFIG. 5, the light-transmitting layer20can further include: a third light-transmitting material layer23located between the first light-transmitting material layer21and a light-shielding layer10adjacent to the side of the first light-transmitting material layer21facing the bottom light-shielding layer10b, where the third light-transmitting material layer23is partially filled in the light-transmitting holes to form the light-transmitting parts11, that is, the third light-transmitting material layer23located above the light-shielding layer10and the light-transmitting parts11are formed integrally. For example, the third light-transmitting material layer23can be made of SiO2, of which the light-transmitting parts11are made.

In some embodiments of the disclosure, in the collimating structure above, the light-transmitting parts11in each light-shielding layer10are arranged periodically as illustrated inFIG. 6orFIG. 7, where the shape of the light-transmitting part11can be a circular, a square, or another shape, although the embodiment of the disclosure will not be limited thereto. As illustrated inFIG. 6, when the shape of the light-transmitting part11is a circular, the diameter d of the light-transmitting part is the diameter of the circular, and the periodicity p thereof is the distance between the centers of two circulars. As illustrated inFIG. 7, when the shape of the light-transmitting part11is a square, the diameter d of the light-transmitting part is the length of a side of the square, and the periodicity p thereof is the distance between the centers of two squares.

The design principle and the structure of the collimating structure above according to the embodiment of the disclosure will be described below in details.

Specifically the range of the light convergence angle θ is defined by the thickness H between the outer surface of the top light-emitting layer10aand the outer surface of the bottom light-emitting layer10bof the collimating structure, and the diameter d of the light-transmitting part11, that is,

tan⁢θ2=d/H.
As illustrated inFIG. 8andFIG. 9, when a texture is being recognized, a light L1, a light L2, and subsequent light Lm arrive at an optical sensor structure below the collimating structure through the light-transmitting layers20so that an acquired image may be blurred, and thus information about the texture may be recognized inaccurately according to the light received by the optical sensor structure. Accordingly the intermediate light-shielding layer10cneeds to be arranged to shield a crosstalk light beam so that light of adjacent light-transmitting parts11can be shielded or absorbed by the light-shielding layer, and thus there isn't interfering stray light.

As illustrated inFIG. 8andFIG. 9, the crosstalk beam can be shielded under such a principle that: as illustrated inFIG. 8, firstly an intermediate light-shielding layer10cis arranged to firstly shield the light L1, and when the intermediate light-shielding layer10cis insufficient to shield the light L1, then another intermediate light-shielding layer10cis further arranged; and thereafter as illustrated inFIG. 9, still another intermediate light-shielding layer10cis arranged to shield the light L2, and so on until the light Lm can be shielded.

Based on above, in some embodiments of the disclosure, in the collimating structure above, in order to shield more crosstalk light beams, the number of intermediate light-shielding layers10cis two or more, as illustrated inFIG. 9. The number of intermediate light-shielding layers10cshall be set in combination with the other parameters, and a repeated description thereof will be omitted here.

In some embodiments of the disclosure, in the collimating structure above, a light-transmitting layer20is filled between two adjacent light-shielding layers10, and in order to control the spacing between any two of light-shielding layers10, the structural materials and thicknesses of the respective light-shielding layers10are typically the same. Optionally as illustrated inFIG. 8andFIG. 9, the thicknesses of the light-shielding layers10are the same for the sake of easy calculation and fabrication. Of course, the thicknesses of the light-shielding layers10may alternatively be different, although the embodiment of the disclosure will not be limited thereto.

In some embodiments of the disclosure, in the collimating structure above, as illustrated inFIG. 8andFIG. 9, the thicknesses of the respective light-transmitting layers20are different, and their corresponding thicknesses shall be determined for different shielding. How to determine the thicknesses of the respective light-transmitting layers20is described below in details with reference toFIG. 10.

As illustrated inFIG. 10, the diameter of the light-transmitting part is d, the periodicity of the light-transmitting parts, i.e., the spacing between the centers of the light-transmitting parts are p, the thickness of the light-shielding layer10is h, and the thicknesses of N light-transmitting layers20are h1, h2, h3, . . . , hN respectively in the direction from the top light-shielding layer10ato the bottom light-shielding layer10b. As illustrated inFIG. 9, the light-transmitting layers20and the light-shielding layers10satisfy the equations of:

Where θ represents the light convergence angle of the collimating structure; d represents the diameter of the light-transmitting part11; p represents the periodicity of the light-transmitting parts11; H represents the thickness from the outside surface of the top light-shielding layer10ato the outside surface of the bottom light-shielding layer10b; h represents the thickness of a light-shielding layer; and hirepresents the thickness of a light-transmitting layer, i=1, . . . , N, and a light-transmitting layer with smaller i is closer to the top light-shielding layer10a.

Equation

∑i=1n⁢⁢hi≤(p-d)+(n-1)⁢pnp*(H-h)-(n-1)⁢h
is obtained as: the intermediate light-shielding layer10ccan shield crosstalk from light of other light-transmitting parts. Take the collimating structure shown inFIG. 10for example to explain the equation. The light L1from the adjacent light-transmitting part P2can be shielded by the intermediate light-shielding layer10cadjacent to the top shielding layer10a, and doesn't interfere to the light of the light-transmitting part P1, the light-transmitting layers20and the light-shielding layers10needs to satisfy

h⁢⁢1≤(p-d)p*(H-h);
the light L2from the light-transmitting part P3can be shielded by the next intermediate light-shielding layer10c, and doesn't interfere to the light of the light-transmitting part P1, the light-transmitting layers20and the light-shielding layers10needs to satisfy

h⁢⁢1+h⁢⁢2≤(p-d)+p2⁢p*(H-h)-h.
And so on,

Specifically the thickness H from the outside surface of the top light-shielding layer10ato the outside surface of the bottom light-shielding layer10b, i.e., the thickness of the collimating structure can be determined according to the smallest light convergence angle θ required to exactly distinguish a valley from a ridge. Thereafter as can be known from the equation above of

Based on the above equations above, firstly H can be calculated based on the light convergence angle θ, and the diameter d and the periodicity p of the light-transmitting parts are given, then the thicknesses h1, h2, h3, . . . , hN of the light-transmitting layers20can be calculated sequentially in the equations above.

Specifically in a real process, the thicknesses h of the light-shielding layers10are far smaller than the thicknesses of the light-transmitting layers20, so the former can be neglected.

Specifically a luminous flux Q per unit area of a light-shielding layer10is the ratio of the total area S0of the light-transmitting parts11to the area A of the light-shielding layer10, i.e., Q=S0/A. Since the light-transmitting parts11in the light-shielding layer10are arranged periodically, the luminous flux Q is defined as the proportion of the total area of the light-transmitting part11in each periodicity (i.e., a unit area p2). When the shape of the light-transmitting part11is a circular,

Q=d24⁢p2⁢π;
and when the shape of the light-transmitting part11is a square,

Q=d2p2.
As can be apparent, the luminous flux Q is dependent upon the diameter d of the light-transmitting part11and the periodicity p of the light-transmitting parts11. With the periodicity p of the light-transmitting parts11, each selected light beam can correspond precisely to a valley or a ridge of a fingerprint in a one-to-one manner; and the luminous flux Q of the collimating structure is determined directly by the diameter d of the light-transmitting part11, and the lower the luminous flux Q required for an optical sensor structure to response to a light beam of a valley or a ridge is, that is, the higher the sensitivity of the optical sensor structure is, then the smaller the diameter d of the light-transmitting part11is.

In some embodiments of the disclosure, in the collimating structure above, as can be apparent from the equations above, the smaller the diameter d of the light-transmitting part11is, then the smaller the thickness H of the collimating structure is. For example, when the smallest light convergence angle θ required to exactly distinguish a valley from a ridge is 5.7°, and the diameter d of the light-transmitting part11is 6 μm, then the thickness H of the collimating structure from the outer surface of the top light-shielding layer10ato the outer surface of the bottom light-shielding layer10b is42 μm. With the related process, the diameter d of the light-transmitting part11can be made approximately 2 μm, so the thickness of the collimating structure can be made approximately 20 μm, thus making the collimating structure more light-weighted and thinner.

In some embodiments of the disclosure, the transmittivity of the collimating structure, i.e., the amount of effective light information which can be received by an optical sensor structure, is taken into account in a real design process. Firstly the luminous flux Q can be determined according to the sensitivity of an optical sensor structure, and the diameter d of the light-transmitting part11can be determined for a photosensitive area of the optical sensor structure; and thereafter the periodicity p of the light-transmitting parts11can be determined according to the luminous flux Q and the diameter d. Then the thickness H of the collimating structure can be determined according to the diameter d and the smallest light convergence angle θ. Lastly the thicknesses h1, h2, h3, . . . , hN of the respective light-transmitting layers20can be calculated sequentially according to the diameter d, the periodicity p, and the thickness H, thus resulting in an anti-crosstalk structure.

Specifically the thickness H of the collimating structure can be controlled at approximately 20 μm according to the sensitivity of the existing light sensor structure, that is, the higher the sensitivity of the light sensor structure is, then the smaller the diameter d is, and the smaller the overall thickness H of the collimating structure is, so the collimating structure can be made thinner. In some embodiments of the disclosure, in the collimating structure above, the thickness H of the collimating structure is generally 100 μm or smaller.

For example, when the diameter d is 6 μm, and thus the thickness H of the collimating structure is 42 μm, then the luminous flux Q is 13% at the periodicity p of 15 μm, and thus four light-shielding layers10can shield crosstalk from light of adjacent light-transmitting parts11; and as can be determined as a result of optical simulation, the numbers of light-shielding layers10and light-transmitting layers20, and their positions can be controlled so that each selected light beam can correspond precisely to a valley or a ridge of a fingerprint in a one-to-one manner, and there isn't other interfering stray light, so the fingerprint can be recognized precisely, and the performance of the structure with the designed parameters can be satisfactory.

In another example, when the diameter d is 6 μm, and thus the thickness H of the collimating structure is 42 μm, then the luminous flux Q is 20% at the shorter periodicity p of 12 μm, that is, the luminous flux Q is increased, and when four light-shielding layers10are structurally designed again, then a result of optical simulation may show crosstalk between light, so information about a valley cannot be distinguished from information about a ridge, that is, the four-layer structure cannot provide an anti-crosstalk structure. The calculation above is repeated so that a new anti-crosstalk collimating structure shall include five light-shielding layers10. As can be determined as a result of optical simulation, the five-layer structure can shield crosstalk between light beams of adjacent light-transmitting parts11so that information about a valley can be distinguished from information about a ridge.

In still another example, when the diameter d is 6 μm, and thus the thickness H of the collimating structure is 42 μm, then the luminous flux Q is 35% at the even shorter periodicity p of 9 μm, that is, the luminous flux Q is increased, and when five light-shielding layers10are structurally designed again, then a result of optical simulation may show crosstalk between light, so information about a valley cannot be distinguished from information about a ridge, that is, the five-layer structure cannot provide an anti-crosstalk structure. The calculation above is repeated so that a new anti-crosstalk collimating structure shall include seven light-shielding layers10. As can be determined as a result of optical simulation, the seven-layer structure can shield crosstalk between light beams of adjacent light-transmitting parts11so that information about a valley can be distinguished from information about a ridge.

As can be apparent from the examples above, the value of the luminous flux Q shall be improved by designing different anti-crosstalk structures. In the embodiment of the disclosure, a structure with a high luminous flux Q can be designed, and also crosstalk between light can be prevented to thereby recognize information about a valley and a ridge precisely. In some embodiments of the disclosure, in the collimating structure above, when the light-transmitting parts11at the light-shielding layers10are arranged periodically, when the shorter the periodicity p of the light-transmitting parts11is, then the more the number of light-shielding layers10is needed. The transmittivity of the collimating structure can be improved by shortening the periodicity p of the light-transmitting parts11. Furthermore the numbers of light-shielding layers10and light-transmitting layers20, and the thicknesses of the light-transmitting layers20can be controlled so that each selected light beam corresponds to a valley or a ridge of a fingerprint, and there will be no other interfering stray light, so that light of all the adjacent light-transmitting parts11can be shielded by the light-shielding layers10.

Based upon the same inventive idea, an embodiment of the disclosure provides a method for fabricating a collimating structure, and since the fabricating method addresses the problem under a similar principle to the collimating structure above, reference can be made to the implementation of the collimating structure for an implementation of the fabricating method, so a repeated description thereof will be omitted here.

Specifically a method for fabricating a collimating structure according to an embodiment of the disclosure includes the following steps.

Forming a plurality of light-shielding layers10with the light-transmitting parts11and the light-shielding parts, and a plurality of light-transmitting layers20alternately on a base substrate, where 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 layers20includes: forming a first light-transmitting material layer21and a second light-transmitting material layer22sequentially.

In some embodiments of the disclosure, as illustrated inFIG. 4, the second light-transmitting material layer22is located between the first light-transmitting material layer21and a light-shielding layer10adjacent to the side of the first light-transmitting material layer21facing the top light-shielding layer10a, to isolate the first light-transmitting material layer21from the light-shielding layer10, so that the light-shielding layer10fabricated on the second light-transmitting material layer22is exposed completely, thus forming the light-transmitting parts11. For example, the first light-transmitting material layer21can be made of transparent PI, and the second light-transmitting material layer22can be made of SiO2on which a light-shielding material BM can be exposed completely, so such a problem will not occur that a BM on PI is exposed incompletely.

In this manner, as illustrated inFIG. 4, the first light-transmitting material layer21can be partially filled in the light-transmitting holes to form light-transmitting parts11, that is, the light-transmitting parts11are made of a transparent PI material.

Alternatively in the fabricating method above according to the embodiment of the disclosure, as illustrated inFIG. 5, forming each of the light-transmitting layers20can further include: forming a third light-transmitting material layer23before the first light-transmitting material layer21is formed, that is, the third light-transmitting material layer23is located between the first light-transmitting material layer21and a light-shielding layer10adjacent to the side the first light-transmitting material layer21facing the bottom light-shielding layer10b, and the third light-transmitting material layer23is partially filled in the light-transmitting holes to form light-transmitting parts11, that is, the third light-transmitting material layer23located above the light-shielding layer10is structured integral to the light-transmitting parts11. For example, the third light-transmitting material layer23can be made of SiO2, of which the light-transmitting parts11are made.

Based upon the same inventive idea, an embodiment of the disclosure further provides a display device, which can be a mobile phone, a tablet computer, a TV set, a display, a notebook computer, a digital photo frame, a navigator, or any other product or component with a display function. Reference can be made to the embodiment of the collimating structure above for an implementation of the display device, and a repeated description thereof will be omitted here.

An embodiment of the disclosure provides a display device as illustrated inFIG. 11including the collimating structure1above according to the embodiment of the disclosure, a display panel2, and an optical sensor structure3.

The collimating structure1is arranged at a surface of the display panel2away from a display surface thereof; and the optical sensor structure3is arranged at a surface of the collimating structure1away from the display panel2.

In some embodiments, the display surface of the display panel refers to the light-emitting surface of the display panel.

In some embodiments, the collimating structure1is 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 layer and the light-transmitting layers; and the optical sensor structure is configured to receive the light collimated by the collimating structure to recognize fingerprint.

In some embodiments, the optical sensor structure3includes a plurality of sensors corresponding to the plurality of light-transmitting parts11in a one-to-one manner, and when a finger is being recognized, when a finger touches a display screen, the light-shielding layers can select light incident at a small angle by substantially collimating them so that they arrive at the sensors below, and the sensors can detect the strengths of the selected light; and since there are different energies of light diffusively reflected downward by a valley and a ridge, there are different strengths of the light detected by the sensors, so that information about the fingerprint can be acquired.

Specifically the display panel2can be an OLED display panel, which can include a protection cover, optical adhesive, a polarizing sheet, a thin film encapsulation component, a cathode, a light-emitting layer, respective functional layers, an OLED base backboard, and other components, for example.

In the collimating structure, the method for fabricating the same, and the display device above according to the embodiments of the disclosure, the collimating structure including the plurality of light-shielding layers with the light-transmitting parts is arranged so that the distances between the respective light-shielding layers are adjusted using the light-transmitting layers to thereby achieve a desirable depth-to-width ratio of a column of holes, so as to define the light convergence angle of the collimating structure. Since a better collimating effect can be achieved by fabricating the plurality of structurally simple light-shielding layers and light-transmitting layers, and the structure of the device is light-weighted and thin, the process difficulty of the device can be lowered. Furthermore at least one intermediate light-shielding layer between the top light-shielding layer and the bottom light-shielding layer is arranged, 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 texture information.