WO2019127164A1 - Preparation method for anti-aliasing imaging element and optical sensor - Google Patents

Abstract

Disclosed in the present invention is a preparation method for an anti-aliasing imaging element and an optical sensor. The preparation method for the anti-aliasing imaging element comprises the following steps: S11, providing a plurality of optical transmission fibers, the optical transmission fibers comprising a transmitting body and a non-transmitting layer located at the outer side of the transmitting body; and S12, bunching together and fixing in place the plurality of optical transmission fibers. The optical sensor is manufactured by using the anti-aliasing imaging element prepared according to the preparation method for an anti-aliasing imaging element.

Description

Anti-aliasing imaging element and method of preparing optical sensor Technical field

The present invention relates to the field of photoelectric sensing, and in particular to an anti-aliasing imaging element and a method of preparing the optical sensor.

Background technique

At present, biometric information sensors, especially fingerprint identification devices, have gradually become the standard components of electronic products such as mobile terminals. Since the optical fingerprint recognition device has stronger penetration capability than the capacitive fingerprint recognition device, more consideration is given to applying the optical fingerprint recognition device to the mobile terminal. However, when the existing optical fingerprint recognition device is applied to a mobile terminal, a clear and accurate fingerprint image cannot be obtained, and improvement is required.

Summary of the invention

The embodiments of the present invention aim to at least solve one of the technical problems existing in the prior art. To this end, embodiments of the present invention are required to provide an anti-aliasing imaging element and a method of fabricating the optical sensor.

Embodiments of the present invention provide a method for preparing an anti-aliasing imaging element, including the following steps:

S11, providing a plurality of optical transmission fibers, the optical transmission fiber comprising a light transmissive body and a non-transparent layer located outside the light transmissive body;

S12, the plurality of optical transmission fibers are gathered and fixed.

The anti-aliasing imaging element of the embodiment of the invention has low preparation cost, and the prepared anti-aliasing imaging element has a simple structure, and when applied to an optical sensor, the sensing precision of the optical sensor is improved.

In certain embodiments, the step S12 includes: gathering a plurality of light-transmitting fibers, filling the cured glue of the non-translucent material in a vacuum environment, and then curing the fibers.

In some embodiments, the step S11 further includes:

S111, providing a light rod;

S112, the light rod is drawn to form a light-transmitting body of the light-transmitting fiber, and a non-light-transmitting material is sprayed on the outer surface of the light-transmitting body to form a non-transmissive layer of the light-transmitting fiber.

In certain embodiments, the light bar comprises one or more of quartz, glass, polymer.

In some embodiments, the light transmissive body has a circular, square, rectangular, or elliptical cross section.

In some embodiments, the light-transmissive body has a rectangular cut surface and the axial cut surface has a width of 5 to 50 um.

In some embodiments, the step S12 includes coating a cured adhesive of a non-translucent material on the outside of the optical transmission fiber to bond the plurality of optical transmission fibers.

In some embodiments, after the step S12, the method further comprises:

The fixed optical transmission fibers are cut according to the required size and length.

Embodiments of the present invention provide a method of fabricating an optical sensor, including the following steps:

S21, providing a substrate;

S22, forming a plurality of photosensitive cells on the substrate;

S23, providing an anti-aliasing imaging element, and attaching the anti-aliasing imaging element to the photosensitive unit; the anti-aliasing imaging element is prepared by the method for preparing an anti-aliasing imaging element of any of the above embodiments to make;

S24, encapsulating the substrate and the photosensitive unit and the anti-aliasing imaging element on the substrate.

Since the anti-aliasing imaging element is prepared by the above preparation method, the preparation cost of the optical sensor is low, and the anti-aliasing imaging element is utilized to improve the sensing accuracy of the optical sensor.

In certain embodiments, the ratio of length to diameter of the optical axis section of the anti-aliasing imaging element is greater than or equal to 5 and less than or equal to 50.

In some embodiments, the optical sensor is used to acquire biometric information of an object above the sensor.

In some embodiments, the biometric information includes one or more of a fingerprint, a palm print, a vein, a blood pressure, a heart rate, and a blood oxygen concentration.

Embodiments of the present invention provide a method of fabricating another optical sensor, including the following steps:

S31, providing a wafer, the wafer comprising a plurality of optical sensor chips arranged at intervals;

S32, cutting the wafer to obtain a plurality of optical sensor chips;

S33, providing an anti-aliasing imaging plate, the anti-aliasing imaging plate comprising a plurality of optical transmission fibers;

S34, cutting the anti-aliasing imaging plate according to the size and shape of the optical sensor chip to obtain an anti-aliasing imaging element corresponding to the optical sensor chip;

S35. The anti-aliasing imaging element is attached to the optical sensor chip and packaged.

When the optical sensor of the embodiment of the present invention is prepared, the optical sensor chip and the anti-aliasing imaging element can be independently fabricated, and can be formed in plurality at a time, thereby improving the preparation efficiency of the optical sensor.

In some embodiments, in step S33, the anti-aliasing imaging plate is fabricated using the method of preparing the anti-aliasing imaging element of any of the above embodiments.

In some embodiments, the ratio of the length to the diameter of the optical axis of the anti-aliasing imaging element obtained in the step S34 is greater than or equal to 5 and less than or equal to 50.

Additional aspects and advantages of the embodiments of the invention will be set forth in part in

DRAWINGS

The above and/or additional aspects and advantages of the embodiments of the present invention will become apparent and readily understood from

1 is a schematic structural view of a conventional optical fingerprint sensor;

2 is a schematic structural view of a photosensitive unit of an optical fingerprint sensor corresponding to an axial section of an optical fiber;

3 is a schematic cross-sectional structural view of an anti-aliasing imaging element according to an embodiment of the present invention;

4 is a schematic structural view showing an axial section of an optical transmission fiber and a photosensitive unit in an optical sensor according to an embodiment of the present invention;

Figure 5a is a schematic diagram of an optical signal of an optical transmission fiber in the anti-aliasing imaging element of Figure 3;

Figure 5b is a schematic diagram of another optical signal of one optical transmission fiber in the anti-aliasing imaging element of Figure 3;

6 is a schematic view showing a preparation process of an optical transmission fiber according to an embodiment of the present invention;

7 is a schematic flow chart of a method for preparing an anti-aliasing imaging element according to an embodiment of the present invention;

8a is a schematic view showing an arrangement structure of optical transmission fibers in an anti-aliasing imaging element according to an embodiment of the present invention;

8b is a schematic view showing another arrangement structure of optical transmission fibers in an anti-aliasing imaging element according to an embodiment of the present invention;

9 is a schematic flow chart of a method for preparing an anti-aliasing imaging element according to another embodiment of the present invention;

Figure 10 is a cross-sectional structural view showing an optical sensor according to an embodiment of the present invention;

Figure 11 is a view showing the configuration of an optical sensor according to still another embodiment of the present invention;

FIG. 12 is a schematic circuit diagram of an optical sensor according to another embodiment of the present invention; FIG.

Figure 13 is a schematic view showing a specific structure of a photosensitive unit of Figure 12;

Figure 14 is a schematic view showing another specific structure of a photosensitive unit of Figure 12;

15 is a schematic flow chart of a method of fabricating an optical sensor according to an embodiment of the present invention;

16 is a schematic flow chart of a method of fabricating an optical sensor according to another embodiment of the present invention;

17 is a schematic front view of a wafer according to an embodiment of the present invention;

18 is a schematic front structural view of an electronic device according to an embodiment of the present invention;

19 is a cross-sectional structural view of the electronic device of FIG. 18 taken along line I-I.

Detailed ways

The embodiments of the present invention are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals indicate the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are intended to be illustrative of the invention and are not to be construed as limiting.

In the description of the present invention, it is to be understood that the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" or "second" may include one or more of the described features either explicitly or implicitly. In the description of the present invention, the meaning of "a plurality" is two or more unless specifically and specifically defined otherwise. "Contact" or "touch" includes direct or indirect contact. For example, the optical sensor disclosed hereinafter is disposed inside the electronic device, such as below the display screen, and the user's finger indirectly contacts the optical sensor through the protective cover and the display screen.

In the description of the present invention, it should be noted that the terms "installation", "connected", and "connected" are to be understood broadly, and may be fixed or detachable, for example, unless otherwise explicitly defined and defined. Connected, or integrally connected; may be mechanically connected, or may be electrically connected or may communicate with each other; may be directly connected or indirectly connected through an intermediate medium, may be internal communication of two elements or interaction of two elements relationship. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the invention. In addition, the present invention may be repeated with reference to the numerals and/or reference numerals in the various examples, which are for the purpose of simplification and clarity, and do not indicate the relationship between the various embodiments and/or settings discussed. Moreover, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the use of other processes and/or the use of other materials.

Further, the described features, structures may be combined in one or more embodiments in any suitable manner. In the following description, numerous specific details are set forth However, those skilled in the art will appreciate that the technical solution of the present invention can be practiced without one or more of the specific details or other structures, components, and the like. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring the invention.

Referring to FIG. 1, FIG. 1 is a schematic structural view of a conventional optical fingerprint sensor. An existing optical fingerprint sensor is used for identification of an electronic device. The optical fingerprint sensor 200 is located below the display screen 100 of the electronic device and is at least partially located within the display area of the display screen 100. The optical fingerprint sensor 200 includes a plurality of photosensitive units 210 arranged in an array. When a certain part of the object (for example, a human finger) is placed on the display screen 100, after the light signal emitted by the display screen 100 reaches the finger, part of the light signal is absorbed by the finger, and part of the light signal is reflected; the reflected light signal is reflected. After passing through the display screen 100 to reach the optical fingerprint sensor 200, the photosensitive unit 210 of the optical fingerprint sensor 200 receives the reflected light signal, and converts the received optical signal into a corresponding electrical signal, thereby based on the converted electrical signal. , obtain biometric information of the object. The biometric information herein includes, for example, one or more of a fingerprint, a palm print, a vein, a blood pressure, a heart rate, and a blood oxygen concentration. Objects such as, but not limited to, human bodies, may also be other suitable types of organisms.

Since the biometric information of the object is an inherent physiological feature of the human body, the biometric information of the object will be used as an important basis for the identification of the object, and it is used to determine whether the identity of the user of the electronic device is legal, and thus the electronic device is controlled to perform corresponding operations, for example, Unlock operations, view data, mobile payments, and more.

The electronic device mentioned in the embodiments of the present invention is, for example, but not limited to, a suitable type of electronic product such as a consumer electronic product, a home electronic product, a vehicle-mounted electronic product, a financial terminal product, or the like. Among them, consumer electronic products are, for example, mobile phones, tablet computers, notebook computers, desktop displays, computer integrated machines, and the like. Home-based electronic products such as smart door locks, televisions, refrigerators, wearable devices, and the like. Vehicle-mounted electronic products are, for example, car navigation systems, car DVDs, and the like. Financial terminal products such as ATM machines, terminals for self-service business, etc.

It should be noted that, if the optical fingerprint sensor further includes a light source, the display screen of the electronic device may not work when the optical fingerprint sensor is in operation. As such, the electronic device to which the optical fingerprint sensor is applied is not limited to the display screen structure, that is, an electronic product without a display screen is also included.

Further, since the light signal is reflected by the object above the display screen 100, the reflected light signal is many and disordered, and the distance between the photosensitive cells 210 is very small, so the light signal reflected by the object above the photosensitive unit 210 may be The adjacent photosensitive unit 210 receives, thereby causing the biometric information obtained by the optical fingerprint sensor 200 to be inaccurate and unclear. In response, it has been proposed to use fiber optic structures to solve this problem. As shown in FIG. 2, FIG. 2 is a schematic structural view of a photosensitive unit of an optical fingerprint sensor corresponding to an axial section of the optical fiber. An optical fiber 220 is disposed on the photosensitive unit 210. The optical fiber 220 includes a light-tight dielectric layer 221 and a light-diffusing dielectric layer 222 and a plastic coating layer 223 from the inside to the outside. The optically dense dielectric layer 221 is a dielectric layer having a large refractive index. The dielectric layer 222 is a dielectric layer having a small refractive index, whereby a critical plane L is formed between the optically dense dielectric layer 221 and the optically dispersed dielectric layer 222. Due to the difference in refractive index on both sides of the critical surface L, when the optical signal enters from the incident surface S1 of the optical fiber 220, only a certain range of optical signals can be totally reflected at the critical plane L until it is emitted from the exit surface S2 of the optical fiber. Assuming that the critical angle when the fiber is totally reflected is θ, the calculation formula of the maximum angle of incidence β _max entering the incident surface S1 of the fiber is as follows:

Where n ₀ is the refractive index in the air, n ₁ is the refractive index of the optically dense medium layer 221, and n ₂ is the refractive index of the light-diffusing dielectric layer 222. Since the refractive index in the air is 1, substantially the incident angle maximum value β _max is only related to the refractive indices of the optically dense medium layer 221 and the light-diffusing dielectric layer 222. As can be seen from the above equation, an optical signal having an incident angle less than or equal to the maximum value of the incident angle β _max can be totally reflected at the critical plane L and emitted from the exit surface S2 of the optical fiber.

The inventors have found that although the above-mentioned optical fiber structure can avoid the optical signal larger than the incident angle maximum value β _max reaching the photosensitive unit 210, the biometric information collected by the optical fingerprint sensor is still not clear enough, and the main reason is found after analysis. Two: First, the maximum incident angle β _{max of} the fiber structure is too large, and there are still some adjacent interference signals. By changing the refractive index of the fiber dielectric layer, the incident angle maximum value β _{max of the} fiber structure is reduced, although The optical fingerprint sensor collects clear biometric information, but the manufacturing process cost of the optical fiber structure also increases accordingly. Second, an optical signal larger than the incident angle maximum β _max enters the optical fiber, passes through the optically dense dielectric layer 221 and the optically dispersed dielectric layer. After the refraction of 222, it will be reflected on the critical surface of the light-diffusing dielectric layer 222 and the plastic coating 223, and the reflected optical signal will re-enter the optical-dense dielectric layer 221 and be emitted from the exit surface S2 of the optical fiber.

Therefore, the inventors propose a new structure, that is, an anti-aliasing imaging element, which can solve the problem of the manufacturing process cost and enable the optical sensor to collect clearer and more accurate biometric information.

3 and FIG. 4, FIG. 3 is a schematic cross-sectional view of an anti-aliasing imaging element according to an embodiment of the present invention, and FIG. 4 is an axial section of an optical transmission fiber and a photosensitive unit in an optical sensor according to an embodiment of the present invention. Schematic. The anti-aliasing imaging element 30 includes a plurality of optical transmission fibers 310, and each of the optical transmission fibers 310 includes a light transmissive body 311 and a non-transmissive layer 312 located outside the light transmissive body 311. The light transmitting body 311 is, for example, a core in an optical fiber structure. The non-transmissive layer 312 is formed of a light absorbing material and covers a cladding layer on the outer side of the light-transmitting body 311, and the non-light-transmitting layer 312 and the light-transmitting body 311 are in close contact with each other. In order to ensure a close adhesion between the non-transmissive layer 312 and the light-transmitting body 311, the light-transmitting body 311 is formed, and a non-light-transmitting material (that is, a light-absorbing material) is applied to the outer periphery of the light-transmitting body 311, and then subjected to a curing treatment. Of course, the non-transmissive layer 312 and the light-transmitting body 311 may be separately pressed and bonded together after being separately formed.

In certain embodiments, the light absorbing material comprises a metal oxide, a carbon black coating, a black ink, and the like. Wherein the metal in the metal oxide is, for example but not limited to, one of chromium (Cr), nickel (Ni), iron (Fe), tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo) or Several.

In the anti-aliasing imaging element 30, both ends of the optical transmission fiber 310 are an incident end surface 301 and an emission end surface 302, respectively, and an optical signal is incident from the incident end surface 301, is emitted from the emission end surface 302, and reaches the photosensitive unit 32. When the optical signal is incident on the transparent body 311 from the incident end surface 301, the optical signal will be refracted due to the difference of the medium, and most of the optical signals of the refracted optical signal will reach the critical surface of the transparent body 311 and the non-transmissive layer 312. L' is absorbed by the non-transmissive layer 312; the remaining optical signal will be substantially parallel to the axial direction of the light-transmitting body 311, and will be emitted from the exit end face 302 and reach the photosensitive unit 32.

Specifically, referring to FIG. 5a, FIG. 5a is a schematic diagram of an optical signal of an optical transmission fiber in the anti-aliasing imaging element of FIG. When an incident light signal P1 enters the incident end surface 301, refraction occurs, and the refracted light signal P1' reaches the critical surface L' of the light transmitting body 311 and the non-light transmitting layer 312, and is absorbed by the non-light transmitting layer 312.

Referring to Figure 5b, Figure 5b is a schematic illustration of another optical signal of one of the optical transmission fibers of the anti-aliasing imaging element of Figure 3. When an incident light signal P2 enters the incident end surface 301, refraction occurs, and the direction of the refracted light signal P2' is substantially parallel to the axial direction P3 of the light transmitting body 311, and is emitted from the exit end surface 302, and is received by the photosensitive unit 32.

Further, with continued reference to FIG. 4, it is assumed that the width of the light transmitting body 311 in the axial section of the optical transmission fiber 310 is D and the height is H; the medium refractive index of the light transmitting body 311 in the optical transmission fiber 310 is n ₃ , and the optical transmission fiber The medium other than 310 has a refractive index of n ₄ . According to the principle of refraction, the calculation formula of the incident angle maximum γ _max is as follows:

That is, the optical signal having an incident angle smaller than or equal to the incident angle maximum γ _max can pass through the light transmitting body 311 of the optical transmission fiber 310 and reach the photosensitive unit 32. In order to improve the anti-aliasing effect of the anti-aliasing imaging element 30, the incident angle maximum γ _{max is} reduced. It can be seen from the above formula (2) that the incident angle maximum value γ _{max is} related to the refractive index of the medium and the height H and the width D of the axial section of the light transmitting body 311. Therefore, it is possible to reduce the incident angle maximum value γ _max . This is accomplished, for example, by increasing the overall height H of the anti-aliasing imaging element 30 (which may also be referred to as thickness), reducing the width D of the axial section of the light transmissive body 311 in the optical transmission fiber 310, and reducing the optical transmission fiber 310. The refractive index n3 of the medium-transmissive body 311 increases the refractive index n4 of the medium other than the optical transmission fiber 310. Moreover, the anti-aliasing imaging element 30 has a simple structure and a low manufacturing process cost. In addition, since the outer side of the light transmitting body 311 is a light absorbing material layer, the light signal entering the anti-aliasing imaging element 30 does not leak from the side, and the incident angle of the light signal entering the anti-aliasing imaging element 30 is not larger than the incident. The optical signal of the angular maximum γ _max is emitted from the exit end face 302 and reaches the photosensitive unit 32. Therefore, the anti-aliasing imaging element 30 of the embodiment of the present invention has a simple structure and a low manufacturing process cost, and also makes the biometric information collected by the optical sensor 300 clearer and more accurate than the prior art.

In some embodiments, the cross section of the light transmissive body 311 is, for example, a circle, a square, a rectangle, an ellipse, or the like. Moreover, the axial section of the transparent body 311 is rectangular, and the width D of the axial section ranges from 5 to 50 μm, and the width can be set to, for example, 10 μm, 15 μm, 20 μm, 30 μm, and 35 μm according to actual use and preparation processes. , 40 μm, 45 μm, etc.

In some embodiments, the light transmissive body 311 includes, for example, one or more materials of materials such as quartz, glass, plastic, infrared, and the like.

Further, referring to FIG. 6, FIG. 6 is a schematic diagram of a preparation process of an optical transmission fiber according to an embodiment of the present invention. The preparation process of the optical transmission fiber specifically includes the following steps:

S101, providing a light bar;

The light bar includes, for example, a rod of one or more materials of materials such as quartz, glass, plastic, infrared, and the like.

S102, the light rod is drawn to form a light transmitting body 311 of the optical transmission fiber;

Using a wire drawing machine, the light bar is fixed to the top of the wire drawing machine and gradually heated to a certain temperature, for example, 2000 ° C. The one end of the light bar on the heating side is gradually melted after being heated and accumulates as a liquid at the end, and when it is naturally suspended, the light transmitting body 311 of the light transmitting fiber is formed.

S103, spraying a non-transparent material on the outer periphery of the transparent body 311 to form a non-transparent layer of the optical transmission fiber;

A non-transmissive material is uniformly sprayed on the outer periphery of the formed light-transmitting body 311 to form a non-transmissive layer 312 of the light-transmitting fiber 310. Of course, alternatively, the formed light-transmitting body 311 may be placed in a sol of a non-light-transmitting material and then taken out.

S104, curing the non-transmissive layer of the optical transmission fiber.

The light transmitting fiber 310 is irradiated with ultraviolet rays to cure the non-light transmitting layer 312 of the light transmitting fiber 310. Of course, the light transmitting fiber 310 can also be naturally cooled.

It should be noted that the preparation process of the optical transmission fiber 310 described above is performed in a dust-free environment to ensure the optical quality of the optical transmission fiber 310. In addition, the above steps S103 and S102 may be performed simultaneously, that is, spraying of the non-transparent material is performed while forming the light-transmitting body 311.

Further, referring to FIG. 7, FIG. 7 is a schematic flow chart of a method for preparing an anti-aliasing imaging element according to an embodiment of the present invention. The method for preparing the anti-aliasing imaging element comprises the following steps:

S201, providing a plurality of optical transmission fibers, the optical transmission fiber comprising a light transmissive body and a non-transparent layer located outside the light transmissive body;

S202, the plurality of optical transmission fibers are gathered and fixed.

Specifically, for example, a plurality of optical transmission fibers are produced according to the production method shown in Fig. 6, and of course, it is not limited to other preparation methods. The resulting optical transmission fiber includes the structures described in the above embodiments, and includes, for example, a light transmitting body 311 and a non-light transmitting layer 312 located outside the light transmitting body 311. The plurality of light transmitting fibers are then gathered together and fixed. For example, in one embodiment, the curing glue of the non-translucent material is coated on the periphery of the plurality of optical transmission fibers to bond the plurality of optical transmission fibers; or in another embodiment, the optical transmission fibers are in a vacuum environment. The gap between the gaps is filled with a curing adhesive of a non-translucent material and cured.

Further, after the optical transmission fiber 310 is prepared, the plurality of optical transmission fibers 310 are gathered together in a predetermined arrangement to form the anti-aliasing imaging element 30. In some embodiments, the axes of the plurality of optical transmission fibers 31 gathered together are parallel to each other, and the optical transmission fibers 310 are bonded by a cured adhesive of a non-translucent material. Specifically, a layer of curing glue is applied to the outer periphery of the optical transmission fiber 310, and then a plurality of optical transmission fibers 310 are gathered together, and the optical transmission fiber 310 is bonded and fixed by the peripheral curing glue to form an anti-aliasing imaging element. 30. As shown in Fig. 8a, the optical transmission fibers are arranged in a rectangular arrangement. As shown in Figure 8b, the optical transmission fibers are arranged in a honeycomb-like structure. The arrangement shown in Fig. 8b is smaller than the arrangement shown in Fig. 8a, and the gap between the optical transmission fibers is small.

In certain embodiments, when the plurality of light transmitting fibers 310 are brought together, there is a gap between the light transmitting fibers 310, the gap being filled with a cured glue of a non-translucent material. Specifically, the optical transmission fibers 310 are first gathered together, and then glued from one end or both ends of the optical transmission fibers 310 so that the curing glue fills the gap between the optical transmission fibers 310. Further, the potting process will be performed under a vacuum environment to avoid the presence of air bubbles during the filling process that affect the optical quality of the anti-aliasing imaging element 30.

In some embodiments, the anti-aliasing imaging element 30 has an aperture ratio greater than or equal to 30%. Preferably, the aperture ratio is greater than or equal to 50%. In order to ensure both the anti-aliasing effect and the sufficient amount of optical signal to pass through the anti-aliasing imaging element 30, a preferred value may be selected depending on the actual use, such as 55%, 60%, 70%, and the like. It is to be noted that the aperture ratio of the anti-aliasing imaging element 30 is a percentage of the cross-sectional area of the cross-sectional area of the anti-aliasing imaging element 30 in the entire cross-sectional area.

In some embodiments, the non-transmissive material in the cured gel filled in the gap is consistent with the material of the non-transmissive layer 312 in the optical transmission fiber 310. This causes the non-transmissive layer 312 of the optical transmission fiber 310 to be completely fused with the cured glue in the gap, thereby making the bonding between the optical transmission fibers 310 more stable.

In some embodiments, the non-transmissive layer 312 may be semi-cured or not cured after the above step S103, and after the plurality of optical transmission fibers 310 are gathered together, the extrusion process is performed to make the non-transparent layer. 312 fills the gap between the optical transmission fibers 310.

Further, referring to FIG. 9, FIG. 9 is a schematic flow chart of a method for preparing an anti-aliasing imaging element according to another embodiment of the present invention. Based on the foregoing embodiment, after step S202, the method further includes:

S203, cutting the fixed optical transmission fiber according to the required size and thickness.

In the actual use of the anti-aliasing imaging element, its corresponding size and thickness will be set according to actual use requirements. For example, when applied to an optical sensor, the shape of the optical sensor may include a rectangle, a square, a circle, etc., and as described above, by adjusting the thickness of the anti-aliasing imaging element, the anti-aliasing imaging element can be reduced. The maximum angle of incidence, thereby improving the sensing accuracy of the optical sensor, and the manufacturing process cost is reduced. Therefore, in the production of the anti-aliasing imaging element, the longer optical transmission fibers are gathered and fixed, and then laterally cut to obtain an anti-aliasing imaging plate of a desired thickness. At the same time, the transversely-cut anti-aliasing imaging plate is longitudinally cut according to the actual size of the optical sensor to obtain an anti-aliasing imaging element of a desired size. Here, the longitudinal cutting means cutting in a direction parallel to the axis of the optical transmission fiber, and the transverse cutting means cutting in a direction perpendicular to the axis of the optical transmission fiber.

Further, after longitudinally cutting the folded and fixed optical transmission fiber, in order to avoid optical transmission of the optical transmission fiber, the optical quality is affected. In the embodiment, the outer periphery of the anti-aliased imaging element after cutting is coated with one. The layer is a non-transparent material.

In some embodiments, the anti-aliasing imaging element described above is applied, for example, to an optical sensor to prevent optical signals received by adjacent photosensitive units from interfering with each other and affecting the sensing accuracy of the optical sensor. Of course, the anti-aliasing imaging element can also be applied to other optical components.

Specifically, referring to FIG. 10, FIG. 10 is a schematic cross-sectional structural view of an optical sensor according to an embodiment of the present invention. The optical sensor 300 is configured to collect biometric information of an object above the sensor, and the biometric information includes one or more of a fingerprint, a palm print, a vein, a blood pressure, a heart rate, and a blood oxygen concentration. The optical sensor 300 includes, for example, a substrate 31, a plurality of photosensitive cells 32 arranged on the substrate 31, and an anti-aliasing imaging element 30 on the photosensitive unit 32. The anti-aliasing imaging element 30 is implemented with reference to the structure described in the above embodiments for enabling an optical signal having an incident angle smaller than the incident angle maximum γ _max to pass through and reach the photosensitive unit 32, and the remaining optical signals are anti-aliased The imaging element 30 absorbs, thus improving the sensing accuracy of the optical sensor, resulting in clearer, more accurate biometric information.

In some embodiments, the ratio between the length and the width of the optical axis section of the anti-aliasing imaging element 30 ranges from 5 to 50, ie, the ratio is greater than or equal to 5 and less than or equal to 50. For example, 10, 15, 20, 30, 40, etc. By setting the ratio, the maximum incident angle of the optical transmission fiber in the anti-aliasing imaging element 30 is adjusted to improve the sensing accuracy of the optical sensor.

In some embodiments, since each of the light-transmitting fibers of the anti-aliasing imaging member 30 has a light-transmissive axis-cut width that is small, one photosensitive unit 32 corresponds to a plurality of light-transmitting fibers, thus making the anti-aliasing imaging element When placed on the photosensitive unit 32, the alignment is not required, thereby reducing the manufacturing process cost of the optical sensor, and also improving the sensing accuracy of the optical sensor 300.

Further, the optical sensor 300 further includes a light source 33 disposed on the substrate 31 and located outside the photosensitive region, which is a photosensitive region formed by the plurality of photosensitive cells 32. The light source 33 is for emitting an optical signal of a predetermined wavelength, such as a white light signal, an infrared light signal, an ultraviolet light signal, a fluorescent signal, or the like.

In some embodiments, please refer to FIG. 11, which is a configuration of an optical sensor 300 according to still another embodiment of the present invention. In some embodiments, the optical sensor 300 further includes a package body 34 for packaging the substrate 31 and all devices on the substrate 31, such as the photosensitive unit 32. The anti-aliasing imaging element 30, the light source 33, and the like are packaged.

In some embodiments, the substrate 31 and the plurality of photosensitive cells 32 on the substrate 31 form a photosensitive die, and the photosensitive die (Die) is a semiconductor integrated circuit device. The substrate 31 is further formed with a scan line group and a data line group electrically connected to the photosensitive unit 32, and the scan line group is configured to transmit a scan driving signal to the photosensitive unit 32 to activate the photosensitive unit 32 to perform light sensing, data. The line group is used to output an electric signal generated by the photosensitive unit 32 performing light sensing. The substrate 31 is, for example but not limited to, a silicon substrate or the like.

Specifically, in some embodiments, please refer to FIG. 12, which is a schematic diagram of a circuit structure of an optical sensor according to another embodiment of the present invention. The photosensitive cells 32 are distributed in an array, such as a matrix distribution. Of course, it can also be distributed in other rule manners or in an irregular manner. The scan line group includes a plurality of scan lines 303. The data line group includes a plurality of data lines 304. The plurality of scan lines 303 and the plurality of data lines 304 are disposed to cross each other and disposed between adjacent photosensitive units 32. For example, a plurality of scanning lines G1, G2, ..., Gm are arranged at intervals in the Y direction, and a plurality of data lines S1, S2, ..., Sn are arranged at intervals in the X direction. However, the plurality of scanning lines 303 and the plurality of data lines 304 are not limited to the vertical arrangement shown in FIG. 12, and may be disposed at an angle, for example, 30°, 60°, or the like. In addition, due to the conductivity of the scan line 303 and the data line 304, the scan line 303 and the data line 304 at the intersection are separated by an insulating material.

It should be noted that the distribution and the number of the scan lines 303 and the data lines 304 are not limited to the above-exemplified embodiments, and the corresponding scan line groups and data line groups may be correspondingly set according to the structure of the photosensitive pixels. .

Further, a plurality of scan lines 303 are connected to a driving circuit 35, and a plurality of data lines 304 are connected to a signal processing circuit 36. The driving circuit 35 is configured to provide a corresponding scan driving signal and transmit it to the corresponding photosensitive unit 32 through the corresponding scanning line 303 to activate the photosensitive unit 32 to perform light sensing. The driving circuit 35 is formed on the substrate 31. Of course, the flexible circuit board can also be electrically connected to the photosensitive unit 32, that is, the plurality of scanning lines 303 are connected. The signal processing circuit 36 receives an electrical signal generated by the corresponding photosensitive unit 32 performing light sensing through the data line 303, and acquires biometric information of the target object based on the electrical signal.

In some embodiments, the optical sensor 300 further includes a controller 37 for controlling the drive circuit to output a corresponding scan drive signal, such as, but not limited to, progressively activating the photosensitive unit 32 to perform light sensing. The controller 37 is further configured to control the signal processing circuit 36 to receive the electrical signal output by the photosensitive unit 32, and after receiving the electrical signals output by all the photosensitive units 32 that perform light sensing, generate biometric information of the target object based on the electrical signals. .

Further, the signal processing circuit 36 and the controller 37 may be formed on the substrate 31 or electrically connected to the photosensitive die through the flexible circuit board.

In some embodiments, as shown in FIG. 13, FIG. 13 is a detailed structural diagram of a photosensitive unit 32 of FIG. The photosensitive unit 32 includes a photosensitive device 320 and a switching device 322. The switching device 322 has a control terminal C and two signal terminals, such as a first signal terminal Sn1 and a second signal terminal Sn2. The control terminal C of the switching device 322 is connected to the scan line 304. The first signal terminal Sn1 of the switching device 322 is connected to the reference signal L via the photosensitive device 320. The second signal terminal Sn2 of the switching device 322 is connected to the data line 304. It should be noted that the photosensitive unit 32 shown in FIG. 13 is for illustrative purposes only and is not limited to other constituent structures of the photosensitive unit 32.

Specifically, the above-mentioned photosensitive device 320 is, for example but not limited to, any one or several of a photodiode, a phototransistor, a photodiode, a photo resistor, and a thin film transistor. Taking a photodiode as an example, a negative voltage is applied across the photodiode. At this time, if the photodiode receives the optical signal, a photocurrent is generated in a proportional relationship with the optical signal, and the received optical signal is more intense. Larger, the larger the photocurrent generated, the faster the voltage drop on the negative pole of the photodiode. Therefore, by collecting the voltage signal on the negative pole of the photodiode, the intensity of the optical signal reflected from different parts of the target object is obtained, and the target is obtained. Biometric information of the object. It can be understood that in order to increase the photosensitive effect of the photosensitive device 320, a plurality of photosensitive devices 320 may be disposed.

Further, the switching device 322 is, for example but not limited to, any one or several of a triode, a MOS transistor, and a thin film transistor. Of course, the switching device 322 may also include other types of devices, and the number may also be two, three, and the like.

Taking the structure of the photosensitive unit 32 shown in FIG. 13 as an example, the gate of the MOS transistor serves as the control terminal C of the switching device 322, and the source and the drain of the MOS transistor correspond to the first signal terminal Sn1 and the second of the switching device 322. Signal terminal Sn2. The gate of the MOS transistor is connected to the scanning line 303, the source of the MOS transistor is connected to the cathode of the photodiode D1, and the drain of the MOS transistor is connected to the data line 304. The anode of the photodiode D1 is connected to a reference signal L, which is, for example, a ground signal or a negative voltage signal.

When the photosensitive unit 32 performs photo sensing, a scan driving signal is applied to the gate of the thin film transistor TFT through the scan line 303 to drive the MOS transistor to be turned on. At this time, the data line 304 is connected to a positive voltage signal. When the MOS transistor is turned on, the positive voltage signal on the data line 304 is applied to the negative electrode of the photodiode D1 via the MOS transistor. Since the positive electrode of the photodiode D1 is grounded, the photodiode D1 is A reverse voltage will be applied across the terminals such that the photodiode D1 is in a reverse bias, ie, in operation. At this time, when an optical signal is irradiated to the photodiode D1, the reverse current of the photodiode D1 rapidly increases, thereby causing a change in current on the photodiode D1, which can be obtained from the data line 304. Since the intensity of the optical signal is larger, the reverse current generated is also larger. Therefore, according to the current signal acquired on the data line 304, the intensity of the optical signal can be obtained, thereby obtaining the biometric information of the target object.

In some embodiments, the reference signal L may be a positive voltage signal, a negative voltage signal, a ground signal, or the like. As long as the electrical signal provided on the data line 304 and the reference signal L are applied across the photodiode D1 such that a reverse voltage is formed across the photodiode D1 to perform photo sensing, both are within the scope of protection defined by the present invention.

It can be understood that the connection manner of the MOS tube and the photodiode D1 in the above-mentioned photosensitive unit 32 is not limited to the connection manner shown in FIG. 13, and may be other connection methods. For example, as shown in FIG. 14, the gate G of the MOS transistor is connected to the scanning line 303, the drain D of the MOS transistor is connected to the anode of the photodiode D1, and the source S of the MOS transistor is connected to the data line 304. The negative terminal of the photodiode D1 is connected to a positive voltage signal.

Further, referring to FIG. 15, FIG. 15 is a flow chart showing a method of manufacturing an optical sensor according to an embodiment of the present invention. The preparation method comprises the following steps:

S301, providing a substrate;

The substrate 31 is, for example but not limited to, a silicon substrate, a metal plate, a circuit printing plate, or the like, and may of course be a substrate such as a glass substrate.

S302, forming a plurality of photosensitive cells on the substrate;

A photosensitive device 320 and a switching device 322 of the photosensitive unit 32 are formed on the substrate 31, respectively. In addition, data lines and scan lines, and corresponding circuit structures such as the drive circuit 35, the signal processing circuit 36, and the like, will also be formed on the substrate 31.

S303, providing an anti-aliasing imaging element and attaching the anti-aliasing imaging element to the photosensitive unit.

The anti-aliasing imaging element 30 is produced by the preparation method of each of the above embodiments, and the anti-aliasing imaging element 30 is cut to a desired size and thickness and then attached to the photosensitive unit 32. Of course, if the size and thickness of the anti-aliasing imaging element meet the requirements, it is directly attached to the photosensitive unit 32 without a cutting process.

Further, referring to FIG. 16, FIG. 16 is a schematic flow chart of a method for fabricating an optical sensor according to another embodiment of the present invention. The preparation method comprises the following steps:

S401, providing a wafer, the wafer comprising a plurality of optical sensing chips arranged at intervals;

Referring to Fig. 17, Fig. 17 is a front view showing the structure of a wafer according to an embodiment of the present invention. The wafer 400 includes a substrate and a plurality of optical sensing circuits formed on the substrate, the substrate including a plurality of spaced apart sensing chip regions 410, each of the sensing chip regions 410 for forming an optical Sensor chip. The sensing chip regions 410 are arranged in an array, and a cutting region 420 is formed between adjacent sensing chip regions 410.

S402, cutting the wafer to obtain a plurality of optical sensor chips;

The wafer is diced in the dicing zone to obtain a plurality of independent optical sensing chips.

S403, providing an anti-aliasing imaging plate, the anti-aliasing imaging plate comprising a plurality of optical transmission fibers;

According to the above-described method for preparing an anti-aliasing imaging element, an optical transmission fiber strip is produced, that is, a plurality of optical transmission fiber ribbons are gathered together and fixedly formed. The plurality of transport fiber strips are transversely cut to the thickness required for the anti-aliasing imaging plate to form an anti-aliasing imaging plate.

S404, cutting the anti-aliasing imaging board according to the size and shape of the optical sensing chip to obtain an anti-aliasing imaging element corresponding to the optical sensing chip;

According to the size and shape of the optical sensor chip, the anti-aliasing imaging plate is longitudinally cut to obtain an anti-aliasing imaging element. Since the anti-aliasing imaging element is identical in size and shape to the optical sensing chip, the obtained anti-aliasing imaging element does not need to be aligned and directly attached to the optical sensing chip. Of course, the anti-aliasing imaging element can also be longitudinally cut against the aliasing imaging plate according to the size and shape of the sensing area of the optical sensing chip, thus saving the cost of the anti-aliasing imaging element.

S405. The anti-aliasing imaging element is bonded to an optical sensing chip and packaged.

The anti-aliasing imaging element is attached to the optical sensing chip such that the anti-aliasing imaging element is located at least above the sensing region of the optical sensing chip. The bonded anti-aliasing imaging element and the optical sensor chip are then packaged to form an optical sensor.

Further, referring to FIG. 18 and FIG. 19, FIG. 18 is a schematic front structural view of an electronic device according to an embodiment of the present invention, and FIG. 19 is a cross-sectional structural view of the electronic device of FIG. 18 taken along line I-I. The electronic device 1 includes, for example, a display screen 500 and an optical sensor 300 located below the display screen 500. The sensing area R2 of the optical sensor 300 is located at a partial position of the display area R1 of the display screen 500, such as the middle-lower position of the display area R1 shown in FIG. 18, facilitating the one-hand touch electronic device 1 to perform a fingerprint recognition operation. Of course, if the size and shape of the electronic device 1 are different, the installation position of the optical sensor 300 will also vary according to actual needs.

It should be noted that, in actual use, the sensing region R2 of the optical sensor in FIG. 18 will not be displayed in the display screen or displayed in other forms.

Further, the optical sensor 300 is implemented by referring to the optical sensor of each of the above embodiments. In addition, the display screen 500 and the optical sensor 300 are fixed by optical glue bonding.

In some embodiments, a protective cover 600 is also disposed over the display screen to prevent the display screen 500 from directly contacting the object and damaging the display screen 500. Taking the target object as a finger as an example, when the finger is located on the protective cover 600 of the electronic device 1 and located in the fingerprint recognition area R2, the light signal emitted by the display screen 500 will be reflected after reaching the finger, and the reflected light signal is worn. The optical sensor 300 is reached after the display screen 500. The optical sensor 300 receives the reflected optical signal and converts the received optical signal into a corresponding electrical signal. Since the valley portion and the ridge portion of the finger have different degrees of reflection on the optical signal, for example, the valley portion totally reflects the optical signal, and the ridge portion diffuses the optical signal, so that the fingerprint image of the finger is obtained according to the converted electrical signal, This carries out the identification of the user of the electronic device.

In the description of the present specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples", etc. The specific features, structures, materials or characteristics described in the embodiments or examples are included in at least one embodiment or example of the invention. In the present specification, the schematic representation of the above terms does not necessarily mean the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described, it is understood that the above-described embodiments are illustrative and are not to be construed as limiting the scope of the invention. The embodiments are subject to changes, modifications, substitutions and variations.

Claims (15)

1. A method for preparing an anti-aliasing imaging element, comprising the steps of:

   S11, providing a plurality of optical transmission fibers, the optical transmission fiber comprising a light transmissive body and a non-transparent layer located outside the light transmissive body;

   S12, the plurality of optical transmission fibers are gathered and fixed.
2. The method for preparing an anti-aliasing imaging device according to claim 1, wherein the step S12 comprises: gathering a plurality of optical transmission fibers, and filling the curing adhesive of the non-transparent material in a vacuum environment, and then It is cured.
3. The method for preparing an anti-aliasing imaging element according to claim 1, wherein the step S11 further comprises:

   S111, providing a light rod;

   S112, the light rod is drawn to form a light-transmitting body of the light-transmitting fiber, and a non-light-transmitting material is sprayed on the outer surface of the light-transmitting body to form a non-transmissive layer of the light-transmitting fiber.
4. The method of preparing an anti-aliasing imaging element according to claim 3, wherein the light bar comprises one or more of quartz, glass, and polymer.
5. The method of preparing an anti-aliasing imaging element according to claim 3, wherein the light transmissive body has a circular, square, rectangular, or elliptical cross section.
6. The method for preparing an anti-aliasing imaging element according to claim 1, wherein the light-transmissive body has a rectangular cut surface and the width of the axial cut surface is 5 to 50 um.
7. The method for preparing an anti-aliasing imaging element according to claim 1, wherein the step S12 comprises: coating a cured adhesive of a non-transparent material on the outside of the optical transmission fiber to The transfer fiber is bonded and fixed.
8. The method for preparing an anti-aliasing imaging device according to claim 1, wherein the step S12 further comprises:

   The fixed optical transmission fibers are cut according to the required size and length.
9. A method for preparing an optical sensor includes the following steps:

   S21, providing a substrate;

   S22, forming a plurality of photosensitive cells on the substrate;

   S23, providing an anti-aliasing imaging element, and attaching the anti-aliasing imaging element to the photosensitive unit; the anti-aliasing imaging element is made by the method of any one of claims 1-8 ;

   S24, encapsulating the substrate and the photosensitive unit and the anti-aliasing imaging element on the substrate.
10. The method of manufacturing an optical sensor according to claim 9, wherein a ratio of a length to a diameter of the optical axis section of the anti-aliasing imaging element is greater than or equal to 5 and less than or equal to 50.
11. The method of manufacturing an optical sensor according to claim 9, wherein the optical sensor is configured to collect biometric information of an object above the sensor.
12. The method of manufacturing an optical sensor according to claim 11, wherein the biometric information comprises one or more of a fingerprint, a palm print, a vein, a blood pressure, a heart rate, and a blood oxygen concentration.
13. A method for preparing an optical sensor includes the following steps:

    S31, providing a wafer, the wafer comprising a plurality of optical sensor chips arranged at intervals;

    S32, cutting the wafer to obtain a plurality of optical sensor chips;

    S33, providing an anti-aliasing imaging plate, the anti-aliasing imaging plate comprising a plurality of optical transmission fibers;

    S34, cutting the anti-aliasing imaging plate according to the size and shape of the optical sensor chip to obtain an anti-aliasing imaging element corresponding to the optical sensor chip;

    S35. The anti-aliasing imaging element is attached to the optical sensor chip and packaged.
14. The method of manufacturing an optical sensor according to claim 13, wherein in the step S33, the anti-aliasing imaging plate is produced by the method according to any one of claims 1-8.
15. The method of manufacturing an optical sensor according to claim 13, wherein the ratio of the length to the diameter of the optical axis of the anti-aliasing imaging element obtained in step S34 is greater than or equal to 5, and less than or Equal to 50.

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