CN106295488B

CN106295488B - Fingerprint sensor cover plate, manufacturing method thereof, fingerprint sensor module and mobile phone

Info

Publication number: CN106295488B
Application number: CN201510359021.7A
Authority: CN
Inventors: 陈雷; 朱虹
Original assignee: Shanghai Oxi Technology Co Ltd
Current assignee: Shanghai Oxi Technology Co Ltd
Priority date: 2015-06-25
Filing date: 2015-06-25
Publication date: 2023-08-01
Anticipated expiration: 2035-06-25
Also published as: CN106295488A

Abstract

A fingerprint sensor cover plate, a manufacturing method thereof, a fingerprint sensor module and a mobile phone. The manufacturing method of the fingerprint sensor cover plate comprises the following steps: a plurality of optical fibers are fused and pressed into a prismatic optical fiber rod, and the length direction of the optical fibers is the same as the length direction of the prismatic optical fiber rod; processing the prismatic optical fiber rods into one or more cylindrical optical fiber rods, wherein the length direction of the optical fiber is the same as the length direction of the cylindrical optical fiber rods; processing two mutually parallel flat surfaces on the side surface of the cylindrical optical fiber rod, wherein the flat surfaces are parallel to the length direction of the optical fiber; and cutting the optical fiber rod with the flat surface, wherein the cutting surface is perpendicular to the flat surface, and thus the fingerprint sensor cover plate is obtained. The manufacturing method of the fingerprint sensor cover plate can improve the manufacturing process efficiency of the fingerprint sensor cover plate and reduce the cost.

Description

Fingerprint sensor cover plate, manufacturing method thereof, fingerprint sensor module and mobile phone

Technical Field

The invention relates to the field of optical fingerprint sensors, in particular to a fingerprint sensor cover plate, a manufacturing method thereof, a fingerprint sensor module and a mobile phone.

Background

The fingerprint imaging recognition technology is a technology for acquiring fingerprint images of a human body through a fingerprint sensor, and then comparing the fingerprint images with the existing fingerprint imaging information in a system to judge whether the fingerprint images are correct or not so as to realize identity recognition. Fingerprint imaging recognition technology has been widely used in various fields due to its convenience in use and uniqueness of human fingerprints. Such as security inspection fields of public security bureau, customs, etc., access control systems of buildings, consumer product fields of personal computers, mobile phones, etc.

The implementation mode of the fingerprint imaging recognition technology comprises various technologies such as optical fingerprint imaging, capacitance fingerprint imaging, ultrasonic fingerprint imaging and the like. The imaging effect of the optical fingerprint imaging technology is relatively good, and the equipment cost is relatively low, so that the optical fingerprint imaging technology is widely applied.

In optical fingerprint imaging technology, it is often necessary to provide a fingerprint sensor cover over the corresponding fingerprint sensor. Because at least one surface of the fingerprint sensor cover plate is exposed outside, the fingerprint sensor cover plate is required to have good strength and scratch resistance, and the existing fingerprint sensor cover plate is made of materials such as sapphire or special ceramics, and the cost is high. Moreover, the processing difficulty of the materials is high, the processing modes of the existing fingerprint sensor cover plate are usually laser cutting, water jet cutting and the like, and the processing cost is high and the efficiency is low due to the adoption of single-chip processing.

Disclosure of Invention

The invention solves the problem of providing a fingerprint sensor cover plate, a manufacturing method thereof, a fingerprint sensor module and a mobile phone, so as to improve the processing efficiency of the existing fingerprint sensor cover plate, reduce the cost, correspondingly reduce the cost of the fingerprint sensor module and the mobile phone and improve the processing efficiency of the fingerprint sensor module and the mobile phone.

In order to solve the above problems, the present invention provides a method for manufacturing a fingerprint sensor cover plate, comprising:

a plurality of optical fibers are fused and pressed into a prismatic optical fiber rod, and the length direction of the optical fibers is the same as the length direction of the prismatic optical fiber rod;

processing the prismatic optical fiber rods into one or more cylindrical optical fiber rods, wherein the length direction of the optical fiber is the same as the length direction of the cylindrical optical fiber rods;

processing two mutually parallel flat surfaces on the side surface of the cylindrical optical fiber rod, wherein the flat surfaces are parallel to the length direction of the optical fiber;

and cutting the optical fiber rod with the flat surface, wherein the cutting surface is perpendicular to the flat surface, and thus the fingerprint sensor cover plate is obtained.

Optionally, the optical fiber rod with the flat surface is cut simultaneously by adopting a multi-wire cutting method, so that a plurality of fingerprint sensor cover plates are obtained by cutting at one time.

Optionally, the prismatic optical fiber rod is in a regular quadrangular prism or a regular hexagonal prism.

Optionally, processing the prismatic fiber rod into a plurality of cylindrical fiber rods includes: and cutting the regular quadrangular prism or the regular hexagonal prism into four identical quadrangular prisms, and then rounding the quadrangular prisms to form the cylindrical optical fiber rod.

Alternatively, the flat surface is formed by a symmetrical grinding method.

Optionally, the method further comprises: and placing the fingerprint sensor cover plates obtained after the cutting into a chamfering machine, and adding grinding sand and water to chamfer.

Optionally, the thickness range of the fingerprint sensor cover plate is 0.1 mm-8 mm.

In order to solve the above problems, the present invention provides a fingerprint sensor cover plate:

the top view shape of the fingerprint sensor cover plate is a combination of two identical arches and a rectangle, the rectangle is positioned between the two arches, the circle center of the arch is coincident with the centroid of the rectangle, a first group of opposite sides of the rectangle are respectively coincident with the chords of the two arches, and the side surfaces corresponding to a second group of opposite sides of the rectangle are flat surfaces;

the fingerprint sensor cover plate is made of optical fibers, and the length direction of the optical fibers is perpendicular to the upper surface and the lower surface of the fingerprint sensor cover plate.

In order to solve the above problems, the present invention provides a fingerprint sensor module, including the fingerprint sensor cover plate described above.

In order to solve the above problems, the present invention provides a mobile phone, which includes the fingerprint sensor module.

Compared with the prior art, the technical scheme of the invention has the following advantages:

in the technical scheme of the invention, the prismatic optical fiber rod is firstly formed, then the prismatic optical fiber rod is processed into one or more cylindrical optical fiber rods, then two mutually parallel flat surfaces are processed on the side surfaces of the cylindrical optical fiber rods, and the optical fiber rods with the flat surfaces are cut, so that the corresponding fingerprint sensor cover plate can be formed. Meanwhile, the optical fiber is used as a material, so that the manufacturing cost is reduced. More importantly, the manufactured fingerprint sensor cover plate is provided with two flat surfaces, so that the fingerprint sensor cover plate is easy to grasp, and the assembly difficulty in the assembly process is reduced. Meanwhile, the cylindrical optical fiber rod is used for processing two parallel flat surfaces and then is directly cut into the shape, so that the whole fingerprint sensor cover plate has the advantage of large side length and area, and is used for identifying human fingers. In addition, because the length direction of the optical fiber is the same as the length direction of the prismatic optical fiber rod in the manufacturing process, it is known that in the manufactured fingerprint sensor cover plate, the length direction of the optical fiber is perpendicular to the upper surface and the lower surface of the fingerprint sensor cover plate, and the length direction of the optical fiber has good light conduction performance, so that the fingerprint identification performance can be improved.

Drawings

FIG. 1 is a schematic diagram of a conventional mobile phone;

FIG. 2 is a schematic diagram of another conventional mobile phone;

FIG. 3 is an enlarged schematic top view of the cover plate of the fingerprint sensor in the mobile phone shown in FIG. 2;

FIG. 4 is a schematic diagram of another conventional mobile phone;

FIG. 5 is a schematic diagram of a prior art fingerprint sensor cover plate having a chamfered rectangular shape;

FIG. 6 is a schematic diagram of a plurality of optical fibers provided in a method of manufacturing according to an embodiment of the present invention;

FIG. 7 is a bottom elevation view of a regular hexagonal prism-shaped fiber rod formed using the optical fiber of FIG. 6;

FIG. 8 is a schematic perspective view of a regular hexagonal prism-shaped optical fiber rod formed using the optical fiber of FIG. 6;

FIG. 9 is a schematic perspective view of a cylindrical fiber optic rod formed using the regular hexagonal prism-shaped fiber optic rod of FIG. 8;

FIG. 10 is a schematic perspective view of a fiber optic rod having a planar surface formed using the cylindrical fiber optic rod of FIG. 9;

FIG. 11 is a schematic perspective view of a fingerprint sensor cover obtained by cutting the optical fiber rod shown in FIG. 10;

FIG. 12 is a schematic top view of the fingerprint sensor cover of FIG. 11;

FIG. 13 is a schematic perspective view of the fingerprint sensor cover plate of FIG. 11 after chamfering;

FIG. 14 is a schematic cross-sectional view of one of the optical fibers comprising the fingerprint sensor cover of FIG. 11;

FIG. 15 is a schematic diagram of a fingerprint sensor module according to an embodiment of the present invention;

FIG. 16 is a schematic view of a portion of the fingerprint sensor module shown in FIG. 15;

fig. 17 is a schematic diagram of a mobile phone according to an embodiment of the present invention.

Detailed Description

The fingerprint sensor cover plate of the current fingerprint module generally has a shape like a circle, a runway, a rectangle, a chamfer rectangle and the like, and is shown in fig. 1 to 5.

Fig. 1 shows a mobile phone 10, the mobile phone 10 having a fingerprint sensor cover 11 with a circular shape in plan view. The fingerprint sensor cover plate 11 is not easy to grasp in the assembly process, so that the assembly difficulty is increased, and a piece of material such as sapphire is generally required to be manufactured, so that the processing efficiency is low.

Fig. 2 shows a mobile phone 20, the mobile phone 20 having a fingerprint sensor cover 21 shaped like a racetrack in plan view. Fig. 3 further shows an enlarged top view of the fingerprint sensor cover 21. In the top view shape of the fingerprint sensor cover 21, the middle is a rectangle, and two semicircles at two ends are respectively connected with the rectangle in a tangential manner (the other half of the circle is shown by a dotted line in the figure). In the fingerprint sensor cover 21, processing the two semicircular portions in the planar structure requires a long process time, and the overall shape is relatively slender, which is not conducive to the identification of the finger print.

Fig. 4 shows a mobile phone 30, the mobile phone 30 having a fingerprint sensor cover 31 having a rectangular shape in plan view. The fingerprint sensor cover 31 has a large side length and has obvious four right angles, and has poor hand feeling.

Fig. 5 shows a fingerprint sensor cover 41 having a chamfered rectangular shape, the fingerprint sensor cover 41 can also be seen as another fingerprint sensor cover having a racetrack shape in plan view. The fingerprint sensor cover 41 is manufactured by processing the fingerprint sensor cover into a rectangular structure in a plan view, and then rounding the structure. Because four corners need to be chamfered, and the chamfer part is larger, the processing difficulty is larger, and the processing period is longer.

In order to solve the defects of the existing fingerprint sensor cover plate, the invention provides a novel fingerprint sensor cover plate, wherein the overlooking shape of the fingerprint sensor cover plate is a combination of two identical arches and a rectangle, the rectangle is positioned between the two arches, the circle center of the arch is coincident with the centroid of the rectangle, a first group of opposite sides of the rectangle are respectively coincident with chords of the two arches, and the side surface corresponding to a second group of opposite sides of the rectangle is a flat surface; the fingerprint sensor cover plate is made of optical fibers, and the length direction of the optical fibers is perpendicular to the upper surface and the lower surface of the fingerprint sensor cover plate. Because the top view shape of the fingerprint sensor cover plate is a combination of two identical bows and one rectangle, and the side corresponding to the opposite sides of the second group of rectangles is a flat surface, the flat surface can be used for grabbing during assembly, so that the installation process is simpler. And the circle center of the arc shape is coincident with the centroid of the rectangle, so that the whole fingerprint sensor cover plate can be directly cut to obtain a corresponding shape after two mutually parallel flat side surfaces are processed by using a regular cylindrical rod body, and the manufacturing process is simplified. Meanwhile, the fingerprint sensor cover plate is made of optical fibers, so that the cost is reduced, the processing technology is simplified, and the processing efficiency is improved.

In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings.

The embodiment of the invention provides a manufacturing method of a fingerprint sensor cover plate, and please refer to fig. 6 to 14 in combination.

Referring to fig. 6 to 8 in combination, a plurality of optical fibers are melt-pressed into a prismatic optical fiber rod, and the length direction of the optical fibers is the same as the length direction of the prismatic optical fiber rod.

Referring to fig. 6, a plurality of optical fibers 111 are provided.

Currently, optical fibers are manufactured mainly by in-tube Chemical Vapor Deposition (CVD), in-rod CVD, plasma Chemical Vapor Deposition (PCVD), and axial vapor deposition (VAD). In either method, the core is first sleeved into the sheath (the core and the sheath may be refer to fig. 14) at a high temperature to form a preform (not shown), and then the preform is softened by heating in a high temperature furnace, and drawn Cheng Changsi by a drawing apparatus, thereby obtaining an optical fiber. It should be noted that, the optical fiber 111 used in this embodiment does not include a plastic sheath, that is, the optical fiber 111 is not encapsulated in the plastic sheath.

Referring to fig. 7 and 8, a plurality of optical fibers 111 are melt-pressed into a regular hexagonal prism-shaped optical fiber rod 113. Fig. 7 shows a bottom front view of the regular hexagonal-prism-shaped optical fiber rod 113, and fig. 8 shows a perspective view of the regular hexagonal-prism-shaped optical fiber rod 113.

The specific manufacturing process of the regular hexagonal prism optical fiber rod 113 includes the following steps.

Drawing a composite wire: the optical fibers 111 shown in fig. 6 are selected, arranged on a designed die to be a rod shape with a regular hexagon in cross section, and then are bundled together, and both ends can be bundled by a nonflammable copper wire. They are clamped on a wire drawing machine and drawn, thereby obtaining a composite wire 112.

In other embodiments, each optical fiber 111 in the composite filament 112 may be drawn once, twice or three times (i.e., the primary composite filament may be drawn again to form a secondary composite filament, and the secondary composite filament may be drawn again to form a tertiary composite filament), so that each optical fiber 111 in the composite filament 112 is reduced to a desired diameter range, that is, the number of optical fibers 111 in each composite filament 112 may be controlled.

The diameter of the optical fiber 111 after final drawing may be controlled to about 6 μm to 12 μm, and the diameter of the first drawing may be controlled by a die and a device. The size of the desired fiber diameter in the final formed fingerprint sensor cover, in turn, if determined, may be reversed to determine the diameter of the optical fiber 111 at the time of the first drawing.

Row plates: the composite wires 112 drawn in the front are cut into a certain length according to the length of the melt-pressing die, and then the number of the composite wires 112 on each side of the row plate is designed in a way that the size of the finished optical fiber rod can be met and the requirements of machining allowance and melt-pressing shrinkage are considered. The composite wires 112 are sequentially discharged into the corresponding molds, and are bundled with steel wires at a certain distance.

And (3) melting and pressing: the aligned composite filaments 112 are assembled, transferred to respective meltdown dies, and placed into a meltdown furnace. Then vacuumizing according to a proper program, pressurizing according to a set temperature time curve, controlling the shrinkage to be 8% -9% in the pressing process, fusing and pressing the combination formed by the composite wires 112 into a tightly attached integral blank, and cooling, moving the furnace and demolding after the pressing is completed to form the regular hexagonal prism-shaped optical fiber rod 113.

Referring to fig. 8, in the present embodiment, the distance between two parallel sides of the bottom surface of the regular hexagonal prism-shaped optical fiber rod 113 (i.e. the height of the regular hexagon) may be about 29mm, and the length of the regular hexagonal prism-shaped optical fiber rod 113 may be about 180 mm.

In this embodiment, the regular hexagonal prism-shaped optical fiber rod 113 has three pairs of parallel sides, and thus, the corresponding melt-press molding process is facilitated. And, the formed prismatic optical fiber rod 113 has a regular structure, which is beneficial to the next process.

In other embodiments, a plurality of optical fibers may be fused into a prism-shaped optical fiber rod of a general shape. For example, the prismatic optical fiber rod may have a regular quadrangular shape. The prismatic optical fiber rod is processed into a regular quadrangular prism and processed into a regular hexagonal prism, and the regular quadrangular prism has two pairs of mutually parallel side surfaces, so that the corresponding melt-pressing forming process is facilitated, and the formed prismatic optical fiber rod is regular in structure and is beneficial to the next process. In other embodiments, the prismatic optical fiber rod may have other prismatic shapes, such as a regular octagon, a regular dodecagon, etc., and may have a diagonal prismatic shape, such as a diagonal quadrangle, a diagonal hexagon, a diagonal octagon, a diagonal dodecagon, etc.

Referring to fig. 8 and 9 in combination, the regular hexagonal prism-shaped optical fiber rod 113 shown in fig. 8 is cut along the cross-dash lines in fig. 8, each dash line representing a cutting plane, and both cutting planes are parallel to the length of the regular hexagonal prism-shaped optical fiber rod 113 (i.e., both cutting planes are perpendicular to the bottom surface), so as to obtain four identical prisms (not shown). That is, in the present embodiment, processing the prismatic optical fiber rod into a plurality of cylindrical optical fiber rods includes: the regular hexagonal prism-shaped optical fiber rod 113 is cut into four identical quadrangular prisms, and then the quadrangular prisms are rounded to form a cylindrical optical fiber rod 114 shown in fig. 9.

In this embodiment, the regular hexagonal prism-shaped optical fiber rod 113 is cut into four identical prisms to obtain four cylindrical optical fiber rods 114, so that the utilization rate of the regular hexagonal prism-shaped optical fiber rod 113 is improved.

In this embodiment, the diameter of the bottom surface of the cylindrical optical fiber rod 114 is controlled to be 9mm to 11mm to provide a machining allowance for the subsequent machining and simultaneously reduce the burden of the subsequent machining. The distance between the two parallel sides of the bottom surface of the regular hexagonal prism-shaped optical fiber rod 113 is set to about 29mm, so that the diameters of the four cylindrical optical fiber rods 114 can be ensured to be 9mm to 11mm. While the length of the cylindrical fiber rod 114 remains around 180 mm. In other embodiments, the dimensions of the cylindrical fiber optic rod 114 may be adjusted according to actual needs.

It should be noted that, in other embodiments, the prismatic fiber rod of other shapes may be processed into one or more cylindrical fiber rods 114, and the length direction of the optical fiber 111 remains the same as the length direction of the cylindrical fiber rods 114.

Referring to fig. 10, two parallel flat surfaces, i.e., a flat surface 1151 and a flat surface 1152, are machined on the side surface of the cylindrical fiber rod 114, and the flat surfaces 1151 and 1152 are parallel to the length direction of the optical fiber 111, so that the cylindrical fiber rod 114 is machined into the fiber rod 115.

In this embodiment, the flat surface 1151 and the flat surface 1152 may be formed by a symmetrical grinding method. Specifically, symmetrical grinding is performed on two sides of the obtained round bar with the bottom surface diameter of 9-11 mm until the flat surface 1151 and the flat surface 1152 meet the required width requirement, and the specific size of the width is further selected later. While the length of the flat surfaces 1151 and 1152 is the length of the cylindrical fiber rod 114, i.e., about 180mm, i.e., the length of the fiber rod 115.

Referring to fig. 10 to 12 in combination, the optical fiber rod 115 of fig. 10 having a flat surface 1151 and a flat surface 1152 is cut, and a cut surface (not shown) is perpendicular to the flat surface, thereby obtaining the fingerprint sensor cover plate 100 shown in fig. 11 and 12. Fig. 11 is a schematic perspective view of the fingerprint sensor cover 100, and fig. 12 is a schematic top view of the fingerprint sensor cover 100.

In this embodiment, the optical fiber rod 115 having the flat surface 1151 and the flat surface 1152 shown in fig. 10 may be cut simultaneously by a multi-wire cutting method to obtain a plurality of fingerprint sensor cover plates 100 at a time. The fingerprint sensor cover has a thickness T as shown in fig. 11. The thickness T of the fingerprint sensor cover 100 is the desired design thickness, or may be greater than the design thickness to provide a margin for subsequent grinding operations.

Specifically, the thickness T of the fingerprint sensor cover 100 ranges from 0.1mm to 8mm. On the one hand, in view of workability, the thickness T of the fingerprint sensor cover plate made of the optical fiber provided in the present embodiment needs to be set above 0.1mm, and if the thickness T is smaller than 0.1mm, the fingerprint sensor cover plate is easy to break, and even other materials such as the existing sapphire or special ceramics have similar problems; on the other hand, increasing the thickness contributes to increasing the strength of the fingerprint sensor cover 100, but the thickness of a mobile phone generally used for assembling the fingerprint sensor cover 100 is about 8mm to 9mm, and thus, the thickness T of the fingerprint sensor cover 100 is controlled to be 8mm or less.

It should be noted that, in order to ensure that the capacitance is large, the existing fingerprint sensor cover plate using sapphire or special ceramic as the material is generally about 0.25mm, and the thickness of the existing fingerprint sensor cover plate does not exceed 0.3mm. The thickness of the cover plate of the existing fingerprint sensor used on the optical fingerprint sensor is generally not more than 0.3mm, because a better fingerprint image needs to be ensured. Because the thickness of the fingerprint sensor cover plate adopted by the existing fingerprint sensor is usually not more than 0.3mm, and the thickness of the mobile phone front cover plate used for assembling the fingerprint sensor cover plate is usually more than 0.3mm, after the existing mobile phone is assembled with the fingerprint identification module, the fingerprint sensor cover plate usually presents a part which is sunken in the assembling position of the mobile phone front cover plate.

However, in the present embodiment, the thickness limitation of 0.3mm can be broken through by the fingerprint sensor cover plate 100 made of the optical fiber material. This is because the material of the existing fingerprint sensor cover plate is usually sapphire or special ceramic cover plate, and the materials have serious light loss and cannot be made too thick. The implementation does not have the problems due to the use of the optical fiber plate material, and the fingerprint sensor cover plate can be made thicker. In particular, the material can be manufactured to be between 0.3mm and 8mm. For example, the thickness T shown in FIG. 11 can be controlled to be 0.4mm, 0.5mm, 1.0mm, 1.5mm, 2.0mm, 3.0mm, 4.5mm, 5.0mm, 6.5mm, 7.0mm, 8.0mm, or the like. The fingerprint sensor cover 100 can be made thicker and its own strength will increase. And more importantly, the fingerprint sensor cover plate 100 can be thickened to be the same as the thickness of the front cover plate of the mobile phone, so that the fingerprint identification module and the front cover plate of the mobile phone can be leveled without a concave part. Meanwhile, since the optical fiber can have good optical performance, even if the thickness T of the fingerprint sensor cover plate reaches 8mm, optical fingerprint identification can be effectively performed.

Referring to fig. 11 and 12 in combination, the fingerprint sensor cover 100 has a top view of a combination of two identical arcs 1007 and a rectangle 1008, the rectangle 1008 is located between the two arcs 1007, the center of the arc 1007 coincides with the centroid of the rectangle 1008 as a point O, and a first set of opposite sides of the rectangle 1008 respectively coincides with chords of the two arcs 1007 (as shown by dotted lines, not labeled in the figures), the sides corresponding to the second set of opposite sides of the rectangle 1008 are flat surfaces (the flat surfaces are the corresponding portions of the flat surfaces 1151 and 1152 in fig. 10 after cutting), and the second set of opposite sides have a length L.

Referring to fig. 11 and 12 in combination, the entire fingerprint sensor cover 100 has six surfaces, namely, an upper surface 1001, a lower surface 1002, a front flat surface 1003, a rear flat surface 1004 (i.e., the flat surfaces include the front flat surface 1003 and the rear flat surface 1004), a left curved surface 1005, and a right curved surface 1006 (the left curved surface 1005 and the right curved surface 1006 are collectively referred to as curved surface side surfaces).

Due to the existence of the front flat surface 1003 and the rear flat surface 1004, the fingerprint sensor cover 100 can be easily grasped, so that the fingerprint sensor cover 100 is easy to assemble, and the two identical bows 1007 are beneficial to increasing the area of the fingerprint sensor cover 100 for fingerprint identification, meanwhile, the fingerprint identification performance of the fingerprint sensor cover 100 can be improved by adopting the optical fiber material for manufacturing, the process efficiency is improved, and the cost is saved.

In this embodiment, the radius of the circle corresponding to the arcuate shape 1007 is the radius R of the circle corresponding to the fingerprint sensor cover 100. The radius R is controlled to be 4.5mm to 5.5mm (which is half the diameter of the bottom surface of the cylindrical optical fiber rod 114).

In this embodiment, as described above, the cylindrical optical fiber rod 114 is manufactured to have a bottom diameter of 9mm to 11mm, and thus the radius R in FIG. 12 can be determined accordingly. And length L (length L being the length of the second set of opposite sides of rectangle 1008) becomes an element in the design. The length L is usually designed according to the resolution of the fingerprint recognition module, which is determined by the number of pixels.

In this embodiment, when the fingerprint recognition module has pixels arranged in 80 rows and 200 columns, the resolution is 80×200 at this time, that is, when a single pixel is square with a side length of 50 μm, the width of the entire pixel area is 80×0.05=4 mm, and the length is 200×0.05=10 mm. At this time, the following two designs are generally used:

first, the diameter corresponding to the fingerprint sensor cover plate is designed to be equal to the length of the pixel area (i.e. in a square taking the length of the pixel area as the side length, the circle of the radius R is just the inscribed circle thereof), i.e. the radius R is 5.0mm, at this time, the shorter side of the rectangle 1008 is set to be controlled to be 4 mm-4.4 mm (the width of the whole pixel area is greater than or equal to), at this time, the length L is calculated according to the mathematical relationship to be 8.98 mm-9.17 mm. However, in this design, there is a small portion of the pixels at the four corners of the pixel area that is not used.

Second, the circle corresponding to the fingerprint sensor cover plate is designed to be the circumscribing circle of the whole pixel area, and at the moment, the diameter of the circle corresponding to the fingerprint sensor cover plate is calculated to be 10.77mm. Correspondingly, the shorter side of the rectangle 1008 is controlled to be 4 mm-4.4 mm, and the length L is calculated to be 9.83 mm-10 mm according to the mathematical relation.

Referring to fig. 13, the manufacturing method further includes: and placing the fingerprint sensor cover plates 100 obtained after the cutting into a chamfering machine, and adding grinding sand and water to chamfer to form the fingerprint sensor cover plates 100a.

Specifically, a plurality of fingerprint sensor cover plates 100 are placed into a chamfering machine, grinding sand and water are added, sharp corners on the periphery of the fingerprint sensor cover plates are removed through collision of sand grains and products, the purpose of chamfering is achieved, and the fingerprint sensor cover plates 100a with smooth transition between curved side surfaces and flat surfaces are formed.

Referring to fig. 14, a cross-sectional structure of one of the optical fibers constituting the fingerprint sensor cover 100 (which may also be the fingerprint sensor cover 100 a) is shown. The optical fiber includes a core 1111 and a sheath 1112, the core 1111 and the sheath 1112 typically being made of optical materials having different refractive indices, the refractive index of the sheath 1112 being greater than the core 1111. Thus ensuring that most of the other rays, except straight from the core 1111, can propagate forward by total reflection from the core 1111, i.e. most of the incident light in a certain angular range can propagate from one end to the other along the fiber without loss, as shown in fig. 14. When the optical fiber is used as the material of the fingerprint sensor cover plate, the loss of reflected light can be reduced due to the special characteristic of the optical fiber for light transmission, so that the performance of the corresponding optical fingerprint sensor is improved.

The manufacturing method of the embodiment comprises the following steps: the length direction of the optical fiber 111 is the same as the length direction of the prismatic optical fiber rod, and the length direction of the optical fiber 111 is the same as the length direction of the cylindrical optical fiber rod 114, the flat surface (refer to fig. 10) is parallel to the length direction of the optical fiber, and when the optical fiber rod having the flat surface is cut, the cut surface is perpendicular to the flat surface, and thus, the length direction of the final optical fiber is perpendicular to the upper surface 1001 and the lower surface 1002 of the fingerprint sensor cover plate.

In the manufacturing method provided by the embodiment, when millions of optical fibers are arranged and combined and then melt-pressed into a rod body, a prismatic optical fiber rod is obtained, then the prismatic rod body is mechanically processed to form a cylindrical optical fiber rod 114, the cylindrical optical fiber rod 114 is symmetrically ground to form a special shape with mutually parallel flat surfaces, and the corresponding fingerprint sensor cover plate is obtained through cutting, so that the production efficiency is improved. And can once carry out multi-wire saw and obtain a plurality of fingerprint sensor apron, further improve production efficiency. In addition, since the fingerprint sensor cover plate is processed by the regular cylindrical optical fiber rods 114, the processing process is easy to control and the size is easy to be precise, and meanwhile, the process difficulty is reduced. In addition, the fingerprint sensor cover plate manufactured has a flat surface, is easy to grasp and is convenient to assemble.

Another embodiment of the present invention further provides a fingerprint sensor cover, which is formed by the manufacturing method provided in the foregoing embodiment, so that the content of the fingerprint sensor cover may refer to the content corresponding to the foregoing embodiment, and refer to fig. 11 to 14 in combination.

Specifically, referring to fig. 11 and 12 in combination, the top view of the fingerprint sensor cover 100 is a combination of two identical arcs 1007 and a rectangle 1008, the rectangle 1008 is located between the two arcs 1007, the center of the arc 1007 coincides with the centroid of the rectangle 1008 as a point O, a first set of opposite sides of the rectangle 1008 respectively coincides with the chords of the two arcs 1007, and the sides of the rectangle 1008 corresponding to the second set of opposite sides are flat surfaces. The entire fingerprint sensor cover 100 has six surfaces, an upper surface 1001, a lower surface 1002, a front flat surface 1003, a rear flat surface 1004, a left side curved surface 1005 and a right side curved surface 1006. For more reference to the corresponding content of the previous embodiments.

In this embodiment, the radius of the circle corresponding to the arcuate shape 1007 is the radius R of the circle corresponding to the fingerprint sensor cover 100. The radius R is controlled to be 4.5mm to 5.5mm (which is half the diameter of the bottom surface of the cylindrical optical fiber rod 114). And the length L may be 8.98mm to 9.17mm, or 9.83mm to 10mm, for which reference is made to the corresponding content of the previous embodiment. The thickness T of the fingerprint sensor cover 100 may range from 0.1mm to 8mm for reasons corresponding to those described in the previous embodiments.

In this embodiment, the fingerprint sensor cover 100 is made of optical fibers, and the length direction of the optical fibers is perpendicular to the upper surface 1001 and the lower surface 1002 of the fingerprint sensor cover. Such a fingerprint sensor cover plate 100 has advantages of good optical performance, high strength (strength is high because it can be made to have a large thickness), and low cost.

The embodiment of the invention further provides a fingerprint sensor module, which includes the fingerprint sensor cover plate 100 as described above, please refer to fig. 15 and 16 in combination. Fig. 15 shows the structure of a fingerprint sensor module, which includes fingerprint sensor cover 100, fingerprint sensor 204, light guide plate 206, light source 205, chip (IC) 203, flexible printed circuit board (FPC) 207, upper protective case 201, lower protective case 202, and the like. Wherein the light source 205 may be an LED lamp.

Fig. 16 shows a part of the structure shown in fig. 15 in an enlarged manner, and the working principle of the fingerprint sensor module can be described with reference to fig. 16: the light emitted by the light source 205 passes through the light guide plate 206 and is converted into uniform incident light (incident light is incident on the surface light source), the incident light (not labeled) passes through the fingerprint sensor 204 and the fingerprint sensor cover plate 100, then reaches the finger 300, is reflected by the surface of the finger 300 and becomes reflected light (not labeled), and the reflected light passes through the fingerprint sensor cover plate 100, returns to the surface of the fingerprint sensor 204 and is received by a photosensitive element (not shown) of the fingerprint sensor 204. The reflected light intensity reflected by the finger 300 is also different due to the asperity of the finger. The reflected light information is processed by the chip 203 (refer to fig. 15) and then output to a system such as a mobile phone or a computer through the flexible printed circuit board 207 for imaging.

It should be noted that, in other embodiments, the fingerprint sensor module may also include the fingerprint sensor cover 100a provided in the foregoing embodiments.

In the fingerprint sensor module provided in this embodiment, because of having fingerprint sensor apron 100, consequently, can improve the optical recognition performance of fingerprint sensor module to reduce the assembly degree of difficulty of fingerprint sensor module, reduce the manufacturing technology degree of difficulty of fingerprint sensor module, simultaneously, improve the technology efficiency of fingerprint sensor module, reduce the cost of fingerprint sensor module.

In another embodiment of the present invention, a mobile phone 400 is provided, where the mobile phone 400 includes the fingerprint sensor module provided in the foregoing embodiment, and the fingerprint sensor module includes the fingerprint sensor cover 100 provided in the foregoing embodiment. It should be noted that, in other embodiments, the mobile phone 400 may also include the fingerprint sensor cover 100a provided in the foregoing embodiments.

In the mobile phone 400 provided in this embodiment, the fingerprint sensor module provided in the previous embodiment is provided, and the fingerprint sensor module has the fingerprint sensor cover 100. Therefore, the fingerprint sensor cover plate 100 can improve the optical recognition performance of the middle fingerprint sensor module in the mobile phone, reduce the assembly difficulty of the mobile phone, reduce the manufacturing process difficulty of the middle fingerprint sensor module in the mobile phone, improve the process efficiency and reduce the cost of the mobile phone.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be assessed accordingly to that of the appended claims.

Claims

1. A method for manufacturing a fingerprint sensor cover plate, comprising the steps of:

2. The method for manufacturing a fingerprint sensor cover according to claim 1, wherein the optical fiber rods with the flat surfaces are cut simultaneously by a multi-wire cutting method to obtain a plurality of fingerprint sensor covers at a time.

3. The method for manufacturing a fingerprint sensor cover plate according to claim 1, wherein the prismatic optical fiber rod is in a regular quadrangular prism or a regular hexagonal prism.

4. The method of manufacturing a fingerprint sensor cover of claim 3, wherein processing the prismatic fiber optic rod into a plurality of cylindrical fiber optic rods comprises: and cutting the regular quadrangular prism or the regular hexagonal prism into four identical quadrangular prisms, and then rounding the quadrangular prisms to form the cylindrical optical fiber rod.

5. The method of manufacturing a fingerprint sensor cover of claim 1, wherein the flat surface is formed by a symmetrical grinding process.

6. The method for manufacturing a fingerprint sensor cover of claim 1, further comprising: and placing the fingerprint sensor cover plates obtained after the cutting into a chamfering machine, and adding grinding sand and water to chamfer.

7. The method for manufacturing a fingerprint sensor cover plate according to claim 1, wherein the thickness of the fingerprint sensor cover plate ranges from 0.1mm to 8mm.

8. A fingerprint sensor cover plate, characterized in that:

the top view shape of the fingerprint sensor cover plate is a combination of two identical arches and a rectangle, the rectangle is positioned between the two arches, the circle center of the arch is coincident with the centroid of the rectangle, a first group of opposite sides of the rectangle are respectively coincident with the chords of the two arches, and the side surfaces corresponding to a second group of opposite sides of the rectangle are flat surfaces.

9. The fingerprint sensor cover of claim 8, wherein the fingerprint sensor cover material is an optical fiber, and wherein the optical fiber has a length direction perpendicular to the upper and lower surfaces of the fingerprint sensor cover.

10. The fingerprint sensor cover of claim 8, wherein the fingerprint sensor cover has a thickness in the range of 0.1mm to 8mm.

11. A fingerprint sensor module comprising a fingerprint sensor cover according to any one of claims 8 to 10.

12. A mobile phone comprising the fingerprint sensor module of claim 11.