WO2022252783A1

WO2022252783A1 - Preparation method for cover plate, and cover plate and electronic device

Info

Publication number: WO2022252783A1
Application number: PCT/CN2022/083702
Authority: WO
Inventors: 唐中帜; 杨自美; 颜瑞
Original assignee: Oppo广东移动通信有限公司
Priority date: 2021-06-01
Filing date: 2022-03-29
Publication date: 2022-12-08
Also published as: CN113301753A

Abstract

A preparation method for a cover plate, and a cover plate and an electronic device. The preparation method for a cover plate provided in the embodiments of the present application comprises: bonding a first core material, a second core material and a peripheral material together, by means of extrusion, so as to obtain a cover plate. The first core material in the cover plate is an optical fiber, and therefore light entering the first core material can only be propagated in a direction limited by the optical fiber and does not enter the second core material, thereby avoiding the phenomenon of light crosstalk between the first core material and the second core material.

Description

Preparation method of cover plate, cover plate and electronic device

This application claims the priority of the Chinese patent application with the application number 202110610791.X and the application title "Preparation method of cover plate, cover plate and electronic equipment" submitted to the China Patent Office on June 1, 2021, the entire content of which is passed References are incorporated in this application.

technical field

The present application relates to the field of electronic technology, in particular to a method for preparing a cover, the cover and electronic equipment.

Background technique

Optical components inside electronic devices can be used to detect environmental parameters or human body parameters. For example, there is a blood oxygen detection function among the health functions of smart watches. The current mainstream blood oxygen detection method is photoplethysmographic (PPG). The light-transmitting area of the body enters the outside world, and then passes through the tissues and arteries and veins in the skin. Part of it is absorbed, and part of it is reflected back to the light sensor. The light signal received by the light sensor is converted into an electrical signal, and the blood oxygen data is obtained after conversion.

The existing PPG structure generally includes a housing, the housing includes a back cover, the back cover is provided with a first optical window and a second optical window, and the optical signal sent by the light transmitter can pass through the first optical window to reach the skin, Light signals returning from the skin can pass through the second optical window to the light sensor. However, when the light emitted by the light emitter into the first optical window is strung into the second optical window and then received by the light sensor (that is, the light signal emitted by the light emitter is directly received by the light sensor without being absorbed and reflected by the skin), It will lead to the deviation of the calculation result, which will reduce the accuracy of the detection result.

Contents of the invention

Embodiments of the present application provide a method for preparing a cover plate, the cover plate, and an electronic device, which can solve the problem of light crossing.

In the first aspect, the embodiment of the present application provides a method for preparing a cover plate, including:

Provide a first core material, a second core material and a peripheral material, the first core material is an optical fiber, the second core material is a light-transmitting material, and the peripheral material includes a non-optical fiber material;

disposing the peripheral material on the outer periphery of the first core material and the outer periphery of the second core material;

Extruding the first core material, the second core material and the peripheral material to obtain a composite rod;

The composite rod is processed to obtain the cover plate.

In the second aspect, the embodiment of the present application provides a method for preparing a cover plate, including:

Provide a first core material, a second core material and a peripheral material, both of the first core material and the second core material are light-transmitting materials, and the refractive index of the first core material is greater than that of the peripheral material ;

The first core material and the second core material are arranged at intervals, and the peripheral material is arranged on the outer periphery of the first core material and the outer periphery of the second core material;

The composite rod is processed to obtain the cover plate.

In a third aspect, the embodiment of the present application provides a cover plate, including:

first window area;

The second window area is set apart from the first window area;

a peripheral area disposed around the first window area and disposed around the second window area;

Wherein, the material of the first window area and the material of the second window area are light-transmitting materials, and the refractive index of the material of the first window area is greater than that of the material of the peripheral area.

In a fourth aspect, the embodiment of the present application provides an electronic device, including:

a cover plate, the cover plate is the above cover plate;

The light emitter is arranged on one side of the cover plate, and the light emitted by the light emitter enters the first window area and is transmitted to the cover plate through the first window area to be away from the light emitter side of

The light detector and the light emitter are arranged on the same side of the cover plate, and the light incident on the second viewing window area from the side of the cover plate away from the light detector passes through the second viewing window zone after transmission into the photodetector.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings that need to be used in the description of the embodiments.

FIG. 1 is a flowchart of a method for preparing a cover plate provided in an embodiment of the present application.

Fig. 2 is a process flow chart of the first preparation method of the composite rod provided in the embodiment of the present application.

Fig. 3 is a process flow diagram of the second preparation method of the composite rod provided in the embodiment of the present application.

Fig. 4 is a process flow chart for processing and preparing a cover plate from a composite bar provided in the embodiment of the present application.

FIG. 5 is a schematic structural diagram of a cover plate provided by an embodiment of the present application.

FIG. 6 is another flow chart of the method for preparing the cover plate provided by the embodiment of the present application.

FIG. 7 is a schematic diagram of a partial structure of an electronic device provided by an embodiment of the present application.

FIG. 8 is a partial structural diagram of the electronic device shown in FIG. 7 .

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Apparently, the described embodiments are only some of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of this application.

Please refer to FIG. 1 . FIG. 1 is a flow chart of a method for preparing a cover provided in an embodiment of the present application. The preparation method of cover plate comprises:

110. Provide a first core material, a second core material, and a peripheral material, the first core material is an optical fiber, and the peripheral material includes a non-fiber material.

The first core material can be a single optical fiber or multiple optical fibers, and the multiple optical fibers can be disconnected or connected together. Exemplarily, the transmittance of the first core material to the light of 400nm-1200nm is greater than or equal to 20%, such as 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 100% %.

The working principle of optical fiber is: light is incident from one end of the optical fiber, propagates along the optical fiber, and finally exits from the other end. The optical fiber includes a core and a cladding covering the outer surface of the core. The refractive index of the core is higher than that of the cladding, so that the light enters the core and undergoes total reflection, and continues to transmit forward in the core, and the theory There is no loss on the surface, and the light can be transmitted for a long distance without loss.

The second core material is a light-transmitting material. Exemplarily, the second core material may be an optical fiber. The second core material may be a single optical fiber or multiple optical fibers. The multiple optical fibers may be disconnected or connected together. In some other embodiments, the second core material can also be a non-optical fiber material with light transmission properties, such as transparent glass, transparent plastic, sapphire or transparent ceramics, etc., and the transparent plastic can be polymethyl methacrylate (polymethyl methacrylate, PMMA). Certainly, the second core material may also be a combination of optical fiber and non-fiber material. Exemplarily, the transmittance of the second core material to the light of 400nm-1200nm is greater than or equal to 20%, such as 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 100% %.

Optionally, the peripheral material can be a single non-fiber material, or the peripheral material is a combination of optical fiber and non-fiber material, the non-fiber material can be plastic, glass or metal, etc., and the plastic can be polycarbonate (Polycarbonate, PC), Polyamide (Polyamide, PA), polyetheretherketone (Polyetheretherketone, PEEK), polymethyl methacrylate (polymethyl methacrylate, PMMA), etc. The peripheral material may be a light-transmitting material or a light-shielding material. Exemplarily, the color of the peripheral material may be black, dark or transparent.

When the second core material is a light-transmitting non-optical fiber material, the peripheral material can be set as a light-shielding material, and the light-shielding material can be selected from at least one of opaque glass, opaque plastic, opaque ceramics, and metal, and the color of "opaque" can be black or dark. Exemplarily, the light shielding material has a transmittance of 400nm-1200nm light less than or equal to 10%, such as 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1% or 0.

120. Arranging the first core material and the second core material at intervals, and disposing peripheral materials on the outer periphery of the first core material and the outer periphery of the second core material.

Please refer to FIG. 2, which is a process flow diagram of the first preparation method of the composite rod provided in the embodiment of the present application. The peripheral material 131 can be a single rod, and the peripheral material 131 has a plurality of hollow structures 101 arranged at intervals; at this time, the peripheral material is arranged on the outer periphery of the first core material and the outer periphery of the second core material Specifically, it may include: disposing the first core material 111 and the second core material 121 in different hollow structures 101 respectively. The hollow structure 101 may be a through hole or a groove. The number of hollow structures 101 in the peripheral material 131 is at least 2, and may be more than 2, such as 3, 4, 5, 6, 7, 8 and so on.

Please refer to FIG. 3 , which is a process flow chart of the second preparation method of the composite rod provided in the embodiment of the present application. The peripheral material 131 may include a plurality of fiber filaments; at this time, arranging the peripheral material on the outer periphery of the first core material and the outer periphery of the second core material may specifically include: arranging a plurality of fiber filaments on the outer periphery of the first core material 111 and the outer periphery of the second core material 121 . When the peripheral material 131 adopts a rod with integral structure, since it is necessary to punch holes in the peripheral material 131 to form the hollow structure 101, it is often difficult to punch holes and the rod is easy to crack for materials that are difficult to process (such as glass). However, when the peripheral material 131 adopts multiple fiber filaments, the above-mentioned perforation problem is avoided, the processing difficulty is reduced, the production yield is improved, and the production cost is reduced at the same time. It should be noted that in this application, "fiber filament" is only used to indicate that the length of the material is greater than its cross-sectional width, and does not limit the specific fineness of the material.

Optionally, arranging the peripheral material on the outer periphery of the first core material and the outer periphery of the second core material may specifically include: arranging the first core material 111 and the second core material 121 at intervals, and arranging the peripheral material 131 on the first core material The outer periphery of the core material 111 and the outer periphery of the second core material 121. It can be understood that the first core material 111 is used to form the first window area of the cover plate, and the second core material 121 is used to form the second window area of the cover plate. Since the first core material 111 is an optical fiber, no matter the first Whether the core material 111 and the second core material 121 are arranged at intervals, the light in the first core material 111 will not be strung into the second core material 121, that is, in some embodiments, the first core material 111 and the second core material Material 121 may be adjacent.

130. Extrude the first core material, the second core material, and the peripheral material to obtain a composite rod.

Please continue to refer to Fig. 2 or Fig. 3, when the peripheral material 131 can be deformed under the action of an external force under normal temperature conditions, for example, when the peripheral material 131 is a plastic metal or plastic under normal temperature conditions, it can be deformed only by extrusion without heating. To realize the combination of the first core material 111, the second core material 121 and the peripheral material 131, of course, the first core material 111, the second core material 121 and the peripheral material 131 can also be heated to improve the plasticity of the material; when the peripheral material When 131 is not deformable under normal temperature conditions, for example, when the peripheral material 131 is glass or plastic that does not have plasticity under normal temperature conditions, it is necessary to heat the peripheral material 131 to soften it, and then the first core material 111, The combination of the second core material 121 and the peripheral material 131, at this time, the first core material, the second core material and the peripheral material are extruded to obtain the composite rod. Specifically, it may include: first core material 111, the second core material After the material 121 and the peripheral material 131 are heated, the first core material 111 , the second core material 121 and the peripheral material 131 are extruded to obtain a composite rod 170 .

It can be understood that, for the fiber material, force is applied from the side of the fiber during extrusion. When the first core material 111 and/or the second core material 121 are multiple unconnected optical fibers, the first core material 111, the second core material 121 and the peripheral material 131 should be heated before extrusion, so that the skin of the optical fiber After softening, multiple optical fibers are fused together by extrusion.

Optionally, the percentage difference between the coefficient of thermal expansion (coefficient of thermal expansion, CTE) of the peripheral material 131 and the coefficient of thermal expansion of the first core material 111 is less than or equal to 20%. It can be understood that the coefficient of thermal expansion of the peripheral material 131 and the first core material 111 The coefficient of thermal expansion of the first core material 111 needs to be as close as possible to avoid or reduce cracking of the peripheral material 131 and/or inside the first core material 111 caused by excessive CTE difference after high temperature treatment and cooling. The definition of "difference percentage" is: if A is greater than or equal to B, then the difference percentage between A and B (or the difference percentage between B and A) = (A-B)/B, all "differences" recorded in this application Percentage" adopts this definition. Exemplarily, the percentage difference between the thermal expansion coefficient of the peripheral material 131 and the thermal expansion coefficient of the first core material 111 may be 20%, 15%, 10%, 5%, 4%, 3%, 2%, 1% or 0 , when the difference percentage between the two is 0, it means that the thermal expansion coefficient of the peripheral material 131 is equal to the thermal expansion coefficient of the first core material 111 .

Optionally, the percentage difference between the coefficient of thermal expansion of the peripheral material 131 and the coefficient of thermal expansion of the second core material 121 is less than or equal to 20%. It can be understood that the coefficient of thermal expansion of the peripheral material 131 and the coefficient of thermal expansion of the second core material 121 require As close as possible to avoid or reduce the internal cracking of the peripheral material 131 and/or the second core material 121 caused by excessive CTE differences after high-temperature treatment and cooling. Exemplarily, the percentage difference between the thermal expansion coefficient of the peripheral material 131 and the thermal expansion coefficient of the second core material 121 may be 20%, 15%, 10%, 5%, 4%, 3%, 2%, 1% or 0 , when the difference percentage between the two is 0, it means that the thermal expansion coefficient of the peripheral material 131 is equal to the thermal expansion coefficient of the second core material 121 .

It should be noted that, when the cross-sectional size of the composite rod 170 obtained after extrusion is larger than the cross-sectional size of the target product (cover plate), a step of drawing the composite rod 170 can be set after extrusion to make the composite The cross-sectional size of the bar 170 is adjusted. Compared with the simple extrusion method, extrusion plus drawing can quickly obtain the target product that meets the size requirements, thereby greatly improving production efficiency and reducing production costs. It can also improve the bonding effect of the first core material 111 , the second core material 121 and the peripheral material 131 , so that the three can be combined more tightly.

From the perspective of improving the drawing effect, optionally, the softening point temperature of the first core material 111 is higher than or equal to the softening point temperature of the peripheral material 131 . Otherwise, when the softening point temperature of the first core material 111 is lower than the softening point temperature of the peripheral material 131, it is easy to occur that the peripheral material 131 has not softened and cannot be drawn during the process of heating the material before drawing. A phenomenon that the core material 111 has melted or softened, making it impossible to process. Exemplarily, the softening point temperature of the peripheral material 131 is equal to the softening point temperature of the first core material 111 .

From the perspective of improving the drawing effect, optionally, the softening point temperature of the second core material 121 is higher than or equal to the softening point temperature of the peripheral material 131 . Otherwise, when the softening point temperature of the second core material 121 is lower than the softening point temperature of the peripheral material 131, it is easy to occur that the peripheral material 131 has not softened and cannot be drawn during the process of heating the material before drawing. The phenomenon that the second core material 121 has been melted or softened makes it impossible to process. Exemplarily, the softening point temperature of the peripheral material 131 is equal to the softening point temperature of the second core material 121 .

It can be understood that when the first core material 111, the second core material 121 and the peripheral material 131 are all softened, the composite rod 170 can be drawn, and the first core material 111 and the second core material can be simultaneously changed by drawing. 121 and the respective cross-sectional dimensions of the peripheral material 131; when the first core material 111 and the second core material 121 are not softened and the peripheral material 131 has been softened, the composite rod 170 can also be drawn, and the drawing is only for the peripheral material 131 , changing only the cross-sectional dimension of the peripheral material 131 without changing the cross-sectional dimension of the first core material 111 and the second core material 121 by drawing.

In order to eliminate the internal stress generated during processing and avoid or reduce the possibility of subsequent deformation and cracking of the composite rod 170, in some embodiments, after extrusion or extrusion plus drawing, it is also possible to set the composite rod Step 170 of performing annealing treatment, the annealing temperature is determined according to the specific properties of the material.

140. Process the composite bar to obtain a cover plate.

Please refer to FIG. 4 , which is a process flow chart of manufacturing a cover plate from a composite rod provided in the embodiment of the present application. Processing the composite rod may specifically include: cutting the composite rod 170 . Of course, the specific means of "processing the composite rod" may also be a non-cutting method. The composite bar 170 can be processed according to the designed shape and size of the cover plate 10, and the shape of the cover plate 10 can be circular, polygonal (such as triangular, quadrilateral, pentagonal, hexagonal), irregular, etc. After the treatment, subsequent processing can be performed on the cover plate 10 , such as computer numerical control (CNC) processing, grinding, polishing, coating/silk-screen printing and other processes, so as to improve the quality of the cover plate 10 . Exemplarily, the thickness of the cover plate 10 can be processed to about 1 mm, and the cover plate 10 can be processed into a 2D form (flat plate shape), a 2.5D form (a lower flange is provided around the plate plate) or a 3D form (a flat plate around the plate) as required. with higher flanges).

Please continue to refer to FIG. 4 , the cover plate 10 may include a first window area 11 , a second window area 12 and a peripheral area 13 , the first window area 11 and the second window area 12 are spaced apart, and the peripheral area 13 surrounds the first window area 11 Set and set around the second window area 12. Wherein, the first window area 11 is formed by the first core material 111 , the second window area 12 is formed by the second core material 121 , and the peripheral area 13 is formed by the peripheral material 131 .

In the preparation method of the above-mentioned cover plate, the first core material 111, the second core material 121 and the peripheral material 131 are combined together by extrusion or extrusion plus drawing to obtain the cover plate 10, and the cover plate 10 The first core material 111 is an optical fiber, so the light entering the first core material 111 can only propagate in the direction restricted by the optical fiber, and will not enter the second core material 121, thus avoiding the gap between the first core material 111 and the second core material 121. The phenomenon of light crosstalk occurs.

The embodiment of the present application also provides a cover plate, please refer to FIG. 5 , which is a schematic structural diagram of the cover plate provided in the embodiment of the present application. The cover plate 10 may include a first window area 11, a second window area 12 and a peripheral area 13, the first window area 11 and the second window area 12 are arranged at intervals, and the first window area 11 and the second window area 12 are both used to use Light passes through, and the peripheral area 13 is arranged around the first window area 11 and the second window area 12 , wherein the material of the first window area 11 is optical fiber, and the material of the peripheral area 13 includes non-fiber material. Because the material of the first viewing window area 11 adopts optical fiber, the light entering the first viewing window area 11 can only propagate in the direction restricted by the optical fiber, and will not enter the second viewing window area 12, thus avoiding the first viewing window area 11 and the second viewing window. Occurrence of light crosstalk phenomenon between zones 12.

The cover plate 10 can be prepared by the method for preparing the cover plate shown in FIG. 1 , or can be prepared by other preparation methods (such as injection molding process).

The material of the second window area 12 can be an optical fiber, the material of the second window area 12 can be a single optical fiber or a plurality of optical fibers connected together, and the plurality of optical fibers can be fused together by heating and extruding, or by other fixedly connected together. In some other embodiments, the material of the second window area 12 can also be a non-optical fiber material with light transmission properties, such as transparent glass, transparent plastic (such as PMMA, etc.), sapphire, or transparent ceramics. Certainly, the material of the second window region 12 may also be a combination of optical fiber and non-fiber material.

It can be understood that when the material of the first window area 11 is optical fiber, or the material of the first window area 11 and the material of the second window area 12 are both optical fibers, the incident end face of the optical fiber is set close to one end face of the cover plate 10 Or be flush with the end face, and the exit end face of the optical fiber is arranged close to or flush with the other end face of the cover plate 10 .

Optionally, the material of the peripheral area 13 can be a single non-fiber material, or the material of the peripheral area 13 is a combination of optical fiber and non-fiber material, the non-fiber material can be plastic, glass or metal, etc., and the plastic can be polycarbonate (Polycarbonate, PC), polyamide (Polyamide, PA), polyether ether ketone (Polyetheretherketone, PEEK), polymethyl methacrylate (polymethyl methacrylate, PMMA), etc. The material of the peripheral area 13 may be a light-transmitting material or a light-shielding material. Exemplarily, the color of the material of the peripheral area 13 may be black, dark or transparent. It can be understood that since the peripheral area 13 is a non-working area, there is no requirement for light transmittance, so the transparency and color of the peripheral area 13 can be adjusted according to specific needs, so as to increase the richness of the shape of the cover plate 10 and enhance the cover plate. 10, thereby improving the appearance and market competitiveness of electronic equipment including the cover 10.

When the material of the second viewing window area 12 is a light-transmitting non-optical fiber material, the material of the peripheral area 13 can be set as a light-shielding material, and the light-shielding material can be selected from at least one of opaque glass, opaque plastic, opaque ceramics, and metal, " Opaque" can be black or dark in color. Exemplarily, the light shielding material has a transmittance of 400nm-1200nm light less than or equal to 10%, such as 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1% or 0.

It should be noted that when the cover plate 10 is applied to an electronic device with a PPG structure, both the first window area 11 and the second window area 12 should allow light in the wavelength range from visible light to near infrared (400nm-1200nm) to pass through. And the higher the transmittance, the better. Exemplarily, the transmittance of the first viewing window region 11 to the light of 400nm-1200nm is greater than or equal to 20%, such as 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100%; the transmittance of the second viewing window area 12 to the light of 400nm-1200nm is greater than or equal to 20%, such as 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 100% %.

The number of the first viewing window area 11 provided on the cover plate 10 may be one or more, and the number of the second viewing window area 12 provided on the cover plate 10 may be one or more. In the present application, "plurality" refers to two or more, such as three, four, five, six, seven, eight, etc.

The above-mentioned cover plate 10, wherein the material of the first viewing window area 11 is optical fiber, so the light entering the first viewing window area 11 can only propagate in the direction restricted by the optical fiber, and will not enter the second viewing window area 12, avoiding the first viewing window The phenomenon of light crosstalk between the area 11 and the second window area 12 occurs.

Please refer to FIG. 6 . FIG. 6 is another flow chart of the method for preparing the cover provided in the embodiment of the present application. The preparation method of cover plate comprises:

210. Provide a first core material, a second core material, and a peripheral material, both of the first core material and the second core material are light-transmitting materials, and the refractive index of the first core material is greater than that of the peripheral material.

The first core material can be transparent plastic (such as PMMA, etc.), transparent glass, transparent ceramics, sapphire, etc. Exemplarily, the transmittance of the first core material to the light of 400nm-1200nm is greater than or equal to 20%, such as 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 100% %.

The color of the peripheral material can be transparent, black or dark, and the peripheral material 131 can be plastic (such as PMMA, PC, PA, PEEK, etc.), glass or metal.

The second core material can be transparent plastic (such as PMMA etc.), transparent glass, transparent ceramics, sapphire, optical fiber, etc., and the refractive index of the second core material can be greater than the refractive index of the peripheral material, and can also be less than or equal to the refractive index of the peripheral material , when the second core material is an optical fiber, the second core material can be a single optical fiber or multiple optical fibers, and the multiple optical fibers can be disconnected or connected together. Exemplarily, the transmittance of the second core material to the light of 400nm-1200nm is greater than or equal to 20%, such as 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 100% %.

Exemplarily, the first core material, the second core material and the peripheral material are all glass.

220, arrange the first core material and the second core material at intervals, and arrange the peripheral material on the outer periphery of the first core material and the outer periphery of the second core material.

The manufacturing method of the cover plate shown in FIG. 6 can adopt the process flow charts in FIGS. 2 to 4 , which will be described in detail below.

Please refer to FIG. 3 , which is a process flow chart of the second preparation method of the composite rod provided in the embodiment of the present application. The peripheral material 131 may include a plurality of fiber filaments; at this time, arranging the peripheral material on the outer periphery of the first core material and the outer periphery of the second core material may specifically include: arranging a plurality of fiber filaments on the outer periphery of the first core material 111 and the outer periphery of the second core material 121 .

230. Extrude the first core material, the second core material, and the peripheral material to obtain a composite rod.

Please continue to refer to FIG. 2 or FIG. 3, when the peripheral material 131 can be deformed under the action of an external force under normal temperature conditions, for example, when the peripheral material 131 is a plastic plastic under normal temperature conditions, the first extrusion can be achieved without heating. The combination of a core material 111, the second core material 121 and the peripheral material 131 can certainly also heat the first core material 111, the second core material 121 and the peripheral material 131 to improve the plasticity of the material; when the peripheral material 131 is When it is not deformable under normal temperature conditions, for example, when the peripheral material 131 is glass or plastic that does not have plasticity under normal temperature conditions, it is necessary to heat the peripheral material 131 to make it soften, and then the first core material 111 and the second core material 111 can be realized by extrusion. The combination of the core material 121 and the peripheral material 131, at this time, extruding the first core material 111, the second core material 121 and the peripheral material 131 to obtain the composite rod 170 may specifically include: first core material 111, the second core material After the second core material 121 and the peripheral material 131 are heated, the first core material 111 , the second core material 121 and the peripheral material 131 are extruded to obtain the composite rod 170 . It can be understood that, before extrusion, the first core material 111 and the second core material 121 may or may not have plasticity.

When the second core material 121 is a plurality of unconnected optical fibers, the first core material 111, the second core material 121, and the peripheral material 131 should be heated before extrusion to soften the cortex of the optical fiber and then extrude the multiple optical fibers. The fibers are fused together. It can be understood that, for the fiber material, force is applied from the side of the fiber during extrusion.

Optionally, the percentage difference between the coefficient of thermal expansion of the peripheral material 131 and the coefficient of thermal expansion of the first core material 111 is less than or equal to 20%. It can be understood that the coefficient of thermal expansion of the peripheral material 131 and the coefficient of thermal expansion of the first core material 111 require As close as possible to avoid or reduce the internal cracking of the peripheral material 131 and/or the first core material 111 caused by the large difference in CTE after high temperature treatment and cooling. Exemplarily, the percentage difference between the thermal expansion coefficient of the peripheral material 131 and the thermal expansion coefficient of the first core material 111 may be 20%, 15%, 10%, 5%, 4%, 3%, 2%, 1% or 0 , when the difference percentage between the two is 0, it means that the thermal expansion coefficient of the peripheral material 131 is equal to the thermal expansion coefficient of the first core material 111 .

It should be noted that, when the cross-sectional size of the composite rod 170 obtained after extrusion is larger than the cross-sectional size of the target product (cover plate), a step of drawing the composite rod 170 can be set after extrusion to make the composite The cross-sectional size of the bar 170 is adjusted. Compared with the simple extrusion method, extrusion plus drawing can quickly obtain the target product that meets the size requirements, thereby greatly improving production efficiency and reducing production costs. It can also improve the bonding effect among the first core material 111 , the second core material 121 and the peripheral material 131 , so that the three are combined more tightly.

240. Process the composite bar to obtain a cover plate.

Please refer to FIG. 4 , which is a process flow chart of manufacturing a cover plate from a composite rod provided in the embodiment of the present application. Processing the composite rod may specifically include: cutting the composite rod 170 . Of course, the specific means of "processing the composite rod" may also be a non-cutting method. The composite bar 170 can be processed according to the designed shape and size of the cover plate 10, and the shape of the cover plate 10 can be circular, polygonal (such as triangular, quadrilateral, pentagonal, hexagonal), irregular, etc. After the treatment, subsequent processing can be performed on the cover plate 10 , such as CNC machining, grinding, polishing, coating/silk-screen printing, etc., so as to improve the quality of the cover plate 10 . Exemplarily, the thickness of the cover plate 10 can be processed to about 1 mm, and the cover plate 10 can be processed into a 2D form (flat plate shape), a 2.5D form (a lower flange is provided around the plate plate) or a 3D form (a flat plate around the plate) as required. with higher flange).

Please continue to refer to FIG. 5 , the cover plate 10 may include a first window area 11 , a second window area 12 and a peripheral area 13 , the first window area 11 and the second window area 12 are spaced apart, and the peripheral area 13 surrounds the first window area 11 Set and set around the second window area 12. Wherein, the first window area 11 is formed by the first core material 111 , the second window area 12 is formed by the second core material 121 , and the peripheral area 13 is formed by the peripheral material 131 .

It can be understood that since the refractive index of the first core material 111 is greater than the refractive index of the peripheral material 131, when the light propagates in the first core material 111, a full range of light can occur at the junction of the first core material 111 and the peripheral material 131. reflection, so that the light always keeps propagating in the first core material 111, and will not be strung into the second core material 121 to cause optical crosstalk, that is, the cover plate 10 can be regarded as a thicker optical fiber as a whole, and the first The core material 111 can be regarded as the core of the optical fiber, and the peripheral material 131 can be regarded as the cladding of the optical fiber. For optical fibers, the greater the difference between the refractive index of the core and the cladding, the greater the numerical aperture of the optical fiber, and the greater the angular range of light that the optical fiber can receive. That is to say, the greater the difference in refractive index between the first core material 111 and the peripheral material 131 is, the better. In this way, the angle range of light received by the first window area 11 is greater.

When the refractive index of the second core material 121 is greater than the refractive index of the peripheral material 131, when the light propagates in the second core material 121, the light reaching the junction of the second core material 121 and the peripheral material 131 can be totally reflected, thereby Keeping the light propagating in the second core material 121 all the time, that is to form a fiber-like structure, the second core material 121 can be regarded as the core of the optical fiber, and the peripheral material 131 can be regarded as the cladding of the optical fiber. It can be understood that the greater the difference in refractive index between the second core material 121 and the peripheral material 131 , the greater the angle range of the light that the second window area 12 can receive.

When the second core material 121 adopts an optical fiber, the light can always keep propagating inside the second core material 121 and will not enter other areas.

In the preparation method of the above-mentioned cover plate, the first core material 111, the second core material 121 and the peripheral material 131 are combined together by extrusion or extrusion plus drawing to obtain the cover plate 10, and the cover plate 10 The refractive index of the first core material 111 is higher than the refractive index of the peripheral material 131, so the light entering the first core material 111 can only be limited to propagate in the first core material 111, and will not enter the second core material 121, avoiding the second core material 121. Light crosstalk occurs between the first core material 111 and the second core material 121 .

The embodiment of the present application also provides a cover plate. For example, as shown in FIG. The window areas 12 are arranged at intervals, and the peripheral area 13 is arranged around the first window area 11 and the second window area 12, wherein the material of the first window area 11 and the material of the second window area 12 are both light-transmitting materials, and the first The refractive index of the material of the window area 11 is greater than the refractive index of the material of the peripheral area 13 . The cover plate 10 has a structure similar to that of an optical fiber. The first viewing window area 11 can be regarded as the core of the optical fiber, and the peripheral area 13 can be regarded as the cladding of the optical fiber, so that the light entering the first viewing window area 11 is always kept in the first viewing window. The light propagates in the area 11, and will not be strung into the second window area 12 to cause light crosstalk.

The cover plate 10 can be prepared by the method for preparing the cover plate shown in FIG. 6 , or by other preparation methods (such as injection molding process).

The material of the first window area 11 can be transparent plastic (such as PMMA, etc.), transparent glass, transparent ceramics, sapphire, etc. The material of the second window area 12 can be transparent plastic (such as PMMA, etc.), transparent glass, transparent ceramics, sapphire, optical fiber, and the like.

The material of the peripheral area 13 can be plastic (such as PMMA, PC, PA, PEEK), glass and the like. The material of the peripheral area 13 can be set as a light-transmitting material or a light-shielding material, for example, the color of the material of the peripheral area 13 can be black, dark or transparent. It can be understood that since the peripheral area 13 is a non-working area, there is no requirement for light transmittance, so the transparency and color of the peripheral area 13 can be adjusted according to specific needs, so as to increase the richness of the shape of the cover plate 10 and enhance the cover plate. 10, thereby improving the appearance and market competitiveness of electronic equipment including the cover 10. For example, the first window area 11, the second window area 12 and the peripheral area 13 can all be designed to be colorless and transparent, or the first window area 11 and the second window area 12 can be designed to be colorless and transparent, and the peripheral area 13 The design is black or dark, so that the cover plate 10 presents different appearance effects.

Optionally, the refractive index of the material of the second window area 12 is greater than the refractive index of the material of the peripheral area 13, when the light propagates in the second window area 12, the light that reaches the junction of the second window area 12 and the peripheral area 13 Total reflection can occur, so that the light is always kept propagating in the second window area 12, that is, a fiber-like structure is formed. The second window area 12 can be regarded as the core of the optical fiber, and the peripheral area 13 can be regarded as the cladding of the optical fiber. The material of the peripheral region 13 can be a light-transmitting material or a light-shielding material.

When the material of the peripheral region 13 is a light-shielding material, the refractive index of the material of the second window region 12 may also be less than or equal to the refractive index of the material of the peripheral region 13 . It can be understood that, when the peripheral region 13 has a light-shielding function, no matter whether the refractive index of the material of the second viewing window region 12 is greater than, smaller than or equal to the refractive index of the material of the peripheral region 13, the second viewing window region 12 can constitute an independent The light-transmitting window allows reflected light to pass through the second window area 12 and enter the photodetector.

When the material of the second window area 12 is an optical fiber, for example, the material of the second window area 12 can be a single optical fiber or multiple optical fibers, and the multiple optical fibers can be fused together by heating and extrusion, or by Other ways are fixedly connected together. At this time, the light entering the second window area 12 can only propagate in the direction restricted by the optical fiber, and will not enter other areas of the cover 10, thereby avoiding the loss of light. When the cover 10 is applied to a smart watch and the second window area When 12 corresponds to the setting of the photodetector, the accuracy of the optical signal received by the photodetector can be improved to improve the accuracy of the detection result. It can be understood that when the material of the second viewing window area 12 is optical fiber, the incident end face of the optical fiber can be arranged close to one end face of the cover plate 10 or be flush with the end face, and the outgoing end face of the optical fiber can be close to the other end face of the cover plate 10. One side end face is set or flush with the other side end face.

Exemplarily, the percentage difference between the coefficient of thermal expansion of the material of the peripheral region 13 and the coefficient of thermal expansion of the material of the first viewing window region 11 is less than or equal to 20%, such as 20%, 15%, 10%, 5%, 4%, 3%. %, 2%, 1% or 0; the percentage difference between the coefficient of thermal expansion of the material of the peripheral region 13 and the coefficient of thermal expansion of the material of the second viewing window region 12 is less than or equal to 20%, such as 20%, 15%, 10%, 5% %, 4%, 3%, 2%, 1% or 0. It can be understood that when the thermal expansion coefficient of the material of the peripheral region 13 and the thermal expansion coefficient of the material of the first window region 11 differ greatly, cracking of the peripheral region 13 and/or the first window region 11 is likely to occur in the cover plate 10 In some cases, when the thermal expansion coefficient of the material of the peripheral region 13 is significantly different from that of the material of the second window region 12 , cracking of the peripheral region 13 and/or the second window region 12 is likely to occur in the cover plate 10 . In this embodiment of the present application, the percentage difference between the thermal expansion coefficient of the material in the peripheral region 13 and the thermal expansion coefficient of the material in the first window region 11 and the difference between the thermal expansion coefficient of the material in the peripheral region 13 and the thermal expansion coefficient of the material in the second window region 12 are calculated. The difference percentages are respectively controlled within the range of less than or equal to 20%, which can avoid cracking in the peripheral area 13, the first window area 11 and the second window area 12 or reduce the peripheral area 13, the first window area 11 and the second window area. The probability of cracking in the window area 12.

The number of the first viewing window area 11 provided on the cover plate 10 may be one or more, and the number of the second viewing window area 12 provided on the cover plate 10 may be one or more.

Exemplarily, the material of the first window area 11 , the material of the second window area 12 and the material of the peripheral area 13 may all be glass.

The above-mentioned cover plate 10, wherein the refractive index of the material of the first window area 11 is greater than the refractive index of the material of the peripheral area 13, forms an optical fiber structure, so that the light entering the first window area 11 can only be limited in the first window area 11 Inner propagation does not enter the second window area 12, avoiding the occurrence of light crosstalk between the first window area 11 and the second window area 12.

An embodiment of the present application further provides an electronic device, which may be a wearable device, such as a watch, a bracelet, a ring, an arm cover, clothing, and the like. Optionally, the electronic device has a health monitoring function, and the health monitoring function includes but not limited to a blood oxygen monitoring function, a heart rate monitoring function, and the like. Exemplarily, the health monitoring function of the electronic device is realized by photoplethysmography (PPG). In the following, the electronic device is a smart watch with a health detection function as an example for illustration.

Please refer to FIG. 7 and FIG. 8 . FIG. 7 is a schematic diagram of a partial structure of the electronic device provided by the embodiment of the present application, and FIG. 8 is a schematic diagram of a partial structure of the electronic device shown in FIG. 7 . The electronic device 100 may include: a cover plate 10, a light emitter 20 and a light detector 30, the light emitter 20 and the light emitter 20 are arranged on the same side of the cover plate 10, and the light emitted by the light emitter 20 enters the first window After the area 11 is transmitted to the side of the cover plate 10 away from the light emitter 20 through the first window area 11, the light incident on the second window area 12 from the side of the cover plate 10 away from the light detector 30 passes through the second window area 12 After transmission, it enters the photodetector 30. The cover plate 10 can be the cover plate 10 described in any of the above-mentioned embodiments. Exemplarily, the cover plate 10 can be made by the preparation method of the cover plate shown in FIG. 1 , or the cover plate shown in FIG. Preparation method obtained. The cover 10 can be used as the back cover of the smart watch (that is, the cover on the side close to the skin), the light emitter 20 can include an LED light, and the light detector 30 can include a light sensor.

Please refer to FIG. 8 , the working principle of the electronic device 100 is as follows: the light emitted by the light emitter 20 passes through the first window area 11 of the cover plate 10 and enters the skin, part of the light is absorbed, part of the light is reflected, and the reflected light passes through the cover. The second window area 12 of the panel 10 enters the light detector 30, and the light signal received by the light detector 30 can be converted to obtain relevant physiological information of the human body, such as blood oxygen data.

Please continue to refer to FIG. 8, the electronic device 100 may further include a circuit board 50, the circuit board 50 may be a printed circuit board (Printed Circuit Board, PCB), and the light emitter 20 and the light detector 30 are mounted on the circuit board 50. In addition, the electronic device 100 may also include an optical isolation structure 40, the optical isolation structure 40 is disposed on the same side of the cover plate 10 as the optical emitter 20 and the optical detector 30, and the optical isolation structure 40 is disposed between the optical emitter 20 and the optical detector. 30, in order to prevent the light emitted by the light emitter 20 from entering the photodetector 30, the light isolation structure 40 can be arranged on the circuit board 50, for example, the top surface of the light isolation structure 40 and the bottom surface of the cover plate 10 abutting to block the light emitted by the light emitter 20 to the greatest extent and avoid cross-light. The material of the light isolation structure 40 may be opaque glass, opaque ceramics, or opaque plastic.

The electronic device 100 provided by the embodiment of the present application adopts the above-mentioned cover plate 10, which can prevent the light emitted by the light emitter 20 from passing through the first window area 11 into the second window area 12 and then being received by the photodetector 30, causing the photodetector An error occurs in the optical signal received by the optical detector 30, which improves the signal-to-noise ratio of the optical signal received by the optical detector 30, thereby improving the accuracy of the test result.

The preparation method of the cover plate, the cover plate and the electronic device provided in the embodiments of the present application have been introduced in detail above. In this paper, specific examples are used to illustrate the principles and implementation methods of the present application, and the descriptions of the above embodiments are only used to help understand the present application. At the same time, for those skilled in the art, based on the idea of this application, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be construed as limiting the application.

Claims

A method for preparing a cover plate, comprising:

Provide a first core material, a second core material and a peripheral material, the first core material is an optical fiber, the second core material is a light-transmitting material, and the peripheral material includes a non-optical fiber material;

disposing the peripheral material on the outer periphery of the first core material and the outer periphery of the second core material;

Extruding the first core material, the second core material and the peripheral material to obtain a composite rod;

The composite rod is processed to obtain the cover plate.
The preparation method of the cover plate according to claim 1, wherein the peripheral material is a single rod, and the peripheral material has a plurality of hollow structures arranged at intervals; the said peripheral material is arranged on the first The outer periphery of a core material and the outer periphery of the second core material include: disposing the first core material and the second core material in different hollow structures; or

The peripheral material includes a plurality of fiber filaments; the arranging the peripheral material on the outer periphery of the first core material and the outer periphery of the second core material includes: arranging a plurality of the fiber filaments on the first core material The outer periphery of the first core material and the outer periphery of the second core material.
The manufacturing method of the cover plate according to claim 1, wherein, the percentage difference between the thermal expansion coefficient of the peripheral material and the thermal expansion coefficient of the first core material is less than or equal to 20%, and the thermal expansion coefficient of the peripheral material is different from that of the first core material. The difference percentage of the coefficient of thermal expansion of the second core material is less than or equal to 20%.
The manufacturing method of the cover plate according to claim 1, wherein the softening point temperature of the first core material is higher than or equal to the softening point temperature of the peripheral material, and the softening point temperature of the second core material is higher than Or equal to the softening point temperature of the peripheral material.
The manufacturing method of the cover plate according to claim 1, wherein the second core material comprises an optical fiber.
The preparation method of the cover plate according to claim 1, wherein, processing the composite rod to obtain the cover plate comprises:

drawing the composite rod to obtain the drawn composite rod;

Processing the drawn composite rod to obtain the cover plate;

or

The composite bar is processed to obtain the cover plate comprising:

performing annealing treatment on the composite rod to obtain an annealed composite rod;

Treating the annealed composite rod to obtain the cover plate;

or

The composite bar is processed to obtain the cover plate comprising:

drawing the composite rod to obtain the drawn composite rod;

annealing the drawn composite bar to obtain an annealed composite bar;

The annealed composite bar is processed to obtain the cover plate.
A method for preparing a cover plate, comprising:

Provide a first core material, a second core material and a peripheral material, both of the first core material and the second core material are light-transmitting materials, and the refractive index of the first core material is greater than that of the peripheral material ;

The first core material and the second core material are arranged at intervals, and the peripheral material is arranged on the outer periphery of the first core material and the outer periphery of the second core material;

Extruding the first core material, the second core material and the peripheral material to obtain a composite rod;

The composite rod is processed to obtain the cover plate.
The manufacturing method of the cover plate according to claim 7, wherein the peripheral material is a single rod, and the peripheral material has a plurality of hollow structures arranged at intervals; the said peripheral material is arranged on the first The outer periphery of a core material and the outer periphery of the second core material include: disposing the first core material and the second core material in different hollow structures; or

The peripheral material includes a plurality of fiber filaments; the arranging the peripheral material on the outer periphery of the first core material and the outer periphery of the second core material includes: arranging a plurality of the fiber filaments on the first core material The outer periphery of the first core material and the outer periphery of the second core material.
The manufacturing method of the cover plate according to claim 7, wherein the percentage difference between the thermal expansion coefficient of the peripheral material and the thermal expansion coefficient of the first core material is less than or equal to 20%, and the thermal expansion coefficient of the peripheral material is different from that of the first core material. The difference percentage of the coefficient of thermal expansion of the second core material is less than or equal to 20%.
The manufacturing method of the cover plate according to claim 7, wherein the softening point temperature of the first core material is higher than or equal to the softening point temperature of the peripheral material, and the softening point temperature of the second core material is higher than Or equal to the softening point temperature of the peripheral material.
The manufacturing method of the cover plate according to claim 7, wherein the refractive index of the second core material is greater than the refractive index of the peripheral material; or

The second core material includes optical fiber.
The preparation method of the cover plate according to claim 7, wherein, processing the composite rod to obtain the cover plate comprises:

drawing the composite rod to obtain the drawn composite rod;

Processing the drawn composite rod to obtain the cover plate;

or

The composite bar is processed to obtain the cover plate including:

performing annealing treatment on the composite rod to obtain an annealed composite rod;

Treating the annealed composite rod to obtain the cover plate;

or

The composite bar is processed to obtain the cover plate including:

drawing the composite rod to obtain the drawn composite rod;

annealing the drawn composite bar to obtain an annealed composite bar;

The annealed composite bar is processed to obtain the cover plate.
A cover plate, comprising:

first window area;

The second window area is set apart from the first window area;

a peripheral area disposed around the first window area and disposed around the second window area;

Wherein, the material of the first window area and the material of the second window area are light-transmitting materials, and the refractive index of the material of the first window area is greater than that of the material of the peripheral area.
The cover plate according to claim 13, wherein the refractive index of the material of the second window area is greater than the refractive index of the material of the peripheral area.
The cover plate according to claim 13, wherein the material of the peripheral area is a light-shielding material, and the refractive index of the material of the second window area is less than or equal to the refractive index of the material of the peripheral area.
The cover plate according to claim 13, wherein the material of the second window region comprises a single optical fiber or a plurality of optical fibers.
The cover plate according to claim 13, wherein the percentage difference between the coefficient of thermal expansion of the material of the peripheral region and the coefficient of thermal expansion of the material of the first viewing window region is less than or equal to 20%, and the percentage of the material of the peripheral region is The percentage difference between the coefficient of thermal expansion and the coefficient of thermal expansion of the material of the second window region is less than or equal to 20%.
An electronic device, comprising:

A cover plate, the cover plate is the cover plate according to claim 13;

The light emitter is arranged on one side of the cover plate, and the light emitted by the light emitter enters the first window area and is transmitted to the cover plate through the first window area to be away from the light emitter side of

The light detector and the light emitter are arranged on the same side of the cover plate, and the light incident on the second viewing window area from the side of the cover plate away from the light detector passes through the second viewing window zone after transmission into the photodetector.
The electronic device according to claim 18, wherein the material of the second window region has a higher refractive index than the material of the peripheral region.
The electronic device according to claim 18, wherein the material of the peripheral area is a light-shielding material, and the refractive index of the material of the second window area is less than or equal to the refractive index of the material of the peripheral area.