CN117922071A

CN117922071A - Mold, optical waveguide, preparation method of optical waveguide and augmented reality equipment

Info

Publication number: CN117922071A
Application number: CN202211254964.XA
Authority: CN
Inventors: 刘庆锋
Original assignee: Realme Mobile Telecommunications Shenzhen Co Ltd
Current assignee: Realme Mobile Telecommunications Shenzhen Co Ltd
Priority date: 2022-10-13
Filing date: 2022-10-13
Publication date: 2024-04-26

Abstract

The application provides a die, an optical waveguide, a preparation method of the optical waveguide and augmented reality equipment. The mold comprises a first sub-mold and a second sub-mold, wherein the second sub-mold and the first sub-mold can enclose to form a mold cavity, and the second sub-mold comprises a body part and a first guide pillar; the body part is provided with a first surface facing the die cavity and a first through hole communicated with the die cavity, the first through hole extends along a first direction and penetrates through the first surface, the first guide pillar is movably arranged in the first through hole along the first direction in a penetrating way, and the first direction is inclined to the first surface; the first guide post is provided with a first grid-like structure on a surface thereof facing the die cavity, the first grid-like structure being inclined to the first surface. The mold of the application can be applied to injection molding or casting molding technology to prepare the optical waveguide with the inclined grating, so that the obtained optical waveguide has higher light efficiency, lower cost and lighter weight.

Description

Mold, optical waveguide, preparation method of optical waveguide and augmented reality equipment

Technical Field

The application relates to the field of electronics, in particular to a die, an optical waveguide, a preparation method of the optical waveguide and augmented reality equipment.

Background

Augmented reality (augmented reality, AR) technology can combine virtual with real world, and is now becoming more and more widely used. The optical waveguide is an indispensable element of the augmented reality device, and comprises a geometric optical waveguide and a diffraction optical waveguide, so that compared with the geometric optical waveguide, the optical waveguide has higher flexibility in design and production, higher mass productivity and higher yield, and therefore wider application. Grating morphologies of commonly used diffractive optical waveguides include rectangular gratings, blazed gratings, and tilted gratings. Rectangular gratings are simple in structure and easy to manufacture, but have low light efficiency, while inclined gratings and blazed gratings have the greatest advantage of high diffracted light energy. Compared with blazed gratings, the oblique gratings have wider allowable range of dimensional tolerance, so that the oblique gratings have wider application range and are more suitable for light transmission and imaging of diffraction optical waveguides. However, the inclined grating can only be prepared by a semiconductor etching process, and is difficult to prepare by a nano-imprint process, an injection molding process, a casting molding process or the like, so that the inclined grating is high in preparation cost, and the semiconductor etching process is only suitable for glass, so that the prepared optical waveguide is fragile and heavy, and weight reduction of augmented reality equipment using the optical waveguide is not facilitated.

Disclosure of Invention

In view of the above, embodiments of the present application provide a mold that can be applied to an injection molding or casting process to prepare an optical waveguide with an inclined grating, so that the obtained optical waveguide has high light efficiency, low cost and light weight.

An embodiment of a first aspect of the present application provides a mold comprising:

A first sub-die; and

The second sub-die and the first sub-die can enclose to form a die cavity, and the second sub-die comprises a body part and a first guide post; the body part is provided with a first surface facing the die cavity and a first through hole communicated with the die cavity, the first through hole extends along a first direction and penetrates through the first surface, the first guide pillar is movably arranged in the first through hole along the first direction in a penetrating way, and the first direction is inclined to the first surface; the first guide post is provided with a first grid-like structure on a surface thereof facing the die cavity, the first grid-like structure being inclined to the first surface.

An embodiment of a second aspect of the present application provides a method for manufacturing an optical waveguide, including:

Providing a mold according to the first aspect of the present application, wherein the first guide post has a first position and a second position relative to the second sub-mold, and the first position is closer to the first sub-mold than the second position, so that the first guide post is in the first position;

Injecting resin slurry into a cavity of the mold, and forming the resin slurry to form the optical waveguide, wherein the optical waveguide is provided with a first inclined grating which is complementary to the first grating structure of the first guide post;

moving the first guide post towards a direction away from the first sub-die to a second position of the first guide post; and

The first sub-module is separated from the second sub-module to separate the optical waveguide.

An embodiment of the third aspect of the present application provides an optical waveguide, which is manufactured by using the manufacturing method according to the embodiment of the second aspect of the present application.

An embodiment of a fourth aspect of the present application provides an augmented reality device, comprising:

the projection optical machine is used for projecting optical signals, and the optical signals comprise image information; and

An embodiment of the third aspect of the present application provides an optical waveguide, where the optical waveguide is used to transmit the optical signal.

The mold can be used for injection molding or pouring processes, the first guide pillar is arranged, when demolding is performed, demolding is performed on the first guide pillar first, and then demolding is performed on the first sub mold and the second sub mold, so that the problem that the inclined grating cannot be demolded in the injection molding or pouring process can be effectively solved, the optical waveguide with the inclined grating can be prepared through the injection molding process or the pouring molding process, the problem that the existing optical waveguide with the inclined grating can only be prepared through a semiconductor etching process, and the cost is high is solved, and therefore the preparation cost of the optical waveguide with the inclined grating is greatly reduced, and mass production is easy; in addition, since the injection molding process or the casting molding process can adopt a resin material as a raw material, the prepared optical waveguide can be made of the resin material, so that the prepared optical waveguide with the inclined grating has lighter weight, better anti-falling and shock resistance, and can better lighten the weight of the augmented reality equipment and better anti-falling and shock resistance when being applied to the augmented reality equipment.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of an optical waveguide according to an embodiment of the present application.

Fig. 2 is a schematic cross-sectional view of an optical waveguide according to an embodiment of the present application taken along the direction A-A in fig. 1.

Fig. 3 is a schematic structural view of a mold according to an embodiment of the present application, in which the first guide post is in the first position.

Fig. 4 is a schematic structural view of a mold according to an embodiment of the present application, in which the first guide post is in the second position.

Fig. 5 is a schematic structural view of a first guide post according to an embodiment of the application.

Fig. 6 is a schematic structural view of a mold according to another embodiment of the present application, in which the first guide post is in the first position.

Fig. 7 is a schematic structural view of a mold according to another embodiment of the present application, in which the first guide post is in the second position.

Fig. 8 is a schematic structural view of a mold according to another embodiment of the present application, in which the first guide post is in the first position.

Fig. 9 is a schematic structural view of a mold according to another embodiment of the present application, wherein the first guide post is in the first position and the second guide post is in the third position.

Fig. 10 is a schematic structural view of a mold according to another embodiment of the present application, wherein the first guide post is in the second position and the second guide post is in the fourth position.

Fig. 11 is a schematic structural view of a second guide post according to an embodiment of the application.

Fig. 12 is a schematic structural view of a mold according to still another embodiment of the present application, wherein the first guide post is in the first position and the second guide post is in the third position.

Fig. 13 is a schematic structural view of a mold according to still another embodiment of the present application, wherein the first guide post is in the second position and the second guide post is in the fourth position.

Fig. 14 is a flow chart of a method for manufacturing an optical waveguide according to an embodiment of the present application.

Fig. 15 is a schematic structural diagram corresponding to the preparation flow of the optical waveguide shown in fig. 14.

Fig. 16 is a flow chart of a method for producing an optical waveguide by resin slurry according to an embodiment of the present application.

Fig. 17 is a flow chart showing a method for manufacturing an optical waveguide according to still another embodiment of the present application.

Fig. 18 is a schematic diagram of a structure corresponding to the preparation flow of the optical waveguide shown in fig. 17.

Fig. 19 is a schematic structural view of an optical waveguide of embodiment 1 of the present application.

Fig. 20 is a schematic sectional view of the optical waveguide of embodiment 1 of the present application in the direction C-C in fig. 19.

Fig. 21 is a schematic structural view of an optical waveguide of embodiment 2 of the present application.

Fig. 22 is a schematic sectional view of the optical waveguide of embodiment 2 of the present application in the direction D-D in fig. 21.

Fig. 23 is a schematic structural view of an augmented reality device according to an embodiment of the present application.

Fig. 24 is a schematic cross-sectional structure view of an augmented reality device according to an embodiment of the application along the direction B-B in fig. 23.

Fig. 25 is a circuit block diagram of an augmented reality device according to an embodiment of the application.

Reference numerals illustrate:

100-optical waveguide, 10-light conducting part, 30-in-grating, 50-out-grating, 200-mould, 201-mould cavity, 210-first sub-mould, 230-second sub-mould, 231-body part, 2311-first surface, 2312-first through hole, 2313-second surface, 2314-non-tilting grating, 2316-second through hole, 233-first guide post, 2331-first grating structure, 2332-first penetrating part, 2333-first end face, 2334-first limiting part, 234-first transmission part, 2341-first slide rail, 235-second guide post, 2351-second grating structure, 2352-second penetrating part, 2353-second end face, 2354-second limiting part, 236-second transmission part, 2361-second slide rail, 500-augmented reality device, 510-projection optics, 511-display, 513-lens, 530-wearing part, 531-first wearing part, 533-second wearing part, 550-processor 560-memory.

Detailed Description

In order that those skilled in the art will better understand the present application, a technical solution in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The terms first, second and the like in the description and in the claims and in the above-described figures are used for distinguishing between different objects and not necessarily for describing a sequential or chronological order. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed steps or elements but may include other steps or elements not listed or inherent to such process, method, article, or apparatus.

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings. It should be noted that, for convenience of explanation, like reference numerals denote like components in the embodiments of the present application, and detailed descriptions of the like components are omitted in the different embodiments for brevity.

Augmented reality (augmented reality, AR) technology can organically integrate images of the virtual world with scenes of the real world, so that richer information and immersive experience can be provided for users, and is increasingly widely applied. The AR equipment is taken as the most direct information acquisition way, has very wide application prospect, can be applied to various fields including entertainment arts, game industry, learning education, technical training, medical assistance and the like, and even people can predict that the AR equipment gradually replaces mobile phones to enter the daily life of people.

An optical waveguide (optical waveguide) is a dielectric device that guides the propagation of an optical wave therein. The optical waveguide is an indispensable element of the augmented reality device, and comprises a geometric optical waveguide and a diffraction optical waveguide, so that compared with the geometric optical waveguide, the optical waveguide has higher flexibility in design and production, higher mass productivity and higher yield, and therefore, wider application. For example, the diffractive optical waveguide scheme of the AR glasses is a mainstream technical scheme because the optical lenses are light and thin, the appearance form of the AR glasses is more similar to that of the conventional glasses, and meanwhile, the AR glasses are more convenient to implement and easier to mass produce.

Grating morphologies of commonly used diffractive optical waveguides include rectangular gratings, blazed gratings, and tilted gratings. Rectangular gratings are simple in structure and easy to manufacture, but have low light efficiency, while inclined gratings and blazed gratings have the greatest advantage of high diffracted light energy. Compared with blazed gratings, the tilt grating has wider tolerance range, so the tilt grating has wider application range and is more suitable for light transmission and imaging of the diffraction optical waveguide. The diffraction optical waveguide is used for realizing incidence, expansion and export of light rays by utilizing diffraction action of the grating, and can conduct an image of the light source to human eyes. "light efficiency" refers to the ratio of the luminous flux emitted by a light source to the power consumed, the higher the light efficiency, the lower the loss of light energy transmission.

Since AR diffraction optical waveguides are generally used in the visible light band, the grating size thereof is close to the wavelength of visible light, and in the range of hundreds of nanometers or even tens of nanometers, the requirements of the high-definition grating structure with nanometer size on the processing technology are very high, and semiconductor manufacturing technologies such as photolithography, etching and the like are mostly adopted. At present, the inclined grating can only be prepared by a semiconductor etching process, and is difficult to prepare by a nano-imprint process, an injection molding process, a casting molding process or the like (the processes can only be used for preparing the blazed grating and the rectangular grating), so that the inclined grating has high preparation cost, and the semiconductor etching process is only suitable for glass, so that the prepared optical waveguide is fragile and heavy, and the weight reduction of the augmented reality equipment using the optical waveguide is not facilitated.

Referring to fig. 1 and 2, an optical waveguide 100 is provided in an embodiment of the application, and the optical waveguide 100 includes a light guiding portion 10, an in-coupling grating 30 and an out-coupling grating 50. The coupling-in grating 30 and the coupling-out grating 50 are arranged on the same surface of the light conduction part 10 at intervals; the coupling-in grating 30 is configured to receive an optical signal (i.e., an optical signal output by the display device, the optical signal including image information) entering the optical waveguide 100, and couple the optical signal into the light-conducting portion 10, and the light-conducting portion 10 is configured to transmit the optical signal; the coupling-out grating 50 is used for receiving the optical signal transmitted by the optical conduction portion 10, and coupling the optical signal out of the optical waveguide 100 and into the human eye, so that the human eye can see the image information displayed by the display. At least one of the in-coupling grating 30 and the out-coupling grating 50 is a tilted grating.

Optionally, the optical waveguide 100 may perform one-dimensional pupil expansion or two-dimensional pupil expansion on the optical signal in addition to transmitting the optical signal, so as to increase the orbit range of the augmented reality device, so as to adapt to more people.

Optionally, at least one of the in-coupling grating 30 and the out-coupling grating 50 is a tilted grating. It will be appreciated that the incoupling grating 30 may be a tilted grating; or the out-coupling grating 50 is a tilted grating; or both the in-coupling grating 30 and the out-coupling grating 50 are slanted gratings.

The optical waveguide 100 according to the above embodiment of the present application may be manufactured by using an injection molding process or a casting molding process through a mold provided below, thereby manufacturing the diffraction optical waveguide 100 having the inclined grating made of a resin material. The mold provided by the present application will be described in detail below.

Referring to fig. 3 and 4, an embodiment of the present application provides a mold 200, which includes a first sub-mold 210 and a second sub-mold 230, wherein the second sub-mold 230 and the first sub-mold 210 can enclose a mold cavity 201, and the second sub-mold 230 includes a body portion 231 and a first guide post 233; the body portion 231 has a first surface 2311 facing the mold cavity 201 and a first through hole 2312 communicating with the mold cavity 201, the first through hole 2312 penetrates through the first surface 2311, the first through hole 2312 extends along a first direction, the first guide post 233 is movably penetrating through the first through hole 2312 along the first direction (as shown by an arrow O in fig. 4), and the first direction is inclined to the first surface 2311; the first guide post 233 includes a first grating 2331 at a surface of the first guide post 233 facing the mold cavity 201, the first grating 2331 being inclined to the first surface 2311.

The mold 200 of the present application may be used in an injection molding process as well as a cast molding process. Which may be used to prepare the diffractive optical waveguide 100 with the tilted grating by an injection molding process or a cast molding process.

It should be noted that the first sub-mold 210 and the second sub-mold 230 may be detachable or detachable. The mold 200 has a mold-closed state and a mold-released state, and when the mold 200 is in the mold-closed state, the first sub-mold 210 and the second sub-mold 230 enclose a mold cavity 201, and the mold cavity 201 is used for injecting a thermosetting resin or a thermoplastic resin to perform molding, so as to prepare a molded part, such as the optical waveguide 100 made of resin. After the molding is completed, the first sub-mold 210 and the second sub-mold 230 are separated so that the mold 200 is in a release state, and the molded article, for example, the optical waveguide 100 made of resin is taken out.

Optionally, in some embodiments, the first sub-mold 210 is a female mold and the second sub-mold 230 is a male mold; in other embodiments, the first sub-mold 210 is a male mold and the second sub-mold 230 is a female mold. In the embodiment of the present application, the first sub-mold 210 is taken as a male mold, and the second sub-mold 230 is taken as a female mold, which is illustrated, but not limited to, the mold 200 of the present application. The body portion 231 has a first surface 2311 facing the mold cavity 201, and it is understood that the first surface 2311 is a portion of the inner wall of the mold cavity 201. It is understood that the second direction refers to the height direction of the first grating structure 2331. The number of the first grating structures 2331 may be one or more, and when the number of the first grating structures 2331 is plural, the plurality of first grating structures 2331 are arranged at intervals from the surface of the first guide post 233 facing the mold cavity 201.

When the mold 200 of the embodiment of the present application is used for manufacturing the optical waveguide 100, the first guide post 233 and the second sub-mold 230 are pressed, and the resin slurry is injected into the mold cavity 201, so that the optical waveguide 100 is formed by the resin slurry, and the optical waveguide 100 has the first inclined grating which is complementary to the first grating structure 2331. After the optical waveguide 100 is formed, the first guide post 233 is moved in the first direction towards the direction away from the first sub-die 210, so that the first guide post 233 is separated from the first inclined grating, and then the first sub-die 210 and the second sub-die 230 are separated, so that the optical waveguide 100 with the inclined grating (i.e. the first inclined grating) can be manufactured, and the first inclined grating is not damaged in the process of demolding the first sub-die 210 and the second sub-die 230. It can be appreciated that, in demolding, the first guide posts 233 having the first grid structure 2331 are first demolded, and then the first sub-mold 210 and the second sub-mold 230 are demolded.

The mold 200 of the embodiment of the application can be used for injection molding or casting process, by arranging the first guide pillar 233, when demolding, demolding is firstly carried out on the first guide pillar 233, and then demolding is carried out on the first sub-mold 210 and the second sub-mold 230, so that the problem that the inclined grating cannot be demolded in the injection molding or casting process can be effectively solved, the optical waveguide 100 with the inclined grating can be prepared through the injection molding process or casting process, the problem that the existing optical waveguide 100 with the inclined grating can only be prepared through the semiconductor etching process, and the cost is high is solved, thereby greatly reducing the preparation cost of the optical waveguide 100 with the inclined grating and facilitating mass production; in addition, since the injection molding process or the casting molding process can use a resin material as a raw material, the manufactured optical waveguide 100 can be made of a resin material, so that the manufactured optical waveguide 100 with the inclined grating has lighter weight, better anti-falling and shock resistance, and can better lighten the weight of the augmented reality device and better anti-falling and shock resistance when being applied to the augmented reality device.

Further, since the transmittance of the optical resin is slightly lower than that of glass, the light efficiency of the optical waveguide 100 made of the optical resin is lower than that of the optical waveguide 100 made of glass for the same structure of the grating. However, since the inclined grating has better light efficiency than the blazed grating and the rectangular grating, the preparation of the optical waveguide 100 with the inclined grating by using the resin can compensate the negative effect of the reduction of the light efficiency due to the fact that the light transmittance of the optical resin is slightly lower than that of glass to a certain extent.

Optionally, the first guide post 233 abuts against the inner wall of the body 231 defining the first through hole 2312, and it is understood that there is no gap between the surface of the first guide post 233 facing the inner wall of the body 231 defining the first through hole 2312 and the inner wall of the body 231 defining the first through hole 2312, so as to prevent the fluid in the cavity 201 from flowing out of the mold 200 through the first through hole 2312.

Optionally, a first guide post 233 is arranged in the first through hole 2312 in a fluid-tight manner, so that the liquid in the mold cavity 201 cannot flow to the outside of the mold 200 through the first through hole 2312. This can prevent the liquid in the cavity 201 from passing through the outside of the first through hole 2312 runner mold 200 when injection molding or casting molding is performed, so that the surface of the manufactured optical waveguide 100 is smoother, and the post-processing process of the manufactured optical waveguide 100 is reduced. The term "fluid-tight" refers to a fit between two components (e.g., between the first guide post 233 and the inner wall of the body portion 231 defining the first throughbore 2312) that may prevent liquid from penetrating or flowing therethrough.

Optionally, the first grating structure 2331 is inclined in a second direction (as indicated by arrow P in fig. 4), and the angle α between the first direction and the second direction is in the range of 0+.alpha.ltoreq.10°. Specifically, the angle α between the first direction and the second direction may be, but is not limited to, 0 °,1 °,2 °,3 °,4 °,5 °,6 °,7 °,8 °,9 °,10 °, and the like. When the angle α between the first direction and the second direction is too large, the optical waveguide 100 is prepared by adopting the method of the present embodiment, and when the first guide post 233 is moved in the first direction toward the direction away from the first sub-mold 210, and demolding is performed, the acting force of the first guide post 233 on the first inclined grating of the optical waveguide 100 is too large, so that the inclined grating may be damaged. Therefore, the smaller the angle between the first direction and the second direction, the better. In a preferred embodiment, the first direction is parallel to the second direction; in other words, the angle α=0° between the first direction and the second direction. In this way, the angle of the first grating structure 2331 is consistent with the angle of the first guide post 233 pulled out during demolding, so that the first inclined grating can be better prevented from generating acting force when the first guide post 233 is demolded, and the first inclined grating of the manufactured optical waveguide 100 is more complete and has higher accuracy. It will be appreciated that the first tilted grating may be either the in-coupling grating 30 or the out-coupling grating 50.

Further, the angle α between the first direction and the second direction is in the range of 0.ltoreq.α.ltoreq.5°. In other words, the angle α between the extending direction of the first guide post 233 and the extending direction of the first grid structure 2331 ranges from 0+.alpha.ltoreq.5°. When the angle α between the first direction and the second direction is less than or equal to 5 °, the first guide post 233 can be better reduced to move toward the direction away from the first sub-mold 210, and the acting force applied to the first inclined grating can be better reduced, so that the damage to the grating structure of the first inclined grating during demolding can be better reduced.

Optionally, the first guide post 233 has a first position (as shown in fig. 3) and a second position (as shown in fig. 4) relative to the second sub-die 230, the first position being closer to the first sub-die 210 than the second position, the first guide post 233 being in the first position when the die 200 is used for injection molding or casting, and the first guide post 233 being in the second position when the die is removed. The first guide post 233 has a first position and a second position relative to the second sub-die 230, so that the first guide post 233 can be positioned at the first position when the optical waveguide 100 is molded, and the first guide post 233 can be positioned at the second position when the optical waveguide 100 is demolded, thereby avoiding the loss of the first inclined grating on the optical waveguide 100 when the first sub-die 210 and the second sub-die 230 are demolded, and improving the precision and yield of the preparation of the optical waveguide 100.

Referring to fig. 5, in some embodiments, the first guide post 233 includes a first penetrating portion 2332 and a first limiting portion 2334 connected to each other, the body portion 231 further includes a second surface 2313 opposite to the first surface 2311, the first through hole 2312 further penetrates the second surface 2313, the first penetrating portion 2332 is movably penetrating the first through hole 2312 and abuts against an inner wall of the body portion 231 defining the first through hole 2312, and a side of the first penetrating portion 2332 facing away from the first limiting portion 2334 has a first grid structure 2331; the first limiting portion 2334 is located at a side of the second surface 2313 facing away from the first sub-die 210, and protrudes from the first penetrating portion 2332 along an extending direction of the second surface 2313.

Optionally, the first penetrating portion 2332 and the first limiting portion 2334 are integrally formed, so that the assembling process of the first penetrating portion 2332 and the first limiting portion 2334 can be omitted, the manufacturing process of the mold 200 is simplified, and the stability of the connection between the first penetrating portion 2332 and the first limiting portion 2334 can be improved.

In this embodiment, the first penetrating portion 2332 is movably penetrating the first through hole 2312, and the first limiting portion 2334 is located on a side of the second surface 2313 away from the first sub-mold 210 and protrudes from the first penetrating portion 2332 along an extending direction of the second surface 2313. In this way, the length or depth of the first penetrating portion 2332 penetrating the first through hole 2312 can be better controlled, so that the first inclined gratings of the plurality of optical waveguides 100 prepared by using the mold 200 of the embodiment have better consistency.

As can be appreciated, when the first guide post 233 is in the first position relative to the second sub-die 230, the first limiting portion 2334 abuts the second surface 2313 to limit the first guide post 233 from moving further toward the direction approaching the first sub-die 210. In other words, when the first guide post 233 is at the first position relative to the second sub-die 230, the portion of the first limiting portion 2334 protruding from the first penetrating portion 2332 abuts against the second surface 2313, so as to limit the first guide post 233 to move towards the direction approaching the first sub-die 210. Therefore, when the first guide post 233 needs to be located at the first position, only the first guide post 233 needs to be inserted into the position where the first limiting portion 2334 abuts against the second surface 2313 of the second sub-die 230, no debugging is required each time, and the operation is simple and easy to control.

In some embodiments, when the first guide posts 233 are in the first position, the surface of the first guide posts 233 facing the mold cavity 201 is a first end surface 2333, the first end surface 2333 being flush with the first surface 2311. When the first guide post 233 is at the first position, if the first end surface 2333 of the first guide post 233 is recessed in the first surface 2311, the optical waveguide 100 manufactured by injection molding or casting molding has a portion protruding from the surface of the light guiding portion 10 facing the first inclined grating, in addition to the protruding surface of the first inclined grating, the portion of the surface of the light guiding portion 10 facing the first inclined grating corresponding to the bottom of the first inclined grating, and the protruding portion reflects, refracts, etc. the optical signal, so that the risk of generating a "ghost image" of the manufactured optical waveguide 100 is increased. When the first guide post 233 is in the first position, if the first end surface 2333 protrudes from the first surface 2311, the optical waveguide 100 formed by injection molding or casting may be partially recessed from the surface of the light guiding portion 10 facing the first inclined grating except for the first inclined grating, which may also increase the risk of generating a "ghost image" of the optical waveguide 100. Therefore, when the first guide post 233 is in the first position and the first end surface 2333 is flush with the first surface 2311, the risk of generating a "ghost image" of the optical waveguide 100 can be reduced, and the display effect of the augmented reality device using the optical waveguide 100 can be improved.

It will be appreciated that the end of the first penetration 2332 facing the cavity 201 is flush with the first surface 2311, in other words, the end of the first grating 2331 facing the cavity 201 is flush with the first surface 2311.

As shown in FIG. 4, in some embodiments, the first guide post 233 has a movement distance s1 along the first direction in the range of 1 μm.ltoreq.s1.ltoreq.5 cm. In other words, the distance between the first position and the second position ranges between 1 μm and 5 cm. Specifically, the moving distance s1 of the first guide post 233 along the first direction may be, but is not limited to, 1 μm, 50 μm, 80 μm, 100 μm, 300 μm, 500 μm, 800 μm, 1mm, 3mm, 5mm, 7mm, 9mm, 1 cm, 2 cm, 3 cm, 4 cm, 5cm, etc. When the moving distance s1 of the first guide post 233 along the first direction is too small, when the injection molding or the casting molding is finished and the first guide post 233 is demolded, the first guide post 233 may not be completely separated from the first inclined grating, so that the first inclined grating is easily damaged when the first sub-mold 210 and the second sub-mold 230 are demolded, and in addition, the moving distance s1 of the first guide post 233 along the first direction is too small, so that the difficulty of mechanical control is increased; when the moving distance s1 of the first guide post 233 in the first direction is too large, the size of the mold 200 is increased, which is disadvantageous for miniaturization of the mold 200. When the moving distance s1 of the first guide post 233 along the first direction is within the range of 1 μm and s1 and 5cm, the difficulty in mechanically controlling the movement of the first guide post 233 can be reduced, the damage to the first inclined grating when the first guide post 233 is demolded can be reduced, and the die 200 can be made to have a smaller size.

Further, the moving distance s1 of the first guide post 233 along the first direction ranges from 0.1mm to 1 cm. This can reduce the difficulty of mechanically controlling the movement of the first guide post 233, and can also allow the mold 200 to have a smaller size.

Referring to fig. 6 and 7, in some embodiments, the mold 200 further includes a first transmission member 234, where the first transmission member 234 is used to move the first guide post 233 relative to the second sub-mold 230 along the first direction. By arranging the first transmission member 234, the moving distance of the first guide post 233 in the first through hole 2312 can be better controlled, and automation can be better realized.

Optionally, the first transmission member 234 is disposed on a side of the second sub-die 230 facing away from the first sub-die 210, and the first transmission member 234 is slidably connected with the first guide post 233, and the first transmission member 234 can move relative to the second sub-die 230 in a direction approaching or facing away from the second sub-die 230, so as to drive the first guide post 233 to move relative to the second sub-die 230 along the first direction. By arranging the first transmission member 234, the moving distance of the first guide post 233 in the first through hole 2312 can be better controlled, and automation can be better realized.

It will be appreciated that when the first guide post 233 moves in a first direction relative to the second sub-die 230, the first guide post 233 also moves relative to the first transmission 234 in a direction parallel to the second surface 2313.

The first transmission member 234 is slidably connected to the first guide post 233, and further, the first transmission member 234 is slidably connected to the first limiting portion 2334.

When molding is performed, the first transmission member 234 is controlled to move towards the direction approaching the second sub-mold 230, and the first transmission member 234 drives the first guide post 233 to move towards the direction approaching the first sub-mold 210 along the first direction until the first guide post 233 is at the first position relative to the second sub-mold 230, and at this time, molding can be performed; when the demolding is finished, the through hole controls the first transmission member 234 to move towards the direction away from the second sub-mold 230, and the first transmission member 234 drives the first guide post 233 to move towards the direction away from the first sub-mold 210 along the first direction until the first guide post 233 is at the second position relative to the second sub-mold 230, so that the demolding of the first guide post 233 is realized.

Optionally, the first transmission member 234 has a first sliding rail 2341, the extending direction of the first sliding rail 2341 is located in the same plane as the extending direction of the first through hole 2312, and the first guide post 233 is slidably connected to the first sliding rail 2341 (in other words, the first limiting portion 2334 is slidably connected to the first sliding rail 2341). This may allow for a more compact construction of the overall mold 200 and ease of control. Alternatively, the first transmission member 234 may be controlled to move toward or away from the first sub-mold 210 by a driving mechanism (not shown), such as a driving motor or the like.

Referring to fig. 8, alternatively, when the optical waveguide 100 to be fabricated includes only one inclined grating, only one first guide post 233 is designed on the second sub-die 230. At this time, the body 231 may further have a non-inclined grating 2314 disposed on the first surface 2311, and the non-inclined grating 2314 is disposed on the first surface 2311 of the body 231 and spaced apart from the first grating structure 2331. For example, when the coupling-in grating 30 of the optical waveguide 100 to be fabricated is an inclined grating and the coupling-out grating 50 is a rectangular grating or a blazed grating, the first guide post 233 has an inclined grating (i.e., the first grating structure 2331) complementary to the structure of the coupling-in grating 30, and the first surface 2311 is provided with a non-inclined grating 2314 complementary to the structure of the coupling-out grating 50.

Referring to fig. 9 and 10, in some embodiments, the body 231 further has a second through hole 2316 in communication with the mold cavity 201, the second through hole 2316 is spaced apart from the first through hole 2312 and penetrates the first surface 2311, and the second through hole 2316 extends along a third direction (as indicated by an arrow M in fig. 10); the second sub-die 230 further includes a second guide post 235, where the second guide post 235 is movably disposed in the second through hole 2316 along the third direction; the third direction is inclined to the first surface 2311; the second guide post 235 includes a second grating 2351 at a surface of the second guide post 235 facing the mold cavity 201, the second grating 2351 being inclined to the first surface 2311. By providing the second guide posts 235, when the mold 200 of the present embodiment is used for manufacturing the optical waveguide 100 through an injection molding process or a casting molding process, a second inclined grating (not shown) is formed at a position corresponding to the second guide posts 235 of the optical waveguide 100, and the second inclined grating is complementary to the second grating structure 2351. Therefore, the optical waveguide 100 with the coupling-in grating 30 and the coupling-out grating 50 both being inclined gratings can be prepared, so that the light efficiency of the optical waveguide 100 can be better improved, the preparation cost of the inclined gratings can be better reduced, the prepared optical waveguide 100 has lighter weight, and the augmented reality device using the optical waveguide 100 has better wearing comfort. As will be appreciated, the fourth direction refers to the height direction of the second grating structure 2351. The number of the second grating structures 2351 may be one or more, and when the number of the second grating structures 2351 is plural, the plurality of second grating structures 2351 are arranged at intervals from the surface of the second guide pillars 235 facing the mold cavity 201.

Optionally, the second guide post 235 abuts against an inner wall of the body portion 231 defining the second through hole 2316. It will be appreciated that the surface of the second guide post 235 facing the inner wall of the body portion 231 defining the second through hole 2316 is in abutting engagement with the inner wall of the body portion 231 defining the second through hole 2316 without a gap therebetween to prevent fluid within the mold cavity 201 from flowing out of the mold 200 through the second through hole 2316.

Optionally, a second guide post 235 is arranged in a fluid-tight manner in the second through hole 2316, so that the liquid in the mold cavity 201 cannot flow to the outside of the mold 200 through the second through hole 2316. This can prevent the liquid in the cavity 201 from passing through the second through hole 2316 and flowing outside the mold 200 during injection molding or casting, so that the surface of the manufactured optical waveguide 100 is smoother, and the post-processing steps of the manufactured optical waveguide 100 are reduced.

Optionally, the second grating structure 2351 extends in a fourth direction (as indicated by arrow N in fig. 10), and the angle β between the third direction and the fourth direction ranges from 0 β to 10 °. Specifically, the angle β between the third direction and the fourth direction may be, but is not limited to, 0 °,1 °,2 °,3 °,4 °,5 °,6 °, 7 °,8 °, 9 °,10 °, and the like. When the angle β between the third direction and the fourth direction is too large, the optical waveguide 100 is prepared by the method of this embodiment, and when the second guide pillar 235 is moved in the third direction toward the direction away from the first sub-mold 210, the force of the second guide pillar 235 on the inclined grating of the optical waveguide 100 is too large and the inclined grating may be damaged. Therefore, the smaller the angle between the third direction and the fourth direction, the better. In a preferred embodiment, the third direction is parallel to the fourth direction.

It will be appreciated that the second tilted grating may be either the in-coupling grating 30 or the out-coupling grating 50. Optionally, when the first tilted grating is the coupling-in grating 30, the second tilted grating is the coupling-out grating 50; when the first tilted grating is the out-coupling grating 50, the second tilted grating is the in-coupling grating 30.

Optionally, the angle β between the third direction and the fourth direction ranges from 0 Σ to 5 °. In other words, the angle β between the extending direction of the second guide pillar 235 and the extending direction of the second grid-like structure 2351 is in the range of 0+.β+.5 °. When the angle β between the third direction and the fourth direction is smaller than or equal to 5 °, the acting force applied to the second inclined grating by the first guide post 233 moving towards the direction away from the first sub-mold 210 can be reduced better, so that damage to the grating structure of the second inclined grating during demolding can be reduced better.

Optionally, the second guide post 235 has a third position (as shown in fig. 9) and a fourth position (as shown in fig. 10) relative to the second sub-die 230, the third position being closer to the first sub-die 210 than the fourth position, the second guide post 235 being in the third position when the die 200 is used for injection molding or cast molding, and the second guide post 235 being in the fourth position when the stripping is performed. The second guide post 235 has a third position and a fourth position relative to the second sub-die 230, so that the second guide post 235 can be positioned at the third position when the optical waveguide 100 is molded, and the second guide post 235 can be positioned at the fourth position when the optical waveguide 100 is demolded, so that the loss of the second inclined grating on the optical waveguide 100 can be reduced when the first sub-die 210 and the second sub-die 230 are demolded, and the precision and the yield of the preparation of the optical waveguide 100 can be improved.

Optionally, the second direction is parallel to or intersects the fourth direction. The angle between the second direction and the fourth direction may be designed according to the structure of the optical waveguide 100. It will be appreciated that the first guide post 233 is parallel to or intersects the second guide post 235. Specifically, in some embodiments, the second direction is parallel to the fourth direction, in other words, the first oblique grating and the second oblique grating are inclined toward the same direction by the same angle. In other embodiments, the second direction intersects the fourth direction, in other words, the first oblique grating and the second oblique grating are oriented differently, and the second direction is disposed at an angle to the fourth direction, such as an acute angle, a right angle, an obtuse angle, or the like.

Referring to fig. 11, in some embodiments, the second guide post 235 includes a second penetrating portion 2352 and a second limiting portion 2354 connected to each other, the body portion 231 has a second surface 2313 opposite to the first surface 2311, the second through hole 2316 further penetrates the second surface 2313, when the second penetrating portion 2352 is movably penetrating the second through hole 2316 and abuts against an inner wall of the body portion 231 to define the second through hole 2316, a side of the second penetrating portion 2352 facing away from the second limiting portion 2354 has a second grid structure 2351; the second limiting portion 2354 is located at a side of the second surface 2313 facing away from the first sub-die 210, and protrudes from the second penetrating portion 2352 along an extending direction of the second surface 2313.

Optionally, the second penetrating portion 2352 and the second limiting portion 2354 are integrally formed, so that the assembling process of the second penetrating portion 2352 and the second limiting portion 2354 can be omitted, the manufacturing process of the mold 200 is simplified, and the stability of the connection between the second penetrating portion 2352 and the second limiting portion 2354 can be improved.

In this embodiment, the second penetrating portion 2352 is movably penetrating the second through hole 2316, and the second limiting portion 2354 is located on a side of the second surface 2313 away from the first sub-die 210 and protrudes from the second penetrating portion 2352 along the extending direction of the second surface 2313. In this way, the length or depth of the second penetrating portion 2352 penetrating the second through hole 2316 can be better controlled, so that the second inclined gratings of the plurality of optical waveguides 100 prepared by using the mold 200 of the embodiment have better consistency.

As can be appreciated, when the second guide pillar 235 is in the third position relative to the second sub-die 230, the second limiting portion 2354 abuts the second surface 2313 to limit the second guide pillar 235 from moving further toward the direction approaching the first sub-die 210. In other words, when the second guide post 235 is at the third position relative to the second sub-die 230, the portion of the second limiting portion 2354 protruding from the second penetrating portion 2352 abuts against the second surface 2313, so as to limit the second guide post 235 from moving towards the direction approaching the first sub-die 210. Therefore, when the second guide pillar 235 is located at the third position, the second guide pillar 235 is required to be inserted into the position where the second limiting portion 2354 abuts against the second surface 2313 of the second sub-die 230, and debugging is not required each time, so that the operation is simple and easy to control.

In some embodiments, when second guide post 235 is in the third position, the surface of second guide post 235 facing mold cavity 201 is second end surface 2353, second end surface 2353 being flush with first surface 2311. When the second guide post 235 is at the third position, if the second end face 2353 of the second guide post 235 is recessed in the first surface 2311, the optical waveguide 100 manufactured by injection molding or casting molding has a portion protruding from the surface of the light guiding portion 10 facing the second inclined grating, in addition to the protruding surface of the second inclined grating, the portion of the surface of the light guiding portion 10 facing the second inclined grating corresponding to the bottom of the second inclined grating, and the protruding portion reflects, refracts, etc. the optical signal, so that the risk of generating a "ghost image" of the manufactured optical waveguide 100 is increased. When the second guide post 235 is in the third position, if the second end surface 2353 protrudes from the first surface 2311, the optical waveguide 100 formed by injection molding or casting may be partially recessed from the surface of the light guiding portion 10 facing the second inclined grating except for the second inclined grating, which may also increase the risk of generating a "ghost image" of the optical waveguide 100. Therefore, when the second guide post 235 is in the third position and the second end surface 2353 is flush with the first surface 2311, the risk of generating a "ghost image" of the optical waveguide 100 can be reduced, and the display effect of the augmented reality device using the optical waveguide 100 can be improved.

It will be appreciated that the end surface of the second penetrating portion 2352 facing the cavity 201 is flush with the first surface 2311, in other words, the end surface of the second grating structure 2351 facing the cavity 201 is flush with the first surface 2311.

As shown in FIG. 10, in some embodiments, the second guide post 235 has a movement distance s2 in the third direction in the range of 1 μm.ltoreq.s2.ltoreq.5 cm. In other words, the distance between the third position and the fourth position ranges between 1 μm and 5 cm. Specifically, the moving distance s2 of the second guide post 235 along the third direction may be, but is not limited to, 1 μm, 50 μm, 80 μm, 100 μm, 300 μm, 500 μm, 800 μm, 1mm, 3mm, 5mm, 7mm, 9mm, 1 cm, 2 cm, 3 cm, 4 cm, 5cm, etc. When the moving distance s2 of the second guide pillar 235 along the third direction is too small, when the injection molding or the casting molding is finished and the second guide pillar 235 is demolded, the second guide pillar 235 may not be completely separated from the second inclined grating, so that the second inclined grating is easily damaged when the first sub-mold 210 and the second sub-mold 230 are demolded, and in addition, the moving distance s2 of the second guide pillar 235 along the third direction is too small, so that the difficulty of mechanical control is increased; when the moving distance s2 of the second guide post 235 along the third direction is too large, the size of the mold 200 is increased, which is disadvantageous for miniaturization of the mold 200. When the moving distance s2 of the second guide pillar 235 along the third direction is within the range of 1 μm s2 and 5cm, the difficulty in mechanically controlling the movement of the second guide pillar 235 can be reduced, the damage to the second inclined grating when the second guide pillar 235 is demolded can be reduced, and the die 200 can be made to have a smaller size.

Further, the moving distance s2 of the second guide post 235 along the third direction is in the range of 0.1mm less than or equal to s2 less than or equal to 1 cm. This can better reduce the difficulty of mechanically controlling the movement of the second guide post 235 and can also allow the mold 200 to have a smaller size.

Referring to fig. 12 and 13, in some embodiments, the mold 200 further includes a second transmission member 236, the second transmission member 236 is disposed on a side of the second sub-mold 230 facing away from the first sub-mold 210, and the second transmission member 236 is slidably connected to the second guide post 235, and the second transmission member 236 can move relative to the second sub-mold 230 in a direction approaching or facing away from the second sub-mold 230, so as to drive the second guide post 235 to move relative to the second sub-mold 230 along a third direction. By arranging the second transmission member 236, the moving distance of the second guide pillar 235 in the second through hole 2316 can be better controlled, and automation can be better realized.

It will be appreciated that as the second guide post 235 moves in the third direction relative to the second sub-die 230, the second guide post 235 also moves relative to the second driver 236 in a direction parallel to the second surface 2313. The second driving member 236 is slidably connected to the second guide post 235, and further, the second driving member 236 is slidably connected to the second limiting portion 2354.

When molding is performed, the second driving member 236 is controlled to move towards the direction approaching the second sub-mold 230, and the second driving member 236 drives the second guide pillar 235 to move towards the direction approaching the first sub-mold 210 along the third direction until the second guide pillar 235 is at the first position relative to the second sub-mold 230, and molding can be performed at this time; when the demolding is finished, the through hole controls the second transmission member 236 to move towards the direction away from the second sub-mold 230, and the second transmission member 236 drives the second guide pillar 235 to move towards the direction away from the first sub-mold 210 along the third direction until the second guide pillar 235 is at the second position relative to the second sub-mold 230, so that the demolding of the second guide pillar 235 is realized.

Optionally, the second driving member 236 has a second sliding rail 2361, the extending direction of the second sliding rail 2361 is in the same plane with the extending direction of the second through hole 2316, and the second guiding post 235 is slidably connected to the second sliding rail 2361 (in other words, the second limiting portion 2354 is slidably connected to the second sliding rail 2361). This may allow for a more compact construction of the overall mold 200 and ease of control. Alternatively, the second transmission member 236 may be controlled to move in a direction approaching or departing from the first sub-die 210 by a driving mechanism, such as a driving motor or the like.

In some embodiments, the first transmission member 234 is integrally formed with the second transmission member 236, and it is understood that the first transmission member 234 and the second transmission member 236 are two distinct portions of the same transmission member. Thus, only one driving mechanism is needed to control the first transmission member 234 and the second transmission member 236 to synchronously move towards or away from the first sub-die 210, so that the structure of the die 200 can be simplified, and the control flow can be simplified.

It can be appreciated that when the mold 200 includes only one transmission member, for example, the mold includes a second transmission member 236, the second transmission member 236 is disposed on a side of the second sub-mold 230 facing away from the first sub-mold 210, and the second transmission member 236 is slidably connected to both the first guide post 233 and the second guide post 235 for driving the first guide post 233 to move along the first direction relative to the second sub-mold 230, and driving the second guide post 235 to move along the third direction relative to the second sub-mold 230.

Optionally, a roughness of a surface of the first sub-die 210 facing the die cavity 201 is less than or equal to 50nm; further, the roughness of the surface of the first sub-die 210 facing the die cavity 201 is less than or equal to 10nm.

Optionally, the flatness TTV (Total Thickness Variation, TTV: total thickness deviation) of the surface of the first sub-die 210 facing the die cavity 201 is less than or equal to 100um. Further, the flatness of the surface of the first sub-die 210 facing the die cavity 201 is less than or equal to 20um. "flatness" refers to the difference in height between the highest and lowest points. Optionally, the flatness TTV of the first face is less than or equal to 100um. Further, the flatness of the first surface 2311 is less than or equal to 20um. "flatness" refers to the difference in height between the highest and lowest points.

Optionally, the roughness of the first surface 2311 is less than or equal to 50nm; further, the roughness of the first surface 2311 is less than or equal to 10nm. Optionally, the roughness of the first surface 2311 (i.e. the surface of the second sub-die 230 facing the die cavity 201) is < 10nm, and the flatness TTV of the first surface 2311 is < 20um.

Alternatively, the first gate structure 2331 may be directly fabricated using a semiconductor process or may be fabricated using an electroforming process. Alternatively, the second gate structure 2351 may be directly manufactured by a semiconductor process or may be manufactured by an electroforming process.

When the optical waveguide 100 to be manufactured has three inclined gratings, the first guide post 233 or the second guide post 235 may be added to the mold 200, so that the optical waveguide 100 having three inclined gratings may be manufactured.

How to manufacture an optical waveguide 100 of a resin material having an inclined grating using the mold 200 of the present application will be further described.

Referring to fig. 14 and 15, the embodiment of the present application further provides a method for manufacturing an optical waveguide 100, where the method for manufacturing an optical waveguide 100 having one inclined grating, that is, the optical waveguide 100 includes a first inclined grating and a non-inclined grating, includes:

S301, providing the mold 200 according to the above embodiment of the present application, wherein the mold 200 includes a first guide post 233, the first guide post 233 has a first position and a second position relative to the second sub-mold 230, and the first position is closer to the first sub-mold 210 than the second position, so that the first guide post 233 is in the first position;

Optionally, the body 231 further has a non-slanted grating 2314 located on the first surface 2311, and the non-slanted grating 2314 is located on the first surface 2311 of the body 231 and spaced apart from the first grating structure 2331.

For a detailed description of the mold 200, please refer to the detailed description of the above embodiment, and the detailed description is omitted here. In the present embodiment, the mold 200 includes only the first guide posts 233, in other words, the mold 200 of the present embodiment does not include the second guide posts 235.

Optionally, the first guide post 233 is pushed into the position where the first limiting portion 2334 abuts against the second sub-die 230 along the extending direction of the first through hole 2312, so that the first end surface 2333 of the first guide post 233 is flush with the first surface 2311.

S302, injecting resin slurry into the cavity 201 of the mold 200, and molding the resin slurry to form the optical waveguide 100;

alternatively, the optical waveguide 100 of the present embodiment may be manufactured by an injection molding process using a thermoplastic resin; it can also be prepared by casting molding process using thermosetting resin or photo-setting resin.

In some embodiments, when optical waveguide 100 is prepared by an injection molding process using a thermoplastic resin, a resin slurry is injected into cavity 201 of mold 200 and molded such that the resin slurry forms optical waveguide 100, comprising: the molten thermoplastic resin is injected into the cavity 201, press-molded, and pressure-maintained, followed by cooling molding, so that the molten thermoplastic resin forms the optical waveguide 100. Wherein the optical waveguide 100 has a first slanted grating complementary in shape to the first grating structures 2331 of the first guide posts 233.

When optical waveguide 100 is prepared from a thermoplastic resin by an injection molding process, the resin slurry is a molten thermoplastic resin having a melt volume flow rate MVR of 10g/10min or more at a pressure of 2.16Kg at 280 ℃. Since the first grating structure 2331 on the mold 200 is a very fine nano-sized grating structure, when the MVR is too small, the viscosity of the molten thermoplastic resin is large, the fluidity is poor, and the first inclined grating structure 2331 is relatively not easy to enter into the nano-sized gap of the first grating structure 2331, which easily makes the structure of the transferred first inclined grating not complete or not high enough in accuracy, and therefore, the larger the MVR of the thermoplastic resin is, the better.

Optionally, the thermoplastic resin includes at least one of polyethylene terephthalate (PET), optical grade Polycarbonate (PC), cyclic Olefin Polymer (COP), cyclic Olefin Copolymer (COC), and modified materials thereof. These thermoplastic resins have good optical properties and solution volume flow rate, and thus, the optical waveguide 100 having higher light transmittance can be manufactured, and the first inclined grating of the manufactured optical waveguide 100 can be made to better transfer the structure of the first grating structure 2331.

Alternatively, the thermoplastic resin is light transmissive, the thermoplastic resin has a light transmittance of greater than or equal to 90%, and the thermoplastic resin has a refractive index of greater than or equal to 1.5. Optionally, the density of the thermoplastic resin ranges from 1.1g/cm ³ to 1.4g/cm ³, and the optical resin with high light transmittance can greatly reduce the weight of the optical waveguide compared with the optical glass (the density of the optical glass ranges from about 3.0g/cm ³ to 5.0g/cm ³), and has obvious weight reduction effect.

Referring to fig. 16, in other embodiments, the resin slurry is a thermosetting resin monomer (i.e., a thermosetting resin monomer) or a photo-curable resin monomer; the method for forming the optical waveguide 100 by injecting a resin slurry into the cavity 201 of the mold 200 and molding the resin slurry includes:

s3021, positioning the second sub-mold 230 below the first sub-mold 210 along the gravity direction;

The thermal curing resin monomer can generate larger volume shrinkage when being heated to generate polymerization reaction to cure, so that the upper surface of the manufactured optical waveguide 100 along the gravity direction is uneven, therefore, the second sub-die 230 with the first grating structure 2331 is positioned below the gravity, and the first grating structure 2331 can be better transferred onto the optical waveguide 100, so that the first inclined grating can better transfer the structure of the first grating structure 2331, and the deviation between the first inclined grating and the structure of the first grating structure 2331 caused by the volume shrinkage of materials is better avoided. As for the uneven surface of the optical waveguide 100 facing away from the first inclined grating due to volume shrinkage, polishing, CNC processing, or the like may be performed to make the surface flatness of the optical waveguide 100 meet optical requirements.

Similarly, when the photo-curing resin monomer is heated by light (usually ultraviolet light, such as an LED lamp or a mercury lamp emitting ultraviolet light) to perform polymerization reaction to perform curing, a larger volume shrinkage occurs, so that the upper surface of the manufactured optical waveguide 100 along the gravity direction is rugged, and therefore, the second sub-mold 230 with the first grating structure 2331 is located below the gravity, so that the first grating structure 2331 can be better transferred onto the optical waveguide 100, the first inclined grating can better transfer the structure of the first grating structure 2331, and deviation between the first inclined grating and the structure of the first grating structure 2331 caused by the volume shrinkage of the material is better avoided. As for the uneven surface of the optical waveguide 100 facing away from the first inclined grating due to volume shrinkage, polishing, CNC processing, or the like may be performed to make the surface flatness of the optical waveguide 100 meet optical requirements.

S3022, injecting a thermosetting resin monomer or a photo-curable resin monomer into the cavity 201 of the mold 200;

Alternatively, a thermosetting resin monomer or a photo-setting resin monomer at normal temperature is injected into the cavity 201.

S3023, when the resin slurry is a thermosetting resin monomer, heating is performed to thermally cure the thermosetting resin monomer to form the optical waveguide 100; when the resin slurry is a photo-curable resin monomer, light is applied to photo-cure the thermosetting resin monomer to form the optical waveguide 100, wherein at least one of the first sub-mold 210 and the second sub-mold 230 is light-transmissive.

Alternatively, when the resin slurry is a thermosetting resin monomer, heating to a temperature at which the thermosetting resin monomer undergoes polymerization reaction, so that the thermosetting resin monomer undergoes thermal curing to form the optical waveguide 100; when the resin syrup is a photocurable resin monomer, the light waveguide 100 is formed by irradiating the resin syrup with a light source emitting ultraviolet light such as a mercury lamp or an LED lamp to cure the thermosetting resin monomer.

S303, moving the first guide post 233 towards a direction away from the first sub-die 210 until the first guide post 233 is at the second position;

Optionally, after the molding is finished, the first guide posts 233 are pulled out along the first direction towards a direction away from the first sub-mold 210 until the first guide posts 233 are at the second position, so that the first grid-shaped structures 2331 on the first guide posts 233 are separated from the first inclined gratings, and a gap is formed between the first grid-shaped structures 2331 and the first inclined gratings, thereby realizing demolding of the first inclined gratings. When the first direction is parallel to the second direction, the first guide post 233 vertically leaves the first inclined grating, so that damage to the first inclined grating during demolding can be better prevented.

S304, separating the first sub-die 210 from the second sub-die 230 to separate the optical waveguide 100.

Optionally, the first sub-mold 210 and the second sub-mold 230 are de-molded to remove the molded optical waveguide 100.

Optionally, when the first guide post 233 is moved to the direction away from the first sub-die 210 and the first guide post 233 is at the second position at a time t1, and the first sub-die 210 is separated from the second sub-die 230 at a time t2, t2-t1 is less than or equal to 1s. The total time between the injection molding process and the cast molding process is generally set, and the time between the demolding of the first inclined grating and the overall demolding of the optical waveguide 100 should be as short as possible, so as to minimize the risk of deformation of the molded article (i.e., the molded optical waveguide 100).

The same features of the present application as those of the above embodiments are referred to the description of the corresponding portions of the above embodiments, and are not repeated here.

According to the preparation method of the optical waveguide 100, the first guide post 233 is demolded firstly during demolding and then the first sub-die 210 and the second sub-die 230 are demolded, so that the problem that an inclined grating cannot be demolded in the injection molding or pouring process can be effectively solved, the optical waveguide 100 with the inclined grating can be prepared through the injection molding or pouring molding process, the problem that the existing optical waveguide 100 with the inclined grating can only be prepared through the semiconductor etching process and the cost is high is solved, and the preparation cost of the optical waveguide 100 with the inclined grating is greatly reduced; in addition, since the injection molding process or the casting molding process can use a resin material as a raw material, the manufactured optical waveguide 100 can be made of a resin material, so that the manufactured optical waveguide 100 with the inclined grating has lighter weight, better anti-falling and shock resistance, and can better lighten the weight of the augmented reality device and better anti-falling and shock resistance when being applied to the augmented reality device.

Further, since the transmittance of the optical resin is slightly lower than that of glass, the light efficiency of the optical waveguide 100 made of the optical resin is lower than that of the optical waveguide 100 made of glass for the same structure of the grating. However, since the inclined grating has better light efficiency than the blazed grating and the rectangular grating, the optical waveguide 100 with the inclined grating prepared by using the resin can compensate the influence of light efficiency reduction caused by slightly lower light transmittance of the optical resin than that of glass to a certain extent.

Referring to fig. 17 and 18, the embodiment of the present application further provides a method for manufacturing an optical waveguide 100, where the optical waveguide 100 includes a first inclined grating and a second inclined grating, that is, the coupling-in grating 30 and the coupling-out grating 50 are both inclined gratings, and includes:

S401, providing the mold 200 according to the above embodiment of the present application, wherein the mold 200 includes a first guide post 233 and a second guide post 235, the first guide post 233 has a first position and a second position relative to the second sub-mold 230, and the first position is closer to the first sub-mold 210 than the second position; the second guide post 235 has a third position and a fourth position relative to the second sub-die 230, the third position being closer to the first sub-die 210 than the fourth position; bringing the first guide post 233 in a first position, bringing the second guide post 235 in a second position;

S402, injecting resin slurry into the cavity 201 of the mold 200, and molding the resin slurry to form the optical waveguide 100;

S403, moving the first guide post 233 toward a direction away from the first sub-die 210 to a second position of the first guide post 233, and moving the second guide post 235 toward a direction away from the first sub-die 210 to a fourth position of the second guide post 235;

Optionally, after the molding is finished, the first guide posts 233 are pulled out along the first direction towards a direction away from the first sub-mold 210 until the first guide posts 233 are at the second position, so that the first grid-shaped structures 2331 on the first guide posts 233 are separated from the first inclined gratings, and a gap is formed between the first grid-shaped structures 2331 and the first inclined gratings, thereby realizing demolding of the first inclined gratings. The second guide pillar 235 is pulled out along the third direction towards the direction away from the first sub-mold 210 until the second guide pillar 235 is in the fourth position, so that the second grating structure 2351 on the second guide pillar 235 is separated from the second inclined grating, and a gap is formed between the second grating structure 2351 and the second inclined grating, thereby realizing demolding of the second inclined grating. When the first direction is parallel to the second direction, the first guide post 233 vertically leaves the first inclined grating, so that damage to the first inclined grating during demolding can be better prevented. When the third direction is parallel to the fourth direction, the second guide pillar 235 vertically leaves the second inclined grating, so that damage to the second inclined grating during demolding can be prevented better.

S404, separating the first sub-die 210 from the second sub-die 230 to separate the optical waveguide 100.

Optionally, the second guide pillar 235 is moved toward the direction away from the first sub-die 210 until the second guide pillar 235 is at the second position at a time t3, and the first sub-die 210 is separated from the second sub-die 230 at a time t2, where t2-t3 is equal to or less than 1s. The total time between the injection molding process and the cast molding process is generally set, and the time between the demolding of the second inclined grating and the overall demolding of the optical waveguide 100 should be as short as possible, so as to minimize the risk of deformation of the molded article (i.e., the molded optical waveguide 100).

The fabrication of optical waveguide 100 using mold 200 according to embodiments of the present application is further described below by way of specific examples.

Example 1

Referring to fig. 19 and 20, in the present embodiment, the optical waveguide 100 includes a light conducting portion 10, an in-coupling grating 30 and an out-coupling grating 50, wherein the in-coupling grating 30 is an inclined grating (i.e. a first inclined grating), and the out-coupling grating 50 is a rectangular grating (i.e. a non-inclined grating). The mold 200 includes a first sub-mold 210 and a second sub-mold 230, the first sub-mold 210 and the second sub-mold 230 enclose a mold cavity 201, the second sub-mold 230 includes a body portion 231 and a first guide post 233, a surface of the first guide post 233 facing the mold cavity 201 is provided with a first grating structure 2331 complementary to the first inclined grating structure, and a surface of the body portion 231 facing the mold cavity 201 is provided with a non-inclined grating complementary to the rectangular grating structure. As shown in fig. 15, with the mold 200 of the present embodiment, the optical waveguide 100 in which the coupling-out grating 50 is an inclined grating and the coupling-in grating 30 is a rectangular grating is manufactured by an injection molding process.

Example 2

Referring to fig. 21 and 22, in the present embodiment, the optical waveguide 100 includes a light conducting portion 10, an in-coupling grating 30 and an out-coupling grating 50, wherein the in-coupling grating 30 is an inclined grating (i.e. a first inclined grating), and the out-coupling grating 50 is also an inclined grating (a second inclined grating). The mold 200 includes a first sub-mold 210 and a second sub-mold 230, the first sub-mold 210 and the second sub-mold 230 enclose a mold cavity 201, the second sub-mold 230 includes a body 231, a first guide post 233 and a second guide post 235, a surface of the first guide post 233 facing the mold cavity 201 is provided with a first grating structure 2331 complementary to the first inclined grating structure, and a surface of the second guide post 235 facing the mold cavity 201 is provided with a second grating structure 2351 complementary to the second inclined grating structure. The first and second grating structures 2331 and 2351 have different tilt directions. As shown in fig. 18, with the mold 200 of the present embodiment, the optical waveguide 100, in which the coupling-out grating 50 is an oblique grating and the coupling-in grating 30 is also an oblique grating, is manufactured by an injection molding process.

Referring to fig. 23 and 24, an embodiment of the present application further provides an augmented reality device 500, which includes: the projection light engine 510 and the optical waveguide 100 of the present application. The projection optical machine 510 is used for projecting an optical signal, and the optical signal comprises image information; the optical waveguide 100 is disposed on an exit surface of the projector 510 for transmitting an optical signal.

Optionally, the in-coupling grating 30 and the out-coupling grating 50 of the optical waveguide 100 are disposed away from the projection light engine 510.

Optionally, the projection light engine 510 includes a display 511 and a lens 513. The display 511 is configured to emit light signals, the lens 513 is disposed on a display surface side of the display 511 and is configured to modulate the light signals, so that light rays (light signals) with different angles of view emitted from the same pixel point on the display 511 are emitted in a parallel light form after being modulated by the lens 513, so that image information in the light signals is at an infinite position, and can be observed by naked eyes. The optical waveguide 100 is disposed on a side of the lens 513 away from the display 511, and is used for transmitting the optical signal modulated by the lens 513.

The augmented reality device 500 of the present application may be, but is not limited to, a near-eye display device such as augmented reality glasses (AR glasses), an augmented reality helmet, an augmented reality mask, or the like. In some embodiments, the optical waveguide 100 may also pupil the image information in the optical signal exiting the lens 513 in one or two dimensions to increase the range of the orbit, thereby accommodating more people.

In some embodiments, the augmented reality device 500 of the present application further comprises a carrier 550, the carrier 550 for carrying the optical waveguide 100. Alternatively, the carrier 550 may be, but is not limited to, a frame for augmented reality glasses, a helmet body for an augmented reality helmet, a mask body for an augmented reality mask, and the like. Alternatively, the optical waveguide 100 may be disposed on the carrier 550 by an adhesive or a fastener or the like.

In some embodiments, when the augmented reality device 500 is augmented reality glasses, the augmented reality device 500 of an embodiment of the present application further comprises a wear 530. The wearing piece 530 is rotatably connected with the bearing piece 550, and the wearing piece 530 is used for clamping a wearer (such as a human head, or a head prosthesis, etc.).

Optionally, the wearing piece 530 includes a first wearing sub-piece 531 and a second wearing sub-piece 533, wherein the first wearing sub-piece 531 is rotatably connected to one end of the carrier 550, and the second wearing sub-piece 533 is rotatably connected to the other end of the carrier 550 away from the first wearing sub-piece 531. The first wearing sub-piece 531 cooperates with the second wearing sub-piece 533 for clamping the augmented reality device 500 to the wearer. Optionally, the first wearing sub-component 531 and the second wearing sub-component 533 are further used for setting a projection optical machine. Alternatively, both the first wearing sub-piece 531 and the second wearing sub-piece 533 may be, but are not limited to, temples of the augmented reality device 500 (AR glasses).

Referring to fig. 25, the augmented reality device 500 according to an embodiment of the present application further includes a processor 540 and a memory 560. The processor 540 is electrically connected to the display 511 for controlling the display 511 to emit an optical signal having image information, etc. The memory 560 is electrically connected to the processor 540, and is used for storing program codes required for the processor 540 to operate, program codes required for controlling the display 511, image information emitted from the display 511, and the like.

Optionally, processor 540 includes one or more general-purpose processors, wherein a general-purpose processor may be any type of device capable of processing electronic instructions, including a central processing unit (Central Processing Unit, CPU), microprocessor, microcontroller, main processor, controller, ASIC, and the like. Processor 540 is configured to execute various types of digitally stored instructions, such as software or firmware programs stored in memory 560, that enable the computing device to provide a wide variety of services.

Optionally, the Memory 560 may include Volatile Memory (RAM), such as random access Memory (Random Access Memory); the Memory 560 may also include a Non-Volatile Memory (NVM), such as Read-Only Memory (ROM), flash Memory (FM), hard disk (HARD DISK DRIVE, HDD), or Solid state disk (Solid-state disk-STATE DRIVE, SSD). Memory 560 may also include a combination of the above types of memory.

It should be understood that the augmented reality device 500 in this embodiment is only one form of the augmented reality device 500 to which the optical waveguide 100 is applied, and should not be construed as limiting the augmented reality device 500 provided by the present application.

Reference in the specification to "an embodiment," "implementation" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the described embodiments of the application may be combined with other embodiments. Furthermore, it should be understood that the features, structures or characteristics described in the embodiments of the present application may be combined arbitrarily without any conflict with each other, to form yet another embodiment without departing from the spirit and scope of the present application.

Finally, it should be noted that the above-mentioned embodiments are merely for illustrating the technical solution of the present application and not for limiting the same, and although the present application has been described in detail with reference to the above-mentioned preferred embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made to the technical solution of the present application without departing from the spirit and scope of the technical solution of the present application.

Claims

1. A mold, comprising:

A first sub-die; and

2. The mold of claim 1, wherein the first guide post is disposed fluid-tightly within the first through hole; the first grid-shaped structure extends along a second direction, and an angle alpha between the first direction and the second direction is in a range of 0-10 degrees.

3. The mold of claim 1, wherein the first guide post has a first position and a second position relative to the second sub-mold, the first position being closer to the first sub-mold than the second position, the first guide post being in the first position when the mold is used for injection molding or cast molding, the first guide post being in the second position when demolding is performed.

4. The die of claim 3, wherein the first guide post comprises a first penetrating portion and a first limiting portion connected with each other, the body portion further comprises a second surface opposite to the first surface, the first through hole further penetrates through the second surface, the first penetrating portion is movably penetrating through the first through hole, and the first grid-shaped structure is arranged on one side of the first penetrating portion away from the first limiting portion; the first limiting part is positioned on one side of the second surface, which is away from the first sub-die, and protrudes from the first penetrating part in the extending direction along the second surface.

5. The mold of claim 4, wherein a surface of the first guide post facing the mold cavity is flush with the first surface when the first guide post is in the first position, the first stop portion abutting the second surface.

6. The die of claim 1, wherein the first guide post has a movement distance s1 in the first direction in a range of 1 μm ∈s1 ∈5 cm.

7. The mold of any of claims 1-6, further comprising a first drive member for driving the first guide post in the first direction relative to the second sub-mold.

8. The mold of claim 7, wherein the first transmission member is disposed on a side of the second sub-mold facing away from the first sub-mold, and the first transmission member is slidably connected to the first guide post, and the first transmission member is movable relative to the second sub-mold in a direction approaching or facing away from the second sub-mold, so as to drive the first guide post to move relative to the second sub-mold along the first direction.

9. The mold of claim 2, wherein the body portion further has a second through hole in communication with the mold cavity, the second through hole being spaced from the first through hole and extending through the first surface, the second through hole extending in a third direction; the second sub-die further comprises a second guide post, the second guide post is movably arranged in the second through hole in a penetrating manner along the third direction, and the third direction is inclined to the first surface; the surface of the second guide post facing the die cavity is provided with a second grid structure, and the second grid structure is inclined to the first surface.

10. The mold of claim 9, wherein the second guide post is disposed fluid-tightly within the second through hole; the second grid-shaped structure extends along a fourth direction, and the range of an angle beta between the third direction and the fourth direction is more than or equal to 0 and less than or equal to 10 degrees; the second direction is parallel to or intersects the fourth direction.

11. The die of claim 9, wherein the second guide post comprises a second penetrating portion and a second limiting portion connected to each other, the body portion further comprises a second surface opposite to the first surface, the second through hole further penetrates through the second surface, the second penetrating portion is movably penetrating through the second through hole, and the second grid-shaped structure is arranged on one side of the second penetrating portion away from the second limiting portion; the second limiting part is positioned on one side of the second surface, which is away from the first sub-die, and protrudes from the second penetrating part in the extending direction along the second surface.

12. The mold of claim 9, further comprising a second transmission member disposed on a side of the second sub-mold facing away from the first sub-mold, wherein the second transmission member is slidably coupled to both the first guide post and the second guide post for driving the first guide post to move in the first direction relative to the second sub-mold and simultaneously driving the second guide post to move in the third direction relative to the second sub-mold.

13. A method of making an optical waveguide comprising:

Providing a mold as in any of claims 1-12, wherein the first guide post has a first position and a second position relative to the second sub-mold, the first position being closer to the first sub-mold than the second position, the first guide post being in the first position;

Injecting resin slurry into a cavity of the mold and molding the resin slurry to form the optical waveguide, wherein the optical waveguide has a first inclined grating complementary to a first grating structure shape of the first guide post;

14. The method for producing an optical waveguide according to claim 13, wherein the resin slurry is a molten thermoplastic resin having a melt volume flow rate MVR of 10g/10min or more at a pressure of 2.16Kg at 280 ℃.

15. The method of manufacturing an optical waveguide according to claim 14, wherein the thermoplastic resin comprises at least one of polyethylene terephthalate, optical grade polycarbonate, cyclic olefin polymer, cyclic olefin copolymer, and modified materials thereof.

16. The method for producing an optical waveguide according to claim 13, wherein the resin slurry is a thermosetting resin monomer or a photocurable resin monomer; the method for injecting a resin slurry into a cavity of the mold and molding the resin slurry so that the resin slurry forms the optical waveguide includes:

Positioning the second sub-die below the first sub-die along the gravity direction;

injecting a thermosetting resin monomer or a photo-curing resin monomer into a cavity of the mold; and

When the resin slurry is a thermosetting resin monomer, heating is performed to thermally cure the thermosetting resin monomer to form the optical waveguide; when the resin slurry is a photo-curing resin monomer, light is irradiated to enable the thermosetting resin monomer to be photo-cured to form the optical waveguide, wherein at least one of the first sub-die and the second sub-die is light-transmitting.

17. The method of any one of claims 13 to 16, wherein the time when the first guide post is moved to the second position of the first guide post in a direction away from the first sub-die is t1, and the time when the first sub-die is separated from the second sub-die is t2, t2-t1 is equal to or less than 1s.

18. An optical waveguide produced by the production method according to any one of claims 13 to 17.

19. An augmented reality device, comprising:

The optical waveguide of claim 18 for transmitting the optical signal.