WO2018126760A1 - Resin holographic waveguide lens and preparation method therefor, and three-dimension display device - Google Patents

Abstract

A resin holographic waveguide lens and a preparation method therefor, and a three-dimensional display device constructed thereby. The resin holographic waveguide lens comprises one, two, three, or more resin holographic waveguide lens units. The resin holographic waveguide lens unit comprises a polymer substrate (2) and a functional film (21) disposed on the polymer substrate (2). A functional region (201, 202, 203) is disposed on the functional film (21). A nano diffraction grating is disposed in the functional region (201, 202, 203). The resin holographic waveguide lens has good image coupling-in and coupling-out efficiency, and has the advantages of low replication costs and high fidelity under the condition of using a nano diffraction grating to ensure enough angle of view and observation range. The resin holographic waveguide lens prepared from a resin material can be formed by stamping and a conventional lens process is not required.

Description

Resin holographic waveguide lens, preparation method thereof, and three-dimensional display device

The present application claims the priority of the Chinese patent application entitled "Resin holographic waveguide lens and its preparation method, and three-dimensional display device" on the application date of January 5, 2017, application number 201710006845.5, the entire contents of which are The citations are incorporated herein by reference.

Technical field

The present invention relates to the field of display device technologies, and more particularly to a resin holographic waveguide lens, a method for fabricating the same, and a three-dimensional display device.

Background technique

Augmented Reality (AR) technology is a new technology that integrates real world information and virtual world information "seamlessly". It is an entity information (visual information, which is difficult to experience in a certain time and space of the real world. Sound, taste, touch, etc.), through computer and other science and technology, simulation and then superimposed, so that people get a sensory experience beyond reality. Virtual display technology has been used in applications such as cutting-edge weapons, aircraft development and development, data model visualization, virtual training, entertainment and art, and augmented reality technology. In addition, because AR has the ability to enhance the display output of the real environment, it is more obvious than the virtual display technology VR in the fields of medical research and anatomical training, precision instrument manufacturing and maintenance, military aircraft navigation, engineering design and remote robot control. Advantage.

The AR technology uses a high-brightness microdisplay as an image source and a transparent folded-back optical element as a display screen to project an image onto the human eye through a miniaturized optical system. In the traditional AR technology, multiple complex lens groups are used, the structure is complex, the weight and volume of the whole machine are too large, the assembly accuracy is demanding, the maintenance cost is high, and the display performance is improved to increase the system volume and system weight. cost. Waveguide lenses are a new generation of AR display A key core component that combines the principle of total reflection guided waves with diffractive/refracting elements to reduce the volume and weight of the system while achieving large field of view and large exit image output. In addition, the waveguide lens is guided by a transverse waveguide. Light work does not affect people's observation of the real environment in the vertical direction, so the waveguide lens is an inevitable trend in the development of AR technology today.

A waveguide display device based on a volume holographic grating is disclosed in US Pat. No. 6,169,613 B1. The described holographic waveguide comprises a waveguide structure and two or three body grating structures. The image is introduced into the optical waveguide by a volume grating or a composite grating at the coupling, the image is propagated in the waveguide, and the image is output at the output through one or two volume gratings. Chinese patent CN 105549150 A adds a layer of metal grating on the surface of the volume grating of the holographic waveguide to improve the energy utilization of TM light by plasma oscillation. Although the holographic waveguide has a simple structure, the waveguide only serves as a light guiding function, and has no effect on the expansion of the observation field of view. In addition, the volume grating is difficult to copy and the manufacturing cost is high.

A waveguide lens structure suitable for AR display is disclosed in U.S. Patent No. 7,751,122 B2. The waveguide lens described comprises a waveguide structure and a plurality of half-reverse half-lenses embedded inside the waveguide. The image is coupled into the waveguide by the embedded full-reverse prism, and the image is propagated in the waveguide lens. Each time a semi-reverse half-lens is encountered, the image is coupled out and outputted by modulating the reflectivity of the semi-reverse half-lens at different positions. The resulting image is made uniform in intensity throughout the viewing range. The structure has two main advantages. Firstly, by embedding a plurality of semi-reverse half lenses, the input image size is required to be relaxed, thereby obtaining a larger field of view angle. Secondly, the image is expanded and coupled by multiple coupling outputs in the waveguide. Eye observation range. However, the fabrication of a plurality of semi-reverse half-lenses in such a waveguide lens is complicated and costly, and mainly relies on conventional optical processing, and there is almost no possibility of mass reproduction production, and a half-reverse half is embedded therein. The appearance of the lens of the lens presents a plurality of strips, which affects the wearer's observation. Finally, the solution relies on the side image coupling, so that the space occupied by both sides is large, which affects the wearer's observation comfort.

US Patent No. US 2016/0231568 A1 discloses a holographic waveguide lens for augmented reality, which uses a specific grating to couple and output an image, the image being totally reflected in the waveguide lens, each time traveling to a mirror with a grating On the surface, a part of the energy is coupled out, and the X and Y directions are respectively used to expand the X and Y directions of the image, thereby obtaining a large observation range. Due to the wavelength selection characteristics of the grating, three holographic waveguides are required for red, green and blue. Lens to achieve. The scheme used by Microsoft has the following advantages: First, the sub-wavelength grating has no modulation effect on the light in the vertical direction, so the lens has good penetrability and does not affect the wearer's observation of the surrounding environment; secondly, the lens adopts a center-biased The image coupling method does not affect the wearer's observation on both sides and improves comfort. However, in order to improve the coupling coupling efficiency and ensure that the entire image can be observed within the observation range, the lens needs to be made of a high refractive index glass substrate, which brings problems such as high lens quality, high cost, and great potential danger.

Summary of the invention

At present, there is no simple waveguide lens solution at home and abroad, which can balance the augmented reality display performance (angle of view, viewing range) and the cheap, lightweight and stable lens.

In order to achieve the above object, the technical solution of the present invention is as follows:

A resin holographic waveguide lens comprising one, two, three or more resin holographic waveguide lens units;

The resin holographic waveguide lens unit comprises a polymer substrate and a functional region, wherein the functional region is provided with a nano-diffraction grating; a distance between a bottom of the nano-diffraction grating and a surface of the polymer substrate is greater than 0;

The functional area is disposed on a polymer substrate;

Or the resin holographic waveguide lens unit further includes a functional film, and the functional region is set in the work On the energy film, the functional film is provided on a polymer substrate.

The invention provides a resin type holographic waveguide lens, which has good image coupling and coupling out efficiency, and has the advantages of low copying cost and high fidelity rate when the nanometer diffraction grating is used to ensure a sufficient angle of view and an observation range. Resin holographic waveguide lenses made of resin can be stamped and formed without the need for conventional lens processing.

Preferably, the surface of the nano-diffraction grating is provided with an anti-reflection film.

Preferably, the functional area comprises one, two or three of a coupling functional area, a relay functional area and an outgoing functional area, the coupling functional area, the relay functional area and The nano-diffraction gratings disposed in the functional region are respectively coupled to the coupling grating of the resin holographic waveguide lens, the relay grating for changing the propagation direction of the beam in the resin holographic waveguide lens, and the resin holographic waveguide lens. An exit grating that is output from the beam to the outside of the resin holographic waveguide lens.

Preferably, the resin holographic waveguide lens is of a projection type, the nano-diffraction grating is located at a coupling surface; or the resin holographic waveguide lens is of a reflective type, the nano-diffraction grating is located opposite the coupling surface; and the reflective resin waveguide lens The depth of the nano-diffraction grating is set to be equal to or close to half of the nano-diffraction grating provided on the transmissive resin holographic waveguide lens.

Preferably, the resin holographic waveguide lens is formed by stacking two, three or more resin holographic waveguide lens units; the nano-diffraction grating in the functional region of the different resin holographic waveguide lens unit is corresponding to the optical signals of different wavelengths. That is, the period and arrangement of the nano-diffraction gratings in the functional regions on the different resin holographic waveguide lens units are different.

Preferably, the nano-diffraction grating corresponding to the blue light is coupled to the grating with a period between 290 nm and 410 nm, a grating depth between 100 nm and 500 nm, a relay grating period between 200 nm and 290 nm, and a grating depth of 30 nm to 300 nm. The exit grating period is consistent with the coupled grating period, and the depth is between 30nm and 300nm. between.

Preferably, the nano-diffraction grating corresponding to the green light is coupled between 350 nm and 480 nm, the grating depth is between 100 nm and 600 nm, the relay grating period is between 250 nm and 335 nm, and the grating depth is between 30 nm and 350 nm. The exit grating period is consistent with the coupled grating period and the depth is between 30 nm and 400 nm.

Preferably, the nano-diffraction grating corresponding to red light is coupled to the grating with a period between 415 nm and 550 nm, a grating depth between 100 nm and 800 nm, a relay grating period between 295 nm and 390 nm, and a grating depth of 40 nm to 400 nm. The exit grating period is consistent with the coupled grating period and the depth is between 30 nm and 400 nm.

Preferably, the relay grating adopts a positive grating, and the grating depth is linearly increased from left to right from 20 nm to 70 nm.

Preferably, the exit grating adopts a positive grating, and the grating depth is linearly increased from 20 nm to 100 nm from top to bottom.

Preferably, the relay grating adopts a positive grating, and the grating depth is linearly increased from left to right from 30 nm to 90 nm.

Preferably, the exit grating adopts a positive grating, and the grating depth increases linearly from top to bottom and from 30 nm to 130 nm.

Preferably, the relay grating adopts a positive grating, and the grating depth is linearly increased from left to right from 40 nm to 100 nm.

Preferably, the exit grating adopts a positive grating, and the grating depth increases linearly from 40 nm to 150 nm from top to bottom.

Preferably, the coupling grating is an inclined grating with an inclination angle between 5 and 50 degrees.

Preferably, the exit grating is a positive grating or a tilt grating.

Preferably, the angle between the coupled grating grating vector and the outgoing grating grating vector is between 80° and 120°, and the grating vector of the relay grating is located on the angle bisector of the coupled grating vector and the outgoing grating vector.

Preferably, the polymer substrate is PMMA polymethyl methacrylate, PC polycarbonate, CR39 epoxy resin, PS polystyrene, PEN polyethylene naphthalate, which has good visible light transmittance. Or an episulfide resin having a refractive index between 1.5 and 1.9 and a thickness of from 0.3 mm to 1.5 mm.

Preferably, the functional film is a photocurable or thermosetting resin having a refractive index between 1.5 and 1.9.

Preferably, the spacing between the resin holographic waveguide lens elements corresponding to different wavelengths, i.e., different color lights, is from 5 microns to 100 microns.

Preferably, in the coupling functional region, an anti-reflection film for increasing the coupling efficiency of the image light in the next layer of the resin holographic waveguide lens unit is provided.

Preferably, the photocurable resin is an epoxy acrylate, a urethane acrylate, a polyester acrylate, a polyether acrylate, an acrylated polyacrylic resin, an unsaturated polyester, an episulfide resin, or a double bond or a triple bond, or A monofunctional or polyfunctional monomer of acrylate.

Preferably, the thermosetting resin is a solid resin prepared by mixing a hydroxyl group-containing resin or an epoxy-containing resin with an isocyanate or an amino resin.

Preferably, the functional film further contains a photosensitizer which generates a radical under the action of photons, and initiates polymerization and crosslinking of the room temperature oligomer.

Preferably, the distance between the bottom of the nano-diffraction grating on the functional film and the upper surface of the polymer substrate is any value between 0 micrometers and 20 micrometers that is not zero.

The invention also provides a method for preparing a resin holographic waveguide lens, comprising the steps of:

S1: parameter calculation, determining the period, orientation, and depth distribution of the nano-diffraction grating coupled into the functional region, the relay functional region, and the exit functional region according to the wavelength of the light to be controlled and the imaging field angle of the AR optical path. And waveguide parameters of the resin holographic waveguide lens;

S2: Template preparation, using a photolithography process or mechanical precision machining to make a template (master). One or more transferes can be made as needed;

S3: Firstly, a functional film is coated on the polymer substrate, and the functional region, the relay functional region, and the exit functional region are fabricated onto the functional film by nanoimprint technology.

Preferably, in step S2, the photoresist is spin-coated on the quartz substrate, the laser is used as the interference lithography light source, and the double-beam interference light of the interference light 1 and the interference light 2 is used for photolithography.

In practical applications, the thickness of the photoresist can be selected between 100 nm and 500 nm, and a cadmium cadmium laser having a laser wavelength between 193 nm and 450 nm, preferably 325 nm, is prepared.

The method for preparing the nano-diffraction grating template corresponding to the functional region, the relay functional region, and the exit functional region is respectively as follows:

The preparation of the nano-diffraction grating template coupled into the functional region is covered with a photomask of the photoresist-coated quartz substrate, and only the coupling functional region is transparent, and the interference light 1 and the interference light 2 are located. The normal side of the quartz substrate is on the same side, the interference light 1 and the quartz substrate normal are 10°, and the interference light 2 and the quartz substrate normal are 49.2°;

The preparation of the nano-light diffraction grating template in the relay functional region is covered with a photomask on the photoresist-coated quartz substrate, and only the relay functional region is transparent, and the transmittance of the transparent region is Linearly increasing from left to right, the grating depth varies linearly, and the interference light 1 and the interference light 2 are symmetric with respect to the quartz substrate, and the incident direction and the normal line are 26.8°;

Preparation of a nano-diffraction grating template in an exit functional region, in a photoresist-coated quartz substrate Covering a photomask plate, only the exit functional region is transparent, the transmittance of the light transmissive region increases linearly from top to bottom, the grating depth varies linearly, and the interference light 1 and the interference light 2 are in a quartz substrate method. Line symmetry, and the angle between the normal and the normal is 18.6 °.

Preferably, the step S3 is: firstly, an episulfide-sulfur UV curable resin as a functional film is dripped on the episulfide resin substrate, and the template prepared in the step S2 is pressed onto the episulfide UV curable resin, and applied by a roller. The pressure causes the episulfide UV curable resin to evenly fill between the template and the polymer substrate, and then cures the episulfide UV curable resin, uniformly exposes, and after curing, the episulfide UV curable resin forms a functional film having a nano diffraction grating. Finally demoulding.

The nano-diffraction gratings in the functional regions and their regions can also be fabricated directly on the polymer substrate using thermal nano-imprinting as needed. Including the above-mentioned UV nanoimprinting on the curable polymer, the embossing process includes flat-to-flat embossing, roll-to-roll embossing and roll-to-roll embossing to improve production efficiency. UV sizing methods include dispensing and screen printing (printing according to lens shape). The template can be placed above or below the resin substrate.

Preferably, after step S3, step S4 is further included: preparing a high refractive index optical film on the surface of the nano-imprinted nano-diffraction grating.

Preferably, after step S4, step S5 is further included: stamping the polymer substrate imprinted with the nano-diffraction grating into a resin holographic waveguide lens unit.

Preferably, after step S5, step S6 is further included: aligning the resin holographic waveguide lens units respectively corresponding to different primary colors into a piece of resin holographic waveguide lens.

Preferably, in S1, the waveguide parameters of the resin holographic waveguide lens include a refractive index n1 and a thickness d of the polymer substrate, a refractive index n2 of the functional film, and a distance h from the bottom of the nano-diffraction grating to the upper surface of the polymer substrate.

In S2, the lithography process includes electron beam lithography, interference lithography, deep (polar) ultraviolet lithography, (deep) ultraviolet pixel interference direct writing and other techniques for fabricating sub-wavelength gratings. Mechanical precision machining solutions, such as diamond cutting and scribing, can also be used. The material can be photoresist, organic materials such as PMMA, PS, etc., or can be directly operated on an inorganic substrate such as quartz, or metal lining such as nickel. The bottom is obtained directly.

In S2, the transfer mode includes micro electroforming, flexible transfer, nanoimprinting, and etching techniques such as reactive ion etching and induced ion etching.

In S2, the transfer material used for mold making can be PET, PC, PDMS organic materials, or quartz or silicon wafer inorganic materials, or metal materials such as nickel.

In S2, the three grating functional regions of the lens can be obtained by the same process or by different processes. If it is the former, it can be formed once at the time of the transfer; if it is the latter, it is necessary to combine the gratings of the functional areas of different structural depths and shapes prepared by different methods on the same mold.

In S3, it can be fabricated directly on a polymer substrate by thermal nanoimprinting, or can be fabricated on a curable polymer by UV nanoimprinting. The embossing process includes flat-to-flat embossing, roll-to-roll embossing and Roll-to-flat stamping to increase productivity. UV sizing methods include dispensing and screen printing (printing according to lens shape). The mold can be placed above or below the resin substrate.

In S4, the high refractive index optical film can be prepared by magnetron sputtering, chemical vapor deposition, thermal evaporation or the like.

In S5, the resin lens is press-formed according to the shape of the desired lens. Multi-ply resin lenses are superimposed and need to be aligned. The spacing between the lenses can be controlled by an organic or inorganic film with high transmittance, suitable for selective penetration, improved coupling efficiency, and encapsulation with a frame sealant.

The present invention also provides a three-dimensional display device comprising the above-described resin holographic waveguide lens and an image generating device.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the technical description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some implementations of the present invention. For example, other drawings may be obtained from those of ordinary skill in the art in light of the inventive work.

Figure 1 shows the basic structure of a preferred embodiment of the resin holographic waveguide lens of the present invention for enhancing a display device;

2a and 2b are structural views of a diffraction grating having a structural scale at a nanometer level in an XY plane and an XZ plane;

2c1 is a schematic diagram of a period, a width, a height, and a tilt angle of a nano-diffraction grating coupled into a functional region;

Figure 2c2 is a schematic view of the coupling of the functional region directly onto the polymer substrate;

Figure 2c3 is a schematic view of the functional region being coupled to a functional film;

2d1 is a schematic diagram showing the period, width and height of a nano-diffraction grating that relays and exits a functional region;

2d2 is a schematic view of the relaying and exiting functional regions directly processed on a polymer substrate;

Figure 2d3 is a schematic view of the processing of the relay and exit functional regions on the functional film;

3 is a schematic view of a resin holographic waveguide lens provided with a coupling functional zone, a relay functional zone and an exit functional zone;

Figure 4 is a schematic view showing the operation of constructing a three-dimensional display device using a resin holographic waveguide lens;

Figure 5 is a schematic view showing a method of fabricating a red holographic lens template corresponding to red light;

Figure 6a is a schematic view of a photolithographically processed nano-diffraction grating template, and Figure 6b is a schematic representation of a nickel template structure. Figure

Figure 7 is a schematic view showing a nano-embossed resin holographic waveguide lens;

8 is a schematic view showing a high refractive index dielectric film plated on a surface of a nano diffraction grating;

Figure 9 is a schematic view showing a one-shot molding of a resin holographic waveguide lens by using a stamping grinder;

Figure 10 is a schematic illustration of a resin holographic waveguide lens formed by color stacking of three resin holographic waveguide lens units corresponding to red, green and blue primary colors.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

A resin holographic waveguide lens comprising one, two, three or more resin holographic waveguide lens units;

The resin holographic waveguide lens unit comprises a polymer substrate and a functional region, wherein the functional region is provided with a nano-diffraction grating; a distance between a bottom of the nano-diffraction grating and a surface of the polymer substrate is greater than 0;

The functional area is disposed on a polymer substrate;

Alternatively, the resin holographic waveguide lens unit further comprises a functional film, the functional region being disposed on the functional film, the functional film being disposed on the polymer substrate.

The invention provides a resin type holographic waveguide lens with good image coupling and coupling out efficiency, and has low copying cost and high fidelity rate under the use of the nano-diffraction grating to ensure sufficient field of view and observation range. The advantage is that the resin holographic waveguide lens prepared by the resin material can be stamped and formed, and the processing of the conventional lens is not required.

Preferably, the surface of the nano-diffraction grating is provided with an anti-reflection film.

Fig. 1 shows the basic structure of a preferred embodiment of the resin holographic waveguide lens of the present invention for enhancing a display device. The device includes a miniature image source, a projection optical system, and a resin holographic waveguide lens. The light emitted by the image source passes through the projection optical system and is coupled into the waveguide (polymer substrate) prepared from the resin material from the coupling functional region of the resin holographic waveguide lens. After diffraction, it diffuses into the functional area of the relay, and the angle of light propagation satisfies the condition of total reflection. Each time the light and the surface of the grating act, part of the energy is diffracted, and the remaining energy continues to propagate. After relaying the functional area, the image is stretched in the x direction, and the direction of propagation changes, coupled to the exit functional area, continuing to satisfy the waveguide total reflection condition. Similarly, each time the light and the grating surface act, there is a portion. The light energy is diffracted and the image is stretched in the Y direction. After exiting the nano-diffraction grating of the functional region, the image is coupled out to the observer's glasses, and since the image is stretched in both directions in XY, the human eye can see the entire image in a larger area, improving The comfort of the device and the range of people to use.

The invention adopts the principle of physical optics and diffractive optics, and the resin holographic waveguide lens is composed of two parts, one part is a polymer waveguide prepared by a resin material, and the other part is a functional film and nano diffraction formed on the functional film. Grating, used for optical path folding and imaging. A single nanostructured grating interacts with light to change its phase. Referring to Figures 2a and 2b, Figures 2a and 2b are structural views of a diffraction grating having a structural scale at the nanometer level in the XY plane and the XZ plane. According to the grating equation, the period and orientation angle of the diffraction grating pixel satisfy the following relationship:

(1) tanφ1=sinφ/(cosφ-n sinθ(Λ/λ))

(2) sin2(θ1)=(λ/Λ)2+(n sinθ)2-2n sinθcosφ(λ/Λ)

Wherein, the light (in the three-dimensional display device, the light refers to an image information light beam generated from an image generating device such as a micro-projection device) is incident on the XY plane at a certain angle, and θ1 and φ1 sequentially represent the diffraction angle of the diffracted light (diffracted light) The angle between the positive direction of the z-axis and the azimuth of the diffracted light (the angle between the diffracted ray and the positive x-axis), θ and λ sequentially represent the incident angle of the light source 201 (the angle between the incident ray and the positive z-axis) and the wavelength. Λ and φ sequentially represent the period and orientation angle of the nano-diffraction grating 101 (the angle between the groove shape and the positive direction of the y-axis), and n represents the refractive index of the light wave in the medium. In other words, after specifying the incident light wavelength, the incident angle, and the diffraction angle and the diffraction azimuth of the diffracted light, the period (space frequency) and orientation angle of the desired nanograting can be calculated by the above two formulas. For example, a red light of 650 nm wavelength is incident on the waveguide at an angle of 60°, a diffraction angle of light is 10°, a diffraction azimuth angle is 45°, a corresponding nano-diffraction grating period is 550 nm, and an orientation angle is −5.96°.

Preferably, the functional area comprises one, two or three of a coupling functional area, a relay functional area and an outgoing functional area, the coupling functional area, the relay functional area and The nano-diffraction gratings disposed in the functional region are respectively coupled to the coupling grating of the resin holographic waveguide lens, the relay grating for changing the propagation direction of the beam in the resin holographic waveguide lens, and the resin holographic waveguide lens. An exit grating that is output from the beam to the outside of the resin holographic waveguide lens.

2c1 is a schematic view of the period A, the width W, the height h, and the tilt angle α of the nano-diffraction grating coupled into the functional region. If a positive grating is used, α is 90°.

2c2 is a schematic illustration of the direct coupling of the functional region 201 onto the polymer substrate 2.

2c3 is a schematic illustration of the coupling of the functional region 201 to the functional film 21 (referenced in some embodiments, the material of the functional film is a UV curable resin, also referred to herein as reference numeral 21). The distance from the bottom of the nano-diffraction grating to the upper surface of the polymer substrate 2 is d.

Figure 2d1 shows the period A, the width W, and the height h of the nano-diffraction grating that relays and exits the functional region. Figure.

Figure 2d2 is a schematic illustration of the relaying, exiting functional regions directly processed on a polymer substrate.

2d3 is a schematic view of the relaying and exiting functional regions processed on the functional film 21; the distance from the bottom of the nano-diffraction grating to the upper surface of the polymer substrate 2 is d.

In some embodiments, as shown in FIG. 3, a schematic diagram of a resin holographic waveguide lens having a coupling functional zone, a relay functional zone, and an exit functional zone, the coupling functional region 201 is provided with a nano-diffraction grating. a rectangle close to a square (can be set to a square as needed), and external light is coupled into the optical waveguide 2 (ie, a polymer substrate, or may be referred to as a resin body) prepared from a resin material, coupled into the functional region according to the exit The size setting size, for example, the size may be 4 mm X 4 mm. In the present embodiment, the groove direction of the nano-diffraction grating is parallel to the y-axis, so that the coupling, such as the light in the optical waveguide 2, is conducted in the X direction. The relay functional region 202 is, in this example, a rectangular grating provided with a nano-diffraction grating, the function of which is to conduct light transmitted from the functional region into the Y direction from the X direction to the Y direction, and the size thereof is set as needed. The size in this example is 4 mm x 3 cm, and the groove of the nano-diffraction grating is at an angle of 45 degrees to the X-axis. The exit functional area 203 is a large rectangle provided with a nano-diffraction grating (the size may be square with respect to the coupling functional area), and its function is to output the light transmitted by the relay functional area 202 to the optical waveguide. 1 External space, and is vertically coupled out to the human eye 1, the size of which is set as needed, and the size in this example is 1.5 cm X 3 cm.

The distance between the three functional areas is set as desired. In the example of FIG. 3, the distance between the functional area 201 and the relay functional area 202 is 1.5 mm, between the functional area 202 and the outgoing functionality. The distance of the area 203 is 7 mm.

When constructing a set of augmented reality three-dimensional display devices, two sets of the above-mentioned resin holographic waveguide lenses are generally included, which respectively correspond to left and right eye displays.

In some embodiments, in order to achieve color display, each set of resin holographic waveguide lenses consists of three pieces of resin. The composition of the waveguide lens unit, the three resin holographic waveguide lens units respectively correspond to the three colors of red, green and blue (for the three primary color system, if necessary, such as the four primary color system, four resin holographic waveguide lens units can be used to respectively correspond to each Base color), corresponding to an angle of view of 30 degrees.

In this example, for a red holographic lens, the period of the nano-diffractive grating coupled into the functional region is 510 nm, and the oblique grating is used. The tilt angle of the nano-diffraction grating can be 28 degrees, and the depth of the nano-diffraction grating can be 300 nm. The relay functional region nano-diffraction grating has a period of 360 nm, using a positive grating, the grating depth is from left to right, and linearly increases from 40 nm to 100 nm. The exiting functional region nano-diffraction grating has a period of 510 nm, and a positive grating is used. The grating depth increases linearly from 40 nm to 150 nm from top to bottom. For the green holographic lens, the period of the nano-diffractive grating coupled into the functional region is 440 nm, and the oblique grating is used, the grating tilt angle is 23 degrees, and the grating depth is 250 nm. The relay functional region nano-diffraction grating has a period of 310 nm, using a positive grating, the grating depth is from left to right, and linearly increases from 30 nm to 90 nm. The exiting functional region nano-diffraction grating has a period of 440 nm, and a positive grating is used. The grating depth increases linearly from 30 nm to 130 nm from top to bottom. For the blue holographic lens, the period of the nano-diffraction grating coupled into the functional region is 370 nm, and the oblique grating is used, the grating tilt angle is 18 degrees, and the grating depth is 200 nm. The relay functional region nano-compressed grating has a period of 260 nm, using a positive grating, the grating depth is from left to right, and linearly increases from 20 nm to 70 nm. The exiting functional region nano-diffraction grating has a period of 370 nm, a positive grating, and the grating depth increases linearly from 20 nm to 100 nm from top to bottom.

The polymer substrate of the single resin holographic waveguide lens unit may be an epoxy resin, and the thickness may be set as needed, such as any value between 0.3 mm and 1.5 mm (including the end value), such as 0.8 mm, the nano-diffraction grating The distance between the lower surface of the groove and the upper surface of the polymer substrate may be any value other than 0 between 0 micrometers and 20 micrometers, such as 500 nm.

4 is a schematic view showing the operation of constructing a three-dimensional display device using a resin holographic waveguide lens. A light-emitting point on the image source 101 (image generating device) is collimated by the optical system 102 (lens device). The parallel light is incident on the nano-diffraction grating coupled to the functional region 201, and is diffracted, and the first-order transmission diffracted light satisfies the waveguide total reflection condition and propagates in the optical waveguide 2. Due to the use of a tilted grating, the intensity of the symmetrical negative first-order diffracted light is very weak, and most of the energy is diffracted to the positive level of transmission. Therefore, at the corresponding wavelength position, the coupling efficiency of the nano-diffraction grating coupled into the functional region can reach 80%. After the first-order diffracted light is coupled into the optical waveguide 2, it propagates in the form of total reflection in the optical waveguide 2, first acting with the relay functional region 202, and the propagation surface is easily changed from the XZ plane to the YZ plane, and the image is in the X direction. Being widened. The propagation angle is constant, still satisfies the total reflection condition, continues to propagate in the form of total reflection in the optical waveguide 2, and acts on the nano-diffraction grating of the exit functional region 203, and the image information is coupled out of the optical waveguide 2 by reflection diffraction, in the Y direction. Being widened, the human eye can see images in the range of 1.5cm by 3cm, which improves the comfort of observation and increases the range of applicable people. Since the depth of the nano-diffraction grating of the relay functional region 202 and the exit functional region 203 is gradually distributed with space, the intensity of the image emitted through the resin holographic waveguide lens is uniform throughout the observation range.

In some embodiments, the resin holographic waveguide lens may be selected from a projection type, the nano-diffraction grating and the functional film are located on a coupling surface; or the resin holographic waveguide lens is selectively reflective, the nano-diffraction grating and the functional film are located The opposite side of the coupling surface; the depth of the nano-diffraction grating provided on the reflective resin waveguide lens is equal to or close to half of the nano-diffraction grating provided on the transmissive resin holographic waveguide lens.

In practical applications, the resin holographic waveguide lens can be composed of a single-piece resin holographic waveguide lens unit for constructing a required three-dimensional display device or as an optical component for production, sales and application in product construction, the resin holographic waveguide lens. It can also be formed by stacking two, three or more resin holographic waveguide lens units; the nano-diffraction gratings in the functional regions on different resin holographic waveguide lens units are corresponding to different wavelengths of light signals, ie different resin holographic waveguide lenses The period and arrangement of the nano-diffraction gratings in the functional regions on the cells are different. This makes it easy to implement color display.

For example, in a three-primary color display system, a nano-diffraction grating on a resin holographic waveguide lens unit corresponding to blue light is coupled between a grating having a period between 290 nm and 410 nm and a grating depth between 100 nm and 500 nm; and a relay grating period Between 200nm and 290nm, the grating depth is between 30nm and 300nm; the exit grating period is consistent with the coupled grating period, and the depth is between 30nm and 300nm.

Preferably, the relay grating adopts a positive grating, and the grating depth is linearly increased from left to right from 20 nm to 70 nm.

Preferably, the exit grating adopts a positive grating, and the grating depth is linearly increased from 20 nm to 100 nm from top to bottom.

The nano-diffraction grating on the resin holographic waveguide lens unit corresponding to the green light is coupled between 350 nm and 480 nm, the grating depth is between 100 nm and 600 nm, and the relay grating period is between 250 nm and 335 nm. Between 30nm and 350nm; the exit grating period is consistent with the coupled grating period, and the depth is between 30nm and 400nm.

Preferably, the relay grating adopts a positive grating, and the grating depth is linearly increased from left to right from 30 nm to 90 hm.

Preferably, the exit grating adopts a positive grating, and the grating depth increases linearly from top to bottom and from 30 nm to 130 nm.

Corresponding to the functional grating on the resin holographic waveguide lens unit modulating red light, the period of coupling into the grating is between 415 nm and 550 nm, the grating depth is between 100 nm and 800 nm, and the period of the relay grating is between 295 nm and 390 nm. Between 40nm and 400nm; the exit grating period is consistent with the coupled grating period, and the depth is between 30nm and 400nm.

Preferably, the relay grating adopts a positive grating, and the grating depth is linearly increased from left to right from 40 nm to 100 nm.

Preferably, the exit grating adopts a positive grating, and the grating depth increases linearly from 40 nm to 150 nm from top to bottom.

Wherein, the coupling grating on the resin holographic waveguide lens unit corresponding to each of the primary colors is an inclined grating, and the inclination angle is between 5 degrees and 50 degrees. Used to improve the coupling efficiency of light.

Among them, the exit grating can select either a positive grating or an oblique grating.

Wherein, the depths of the relay grating and the exit grating are linearly increasing according to the spatial variation of each total reflection according to the spatial variation, thereby achieving uniform light output.

For the selection of the above parameters, the foregoing example gives a specific combination of parameters. In practical applications, matching and selection are performed in the above range according to actual needs.

In practical applications, the polymer substrate can be made of PMMA polymethyl methacrylate, PC polycarbonate, CR39 epoxy resin, PS polystyrene, PEN polyethylene naphthalate, which has good visible light transmittance. An alcohol ester, or an episulfide resin, having a refractive index between 1.5 and 1.9, preferably having a refractive index equal to or greater than 1.7, and a thickness selected between 0.3 mm and 1.5 mm.

Preferably, the functional film is a photocurable or thermosetting resin having a refractive index between 1.5 and 1.9.

Preferably, the spacing between the resin holographic waveguide lens elements corresponding to different wavelengths, i.e., different color lights, is from 5 microns to 100 microns.

Preferably, in the coupling functional region, an anti-reflection film for increasing the coupling efficiency of the image light in the next layer of the resin holographic waveguide lens unit is provided.

Preferably, the photocurable resin is an epoxy acrylate, a urethane acrylate, a polyester acrylate, a polyether acrylate, an acrylated polyacrylic resin, an unsaturated polyester, an episulfide resin, or a double bond or a triple bond, or A monofunctional or polyfunctional monomer of acrylate.

Preferably, the thermosetting resin is a solid resin prepared by mixing a hydroxyl group-containing resin or an epoxy-containing resin with an isocyanate or an amino resin.

Preferably, the functional film further contains a photosensitizer which generates a radical under the action of photons, and initiates polymerization and crosslinking of the room temperature oligomer.

Preferably, the distance between the bottom of the nano-diffraction grating on the functional film and the upper surface of the polymer substrate is not any value between 0 and 20 microns.

The present invention also provides a method for preparing a resin holographic waveguide lens, comprising the steps of:

S1: parameter calculation, determining the period, orientation, and depth distribution of the nano-diffraction grating coupled into the functional region, the relay functional region, and the exit functional region according to the wavelength of the light to be controlled and the imaging field angle of the AR optical path. And waveguide parameters of the resin holographic waveguide lens;

S2: template preparation, using a photolithography process to make a master, and performing one or more transfer;

S3: Firstly, a functional film is coated on the polymer substrate, and the functional region, the relay functional region, and the exit functional region are fabricated onto the functional film by nanoimprint technology.

Preferably, as shown in FIG. 5, step S2 is: spin-coating a positive photoresist 8 on the quartz substrate 7 to a thickness of 350 nm, using a cadmium-doped laser having a wavelength of 325 nm as an interference lithography light source, and interfering light 1 and Interfering light 2 double beam interference light for photolithography;

Wherein, the preparation of the nano-diffraction grating template coupled into the functional region is covered with a photomask 9 on the photoresist-coated quartz substrate, and only the coupling functional region is transparent, the interference light 1 and the interference The light 2 is on the same side of the normal of the quartz substrate, the interference light 1 and the quartz substrate normal are 10°, and the interference light 2 and the quartz substrate normal are 49.2°;

Preparation of a nano-light diffraction grating template in a relay functional region, in a quartz substrate coated with photoresist 8 The film 7 is covered with a photomask plate 9, and only the relay functional region is transparent, and the transmittance of the light transmitting region linearly increases from left to right, corresponding to the linear variation of the grating depth, and the interference light 1 and the interference light 2 are The quartz substrate is normal symmetrical, and the incident direction and the normal line are 26.8°;

The preparation of the nano-diffraction grating template in the exit functional region is covered with a photomask 9 on the quartz substrate 7 coated with the photoresist 8, and only the exit functional region is transparent, and the transparent region is transmitted. The rate increases linearly from top to bottom, and the depth of the grating varies linearly. The interference light 1 and the interference light 2 are symmetric with respect to the normal of the quartz substrate, and the angle with the normal is 18.6°.

Preferably, in step S3, first, an episulfide UV curable resin as a functional film is dispensed onto the optical grade polymer substrate, and the template prepared in step S2 is pressed onto the episulfide UV curable resin, and pressure is applied thereto by the roller. The epoxy-curing UV curable resin is evenly filled between the template and the polymer substrate, and then the episulfide UV curable resin is cured, uniformly exposed, and the epoxy-cured UV-curable resin forms a functional film having a nano-diffraction grating after curing. Demoulding.

Preferably, after step S3, step S4 is further included: preparing a high refractive index optical film on the surface of the nano-imprinted nano-diffraction grating.

Preferably, after step S4, step S5 is further included: stamping the polymer substrate imprinted with the nano-diffraction grating into a resin holographic waveguide lens unit.

Preferably, after step S5, step S6 is further included: aligning the resin holographic waveguide lens units respectively corresponding to different primary colors into a piece of resin holographic waveguide lens.

Preferably, in S1, the waveguide parameters of the resin holographic waveguide lens include a refractive index n1 and a thickness d of the polymer substrate, a refractive index n2 of the functional film, and a distance h from the bottom of the nano-diffraction grating to the upper surface of the polymer substrate.

In S2, the lithography process includes electron beam lithography, interference lithography, deep (polar) ultraviolet lithography, (deep) ultraviolet image It is commonly used in the production of sub-wavelength gratings such as interference direct writing. Mechanical precision machining solutions, such as diamond cutting and scribing, can also be used. The material can be photoresist, organic materials such as PMMA, PS, etc., or can be directly operated on an inorganic substrate such as quartz, or metal lining such as nickel. The bottom is obtained directly.

In S2, the transfer mode includes micro electroforming, flexible transfer, nanoimprinting, and etching techniques such as reactive ion etching and induced ion etching.

In S2, the transfer material used for mold making can be PET, PC, PDMS organic materials, or quartz or silicon wafer inorganic materials, or metal materials such as nickel.

In S2, the three grating functional regions of the lens can be obtained by the same process or by different processes. If it is the former, it can be formed once at the time of the transfer; if it is the latter, it is necessary to combine the gratings of the functional areas of different structural depths and shapes prepared by different methods on the same mold.

In S3, it can be fabricated directly on a polymer substrate by thermal nanoimprinting, or can be fabricated on a curable polymer by UV nanoimprinting. The embossing process includes flat-to-flat embossing, roll-to-roll embossing and Roll-to-flat stamping to increase productivity. UV sizing methods include dispensing and screen printing (printing according to lens shape). The mold can be placed above or below the resin substrate.

In S4, the high refractive index optical film can be prepared by magnetron sputtering, chemical vapor deposition, thermal evaporation or the like.

In S5, the resin lens is press-formed according to the shape of the desired lens. Multi-ply resin lenses are superimposed and need to be aligned. The spacing between the lenses can be controlled by an organic or inorganic film with high transmittance, suitable for selective penetration, improved coupling efficiency, and encapsulation with a frame sealant.

Taking the preparation method of the resin holographic waveguide lens unit corresponding to red light as an example, a red holographic lens template is first prepared. As shown in FIG. 5, the green and blue lens template production processes are similar and will not be repeated. A positive photoresist 8 is spin-coated on the quartz substrate 7, and the thickness of the photoresist is between 100 nm and 500 nm, and the thickness of this example is about 350 nm. The preparation laser wavelength is between 193 nm and 450 nm. In this example, a 325 nm wavelength cadmium cadmium laser is used as the interference lithography light source. For the coupling into the functional region grating, the interference light 1 and the interference light 2 are located on the same side of the quartz substrate normal. Interference light 1 and quartz substrate normal

The interference light 2 and the quartz substrate normal are at 49.2°, and a photomask 9 is coated on the quartz substrate 7 coated with the photoresist 8, and only the position where the functional region is coupled is transmitted to control the exposure time. The second exposure uses a photomask of the same shape as the relay functional region, but the transmittance of the light-transmitting region is different. From left to right, the transmittance linearly increases, and the grating depth changes linearly. At this time, the interference light 1 and the interference light 2 are symmetric with respect to the normal direction of the quartz substrate, and the incident direction and the normal line are 26.8°, and the exposure time is controlled. The third exposure uses a photomask of the same shape as the exit functional area, but the transmittance of the opaque light-transmissive region is different. From top to bottom, the transmittance increases linearly, and the grating depth varies linearly. The linear change in depth is shown in Figures 6a and 6b, wherein Figure 6a shows the use of photolithographic techniques to fabricate the desired grating on photoresist 8, and then correspondingly fabricated nickel template 81, as shown in Figure 6b. At this time, the interference lights 1 and 2 are symmetric with respect to the normal of the quartz substrate, and the angle with the normal is 18.6. The exposure of the three-exposure program needs to be matched, the exposure amount and development conditions need to be optimized, and the development rate and exposure amount are linear. After development, the depth of the nano-diffraction grating in the three functional regions is better than that in the photoresist. The depth is slightly larger. The pattern on the photoresist is transferred to the nickel template 81 by an electroforming method, as shown in Figs. 6a and 6b, and the procedure includes cleaning, immersion silver, nickel growth, mold release, and cleaning. The nickel template that is once grown can be directly fabricated by nanoimprinting to produce a resin holographic waveguide lens, or a plurality of nickel templates 81 can be produced by replicating, thereby reducing the cost. Figure 6b shows a schematic view of the structure of the nickel template 81, the grating shape being complementary to the shape of the grating in the photoresist of Figure 5.

FIG. 7 is a schematic view showing a nano-embossed resin holographic waveguide lens, and the present embodiment adopts a flat-to-flat nano-imprinting method. First, an appropriate amount of the episulfide UV curable resin 21 is applied onto the episulfide resin (as the polymer substrate 2, that is, the resin body as a waveguide), and the resin has a high refractive index characteristic, which is convenient for mentioning The coupling efficiency of the entire holographic waveguide lens is high, and at the same time, the light in the entire viewing angle is satisfied to satisfy the total reflection condition, and the thickness of the episulfide substrate (polymer substrate 2) is 0.8 mm. The nickel template 81 in Fig. 6b was pressed onto an episulfide resin coated with a UV curable resin 21, and pressure was applied thereto by a roller so that the UV curable resin 21 was uniformly filled between the nickel template 81 and the episulfide resin substrate. The distance from the bottom of the grating groove to the upper surface of the episulfide resin becomes the residual layer thickness after imprinting, which is 500 nm in this embodiment, and can be controlled to any value between 0 and 20 micrometers, which is not 0, as needed. The thickness thereof is controlled by the coating amount of the UV curable resin 21 at the time of imprinting and the magnitude of the pressure applied to the nickel template 81. It was cured by ultraviolet LED and uniformly exposed, and the exposure amount was 120 mJ/cm 2 . Since the bonding strength of the UV curable resin 21 and the episulfide resin is strong, the bonding strength with the nickel template 81 is weak, and after curing, the mold can be directly released, and the phenomenon that the UV curable resin 21 adheres to the nickel template 81 does not occur, the nickel template The grating pattern in 81 is well transferred to the UV curable resin 21. A functional film having a nano-diffraction grating is formed.

As shown in FIG. 8, after the nano-diffraction grating of the three functional regions is transferred onto the UV-curable resin 21 to form a functional film, a high-refractive-index dielectric layer 211 is prepared on the surface of the nano-diffraction grating, and the embodiment uses magnetic control. In the sputtering process, a 50 nm layer of titanium dioxide was sputtered on the surface of the UV curable resin 21 to improve the coupling efficiency of the entire lens. The high refractive index dielectric layer 211 does not affect the transmittance of the lens, and the magnetron sputtering process and the roll-to-roll process are compatible, and have the advantages of high production efficiency and low cost.

Fig. 9 shows a one-shot molding of a resin holographic waveguide lens by a stamping die 83. A stamping die 83 is formed according to the shape and size of the lens required, and the ring-sulfur resin 2 imprinted with the nano-diffraction grating is fixed to a punch or a press, and the stamping die 83 is used to apply a certain amount of the ring-sulfur resin 2 imprinted with the nano-diffraction grating. The pressure causes the episulfide resin material to be cut and separated to obtain a ring-sulfur resin lens, that is, a resin holographic waveguide lens unit, which meets a certain size requirement and appearance quality. Conventional glass holographic waveguide lenses have the advantage of high flatness, but each piece needs to be polished by conventional optical processing methods, so the efficiency is low and the cost is high. Profit Rapid molding of resin lenses with a hedging die has the advantages of high production efficiency, stable product quality, accurate accuracy and high material utilization. The red, green and blue resin holographic waveguide lens units are all produced by the above process, including photoresist patterning, nickel template pattern transfer, UV nanoimprinting, high refractive index optical layer fabrication, and punching mold forming. After the template is fabricated, subsequent production replication operations, including UV nanoimprinting, high refractive index optical layers, and hedging die forming, are suitable for roll-to-roll or roll-to-flat mass production. In the step of writing the grating structure to the photoresist, the alignment mark can be added in the appropriate area, and after the production by copying, there is a registration mark on each lens, which is convenient for the subsequent corresponding three colors of red, green and blue. The three-piece resin holographic waveguide lens unit performs alignment superposition. As shown in FIG. 10, the blue, green, and red resin holographic waveguide lens units 001, 002, and 003 are stacked by using the alignment mark, and the blue, green, and red resin holographic waveguide lens units are respectively from top to bottom. 001, 002, 003, the distance between the resin holographic waveguide lens unit 00I/002/003 is 0.1mm, and can also be set to other spacing as required, blue, green, red resin holographic waveguide lens unit 001, 002, 003 The distance between the blue, green and red resin holographic waveguide lens units 001, 002, and 003 is controlled by the thickness of the frame sealant. The image light is coupled from the upper blue resin holographic waveguide lens unit 001 (corresponding to the blue light resin holographic waveguide lens unit, the lower green lens and the red lens respectively to the resin holographic waveguide lens unit corresponding to the green light and the red light) The functional region is introduced, and the blue band light is coupled into the first resin holographic waveguide lens unit. Due to the wavelength selectivity of the grating, the diffraction efficiency of other wavelengths of light in the coupled functional region of the blue lens is very low. Focus on level 0 light and continue to spread. When the green resin holographic waveguide lens unit 002 is coupled into the functional region, a similar green band of light is coupled into the second resin holographic waveguide lens unit, and the remaining red band of light continues to propagate downward, eventually being red resin. The coupling functional region of the holographic waveguide lens unit 003 is coupled into the third sheet of resin holographic waveguide lens unit. In order to reduce the reflectivity of light at different interfaces, thereby improving the utilization of light energy, the blue resin holographic waveguide lens unit 001 and the green resin holographic waveguide mirror The sheet unit 002 and the green resin holographic waveguide lens unit 002 and the red resin holographic waveguide lens unit 003 are coupled into the functional region, and an antireflection layer is added. The antireflection layer can still select an epoxy resin material or other materials that meet the requirements. The thickness can be selected to be 100 microns or other values, and the film needs to be coated to achieve an anti-reflection effect. After stacking the three holographic waveguide lens units of blue, green and red, they can be placed in the imaging optical path to finally realize the augmented reality three-dimensional display device.

The present invention also provides a three-dimensional display device comprising the above-described resin holographic waveguide lens and an image generating device. Related technical solutions for how the image generating device and the waveguide lens construct the three-dimensional display device are described in the prior patents and the prior art, and are not described again.

The various embodiments in the present specification are described in a progressive manner, and each embodiment focuses on differences from other embodiments, and similar parts between the various embodiments may be referred to each other. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but the scope of the invention is to be accorded

Claims (27)

1. A resin holographic waveguide lens comprising one, two, three or more resin holographic waveguide lens units;

   The resin holographic waveguide lens unit comprises a polymer substrate and a functional region, wherein the functional region is provided with a nano-diffraction grating; a distance between a bottom of the nano-diffraction grating and a surface of the polymer substrate is greater than 0;

   The functional area is disposed on a polymer substrate;

   Alternatively, the resin holographic waveguide lens unit further comprises a functional film, the functional region being disposed on the functional film, the functional film being disposed on the polymer substrate.
2. The resin holographic waveguide lens according to claim 1, wherein the surface of the nano-diffraction grating is provided with an anti-reflection film.
3. The resin holographic waveguide lens according to claim 1, wherein the functional region comprises one, two or three of a coupling functional region, a relay functional region, and an exit functional region. The nano-diffraction gratings disposed in the functional region, the relay functional region, and the exit functional region are respectively coupled into the grating of the resin holographic waveguide lens and change the propagation direction of the beam in the resin holographic waveguide lens. A relay grating, an outgoing grating that outputs a light beam propagating inside the resin holographic waveguide lens to the outside of the resin holographic waveguide lens.
4. The resin holographic waveguide lens according to claim 3, wherein the resin holographic waveguide lens is of a projection type, the nano-diffraction grating is located at a coupling surface; or the resin holographic waveguide lens is of a reflection type, the nano-diffraction grating Located opposite the coupling face; the depth of the nano-diffraction grating provided on the reflective resin waveguide lens is equal to or close to half of the nano-diffraction grating provided on the transmissive resin holographic waveguide lens.
5. A resin holographic waveguide lens according to claim 3, wherein said resin holographic wave The guide lens is formed by stacking two, three or more resin holographic waveguide lens units; the nano-diffraction grating in the functional region of the different resin holographic waveguide lens unit is corresponding to the optical signals of different wavelengths, that is, different resin holographic waveguide lenses The period and arrangement of the nano-diffraction gratings in the functional regions on the cells are different.
6. The resin holographic waveguide lens according to claim 5, wherein the nano-diffraction grating corresponding to the blue light is coupled between the gratings at a period of between 290 nm and 410 nm and the grating depth between 100 nm and 500 nm; and the relay grating period is Between 200nm and 290nm, the grating depth is between 30nm and 300nm; the exit grating period is consistent with the coupled grating period, and the depth is between 30nm and 300nm.
7. The resin holographic waveguide lens according to claim 5, wherein the nano-diffraction grating corresponding to the green light is coupled to the grating with a period between 350 nm and 480 nm and a grating depth between 100 nm and 600 nm; and the relay grating period Between 250 nm and 335 nm, the grating depth is between 30 nm and 350 nm; the exit grating period is consistent with the coupled grating period, and the depth is between 30 nm and 400 nm.
8. The resin holographic waveguide lens according to claim 5, wherein the nano-diffraction grating corresponding to the red light is coupled to the grating with a period between 415 nm and 550 nm and a grating depth between 100 nm and 800 nm; and the relay grating period Between 295 nm and 390 nm, the grating depth is between 40 nm and 400 nm; the exit grating period is consistent with the coupled grating period and the depth is between 30 nm and 400 nm.
9. The resin holographic waveguide lens according to claim 6, wherein said relay grating employs a positive grating, and the grating depth is linearly increased from left to right from 20 nm to 70 nm.
10. A resin holographic waveguide lens according to claim 6, wherein said exit grating employs a positive grating, and the grating depth increases linearly from 20 nm to 100 nm from top to bottom.
11. The resin holographic waveguide lens according to claim 7, wherein said relay grating employs a positive grating, and the grating depth is linearly increased from left to right from 30 nm to 90 nm.
12. The resin holographic waveguide lens according to claim 7, wherein said exit grating is used With a positive grating, the grating depth increases linearly from top to bottom and from 30 nm to 130 nm.
13. The resin holographic waveguide lens according to claim 8, wherein said relay grating employs a positive grating, and the grating depth is linearly increased from left to right from 40 nm to 100 nm.
14. The resin holographic waveguide lens according to claim 8, wherein said exit grating employs a positive grating, and the grating depth is linearly increased from 40 nm to 150 nm from top to bottom.
15. A resin holographic waveguide lens according to any one of claims 3 to 14, wherein the coupling grating is an inclined grating having an inclination angle of between 5 and 50 degrees.
16. A resin holographic waveguide lens according to any one of claims 3 to 14, wherein the relay grating is a positive grating.
17. The resin holographic waveguide lens according to any one of claims 3 to 14, wherein the exit grating is a positive grating or a tilt grating;

    The angle between the coupled grating grating vector and the outgoing grating grating vector is between 80° and 120°, and the grating vector of the relay grating is located on the angle bisector of the coupled grating vector and the outgoing grating vector.
18. The resin holographic waveguide lens according to any one of claims 1 to 14, wherein the polymer substrate is PMMA polymethyl methacrylate, PC polycarbonate, CR39 epoxy resin, PS polystyrene. , PEN polyethylene naphthalate, or an epoxy resin having a refractive index between 1.5 and 1.9 and a thickness of 0.3 mm to 1.5 mm.
19. The resin holographic waveguide lens according to any one of claims 1 to 14, wherein the functional film is a photocurable or thermosetting resin having a refractive index of between 1.5 and 1.9.
20. The resin holographic waveguide lens according to any one of claims 5 to 14, wherein the spacing between the resin holographic waveguide lens units corresponding to different wavelengths, i.e., different color lights, is from 5 micrometers to 100 micrometers.
21. A resin holographic waveguide lens according to any one of claims 5 to 14, wherein said work The energy-sensitive film also contains a photosensitizer which generates a radical under the action of photons and initiates polymerization and crosslinking of the room temperature oligomer.
22. A method for preparing a resin holographic waveguide lens, characterized in that

    Contains the following steps:

    S1: parameter calculation, determining the period, orientation, and depth distribution of the nano-diffraction grating coupled into the functional region, the relay functional region, and the exit functional region according to the wavelength of the light to be controlled and the imaging field angle of the AR optical path. And waveguide parameters of the resin holographic waveguide lens;

    S2: template preparation, using a photolithography process or mechanical precision processing to make a template;

    S3: Firstly, a functional film is coated on the polymer substrate, and the functional region, the relay functional region, and the exit functional region are fabricated onto the functional film by nanoimprint technology.
23. The method for preparing a resin holographic waveguide lens according to claim 22, wherein the step S2 is: spin-coating a photoresist on the quartz substrate, and performing photolithography with the interference light 1 and the interference light 2 double-beam interference light.
24. The method for preparing a resin holographic waveguide lens according to claim 23, wherein in step S2, a method for preparing a nano-diffraction grating template corresponding to a functional region, a relay functional region, and an emission functional region is coupled They are as follows:

    The preparation of the nano-diffraction grating template coupled into the functional region is covered with a photomask of the photoresist-coated quartz substrate, and only the coupling functional region is transparent, and the interference light 1 and the interference light 2 are located. The normal side of the quartz substrate is on the same side, the interference light 1 and the quartz substrate normal are 10°, and the interference light 2 and the quartz substrate normal are 49.2°;

    The preparation of the nano-light diffraction grating template in the relay functional region is covered with a photomask on the photoresist-coated quartz substrate, and only the relay functional region is transparent, and the transmittance of the transparent region is From left to right, corresponding to the change of the grating depth, the interference light 1 and the interference light 2 are symmetric with respect to the quartz substrate, and the incident direction And the normal line is 26.8°;

    The preparation of the nano-diffraction grating template in the functional region is covered with a photoresist mask on the photoresist-coated quartz substrate, and only the exit functional region is transparent, and the transmittance of the transparent region is from the top to the bottom. The lower rise corresponds to the change of the grating depth, and the interference light 1 and the interference light 2 are symmetric with respect to the normal of the quartz substrate, and the angle with the normal line is 18.6°.
25. The method for preparing a resin holographic waveguide lens according to any one of claims 22 to 24, wherein the step S3 is: firstly, an episulfide UV curable resin as a functional film is dropped on the episulfide resin substrate, The template prepared in step S2 is pressed onto the episulfide UV curable resin, and pressure is applied thereto by the roller, so that the episulfide UV curable resin is evenly filled between the template and the polymer substrate, and then the episulfide UV curable resin is cured and uniformly After exposure and curing, the episulfide UV curable resin forms a functional film having a nano-diffraction grating and is finally demolded.
26. The method for preparing a resin holographic waveguide lens according to claim 25, further comprising the step S4 of forming a high refractive index optical film on the surface of the nano-imprinted nano-diffraction grating after the step S3.
27. A three-dimensional display device comprising the resin holographic waveguide lens according to any one of claims 1 to 14, or a resin holographic waveguide lens prepared according to any one of claims 22 to 25.

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