WO2021208942A1 - 基于二维特征的反射式几何全息膜及其制备方法和应用 - Google Patents

基于二维特征的反射式几何全息膜及其制备方法和应用 Download PDF

Info

Publication number
WO2021208942A1
WO2021208942A1 PCT/CN2021/087146 CN2021087146W WO2021208942A1 WO 2021208942 A1 WO2021208942 A1 WO 2021208942A1 CN 2021087146 W CN2021087146 W CN 2021087146W WO 2021208942 A1 WO2021208942 A1 WO 2021208942A1
Authority
WO
WIPO (PCT)
Prior art keywords
film
reflective
dimensional features
holographic film
film based
Prior art date
Application number
PCT/CN2021/087146
Other languages
English (en)
French (fr)
Inventor
王广军
余为伟
Original Assignee
荆门市探梦科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CN202020572735.2U external-priority patent/CN211698263U/zh
Priority claimed from CN202010303252.7A external-priority patent/CN111338015B/zh
Application filed by 荆门市探梦科技有限公司 filed Critical 荆门市探梦科技有限公司
Publication of WO2021208942A1 publication Critical patent/WO2021208942A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/04—Prisms
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/12—Reflex reflectors
    • G02B5/126—Reflex reflectors including curved refracting surface
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/32—Holograms used as optical elements

Definitions

  • the invention relates to the field of 3D display, in particular to a reflective geometric holographic film based on two-dimensional features, and a preparation method and application thereof.
  • the 3D display technology that can display three-dimensional images in space will be the most important display technology in future life.
  • the mainstream 3D display is still a pseudo 3D display technology based on stereoscopic image pairing based on binocular parallax.
  • This kind of display method itself has many drawbacks, and at the same time it can cause problems such as user's visual fatigue, and it is impossible to become the mainstream display technology in the future.
  • the display method that can form a real three-dimensional picture in the air and can display the three-dimensional picture in the most realistic way is the trend of future display technology development.
  • the solution based on retroreflection and the beam splitter can realize the floating display of the picture.
  • this kind of technology usually requires the use of a micro-structured screen containing a series of very fine three-dimensional features.
  • the prior art contains a series of triangular pyramid light reflection screens. Because the microstructures of these three-dimensional features are very fine, it is very difficult for processing to arrange countless three-dimensional feature microstructures evenly and densely on one screen, and the processing accuracy is very high. It is difficult to guarantee, processing efficiency and yield are difficult to guarantee.
  • the publication number CN108269511A is an aerial floating display system.
  • the application discloses a two-dimensional planar air imaging scheme, and discloses a retroreflective right-angled triangular prism array, which includes a series of right-angled triangular prism light reflecting screens, This right-angled triangular prism can only realize the retroreflective imaging function in the plane.
  • the retroreflective function cannot be realized, and other optical modules are needed to modulate the light to realize the retroreflective imaging.
  • the above-mentioned right-angled triangular prism arrays are usually processed with hard optical materials, and problems such as breakage and residual stress are prone to occur during the processing of hard materials, resulting in low product yield and unable to meet the needs of folding, winding and storage. .
  • a reflective geometric holographic film based on two-dimensional features and a preparation method and application thereof are provided, by simply cutting and processing a primitive film provided with a transparent layer and a reflective layer arranged alternately.
  • the reflective geometric holographic film containing a series of cylindrical elementary prisms is prepared to realize light retroreflective imaging, so that the light irradiated on the reflective geometric holographic film at any angle can be reflected in the original direction, without other optical modules for modulation.
  • Direct 3D imaging is provided.
  • the present invention proposes a reflective geometric holographic film based on two-dimensional features, including a series of pentagonal columnar primitive prisms with a first right-angled triangle or a combination of a rectangle and a second right-angled triangle in cross section. Used to retroreflect the light shining on it;
  • a plurality of transparent layers and reflective layers arranged alternately are arranged inside the columnar element prism along the length direction, and a reflective film is provided on the inclined surface where the right-angle side of the cross section of the columnar element prism is located, which is used to perform light reflection of mirror;
  • the error range of the right angle included in the first right-angled triangle and the pentagon and the angle formed by the reflection layer and the length direction of the columnar element prism is within ⁇ 5°.
  • hypotenuse of the second right-angled triangle coincides with one side of the rectangle, and the length is a, and the length of the other side of the rectangle is b, a ⁇ 2mm, and 0 ⁇ b ⁇ 5mm.
  • first right-angled triangle and/or the second right-angled triangle are isosceles right-angled triangles.
  • the end surface of the columnar elementary prism is also provided with a reflective film.
  • the reflective geometric holographic film based on two-dimensional features is a flexible film.
  • the horizontal clamping and sagging length of the two-dimensional feature-based reflective geometric holographic film is Lcm, and the number of foldable times is n, which satisfies:
  • the horizontal clamping and sagging length of the two-dimensional feature-based reflective geometric holographic film is Lcm, and the number of foldable times is n, which satisfies: n*L ⁇ 28.
  • a protective film is respectively provided on the bottom surface and the reflective film, wherein the protective film provided on the bottom surface is a transparent protective film.
  • the present invention also provides a method for preparing the above-mentioned reflective geometric holographic film based on two-dimensional features, which includes the following steps:
  • Right-angled triangle microstructure processing cut along the direction perpendicular to the transparent layer and the reflective layer to form a pentagonal shape with a plane on one side and a first right-angled triangle in cross section 1) or a combination of a rectangle and a second right-angled triangle
  • the undulating zigzag surface film formed by the arrangement of the columnar element prisms, the error range of the cutting direction is within ⁇ 5°;
  • Plating reflective film Plating a reflective film on the end face of the columnar elementary prism and the slope where the right-angle side of the cross section is located, and then a reflective geometric holographic film based on two-dimensional features can be obtained.
  • the method further includes: adhering a transparent protective film on the bottom surface.
  • the method further includes: adhering a protective film on the zigzag undulating surface provided with the reflective film.
  • the present invention also provides the application of the two-dimensional feature-based reflective geometric holographic film prepared by the above-mentioned two-dimensional feature-based reflective geometric holographic film preparation method in a reflective geometric holographic display system.
  • the holographic film of the present invention is based on the processing of two-dimensional features, which is easy to realize large-scale and high-precision preparation, has high production speed, high product yield, low process cost, and excellent imaging quality;
  • Fig. 1 is a schematic diagram of the reflected light path of light on a mutually perpendicular surface, that is, a right-angle reflecting wall;
  • FIG. 2 is a front view of the reflective geometric holographic film based on two-dimensional features of the present invention with a cross-section of a first right-angled triangle 1;
  • Figure 3 is a partial enlarged view of I in Figure 2;
  • Fig. 4 is an axial view of the reflective geometric holographic film based on two-dimensional features of the present invention with a cross section of the first right-angled triangle 1 after hiding part of the inclined surface 6 and the reflective film 7 on the end surface 5, focusing on showing The internal structure of the holographic film;
  • FIG. 5 is a diagram of the retroreflected light path of a columnar elementary prism 3 with a cross-section of a first right-angled triangle 1 to any light that is not parallel to its cross-section;
  • FIG. 6 is a front view of the two-dimensional feature-based reflective geometric holographic film according to the present invention whose cross-section is a pentagon 2 formed by a rectangle 21 and a second right triangle 22;
  • Figure 7 is a partial enlarged view of II in Figure 6;
  • Figure 8 shows the reflective geometric hologram based on the two-dimensional feature of the present invention with a cross section of a pentagon 2 formed by a rectangle 21 and a second right-angled triangle 22 after concealing part of the inclined surface 6 and the reflective film 7 on the end surface 5
  • FIG. 9 is a diagram of the retro-reflected light path of any light that is not parallel to the cylindrical elementary prism 3 with a pentagonal shape 2 formed by a rectangle 21 and a second right-angled triangle 22 in cross section;
  • Figure 10 is a system schematic diagram of a reflective geometric holographic display system
  • horizontal does not mean that the component is required to be absolutely horizontal or overhanging, but may be slightly inclined.
  • horizontal only means that its direction is more horizontal than “vertical”, and it does not mean that the structure must be completely horizontal, but can be slightly inclined.
  • the present invention proposes a reflective geometric holographic film based on two-dimensional features, including a series of cross-sections of a first right-angled triangle 1 or a combination of a rectangle 21 and a second right-angled triangle 22
  • the first right-angled triangle 1 and/or the second right-angled triangle 22 are isosceles right-angled triangles;
  • a single cylindrical elementary prism 3 is provided with a number of alternately arranged transparent layers 31 and reflective layers 32 along its length.
  • the bottom surface 4 of the cylindrical elementary prism 3 is the light incident surface, the reflective layer 32 and
  • the inclined surface 6 where the right-angled side of the cross section of the columnar element prism 3 is located is a reflective surface, and a reflective film 7 is provided on the inclined surface 6 for specular reflection of light.
  • the end surface 5 of the columnar elementary prism 3 can also be a reflective surface, and a reflective film 7 capable of reflecting light can also be provided on it. It should be noted that if the end surface 5 is the reflective layer 32 during the processing, there is no need to provide the reflective film 7 on the end surface of the reflective layer 32.
  • the reflective layer 32 itself has the function of specularly reflecting light.
  • the cross-section is the first right-angled triangle 1 or the pentagonal shape 2 of the combination of the rectangle 21 and the second right-angled triangle 22
  • there are multiple right-angle reflecting walls including the right-angle reflecting wall formed by two inclined surfaces 6 and the inclined surface 6 respectively and the reflecting layer.
  • 32 or the right-angle reflecting wall formed on the end surface 5 so this kind of microstructure unit has the function of retroreflecting the light in the space, so if a lot of these microstructures are densely arranged on a plane, a large area of incident light can be carried out. Retroreflection.
  • any light that is not parallel to the cross section of the columnar elementary prism 3 is incident on the reflective layer 32 or the reflective film 7 of the end surface 5 from the incident surface, and is reflected once to an adjacent inclined surface 6.
  • the light After the second reflection of the reflective film 7 plated on the inclined surface 6, the light is reflected to another inclined surface 6, and then through the three reflections of the reflective film 7 plated on the inclined surface 6, the light can be offset d and parallel to The direction of the incident light is reflected back, and the retro-reflected light can be 3D imaged;
  • the light retroreflected 3D imaging can be realized by two reflections of the two inclined surfaces 6 according to the optical path principle of FIG. 1.
  • the cylindrical elementary prism 3 and the two-dimensional feature-based reflective geometric holographic film of the present invention composed of a series of cylindrical elementary prisms 3 have the function of retroreflecting the light of any angle irradiated thereon.
  • the light irradiated on it is deviated by a distance of dmm and then retroreflected back.
  • d is the distance from the intersection of the outgoing light and the bottom surface of the reflective geometric holographic film to the incident light, where d ⁇ 2mm.
  • the hypotenuse of the second right-angled triangle 22 coincides with one side of the rectangle 21, the short and long sides of the rectangle 21 have lengths a and b, respectively, and the length of the hypotenuse of the second right-angled triangle 22 is a or b, where a ⁇ 2mm, 0 ⁇ b ⁇ 5mm;
  • the allowable error range of the above mentioned angles is within ⁇ 5°, including the right angles contained in the first right-angled triangle 1 and the pentagon 2 and the angle formed by the reflection layer 32 and the length direction of the cylindrical elementary prism 3.
  • the above principles are based on ideal geometric shapes, but in actual situations, the machining process may not be able to produce a completely ideal geometric shape, and there will be certain errors in the angle.
  • the vertex cannot be an ideal geometric point but a radius. Very small rounded corners.
  • the manufacturing error is relatively small, there will be a slight deviation between the direction of the reflected light and the ideal situation of retroreflection. These deviations cannot be distinguished by the human eye, and the aberrations caused by these errors are also very small, so very good imaging effects can also be achieved.
  • the angle error of the right angle (the right angle included in the first right-angled triangle 1 and the pentagon 2) is within ⁇ 5°, the user experience is relatively satisfactory. When it exceeds this range, the user begins to feel that the imaging effect is unacceptable.
  • the same geometric vertex is allowed to be a relatively small rounded corner (for example, the radius is less than 0.1mm), then a better imaging function can also be achieved.
  • the smaller the error the higher the user evaluation, so the error should be minimized during production.
  • the reflective geometric holographic film based on two-dimensional features of the present invention preferably adopts a flexible film made of flexible materials.
  • the screen produced in this way can not only meet the requirements of folding and winding storage, but also based on the characteristics of flexibility. It is not easy to break and generate residual stress.
  • the flexible material used in the reflective geometric holographic film based on the two-dimensional feature of the present invention is preferably PMMA film, lPMMA film, PS film, PC film, PE film , Styrene acrylonitrile film, MS film, PET film, PETG film, ABS film, PP film, PA film, SAN film, MS film, MBS film, PES film, CR-39 film, TPX film, HEMA film, F4 film , F3 film, EFP film, PVF film, PVDF film, EP film, PF film, UP film, cellulose acetate film, nitrocellulose film, EVA film, PE film, PVC film, new amorphous thermoplastic polyester film, Either an amorphous cycloolefin film and a modified bisphenol A epoxy resin film.
  • the horizontal clamping and sagging length is Lcm
  • the number of foldable times is n
  • the requirements are: L ⁇ 5 or n*L>9.
  • n is the number of folds that can be folded in half
  • take a square sample with an area of 100cm 2 during the test fold the sample along the middle line of the square (or within 1cm of the middle line) into a rectangle, and then use two flat plates to fold the primitive in half
  • the membrane is sandwiched in the middle, apply a force of not less than 10N, the pressure is maintained for 5s or more, and then open (at this time a half-fold test is completed), check whether the sample has local micro-cracks or breaks into two along the crease, if No, repeat the above test until it has a local microcrack or break into two sections, stop the test, the total number of folds during the test is recorded as n;
  • the test method take a narrow strip with a width of 5cm ⁇ 0.5cm and a length of about 25cm, and one end is tightly attached to the horizontal reference tabletop, ensuring that the length of the narrow strip extending from the tabletop is 20cm ⁇ 1cm, and then stand still After the narrow strip is stable, measure the vertical height difference between the end of the narrow strip protruding from the desktop and the horizontal reference desktop and record it as the horizontal sag length L;
  • the above test itself is an accelerated test method, which can quickly determine the reliability of the sample during long-term use.
  • the flexible film When the flexible film is applied, it needs to withstand multiple operations such as winding, storing and opening, and it is calculated according to the design service life of 5 years , The entire life cycle requires about 10,000 storage and unfolding actions.
  • the present invention adopts the above-mentioned half-fold test and horizontal clamping sag length test;
  • n*L 9
  • n*L 9
  • the winding screen is also suitable.
  • the prepared elementary film can be wound into a cylindrical shape with a diameter of less than 5 cm, the elementary film as a whole will be more flexible, and the fracture loss during processing will be small.
  • the elementary film can be wound into a cylindrical shape with a diameter of less than 5cm without breaking.
  • n and L can be limited to: n*L ⁇ 28. In this way, it can be applied to most application scenarios and can guarantee a higher product yield. .
  • the flexibility of the holographic film depends greatly on its raw materials, and the flexibility of the holographic film can be adjusted in a wide range by controlling the thickness of the raw material.
  • the test process is still troublesome in actual operation. If the design requirements are not particularly strict, the following very fast way can be used to determine. Generally, it is easier to guarantee the superiority of the flexible material processing process, so the screen application scenario is given priority. Through actual application testing, it is found that for the reel storage screen, when L is greater than twice the innermost radius of the reel, the reel can be realized well.
  • the storage screen form can be designed with L greater than 3 times or even 5 times the innermost radius of the reel in order to leave enough design margin.
  • a protective film is provided on the reflective film 7 provided on the bottom surface 4, the end surface 5 and the inclined surface 6, respectively.
  • the bottom surface 4 is the light incident surface, so the protective film provided on the bottom surface 4 is transparent.
  • the protective film, and the end surface 5 and the inclined surface 6 are used as reflective surfaces, and the protective film provided thereon is not necessarily transparent, which is not limited here.
  • the material of the above-mentioned protective film is preferably a flexible material, such as PMMA film, lPMMA film, PS film, PC film, PE film, styrene acrylonitrile film, MS film, PET film, PETG film, ABS film, PP film, PA film, SAN film, MS film, MBS film, PES film, CR-39 film, TPX film, HEMA film, F4 film, F3 film, EFP film, PVF film, PVDF film, EP film, PF film, UP film, cellulose acetate Any one of film, nitrocellulose film, EVA film, PE film, PVC film, new amorphous thermoplastic polyester film, amorphous cyclic olefin film and modified bisphenol A epoxy resin film;
  • a flexible material such as PMMA film, lPMMA film, PS film, PC film, PE film, styrene acrylonitrile film, MS film, PET film, PETG film, ABS film, PP film, PA film,
  • It can also be rigid, such as plastic film, glass, etc.
  • the present invention also provides a method for preparing the above-mentioned two-dimensional feature-based reflective geometric holographic film, which includes the following steps:
  • Reflective film coating a reflective film 7 is plated on the end surface 5 of the columnar elementary prism 3 and the inclined surface 6 where the right-angle side of the cross section is located, and a reflective geometric holographic film based on two-dimensional features can be obtained. After the reflective film 7 is plated, another protective film can be coated on the reflective film 7.
  • the elementary film used in step 1) may not use the flexible elementary film, and a flexible holographic elementary film according to the publication number CN110794504A and its preparation method and application can be used with materials that meet the requirements.
  • the preparation method in the preparation of the elementary membrane can be applied to the present invention.
  • the material of the transparent layer 31 is PC film
  • the material of the reflective layer 32 is aluminum foil reflective film; Cutting in the direction of the layer 32, the cross section of the cut waste material is a 1mm high isosceles right-angled triangular prism, and the cut primitive film is a number of cylindrical primitive prisms 3 connected together with a cross-section of 1mm high isosceles right-angled triangles.
  • a film with an undulating jagged surface is formed; then a reflective film 7 is plated on the end surface 5 and the inclined surface 6 of the above film, that is, a reflective geometric holographic film based on two-dimensional characteristics is prepared, and finally the reflective film 7 is plated
  • a protective film protects the internal microstructure of the holographic film.
  • a transparent protective film can be plated on the bottom surface 4 of the primitive film before cutting.
  • the holographic film made in Example 1 includes a series of isosceles right-angled triangular cylindrical elementary prisms 3 with a cross section of 2 mm hypotenuse. Based on the principle of light path in Figure 1, light enters from the incident surface, namely the bottom surface 4, and then passes through The right-angle reflecting wall reflects back, and the existing offset d will not be greater than the length of the hypotenuse of the cross section by 2 mm, that is, d ⁇ 2 mm.
  • the material of the transparent layer 31 is PC film
  • the material of the reflective layer 32 is aluminum foil reflective film; Cutting in the direction of the layer 32, the cross section of the cut waste material is a 0.5 mm high isosceles right-angled triangular prism, the element film after cutting is a number of 0.5 mm high isosceles right-angled triangle cylindrical primitive prisms 3 connected together
  • a film with an undulating jagged surface is formed; then a reflective film 7 is plated on the end surface 5 and the inclined surface 6 of the above film, that is, a reflective geometric holographic film based on two-dimensional characteristics is prepared, and finally the reflective film 7 is plated
  • a protective film protects the internal microstructure of the holographic film.
  • a transparent protective film can be plated on the bottom surface 4 of the primitive film before cutting.
  • the holographic film prepared in Example 2 includes a series of isosceles right-angled triangular cylindrical elementary prisms 3 with a cross section of 1 mm hypotenuse. Based on the principle of light path in Figure 1, light enters from the incident surface, namely the bottom surface 4, and then passes through The right-angle reflecting wall reflects back, and the existing offset d will not be greater than the length of the hypotenuse of the cross section by 1 mm, that is, d ⁇ 1 mm.
  • a flexible elementary film with a thickness of 0.1 mm and a transparent layer 31 and a reflective layer 32 arranged alternately.
  • the material of the transparent layer 31 is PC film
  • the material of the reflective layer 32 is aluminum foil reflective film;
  • Cutting in the direction of the layer 32, the cross-section of the cut waste material is a 0.1mm high isosceles right-angled triangle prism, and the cut primitive film is a number of 0.1mm high isosceles right-angled triangle columnar primitive prisms 3 connected together
  • a film with an undulating jagged surface is formed; then a reflective film 7 is plated on the end surface 5 and the inclined surface 6 of the above film, that is, a reflective geometric holographic film based on two-dimensional characteristics is prepared, and finally the reflective film 7 is plated
  • a protective film protects the internal microstructure of the holographic film.
  • a transparent protective film can be plated on the bottom surface 4 of the elementary film before cutting.
  • the holographic film prepared in Example 3 includes a series of isosceles right-angled triangular cylindrical elementary prisms 3 with a cross section of 0.2 mm hypotenuse. Based on the principle of light path in Figure 1, light enters from the incident surface, namely the bottom surface 4, and then passes through The right-angle reflecting wall reflects back, and the existing offset d will not be greater than the length of the hypotenuse of the cross section 0.2 mm, that is, d ⁇ 0.2 mm.
  • the cross-section of the scrap cut out is a 1mm high isosceles right-angled triangle prism, the primitive film after cutting is composed of several cross-sections of 1mm high isosceles right-angled triangles with short sides 2mm and long sides
  • the film 7 is a reflective geometric holographic film based on two-dimensional characteristics, and finally a protective film is plated on the reflective film 7 to protect the internal microstructure of the holographic film.
  • the holographic film prepared in Example 4 includes a series of cylindrical primitive prisms 3 with a cross-section of a pentagonal 2 composed of a right-angled isosceles triangle with a hypotenuse 2 mm and a rectangle with a short side 2 mm and a long side 6 mm. Based on the light path principle of Figure 1, the light enters from the incident surface, the bottom surface 4, and then reflects back through multiple right-angle reflecting walls. The offset d will not be greater than the hypotenuse length of the cross section 2 mm, that is, d ⁇ 2 mm. .
  • the cross section of the scrap cut out is an isosceles right-angled triangular prism with a height of 0.5 mm, and the primitive film after cutting is composed of a number of cross-sections of 0.5 mm high isosceles right-angled triangles with short sides of 1 mm and long sides.
  • a 1.5 mm rectangular pentagonal 2 columnar element prism 3 is connected to form an undulating jagged surface film; then the end surface 5 of the film and the inclined surface 6 where the right-angle side of the cross section is located are coated with a layer of reflection
  • the film 7 is a reflective geometric holographic film based on two-dimensional characteristics, and finally a protective film is plated on the reflective film 7 to protect the internal microstructure of the holographic film.
  • the holographic film prepared in Example 5 includes a series of cylindrical primitive prisms 3 with a cross-section of a pentagonal 2 composed of a right-angled isosceles triangle with a hypotenuse 1 mm and a rectangle with a short side of 1 mm and a long side of 1.5 mm. Based on the light path principle of Figure 1, the light enters from the incident surface, the bottom surface 4, and then reflects back through multiple right-angle reflecting walls. The offset d will not be greater than the hypotenuse length of the cross section 1 mm, that is, d ⁇ 1 mm. .
  • the cross section of the scrap cut out is a 0.1mm high isosceles right-angled triangle prism, the primitive film after cutting is composed of several cross-sections of 0.1mm high isosceles right-angled triangles with short sides 0.2mm and long sides
  • the film 7 is a reflective geometric holographic film based on two-dimensional characteristics, and finally a protective film is plated on the reflective film 7 to protect the internal microstructure of the holographic film.
  • the holographic film prepared in Example 6 includes a series of cylindrical primitive prisms 3 with a cross-section of a right-angled isosceles triangle with a hypotenuse 0.2 mm and a pentagon 2 with a rectangle with a short side of 1 mm and a long side of 1.5 mm. Based on the light path principle of Figure 1, the light enters from the incident surface, the bottom surface 4, and then reflects back through multiple right-angle reflecting walls. The offset d will not be greater than the hypotenuse length of the cross section 0.2 mm, that is, d ⁇ 0.2 mm. .
  • the thickness of the transparent layer of the primitive film is preferably ⁇ 1mm, while d ⁇ 1mm;
  • the thickness of the transparent layer of the elementary film is less than or equal to 0.5 mm, and d is less than or equal to 0.5 mm;
  • the thickness of the transparent layer is preferably ⁇ 0.3mm, while d ⁇ 0.3mm;
  • the elementary film Through simple cutting and processing of the elementary film provided with the alternately arranged transparent layer 31 and the reflective layer 32, it is a cutting processing based on two-dimensional features, simple operation, easy to achieve large-scale, high-precision production, and fast production speed.
  • the process cost is low, and the elementary film is preferably a flexible elementary film.
  • In the cutting process there will be no problems such as crushing and residual stress that often occur during the processing of hard materials, and the product has a high rate of excellence and flexibility.
  • the characteristics of the product of the present invention can meet the needs of folding, winding and storage;
  • the reflective geometric holographic film product based on the two-dimensional feature of the present invention can realize that the light irradiated on it is shifted by a distance d and then reflected back in the original direction, without the use of additional lens elements. Retroreflective imaging function.
  • the present invention also provides the application of the reflective geometric holographic film based on the two-dimensional feature prepared by the above-mentioned preparation method in a reflective geometric holographic display system, specifically:
  • the reflective geometric holographic display system includes an image source 100, a reflective geometric holographic screen 101, an auxiliary imaging screen 102, a supporting structure 103 and a controller 104;
  • the image source 100 is used to provide a projection screen, and can be an LCD display screen, an LED display screen, a projector, a holographic projector, and other elements capable of generating images, preferably a projector or a holographic projector;
  • the reflective geometric holographic screen 101 is used to shift the light irradiated on it by a distance d and then reflect it back in the original direction.
  • the reflective geometric holographic film based on two-dimensional features prepared by the present invention is adopted;
  • the auxiliary imaging screen 102 is used for light splitting, and is preferably a screen made of a semi-transparent and semi-reflective material;
  • the supporting structure 103 is matched with the image source 100, the reflective geometric holographic screen 101 and the auxiliary imaging screen 102 respectively, and provides physical structural support for the three;
  • the controller 104 is electrically connected to the image source 100 for controlling the image source 100 to adjust the depth of field and display content of the projected picture;
  • the support structure 103 is a structure that can move or deform, electrically connect the support structure 103 and the controller 104, and the support structure 103 makes a corresponding response based on the control information of the controller 104.
  • the reflective geometric holographic screen 101 and the auxiliary imaging screen 102 respond to actions to realize the relative movement and/or overall movement of the image source 100, so that the reflective geometric holographic screen 101 and the auxiliary imaging screen 102, so that the visual window of the system always covers the user's eyes, so that the user can watch normally in different directions
  • the supporting structure 103 is a general existing technology, and those skilled in the art can design it according to the actual application space conditions. For example, it can be easily designed by using some hinge structures and structures similar to umbrella shafts.
  • the structure that can be deformed is not specifically limited here;
  • the holographic display system of the present invention further includes an interactive motion capture unit 105 electrically connected to the controller 104.
  • the interactive motion capture unit 105 is used to identify the user's interactive motion and send the user's interactive motion information to the controller 104.
  • the controller 104 adjusts the content of the display screen according to the user interaction motion information obtained by the received interactive motion capture unit 105, and realizes the interaction between the user and the screen. Specifically, it can use a camera combined with machine vision technology to recognize the user's gestures to obtain the user.
  • the controller 104 can also control the received interactive actions
  • the user interaction action information acquired by the capture unit 105 is used to adjust the content of the display screen in real time to realize the interaction between the user and the screen, such as controlling the screen to pan according to the pan gesture signal, or controlling the zooming, zooming in, and zooming of the screen according to the corresponding other interactive actions. Push far, touch and other operations;
  • the setting of the interactive motion capture unit 105 has positive significance for application scenarios similar to wearable applications where the user's spatial position relative to the display system is fixed;
  • an eye tracking unit 106 electrically connected to the controller 104 needs to be provided.
  • the positioning information is sent to the controller 104, and the controller 104 controls the support structure 103 to make corresponding action responses according to the received eye positioning information obtained by the eye tracking unit 106 to adjust the image source 100 and the reflective geometric holographic screen
  • the relative position and/or overall spatial position of 101 and/or auxiliary imaging screen 102 keep the user's eyes always in the visible space of the system, so that the user's eyes can always receive projection information even when in motion, and view the picture normally.
  • the interactive motion capture unit 105 and the eye tracking unit 106 can be integrated in the same device, such as using a machine vision camera device.
  • the image source 100 projects a picture, the light is irradiated on the auxiliary imaging screen 102, part of the light directly passes through the auxiliary imaging screen 102, this part of the light will not participate in imaging, and the other part of the light is reflected by the auxiliary imaging screen 102 to the reflective geometric holographic screen 101, and this part of the light is optically transformed by the reflective geometric holographic screen 101, offset by a small distance d, and reflected back in the original direction and transmitted through the auxiliary imaging screen 102, forming an off-screen image that can be observed in space.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Holo Graphy (AREA)

Abstract

一种基于二维特征的反射式几何全息膜及其制备方法和应用，其中，反射式几何全息膜包括一系列横截面为第一直角三角形（1）或者矩形（21）和第二直角三角形（22）组合的五边形（2）的柱状基元棱镜（3），用于对照射在其上的光线进行逆反射；柱状基元棱镜（3）内部、沿长度方向上设有若干相间排列的透明层（31）和反射层（32），柱状基元棱镜（3）横截面的直角边所在的斜面（6）上设置有一层反射膜（7），第一直角三角形（1）和五边形（2）内包含的直角以及反射层（32）与柱状基元棱镜（3）长度方向所成角度的误差范围在±5°以内。这种制备方法通过简单的、基于二维特征的切削和加工，工艺成本低，容易实现大规模、高精度生产，再加上基元膜优选地是柔性基元膜，产品优率高，而且柔性的特性使得全息膜可以满足折叠、卷绕收纳的需求。

Description

基于二维特征的反射式几何全息膜及其制备方法和应用
本申请要求于2020年04月17日提交中国专利局、申请号为202020572735.2、发明名称为“基于二维特征的反射式几何全息膜”以及于同日提交中国专利局、申请号为202010303252.7、发明名称为“基于二维特征的反射式几何全息膜及其制备方法和应用”的两件中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本发明涉及3D显示领域，尤其是涉及一种基于二维特征的反射式几何全息膜及其制备方法和应用。
背景技术
能够在空间显示出立体画面的3D显示技术，会是未来生活中最重要的一种显示技术。目前主流的3D显示还是基于双目视差的立体图像对式的伪3D显示技术。这种显示方式本身有很多弊端，同时还会造成用户的视觉疲劳等问题，不可能成为未来的主流显示技术。
能够在空中形成真正的立体画面的显示方式，能够以最真实的方式展示立体画面，是未来显示技术发展的趋势。目前已经有一些技术可以实现在空中悬浮显示画面，例如基于逆反射加上分光镜的方案可以实现画面的悬空显示，但是这类技术通常需要用到含有一系列非常精细三维特征的微结构屏。例如现有技术中含有一系列三角锥的光反射屏，由于这些三维特征的微结构非常精细，在一张屏上均匀密集的布置无数三维特征微结构对于加工而言、难度非常大，加工精度很难保证，加工效率和良品率都难以保证。
公布号为CN108269511A的一种空中悬浮显示系统，该申请公开了一种二维平面空气成像的方案，公开了一种逆反射的直角三角形棱镜阵列，其包括一系列直角三角形棱镜的光反射屏，这种直角三角形棱镜只能实现平面内的逆反射成像功能，光线跟截面不平行时，就无法实现逆反射功能， 需要另外借助其他光学模组来对光线进行调制进而实现逆反射成像。
此外，上述直角三角形棱镜阵列通常会采用硬质的光学材料来加工，而硬质材料加工过程中容易出现破碎以及产生残余应力等问题，造成产品良品率低，无法满足折叠、卷绕收纳等需求。
发明内容
针对上述现有技术的不足，提供一种基于二维特征的反射式几何全息膜及其制备方法和应用，通过对设有相间排列的透明层和反射层的基元膜进行简单的切削和加工，制得包含一系列柱状基元棱镜的反射式几何全息膜，来实现光线逆反射成像，使得任意角度照射在反射式几何全息膜的光线能原方向反射，无需其他光学模组进行调制即可直接进行3D成像。
为解决上述技术问题，本发明提出一种基于二维特征的反射式几何全息膜，包括一系列横截面为第一直角三角形或者矩形和第二直角三角形组合的五边形的柱状基元棱镜，用于对照射在其上的光线进行逆反射；
所述柱状基元棱镜内部、沿长度方向上设有若干相间排列的透明层和反射层，所述柱状基元棱镜横截面的直角边所在的斜面上设置有一层反射膜，用于对光线进行镜面反射；
所述第一直角三角形和五边形内包含的直角以及反射层与柱状基元棱镜长度方向所成角度的误差范围在±5°以内。
进一步地，所述第二直角三角形的斜边与矩形的一条边重合、长度为a，所述矩形的另一边长度为b、a≤2㎜，0≤b≤5㎜。
进一步地，所述第一直角三角形和/或第二直角三角形为等腰直角三角形。
进一步地，所述柱状基元棱镜的端面也设置有一层反射膜。
进一步地，所述基于二维特征的反射式几何全息膜为柔性膜。
进一步地，所述基于二维特征的反射式几何全息膜的水平夹持下垂长度为L㎝，可对折次数为n，满足：
L≥5或者n*L>9。
进一步地，所述基于二维特征的反射式几何全息膜的水平夹持下垂长 度为L㎝，可对折次数为n，满足：n*L≥28。
进一步地，所述底面和反射膜上分别设有保护膜，其中所述底面上设有的保护膜为透明保护膜。
本发明还提供一种上述基于二维特征的反射式几何全息膜的制备方法，包括以下步骤：
1)基元膜准备：准备一张透明层与反射层相间排列的基元膜；
2)直角三角形微结构加工：沿垂直于透明层与反射层的方向上切削，形成一面是平面、另一面是横截面为第一直角三角形1)或矩形与第二直角三角形组合的五边形的柱状基元棱镜排列形成的起伏锯齿状表面的膜，切削方向的误差范围在±5°以内；
3)镀反射膜：在柱状基元棱镜的端面以及横截面的直角边所在的斜面上镀一层反射膜，即可获得基于二维特征的反射式几何全息膜。
进一步地，在步骤2)之前或者之后还包括：在底面上粘接一层透明保护膜。
进一步地，在步骤3)之后还包括：在设置有反射膜的锯齿状起伏表面粘接一层保护膜。
本发明还提供上述的基于二维特征的反射式几何全息膜的制备方法制备的基于二维特征的反射式几何全息膜于反射式几何全息显示系统的应用。
与现有技术相比，本发明的优点在于：
1、本发明的全息膜是基于二维特征的加工，容易实现大规模、高精度的制备，生产速度快、产品优率高、工艺成本低、成像质量优异；
2、无需借助额外透镜元件即可实现逆反射成像功能；
3、可实现柔性屏幕制备，应用形态灵活。
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明中记载的一些实施例，对于本领域普通技 术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1为光线在相互垂直的表面即直角反射壁的反射光路示意图；
图2为横截面为第一直角三角形1的本发明所述的基于二维特征的反射式几何全息膜的正视图；
图3为图2中Ⅰ的局部放大图；
图4为隐藏了部分斜面6和端面5上的反射膜7后，横截面为第一直角三角形1的本发明所述的基于二维特征的反射式几何全息膜的轴侧图，重点展示了全息膜的内部结构；
图5为横截面为第一直角三角形1的柱状基元棱镜3，对与其横截面不平行的任意光线的逆反射光路图；
图6为横截面为矩形21和第二直角三角形22构成的五边形2的本发明所述的基于二维特征的反射式几何全息膜的正视图；
图7为图6中Ⅱ的局部放大图；
图8为隐藏了部分斜面6和端面5上的反射膜7后，横截面为矩形21和第二直角三角形22构成的五边形2的本发明所述的基于二维特征的反射式几何全息膜的轴侧图，重点展示了全息膜的内部结构；
图9为横截面为矩形21和第二直角三角形22构成的五边形2的柱状基元棱镜3，对与其横截面不平行的任意光线的逆反射光路图；
图10为反射式几何全息显示系统的系统示意图，
附图标记如下：
第一直角三角形1，五边形2，矩形21，第二直角三角形22，柱状基元棱镜3，透明层31，反射层32，底面4，端面5，斜面6，反射膜7，图像源100，反射式几何全息屏101，辅助成像屏102，支持结构103，控制器104，交互动作捕捉单元105，人眼跟踪单元106。
具体实施方式
为了使本领域技术人员更好地理解本发明的技术方案，下面结合附图对本发明进行详细描述，本部分的描述仅是示范性和解释性，不应对本发 明的保护范围有任何的限制作用。
应注意到：相似的标号和字母在下面的附图中表示类似项，因此，一旦某一项在一个附图中被定义，则在随后的附图中不需要对其进行进一步定义和解释。
需要说明的是，术语“中心”、“上”、“下”、“左”、“右”、“竖直”、“水平”、“内”、“外”等指示的方位或位置关系为基于附图所示的方位或位置关系，或者是该发明产品使用时惯常摆放的方位或位置关系，仅是为了便于描述本发明和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本发明的限制。此外，术语“第一”、“第二”、“第三”等仅用于区分描述，而不能理解为指示或暗示相对重要性。
此外，术语“水平”、“竖直”、“悬垂”等术语并不表示要求部件绝对水平或悬垂，而是可以稍微倾斜。如“水平”仅仅是指其方向相对“竖直”而言更加水平，并不是表示该结构一定要完全水平，而是可以稍微倾斜。
在本发明的描述中，还需要说明的是，除非另有明确的规定和限定，术语“设置”、“安装”、“相连”、“连接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是机械连接，也可以是电连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通。对于本领域的普通技术人员而言，可以具体情况理解上述术语在本发明中的具体含义。
首先，参考图1，一条光线照射在形成直角的两个反射壁上时，经过两次反射后，出射光线会沿着平行于入射光线的方向传播。当直角反射壁足够小时，出射光线和入射光线之间的距离也会非常小，小到人眼无法分辨，视觉上就像光线原路返回一样。当然，二维平面内直角反射壁只能使平面内的光线进行逆反射，如果能够在空间中形成一个直角三棱锥结构的反射壁，就可以对空间中的光线进行逆反射。
参照图2至图9，基于上述的光路原理，本发明提出一种基于二维特征的反射式几何全息膜，包括一系列横截面为第一直角三角形1或者矩形21和第二直角三角形22组合的五边形2的柱状基元棱镜3，优选的是，第一直角三角形1和/或第二直角三角形22为等腰直角三角形；
如图4和图8，单个柱状基元棱镜3内部、沿长度方向上设有若干相间排列的透明层31和反射层32，柱状基元棱镜3的底面4为光线入射面，反射层32和柱状基元棱镜3的横截面的直角边所在的斜面6为反射面，在斜面6上设置有一层反射膜7，用于对光线进行镜面反射。
柱状基元棱镜3的端面5也可以是反射面，其上也可以设置一层能够反射光线的反射膜7。需要说明的是，如果在加工过程中，端面5为反射层32的话，是没有必要在该反射层32的端面上又设置反射膜7的，反射层32本身具有对光线进行镜面反射的功能。
无论是横截面为第一直角三角形1或者矩形21和第二直角三角形22组合的五边形2都具有多个直角反射壁，包括两个斜面6形成的直角反射壁以及斜面6分别与反射层32或者端面5形成有的直角反射壁，因此这种微结构单元具有对空间的光线进行逆反射的功能，所以如果一个平面上密集布置很多这种微结构，就可以对大面积的入射光进行逆反射。
如图5所示，任意与柱状基元棱镜3的横截面不平行的光线从入射面射到反射层32或者端面5的反射膜7上时，经过一次反射至相邻的一个斜面6上，经过该斜面6镀的反射膜7的二次反射，将光线反射到另一个斜面6上，再经过该斜面6上镀的反射膜7的三次反射，即可实现将光线偏移d后平行于入射光的方向反射回去，这些逆反射回去的光线可以进行3D成像；
同理，如图6所示，任意与柱状基元棱镜3的横截面不平行的光线从入射面射到反射层32或者端面5的反射膜7上时，也可以经过多次反射后逆反射回去进行3D成像；
而对于平行于柱状基元棱镜3横截面的入射光，按照图1的光路原理经过两斜面6的两次反射即可实现光线逆反射3D成像。
因此，该柱状基元棱镜3以及由一系列柱状基元棱镜3构成的本发明的基于二维特征的反射式几何全息膜具有把照射到其上的任意角度的光线进行逆反射的功能，能把照射到其上的光线偏移距离d㎜后逆反射回去，d为出射光线与反射式几何全息膜底面的交点到入射光线的距离，其中d≤2㎜。
优选的是，如图7，上述第二直角三角形22的斜边与矩形21的一条 边重合，矩形21的短边和长边长度分别为a和b，第二直角三角形22的斜边长度为a或者b，其中a≤2㎜，0≤b≤5㎜；
上述涉及到的角度的所允许的误差范围在±5°以内，包括第一直角三角形1和五边形2内包含的直角以及反射层32与柱状基元棱镜3的长度方向所成角度，虽然以上原理是基于理想几何形状来实现的，但是实际情况下，加工过程可能无法制造出完全理想的几何形状，角度也会存在一定的误差，顶点也不可能是一个理想的几何点而是一个半径非常小的圆角。当生产制造误差比较小时，反射光的方向跟逆反射理想的情况发生微小偏差，这些偏差人眼无法分辨，由这些误差带来的像差也非常小，因此同样可以实现非常好的成像效果。
比如直角(第一直角三角形1和五边形2内包含的直角)的角度误差在±5°之内时，用户体验相对比较满意，当超出这个范围后，用户开始觉得成像效果无法接受。同样几何顶点允许是一个比较小的圆角(比如半径小于0.1mm)，那么同样可以实现比较好的成像功能。当然误差越小用户评价越高，所以生产时要尽量降低误差。
具体应用时，客厅应用的角度误差在±2.5°以内时，用户体验相对比较好；
桌面应用的角度误差在±1°以内时，用户体验相对比较好；
移动终端应用的角度误差在±0.5°以内时，用户体验相对比较好。
考虑到柔性膜有相对更加灵活的应用形态，适用范围会更加广泛，同时柔性材料的加工过程不会因为磕碰、跌落、震动等原因损坏。因此，本发明的基于二维特征的反射式几何全息膜优选采用柔性材料制成的柔性膜，这样做出来的屏不仅可以满足折叠、卷绕收纳需求，而且基于柔性的特性，在生产加工过程中，不易容易出现破碎以及产生残余应力等问题，考虑到上述因素，本发明的基于二维特征的反射式几何全息膜所使用柔性材料优选PMMA膜、lPMMA膜、PS膜、PC膜、PE膜、苯乙烯丙烯腈膜、MS膜、PET膜、PETG膜、ABS膜、PP膜、PA膜、SAN膜、MS膜、MBS膜、PES膜、CR-39膜、TPX膜、HEMA膜、F4膜、F3膜、EFP膜、PVF膜、PVDF膜、EP膜、PF膜、UP膜、醋酸纤维素膜、硝酸纤维素膜、EVA膜、PE膜、PVC膜、新型非晶型热塑性聚酯膜、无定形环烯烃膜和 改性双酚A环氧树脂膜中的任意一种。
为了进一步保证可靠性，同时需要满足：其水平夹持下垂长度为Lcm，可对折次数为n，满足：L≥5或者n*L>9。
其中n为可对折次数，测试时取面积为100cm 2的正方形小样，将小样沿着正方形中间线位置(或者中线位置附近1cm范围内)对折成长方形，然后用两块平板将对折后的基元膜夹在中间，施加不小于10N的力，加压维持时间大于或等于5s，然后打开(此时完成一次对折测试)，检查小样是否产生局部微裂纹或者沿折痕断开成两截，如果没有，重复上述测试直到其产生局部微裂纹或者断开为两截，停止测试，测试过程总共折叠次数记为n；
其中L为水平夹持下垂长度，测试方法：取宽度5cm±0.5cm，长度约25cm的窄条，一端紧贴在水平基准桌面上，保证窄条伸出桌面长度为20cm±1cm，然后静置待窄条稳定后测量窄条伸出桌面一端的端点与水平基准桌面的垂直高度差记为水平下垂长度L；
上述的测试本身是一种加速测试手段，可以快速判断样品在长期使用过程中的可靠性，柔性薄膜在应用时，需要承受多次的卷绕收纳和打开等操作，按照设计5年使用寿命计算，整个生命周期需要收纳、展开动作大约10000次，为了加速评估使用可靠性，本发明采用上述对折测试和水平夹持下垂长度测试；
当n*L>9时，n越大表明基元膜的极限弯折曲率半径越小，抗折断能力越强，同时L越大说明基元膜的柔性越好，越不容易因为卷绕破坏膜的结构，实验发现n*L＝9时基本等效10000次开合测试，满足最小设计寿命需求，过小的话，容易在产品的使用周期内出现质量问题，降低客户体验；
在实际应用时，也可以使用一些无法完成无安全对折，但是卷绕起来却不会破坏结构，所以也适用卷绕屏。对于这类材料，只要满足了制备的基元膜可以卷绕成直径小于5cm的圆筒状，基元膜整体也会比较柔顺，加工过程破裂损失也较小。通常L≥5cm时，基元膜可以卷绕成直径小于5cm的圆筒状而不发生断裂。
下表是验证时的一些数据：
Figure PCTCN2021087146-appb-000001
进一步地，结合上表中内容，在具体实践中可以将n和L的关系限定为：n*L≥28，如此，即可以适用于大多数的应用场景，并能够保证较高的产品良率。
补充说明的是，全息膜的柔性特征极大程度取决于其原材料，通过控制原材料的厚度可以大范围的调节全息膜的柔性特征。这些可以通过简单实验获取相应数据，这里不做赘述。
虽然上述加速测试方法可以给出一个比较合适的设计指导，但是实际操作起来测试过程还是比较麻烦，对于设计要求不是特别严格的情况下，还可以通过如下非常快速的方式进行判定。通常，对于柔性材料加工过程的优率比较容易保证，所以优先考虑屏幕应用场景，通过实际应用测试发现对于卷轴收纳屏幕，当L大于两倍的卷轴最内层半径时即可很好的实现卷轴收纳屏形态，当然为了留出足够的设计余量也可以取L大于3倍甚至5倍卷轴最内层半径进行设计。
为了对内部的微结构进行保护，在底面4、端面5以及斜面6设置有的反射膜7上分别设有保护膜，其中底面4为光线入射面，因此底面4上设有的保护膜为透明保护膜，而端面5以及斜面6作为反射面，其上设有的保护膜不一定是透明的，这里不作限定。
上述的保护膜的材质优选柔性材质，如PMMA膜、lPMMA膜、PS膜、PC膜、PE膜、苯乙烯丙烯腈膜、MS膜、PET膜、PETG膜、ABS膜、PP膜、PA膜、SAN膜、MS膜、MBS膜、PES膜、CR-39膜、TPX膜、HEMA膜、F4膜、F3膜、EFP膜、PVF膜、PVDF膜、EP膜、PF膜、 UP膜、醋酸纤维素膜、硝酸纤维素膜、EVA膜、PE膜、PVC膜、新型非晶型热塑性聚酯膜、无定形环烯烃膜和改性双酚A环氧树脂膜中的任意一种；
也可以是刚性的，如塑料膜、玻璃等。
本发明还提供上述基于二维特征的反射式几何全息膜的制备方法，包括以下步骤：
1)基元膜准备：准备一张透明层31与反射层32相间排列的基元膜，优选公开号CN110794504A的一种柔性全息基元膜及其制备方法和应用中的柔性全息基元膜；
2)直角三角形微结构加工：沿垂直于透明层31与反射层32的方向上切削(实际生产时，允许一个较小的误差±5°)，形成一面是平面、另一面为横截面为第一直角三角形1或矩形21与第二直角三角形22组合的五边形2的柱状基元棱镜3排列形成的起伏锯齿状表面的膜，在该步骤之前或者之后，可以在底面4上镀一层透明保护膜；
3)镀反射膜：在柱状基元棱镜3的端面5以及横截面的直角边所在的斜面6上镀一层反射膜7，即可获得基于二维特征的反射式几何全息膜，另外，在镀完反射膜7之后可以在反射膜7上再镀一层保护膜。
需要说明的是，根据实际需求，步骤1)中采用的基元膜也可以不使用柔性基元膜，用符合需求的材料按照公开号CN110794504A的一种柔性全息基元膜及其制备方法和应用中的制备方法制备出基元膜即可应用于本发明。
下面结合实施例对本发明作进一步说明，需要说明的是，以下实施例是对本发明的具体说明，不是对本发明的限制：
实施例1
准备一张厚度为1㎜、透明层31与反射层32相间排列的柔性基元膜，其中透明层31的材质为PC膜，反射层32材质为铝箔反射膜；沿垂直于透明层31与反射层32的方向上切削，切削出废料的截面为高1㎜的等腰直角三角形棱柱，切削后的基元膜为若干横截面为高1㎜等腰直角三角形的柱状基元棱镜3连在一起形成的具有起伏锯齿状表面的膜；然后在上述膜的端面5以及斜面6上镀一层反射膜7，即制得基于二维特征的反射式 几何全息膜，最后在反射膜7上再镀一层保护膜来保护全息膜的内部微结构。为了增加膜的强度，可以在切削之前，在基元膜的底面4上镀一层透明保护膜。
实施例1制得的全息膜包括一系列的横截面为斜边2㎜的等腰直角三角形的柱状基元棱镜3，基于图1的光路原理，光线从入射面即底面4射进来，然后经过直角反射壁反射回去，存在的偏移量d不会大于横截面的斜边长2㎜，即d≤2㎜。
实施例2
准备一张厚度为0.5㎜、透明层31与反射层32相间排列的柔性基元膜，其中透明层31的材质为PC膜，反射层32材质为铝箔反射膜；沿垂直于透明层31与反射层32的方向上切削，切削出废料的截面为高0.5㎜的等腰直角三角形棱柱，切削后的基元膜为若干横截面为高0.5㎜等腰直角三角形的柱状基元棱镜3连在一起形成的具有起伏锯齿状表面的膜；然后在上述膜的端面5以及斜面6上镀一层反射膜7，即制得基于二维特征的反射式几何全息膜，最后在反射膜7上再镀一层保护膜来保护全息膜的内部微结构。为了增加膜的强度，可以在切削之前，在基元膜的底面4上镀一层透明保护膜。
实施例2制得的全息膜包括一系列的横截面为斜边1㎜的等腰直角三角形的柱状基元棱镜3，基于图1的光路原理，光线从入射面即底面4射进来，然后经过直角反射壁反射回去，存在的偏移量d不会大于横截面的斜边长1㎜，即d≤1㎜。
实施例3
准备一张厚度为0.1㎜、透明层31与反射层32相间排列的柔性基元膜，其中透明层31的材质为PC膜，反射层32材质为铝箔反射膜；沿垂直于透明层31与反射层32的方向上切削，切削出废料的截面为高0.1㎜的等腰直角三角形棱柱，切削后的基元膜为若干横截面为高0.1㎜等腰直角三角形的柱状基元棱镜3连在一起形成的具有起伏锯齿状表面的膜；然后在上述膜的端面5以及斜面6上镀一层反射膜7，即制得基于二维特征的反射式几何全息膜，最后在反射膜7上再镀一层保护膜来保护全息膜的内部微结构。为了增加膜的强度，可以在切削之前，在基元膜的底面4上 镀一层透明保护膜。
实施例3制得的全息膜包括一系列的横截面为斜边0.2㎜的等腰直角三角形的柱状基元棱镜3，基于图1的光路原理，光线从入射面即底面4射进来，然后经过直角反射壁反射回去，存在的偏移量d不会大于横截面的斜边长0.2㎜，即d≤0.2㎜。
实施例4
准备一张厚度为6㎜、透明层31与反射层32相间排列的柔性基元膜，其中透明层31的材质为PC膜，反射层32材质为铝箔反射膜；沿垂直于透明层31与反射层32的方向上切削，切削出废料的截面为高1㎜的等腰直角三角形棱柱，切削后的基元膜为由若干横截面为高1㎜等腰直角三角形与短边2㎜、长边6㎜的矩形构成的五边形2的柱状基元棱镜3连在一起形成的起伏锯齿状表面的膜；然后在上述膜的端面5以及横截面的直角边所在的斜面6上镀一层反射膜7，即制得基于二维特征的反射式几何全息膜，最后在反射膜7上再镀一层保护膜来保护全息膜的内部微结构。
实施例4制得的全息膜包括一系列的横截面为由斜边2㎜的等腰直角三角形和短边2㎜、长边6㎜的矩形构成的五边形2的柱状基元棱镜3，基于图1的光路原理，光线从入射面即底面4射进来，然后经过多个直角反射壁反射回去，存在的偏移量d不会大于横截面的斜边长2㎜，即d≤2㎜。
实施例5
准备一张厚度为2㎜、透明层31与反射层32相间排列的柔性基元膜，其中透明层31的材质为PC膜，反射层32材质为铝箔反射膜；沿垂直于透明层31与反射层32的方向上切削，切削出废料的截面为高0.5㎜的等腰直角三角形棱柱，切削后的基元膜为由若干横截面为高0.5㎜等腰直角三角形与短边1㎜、长边1.5㎜的矩形构成的五边形2的柱状基元棱镜3连在一起形成的起伏锯齿状表面的膜；然后在上述膜的端面5以及横截面的直角边所在的斜面6上镀一层反射膜7，即制得基于二维特征的反射式几何全息膜，最后在反射膜7上再镀一层保护膜来保护全息膜的内部微结构。
实施例5制得的全息膜包括一系列的横截面为由斜边1㎜的等腰直角 三角形和短边1㎜、长边1.5㎜的矩形构成的五边形2的柱状基元棱镜3，基于图1的光路原理，光线从入射面即底面4射进来，然后经过多个直角反射壁反射回去，存在的偏移量d不会大于横截面的斜边长1㎜，即d≤1㎜。
实施例6
准备一张厚度为1㎜、透明层31与反射层32相间排列的柔性基元膜，其中透明层31的材质为PC膜，反射层32材质为铝箔反射膜；沿垂直于透明层31与反射层32的方向上切削，切削出废料的截面为高0.1㎜的等腰直角三角形棱柱，切削后的基元膜为由若干横截面为高0.1㎜等腰直角三角形与短边0.2㎜、长边0.9㎜的矩形构成的五边形2的柱状基元棱镜3连在一起形成的起伏锯齿状表面的膜；然后在上述膜的端面5以及横截面的直角边所在的斜面6上镀一层反射膜7，即制得基于二维特征的反射式几何全息膜，最后在反射膜7上再镀一层保护膜来保护全息膜的内部微结构。
实施例6制得的全息膜包括一系列的横截面为由斜边0.2㎜的等腰直角三角形和短边1㎜、长边1.5㎜的矩形构成的五边形2的柱状基元棱镜3，基于图1的光路原理，光线从入射面即底面4射进来，然后经过多个直角反射壁反射回去，存在的偏移量d不会大于横截面的斜边长0.2㎜，即d≤0.2㎜。
具体应用时，通常显示设备距离人眼越近需要的分辨率也就越高，比如对于类似桌面显示优选基元膜的透明层厚度≤1mm，同时d≤1㎜；
对于显示要求更高的设备优选基元膜的透明层厚度≤0.5mm，同时d≤0.5㎜；
对于显示细节要求更高的设备优选透明层厚度≤0.3mm，同时d≤0.3㎜；
通过对设有相间排列的透明层31和反射层32的基元膜进行简单的切削和加工，是基于二维特征的切削加工，操作简单，容易实现大规模、高精度生产，生产速度快，工艺成本低，再加上基元膜优选地是柔性基元膜，在切削加工过程中不会出现硬质材料加工过程中经常出现的破碎以及产生残余应力等问题，产品优率高，而且柔性的特性使得本发明的产品可以满 足折叠、卷绕收纳等需求；
基于直角反射壁的光路原理，本发明的基于二维特征的反射式几何全息膜产品能够实现将照射到其上的光线偏移一个距离d之后原方向反射回去，无需借助额外透镜元件即可实现逆反射成像功能。
本发明还提供了上述制备方法制备的基于二维特征的反射式几何全息膜于反射式几何全息显示系统的应用，具体为：
如图10，反射式几何全息显示系统包括图像源100、反射式几何全息屏101、辅助成像屏102、支持结构103和控制器104；
图像源100用于提供投影画面，可以采LCD显示屏、LED显示屏、投影仪、全息投影仪等能够生成图像的元件，优选投影仪或者全息投影仪；
反射式几何全息屏101用于把照射到其上的光线偏移一个距离d之后原方向反射回去，采用本发明制备的基于二维特征的反射式几何全息膜；
辅助成像屏102用于分光，优选半透半反材质制成的屏幕；
支持结构103分别与图像源100、反射式几何全息屏101和辅助成像屏102相匹配，为三者提供物理结构支撑；
控制器104与图像源100电连接，用于控制图像源100来调节投影画面的景深和显示内容；
为了增加显示系统的灵活性，我们还可以将支持结构103设置为可以运动或者变形的结构，将支持结构103和控制器104电连接，支持结构103根据并控制器104的控制信息，做出相应响应动作，实现图像源100、反射式几何全息屏101和辅助成像屏102的相对运动和/或整体运动，使得系统的可视视窗始终覆盖用户的眼睛，使得用户在不同的方位都可以正常观看画面，需要说明的是，支持结构103为一般现有技术，本领域的技术人员可以根据实际应用的空间条件自行设计，比如：使用一些铰链结构和类似于伞轴的结构可以非常容易的设计出可以变形的结构，这里不做具体限定；
作为优选方案，本发明所述的全息显示系统还包括与控制器104电连接的交互动作捕捉单元105，交互动作捕捉单元105用于识别用户的交互动作并将用户交互动作信息发送给控制器104，控制器104根据接收到的交互动作捕捉单元105获取的用户交互动作信息调整显示画面内容，实现 用户与画面的交互动作，具体可以是采用摄像头结合机器视觉技术来识别用户的手势动作来获取用户的交互信息，从而控制画面显示内容或者控制支持结构103运动来调整图像源100、反射式几何全息屏101和/或辅助成像屏102的空间位置和姿态，控制器104还可以根据接收的交互动作捕捉单元105获取的用户交互动作信息来实时调整显示画面内容，实现用户与画面的交互动作，比如根据平移手势信号，控制画面进行平移，或者根据对应的其他交互动作控制画面的放大、拉近、推远、触碰等操作；
交互动作捕捉单元105的设置对于类似于穿戴式应用这种用户相对显示系统的空间位置固定不变的应用情景具有积极的意义；
另外，对于用户相对显示系统的空间位置实时变动的应用情景，还需要设置一个与控制器104电连接的人眼跟踪单元106，人眼跟踪单元106用于跟踪人眼的位置并将人眼的定位信息发送给控制器104，控制器104根据接收到的人眼跟踪单元106获取的人眼定位信息，来控制支持结构103做出相应的动作响应，来调整图像源100、反射式几何全息屏101和/或辅助成像屏102的相对位置和/或整体空间位置，使用户眼睛始终处于系统的可视空间内，这样用户即使在运动状态下眼睛也可以始终接收到投影信息，正常观看画面。
实际应用中，交互动作捕捉单元105和人眼跟踪单元106可以集成在同一个设备内完成，比如使用一个机器视觉摄像设备等。
图像源100投影出画面，光线照射在辅助成像屏102上，部分光线直接透过辅助成像屏102，这部分光线不会参与成像，另一部分光线经过辅助成像屏102的反射到反射式几何全息屏101上，而这部分光线再经过反射式几何全息屏101的光学转化，偏移微小距离d后原方向反射回去并透过辅助成像屏102，在空间内形成可以被观察到的离屏画面。
以上内容是结合具体的优选实施方式对本发明所作的进一步详细说明，不能认定本发明的具体实施只局限于这些说明。对于本发明所属技术领域的普通技术人员来说，在不脱离本发明构思的前提下，还可以做出若干简单推演或替换，都应当视为属于本发明的保护范围。

Claims (12)

  1. 基于二维特征的反射式几何全息膜，其特征在于：包括一系列横截面为第一直角三角形(1)或者矩形(21)和第二直角三角形(22)组合的五边形(2)的柱状基元棱镜(3)；
    所述柱状基元棱镜(3)内部、沿长度方向上设有若干相间排列的透明层(31)和反射层(32)，所述柱状基元棱镜(3)横截面的直角边所在的斜面(6)上设置有一层反射膜(7)，用于对光线进行镜面反射；
    所述第一直角三角形(1)和五边形(2)内包含的直角以及反射层(32)与柱状基元棱镜(3)长度方向所成角度的误差范围在±5°以内。
  2. 根据权利要求1所述的基于二维特征的反射式几何全息膜，其特征在于：所述第二直角三角形(22)的斜边与矩形(21)的一条边重合、长度为a，所述矩形(21)的另一边长度为b，其中a≤2㎜，0≤b≤5㎜。
  3. 根据权利要求1所述的基于二维特征的反射式几何全息膜，其特征在于：所述第一直角三角形(1)和/或第二直角三角形(22)为等腰直角三角形。
  4. 根据权利要求1所述的基于二维特征的反射式几何全息膜，其特征在于：所述柱状基元棱镜(3)的端面(5)也设置有一层反射膜(7)。
  5. 根据权利要求1所述的基于二维特征的反射式几何全息膜，其特征在于：所述基于二维特征的反射式几何全息膜为柔性膜。
  6. 根据权利要求5所述的基于二维特征的反射式几何全息膜，其特征在于：所述基于二维特征的反射式几何全息膜的水平夹持下垂长度为L㎝，可对折次数为n，满足：
    L≥5或者n*L>9。
  7. 根据权利要求6所述的基于二维特征的反射式几何全息膜，其特征在于：所述基于二维特征的反射式几何全息膜的水平夹持下垂长度为L㎝，可对折次数为n，满足：n*L≥28。
  8. 根据权利要求1所述的基于二维特征的反射式几何全息膜，其特征在于：所述底面(4)和反射膜(7)上分别设有保护膜，其中所述底面(4)上设有的保护膜为透明保护膜。
  9. 根据权利要求1～8任意一项所述的基于二维特征的反射式几何全息膜的制备方法，其特征在于，包括以下步骤：
    基元膜准备：准备一张透明层(31)与反射层(32)相间排列的基元膜；
    直角三角形微结构加工：沿垂直于透明层(31)与反射层(32)的方向上切削，形成一面是平面、另一面是横截面为第一直角三角形(1)或矩形(21)与第二直角三角形(22)组合的五边形(2)的柱状基元棱镜(3)排列形成的起伏锯齿状表面的膜，切削方向的误差范围在±5°以内；
    镀反射膜：在柱状基元棱镜(3)的端面(5)以及横截面的直角边所在的斜面(6)上镀一层反射膜(7)，即可获得基于二维特征的反射式几何全息膜。
  10. 根据权利要求9所述的基于二维特征的反射式几何全息膜的制备方法，其特征在于：在步骤2)之前或者之后还包括：在底面(4)上粘接一层透明保护膜。
  11. 根据权利要求9所述的基于二维特征的反射式几何全息膜的制备方法，其特征在于：在步骤3)之后还包括：在设置有反射膜(7)的锯齿状起伏表面粘接一层保护膜。
  12. 根据权利要求9所述的基于二维特征的反射式几何全息膜的制备方法制备的基于二维特征的反射式几何全息膜于反射式几何全息显示系统的应用。
PCT/CN2021/087146 2020-04-17 2021-04-14 基于二维特征的反射式几何全息膜及其制备方法和应用 WO2021208942A1 (zh)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN202020572735.2U CN211698263U (zh) 2020-04-17 2020-04-17 基于二维特征的反射式几何全息膜
CN202020572735.2 2020-04-17
CN202010303252.7 2020-04-17
CN202010303252.7A CN111338015B (zh) 2020-04-17 2020-04-17 基于二维特征的反射式几何全息膜及其制备方法和应用

Publications (1)

Publication Number Publication Date
WO2021208942A1 true WO2021208942A1 (zh) 2021-10-21

Family

ID=78084011

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/087146 WO2021208942A1 (zh) 2020-04-17 2021-04-14 基于二维特征的反射式几何全息膜及其制备方法和应用

Country Status (1)

Country Link
WO (1) WO2021208942A1 (zh)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1192174A (zh) * 1995-07-28 1998-09-02 日本碳化物工业株式会社 微棱镜母型的制造方法
WO2001038906A2 (en) * 1999-11-23 2001-05-31 Digilens, Inc. Optical retro-reflection device
US20070058259A1 (en) * 2005-09-13 2007-03-15 Samsung Electronics Co., Ltd. Light-condensing member, method of manufacturing the same and display apparatus having the same
CN108269511A (zh) * 2018-02-28 2018-07-10 北京眸合科技有限公司 一种空中悬浮显示系统
CN110888194A (zh) * 2019-11-29 2020-03-17 荆门市探梦科技有限公司 一种柔性全息基元膜及其制备方法和应用
CN111338015A (zh) * 2020-04-17 2020-06-26 荆门市探梦科技有限公司 基于二维特征的反射式几何全息膜及其制备方法和应用

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1192174A (zh) * 1995-07-28 1998-09-02 日本碳化物工业株式会社 微棱镜母型的制造方法
WO2001038906A2 (en) * 1999-11-23 2001-05-31 Digilens, Inc. Optical retro-reflection device
US20070058259A1 (en) * 2005-09-13 2007-03-15 Samsung Electronics Co., Ltd. Light-condensing member, method of manufacturing the same and display apparatus having the same
CN108269511A (zh) * 2018-02-28 2018-07-10 北京眸合科技有限公司 一种空中悬浮显示系统
CN110888194A (zh) * 2019-11-29 2020-03-17 荆门市探梦科技有限公司 一种柔性全息基元膜及其制备方法和应用
CN111338015A (zh) * 2020-04-17 2020-06-26 荆门市探梦科技有限公司 基于二维特征的反射式几何全息膜及其制备方法和应用

Similar Documents

Publication Publication Date Title
US10409065B2 (en) Near-eye display
US11340475B2 (en) Display device for aerial image having retro-reflective part
CN111338015B (zh) 基于二维特征的反射式几何全息膜及其制备方法和应用
US10365492B2 (en) Systems, devices, and methods for beam combining in wearable heads-up displays
EP3351993A1 (en) Optical system and head-mounted display device
TWI292077B (en) Three dimensional image display device
CN110888194B (zh) 一种柔性全息基元膜的制备方法和应用
JP2010262229A (ja) 表示装置
CN111766702A (zh) 眼球追踪的近眼显示光学系统
CN113917701B (zh) 一种投影光场立体显示装置
CN111338177A (zh) 反射式几何全息显示系统
TW200933556A (en) Light illumination of displays with front light guide and coupling elements
JP5828092B2 (ja) 画像表示装置
CN211698263U (zh) 基于二维特征的反射式几何全息膜
JP2012008301A (ja) 体積走査型３次元映像表示装置
CN110989195A (zh) 一种三维图像悬浮显示系统及方法
WO2021052104A1 (zh) 一种全息显示系统
US10139719B2 (en) Aerial image display device
CN109856808A (zh) 悬浮显示装置
CN111338016B (zh) 基于二维特征的反射式几何全息膜及其制备方法和应用
CN110794504A (zh) 一种柔性全息基元膜及其制备方法和应用
CN211577471U (zh) 基于二维特征的反射式几何全息膜
WO2021208942A1 (zh) 基于二维特征的反射式几何全息膜及其制备方法和应用
WO2021208941A1 (zh) 基于二维特征的反射式几何全息膜及其制备方法和应用
KR102295286B1 (ko) 표시 장치

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21788216

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21788216

Country of ref document: EP

Kind code of ref document: A1