Waveguide curvature and microstructure collaborative suspended real image generation device

Abstract

The invention relates to the technical field of optical imaging, in particular to the technical field of aerial imaging, and particularly relates to a waveguide curvature and microstructure collaborative suspended real image generation device which comprises a collimation optical system and an arched waveguide system arranged on the light emitting side of the collimation optical system. The arched waveguide system comprises a first reflection structure and a second reflection structure, the surface, facing the second reflection structure, of the first reflection structure is an arched cambered surface, and an anti-reflection layer is arranged on the side wall, facing the second reflection structure, of the first reflection structure; the second reflection structure comprises a plurality of trapezoidal units, the first reflection structure and the second reflection structure are oppositely arranged, and an air gap is formed between the first reflection structure and the second reflection structure to form a total reflection interface. According to the application, the arched waveguide structure and the trapezoidal unit are combined, the light beam is guided by curvature in the arched waveguide to realize macroscopic deflection, then the microscopic angle calibration is realized through the trapezoidal microstructure inclined surface, and the emergent light beam is intersected in a free space to form a suspended real image.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical imaging technology, especially to the field of aerial imaging technology, and in particular to a suspended real image generation device with waveguide curvature and microstructure cooperation. BACKGROUND

[0002] The existing waveguide imaging technology has the following outstanding problems:

[0003] 1) Limited function of planar waveguide, traditional planar waveguide can only realize beam transmission, and cannot actively control the propagation direction and distribution of light beams in free space. Imaging must rely on a physical screen, and cannot realize true "aerial real image".

[0004] 2) Small field of view angle, limited by optical path design, the field of view angle of the existing system is generally not more than 30°, and the user experience is limited.

[0005] 3) Serious environmental light interference, when the environmental illumination is greater than 500 lux, the image contrast is less than 10:1, resulting in blurred display and poor visibility.

[0006] 4) Outstanding dispersion problem, the focal length deviation of RGB three-color channels is greater than ±2D, far exceeding the focal depth of the human eye (±0.3D), causing serious dispersion and image blur.

[0007] 5) High system complexity and low light efficiency, relying on multiple diffraction or complex optical components, resulting in complex, sensitive and easily distorted system, and low light efficiency. SUMMARY

[0008] The present application aims to solve one of the problems in the background art.

[0009] To this end, the present application provides a suspended real image generation device with waveguide curvature and microstructure cooperation.

[0010] The technical solution adopted by the present application to solve its technical problems is:

[0011] A suspended real image generation device with waveguide curvature and microstructure cooperation, comprising,

[0012] a collimating optical system, and

[0013] an arched waveguide system, the arched waveguide system is arranged on the light output side of the collimating optical system, the arched waveguide system comprises a first reflecting structure and a second reflecting structure, the surface of the first reflecting structure facing the second reflecting structure is arranged as an arc surface arched towards the second reflecting structure, and an anti-reflection layer is arranged on the side wall of the first reflecting structure facing the second reflecting structure; the second reflecting structure comprises a plurality of ladder units, the first reflecting structure and the second reflecting structure are oppositely arranged, an air gap is formed between the first reflecting structure and the second reflecting structure, and a total reflection interface is formed.

[0014] Further, a plurality of said trapezoidal unit rectangular arrays are arranged on the anti-reflection layer to form a trapezoidal microstructure array, and the ratio of the upper base width to the lower base width of said trapezoidal unit is 1:1.6 along the light emission direction.

[0015] Further, the slope angle of said trapezoidal microstructure array is gradient distributed along the light transmission direction, ranging from 45° to 65°, for regulating the emitted light beam to form a divergence angle of about 15° to 25°, and the light beams spatially intersect at a distance of 250mm to 500mm in front, forming a suspended real image that can be observed.

[0016] Further, the spacing between adjacent said trapezoidal units is between 0.1mm and 0.25mm.

[0017] Further, said anti-reflection layer has a plurality of nano-pores, said nano-pores are hexagonal, a plurality of said nano-pores form a hexagonal nano-pore array structure, and the depth of said nano-pores is designed to be one-fourth of the working wavelength.

[0018] Further, the upper surface of said anti-reflection layer is a smooth surface, and the depth of said anti-reflection layer is 100-125nm.

[0019] Further, the spacing between said first reflection structure and said second reflection structure on the side close to the collimating optical system is H1, the minimum distance between said first reflection structure and said second reflection structure is H2, the spacing between said first reflection structure and said second reflection structure on the side close to the collimating optical system is H3, and H2<H1<H3.

[0020] Further, along the light emission direction, the distance between the starting point of said trapezoidal microstructure array on the side close to the collimating optical system and the end point of said arc-shaped reflection surface on the side close to the collimating optical system is D, and the length of said arc-shaped reflection surface is L, and D>30%L.

[0021] Further, the radius of curvature of said first reflection structure arc surface ranges from 80-150mm.

[0022] Further, the material of said first reflection structure is K9 glass or PMMA.

[0023] The beneficial effects of the present application are that the present application combines the arched waveguide structure and the trapezoidal unit, the light beam is guided by the curvature in the arched waveguide to achieve macroscopic deflection, and then the light beam is calibrated by the slope of the trapezoidal microstructure to form a suspended real image by the intersection of the emitted light beams in free space. At the same time, the anti-reflection layer with a hexagonal nano-pore array structure is arranged on the lower surface of the arched waveguide (first reflection structure) to reduce the reflection loss of the light emission interface, improve the light transmittance, and suppress the environmental light interference caused by the interface reflection.

[0024] The scheme breaks through the traditional planar waveguide viewing angle limitation, realizes wider viewing angle, reduces image edge distortion, improves overall image clarity, suppresses environmental light interference, enhances image contrast, improves system optical modulation capability, and realizes higher quality aerial imaging effect. BRIEF DESCRIPTION OF DRAWINGS

[0025] The application will be further described below in conjunction with the drawings and examples.

[0026] Figure 1 is a structural schematic diagram of an aerial imaging device based on the arch waveguide system and the trapezoidal microstructure cooperative regulation in the application.

[0027] Figure 2 is a schematic diagram of the hexagonal nano-hole array structure of the anti-reflection layer in the application.

[0028] Figure 3 is a reflection schematic diagram of light on the trapezoidal unit in the application.

[0029] Figure 4 is a reflection schematic diagram of light on the first reflection structure in the application.

[0030] In the figure: 1, light source; 2, collimating optical system; 3, arch waveguide system; 31, first reflection structure; 32, second reflection structure; 33, anti-reflection layer; 34, trapezoidal unit. DETAILED DESCRIPTION

[0031] The application will be further described below in conjunction with the drawings and examples. These drawings are all simplified schematic diagrams, and only illustrate the basic structure of the application in a schematic manner, and therefore only show the structures related to the application.

[0032] In the description of the application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application. In addition, the features limited as "first" and "second" can be explicitly or implicitly included one or more features. In the description of the application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0033] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "linking" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0034] An aerial imaging device based on an arch-shaped waveguide system and a trapezoidal microstructure cooperative regulation, comprising a collimating optical system 2 and an arch-shaped waveguide system 3.

[0035] The arch-shaped waveguide system 3 is located on the light-emitting side of the collimating optical system 2, for guiding the collimated light beam to transmit inside by total reflection, and the scattered light emitted by the light source 1 (the pattern to be projected) enters the arch-shaped waveguide system 3 after collimation by the collimating optical system 2.

[0036] The arch-shaped waveguide system 3 comprises a first reflecting structure 31 and a second reflecting structure 32, the first reflecting structure 31 is located above the second reflecting structure 32, the first reflecting structure 31 has an arc-shaped surface arched towards the second reflecting structure 32, an anti-reflection layer 33 is arranged on the arc-shaped surface of the first reflecting structure 31 towards the second reflecting structure 32, and the second reflecting structure 32 comprises a trapezoidal microstructure array. In other embodiments, a beam shaping element can also be arranged between the arch-shaped waveguide system 3 and the collimating optical system 2, which can be a diffractive optical element (DOE) or a holographic optical element, for optimizing the distribution and direction of the outgoing light beam and improving the imaging quality.

[0037] The first reflecting structure 31 and the second reflecting structure 32 are oppositely arranged, along the light-emitting direction, the distance between the starting point of the trapezoidal microstructure array on the side close to the collimating optical system 2 and the end point of the arc-shaped reflecting surface on the side close to the collimating optical system 2 is D, the length of the arc-shaped reflecting surface is L, and D>30%L. The distance between the first reflecting structure 31 and the second reflecting structure 32 on the side close to the collimating optical system 2 is H1, the minimum distance between the first reflecting structure 31 and the second reflecting structure 32 is H2, the distance between the first reflecting structure 31 and the second reflecting structure 32 on the side close to the collimating optical system 2 is H3, and H2<H1<H3. In the present embodiment, H1 is 3mm, and H3 is 6mm.

[0038] The trapezoidal microstructure array is used to control the direction of light beam emission. The trapezoidal microstructure array includes several trapezoidal units 34. Each trapezoidal unit 34 has an upper base width of 0.15mm, a lower base width of 0.25mm, and a height of 0.08mm. The inclined surface angle is 55° to 58°, and the upper base to lower base width ratio is 1:1.6±0.1. This allows for differential compensation of the reflection paths of light beams of different wavelengths on the inclined surface. The inclined surface angle of the trapezoidal microstructure array is gradiently distributed along the direction of light transmission, ranging from 45° to 65°. That is, along the light emission direction, the inclined surface angles of multiple trapezoidal units 34 gradually decrease or increase, which is used to control the outgoing light beam to form a divergence angle of approximately 20°, intersecting in space 250mm to 500mm ahead, forming an observable suspended real image. The light beam emitted by the image source passes through the collimation system and is injected into the arched waveguide at an angle of 45° to 50°, satisfying the total reflection condition. During the multiple reflections on the upper surface of the arch, the light beam is deflected downward by about 0.16° to 0.20° each time due to the curvature. After 10 reflections, the cumulative macroscopic deflection angle is about 1.6° to 2.0°. After entering the trapezoidal microstructure area, the light beam hits the inclined surface and undergoes directionally reflected. Figure 3 In the embodiment shown, the slope angle θ of the trapezoidal unit 34 is f is 55°, the incident angle θ in is 30°, and after the light is projected on the trapezoidal unit 34, it is reflected, and the exit angle of the reflected light is θ out =2θ f -θ in .

[0039] The upper surface of the arched waveguide system 3 is an arc surface with a curvature radius R∈[80,150]mm (e.g. Figure 3 ). The upper surface of the anti-reflection layer 33 is set to a flat surface, the depth of the anti-reflection layer 33 is 100-125nm, and the anti-reflection layer 33 is provided with a hexagonal nanohole array structure, whose main function is to reduce the reflection loss at the light beam exit interface, improve the light transmittance, and suppress the ambient light interference caused by interface reflection. The nanohole array structure forms a gradient refractive index layer, which smoothly transitions the refractive index from the waveguide material (n≈1.52) to the air (n=1.0) along the depth direction, reducing Fresnel reflection; the nanohole depth is designed to be one-quarter of the working wavelength (λ / 4), achieving destructive interference at the center wavelength of 550nm, further suppressing reflection; in this embodiment, the aperture size is 250±50nm, and the average depth is 110nm.

[0040] Assume that the local normal direction of the light beam at the i-th reflection point on the first reflection mechanism changes due to the curvature Move Δs_i along the arc length, the corresponding central angle is (Unit: radians). On a circle, arc length = radius × central angle (radians) Therefore, it is concluded It is the rotation angle of the normal direction at the reflection point. Then the propagation direction of the light beam is deflected downward after each reflection. According to the reflection law of geometric optics, when the normal of the interface is rotated , the direction of the reflected light will be deflected by 2 times the angle relative to the original direction. Therefore, there is For a small arc length Δs_i, there is

[0041]

[0042] Substituting the above formula, we get

[0043] Δθ_i = 2Δs_i / R

[0044] The cumulative deflection angle along the total length L = 50 mm is:

[0045] Θ m acro = ∑(2Δs i / R) = 2L / R

[0046] Θ m acro = 2×50 / R = 100 / R (unit: radian)

[0047] Convert to angle (multiply by 180 / π ≈ 57.3):

[0048] Θ_macro(°) ≈ (100 / R)×57.3 = 5730 / R

[0049] Take R = 100 mm, we get:

[0050] Θ m acro = 2×50 / 100 = 1°

[0051] Note: If a larger deflection angle is required, it can be achieved by reducing R.

[0052] In which, the light beam is guided by the curvature of the first reflection structure 31 of the arched waveguide system 3 to achieve macro deflection, and then the micro angle is calibrated by the inclined surface of the trapezoidal microstructure. The outgoing light beam converges in free space to form a suspended real image. Specifically: the light beam emitted by the image source is injected into the arched waveguide system 3 at an angle of 45°-50° after collimation, satisfying the total reflection condition; the light beam is deflected downward by about 0.16°-0.20° each time in the process of multiple reflections on the arched upper surface due to the curvature, and the cumulative macro deflection angle is about 1.6°-2.0° after 10 reflections; the light beam enters the trapezoidal microstructure region and hits the inclined surface to produce directional reflection, and the outgoing angle is determined by the inclination of the inclined surface; the inclination of the inclined surface of the trapezoidal microstructure array presents a gradient distribution along the light transmission direction, ranging from 45° to 65°, and the outgoing light beam forms a divergence angle of about 20°, which converges in space at a distance of 250 mm-500 mm in front to form a suspended real image that can be observed. ​

[0053] With the above ideal embodiments according to the present application as the inspiration, through the above description, relevant staff can make various changes and modifications without deviating from the scope of the technical idea of the present application. The technical scope of the present application is not limited to the content of the specification, and must be determined by the scope of the claims.

Claims

1. A waveguide curvature and microstructure synergistic floating real image generating device, characterized in that, Comprising, a collimating optical system (2), and an arc waveguide system (3) disposed on the light-out side of the collimating optical system (2), the arc waveguide system (3) comprising a first reflecting structure (31) and a second reflecting structure (32), the surface of the first reflecting structure (31) towards the second reflecting structure (32) being disposed as an arc surface arched towards the second reflecting structure (32), and an anti-reflection layer (33) disposed on the sidewall of the first reflecting structure (31) towards the second reflecting structure (32); the second reflecting structure (32) comprising a plurality of trapezoidal units (34), the first reflecting structure (31) and the second reflecting structure (32) being oppositely disposed, forming an air gap between the first reflecting structure (31) and the second reflecting structure (32) to constitute a total reflection interface.

2. The waveguide curvature and microstructure synergized floating real image generating device according to claim 1, characterized in that, The plurality of trapezoidal units (34) are disposed in a rectangular array on the anti-reflection layer (33) to form a trapezoidal microstructure array, and the width ratio of the upper base to the lower base of the trapezoidal units (34) is 1:1.6 along the light-out direction.

3. The waveguide curvature and microstructure synergized floating real image generating device according to claim 2, characterized in that, The inclination angle of the slope of the trapezoidal microstructure array is gradient-distributed along the light transmission direction, ranging from 45° to 65°, for regulating the outgoing light beam to form a divergence angle of about 15° to 25°, and spatially intersecting at a distance of 250mm to 500mm in front to form a suspended real image that can be observed.

4. The waveguide curvature and microstructure synergized floating real image generating device according to claim 1, characterized in that, The spacing between adjacent trapezoidal units (34) is between 0.1mm and 0.25mm.

5. The waveguide curvature and microstructure synergized floating real image generating device according to claim 1, characterized in that, The anti-reflection layer (33) has a plurality of nano-pores, the nano-pores are hexagonal, a plurality of the nano-pores form a hexagonal nano-pore array structure, and the depth of the nano-pores is designed as one-fourth of the working wavelength.

6. The waveguide curvature and microstructure synergized floating real image generating device according to claim 1, characterized in that, The upper surface of the anti-reflection layer (33) is a smooth surface, and the depth of the anti-reflection layer (33) is 100nm to 125nm.

7. The waveguide curvature and microstructure synergized floating real image generating device according to claim 1, characterized in that, The spacing between the first reflecting structure (31) and the second reflecting structure (32) close to the side of the collimating optical system (2) is H1, the minimum distance between the first reflecting structure (31) and the second reflecting structure (32) is H2, the spacing between the first reflecting structure (31) and the second reflecting structure (32) close to the side of the collimating optical system (2) is H3, and H2<H1<H3.

8. The waveguide curvature and microstructure synergized floating real image generating device according to claim 1, characterized in that, Along the light-out direction, the distance between the starting point of the trapezoidal microstructure array close to the side of the collimating optical system (2) and the end point of the arc reflecting surface close to the side of the collimating optical system (2) is D, the length of the arc reflecting surface is L, and D>30%L.

9. The waveguide curvature and microstructure synergized floating real image generating device according to claim 1, characterized in that, The radius of curvature of the arc surface of the first reflecting structure (31) ranges from 80mm to 150mm.

10. The waveguide curvature and microstructure synergized floating real image generating device according to claim 1, characterized in that, The material of the first reflecting structure (31) is K9 glass or PMMA.

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