CN115343855A - Augmented reality display device and display apparatus - Google Patents

Abstract

The utility model provides an augmented reality display device and display device belongs to and shows technical field. The augmented reality display device comprises a waveguide, a superlens and a focusing regulation layer; the super lens is arranged on one side of the waveguide and is provided with a plurality of microstructures; the focusing regulation and control layer is provided with regulation and control structures which correspond to the microstructures one by one; the focus regulation and control layer is used for regulating the focus position of the super lens. The augmented reality display device does not need to adopt an optical lens as an eyepiece, and the limitation of optical transparency to the display device is overcome.

Description

Augmented reality display device and display apparatus

Technical Field

The disclosure relates to the technical field of display, in particular to an augmented reality display device and a display device.

Background

The eyepiece of VR (virtual display)/AR (enhanced display) is an optical lens, which has the characteristics of large volume, heavy weight and compromise of optical capability, and this restricts the development and application of VR/AR technology to a certain extent.

It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the present disclosure, and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

It is an object of the present disclosure to overcome the above-mentioned deficiencies of the prior art and to provide an augmented reality display device and a display apparatus without using an optical lens as an eyepiece.

According to an aspect of the present disclosure, there is provided an augmented reality display device including:

a waveguide;

the super lens is arranged on one side of the waveguide and is provided with a plurality of microstructures;

the focusing regulation layer is provided with regulation structures which correspond to the microstructures one by one; the focus regulation and control layer is used for regulating the focus position of the super lens.

According to one embodiment of the present disclosure, the focus control layer includes a liquid crystal layer and a driving layer, and the microstructures are immersed between liquid crystals of the liquid crystal layer;

the driving layer comprises a regulating circuit and regulating electrodes which are in one-to-one correspondence with the microstructures, and the regulating electrodes are used for regulating the orientation of the liquid crystal around the corresponding microstructures under the driving of the regulating circuit so as to regulate the focusing position of the superlens.

According to an embodiment of the present disclosure, the augmented reality display device further comprises a common electrode layer; the waveguide is arranged on the surface of the common electrode layer, and the super lens is arranged on the surface of the waveguide far away from the common electrode layer; the driving layer is arranged on one side, far away from the common electrode layer, of the liquid crystal layer.

According to one embodiment of the disclosure, the focus regulation layer comprises a liquid crystal layer and a driving layer, and the liquid crystal layer is arranged on one side of the waveguide far away from the superlens;

the liquid crystal layer is provided with regulating units which correspond to the microstructures one to one, the orthographic projection of the microstructures on the liquid crystal layer is positioned in the regulating units, and the regulating units are in contact with the surface of the waveguide;

the driving layer comprises a regulating circuit and regulating electrodes which correspond to the microstructures one by one, and the regulating electrodes corresponding to the microstructures are used for regulating the orientation of liquid crystals of the regulating units corresponding to the microstructures under the driving of the regulating circuit so as to regulate the focusing position of the superlens.

According to one embodiment of the present disclosure, the driving layer is disposed on a side of the waveguide away from the superlens;

the augmented reality display device further comprises a common electrode layer; the public electrode layer is arranged on one side, far away from the super lens, of the driving layer, and the liquid crystal layer is clamped between the driving layer and the public electrode layer.

According to one embodiment of the present disclosure, the focus modulation layer includes a two-dimensional material layer located between the waveguide and the superlens, the two-dimensional material layer having a two-dimensional material structure in one-to-one correspondence with each of the microstructures; the two-dimensional material structure has different refractive indexes under different carrier concentrations;

the microstructures are positioned on one side, far away from the waveguide, of the corresponding two-dimensional material structure; the focus control layer further comprises a control circuit for modulating a carrier concentration of the two-dimensional material structure.

According to one embodiment of the present disclosure, the two-dimensional material structures are interconnected to form a full-surface two-dimensional material layer.

According to an embodiment of the present disclosure, the material of the two-dimensional material structure is graphene or graphene oxide.

According to one embodiment of the present disclosure, the material of the microstructure is silicon nitride, titanium oxide, gallium nitride, or silicon.

According to one embodiment of the present disclosure, the material of the microstructure is a thermal phase change material;

the focusing regulation and control layer is provided with heaters which correspond to the microstructures one by one and a regulation and control circuit for driving the heaters;

the heater is used for adjusting the temperature of the microstructure under the control of the regulating and controlling circuit so as to adjust the focusing position of the super lens.

According to one embodiment of the present disclosure, the heater is transparent conductive sheets, and the transparent conductive sheets are connected to each other to form a transparent conductive layer;

the transparent conducting layer is located on the surface of the waveguide, and the microstructures are located on the surface, far away from the waveguide, of the transparent conducting layer.

According to another aspect of the present disclosure, there is provided a display apparatus including the above-described augmented reality display device.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure. It is to be understood that the drawings in the following description are merely exemplary of the disclosure, and that other drawings may be derived from those drawings by one of ordinary skill in the art without the exercise of inventive faculty.

Fig. 1 is a schematic structural diagram of an augmented reality display device according to an embodiment of the present disclosure.

Fig. 2 is a schematic structural diagram of an augmented reality display device according to an embodiment of the present disclosure.

Fig. 3 is a schematic structural diagram of a model device according to an embodiment of the present disclosure.

Fig. 4-1 is a graph of the light distribution at the coupling into the waveguide for the model device of fig. 3.

Fig. 4-2 shows the light distribution of light in the waveguide transmission region of the model device of fig. 3.

Fig. 4-3 are graphs showing the distribution of light at the out-coupling region in the model device of fig. 3.

Fig. 5 is a schematic diagram of wave vectors and outgoing ray angles at any one microstructure.

Fig. 6 is a schematic structural diagram of a model device according to an embodiment of the present disclosure.

FIG. 7-1 is a light distribution diagram of the blue light out-coupled and focused by the superlens;

fig. 7-2 illustrates the emission of blue light at a microstructure.

FIG. 8-1 is a light distribution diagram of green light out-coupled and focused by a superlens;

fig. 8-2 illustrates the emergence of green light rays at a microstructure.

FIG. 9-1 is a light distribution diagram of the superlens for coupling out and focusing red light;

fig. 9-2 illustrates the emission of red light at a microstructure.

FIG. 10 is a schematic diagram of a model device according to an embodiment of the present disclosure.

FIGS. 11-1 through 11-3 are graphs of light distribution for a superlens focusing light for three different refractive indices of the liquid crystal layer in the model device of FIG. 10.

Fig. 12-1 is a schematic diagram of the movement of the focus position of the superlens up and down along the center normal in the model device of fig. 10.

Fig. 12-2 is a view in which the focus position of the superlens can be moved only to the left of the center normal in the model device of fig. 10.

Fig. 12-3 are views of the model device of fig. 10 in which the focus position of the superlens can only be moved to the right of the center normal.

Fig. 13 is a schematic structural diagram of a model device according to an embodiment of the present disclosure.

FIGS. 14-1-14-3 are graphs of light distribution for a superlens focusing light for three different refractive indices of the liquid crystal layer in the model device of FIG. 13.

Fig. 15 is a schematic partial structure diagram of an augmented reality display device according to an embodiment of the present disclosure.

Fig. 16-1 to 16-5 are light distribution diagrams of the augmented reality display device of fig. 15 under modulation of the focus adjustment layer to change the focus position.

Fig. 17-1 and 17-2 are schematic diagrams illustrating the augmented reality display device of fig. 15 changing a focus position at different times.

Fig. 18 is a schematic partial structure diagram of an augmented reality display device according to an embodiment of the present disclosure.

Fig. 19 is a schematic partial structure diagram of an augmented reality display device according to an embodiment of the present disclosure.

Fig. 20 is a schematic partial structure diagram of an augmented reality display device according to an embodiment of the present disclosure.

Fig. 21-1 to 21-5 are light distribution diagrams of the augmented reality display device of fig. 20 under modulation of the focus adjustment layer to change the focus position.

Fig. 22 is a schematic partial structure diagram of an augmented reality display device according to an embodiment of the present disclosure.

Fig. 23 is a schematic partial structure diagram of an augmented reality display device according to an embodiment of the present disclosure.

Fig. 24 is a schematic partial structure diagram of an augmented reality display device according to an embodiment of the present disclosure.

Fig. 25 is a schematic diagram of an augmented reality display device according to an embodiment of the present disclosure.

Fig. 26 is a schematic partial structure diagram of an augmented reality display device according to an embodiment of the present disclosure.

Fig. 27 is a schematic partial structure diagram of an augmented reality display device according to an embodiment of the present disclosure.

Fig. 28 is a schematic diagram of an augmented reality display device according to an embodiment of the present disclosure.

Fig. 29 is a schematic partial structure diagram of an augmented reality display device according to an embodiment of the present disclosure.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted. Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

Although relative terms, such as "upper" and "lower," may be used in this specification to describe one element of an icon relative to another, these terms are used in this specification for convenience only, e.g., in accordance with the orientation of the examples described in the figures. It will be appreciated that if the device of the icon were turned upside down, the element described as "upper" would become the element "lower". When a structure is "on" another structure, it may mean that the structure is integrally formed with the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via another structure.

The terms "a," "an," "the," "said," and "at least one" are used to indicate the presence of one or more elements/components/parts/etc.; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements/components/etc. other than the listed elements/components/etc.; the terms "first," "second," and "third," etc. are used merely as labels, and are not limiting as to the number of their objects.

The structural layer a is located on a side of the structural layer B facing away from the substrate, and it is understood that the structural layer a is formed on a side of the structural layer B facing away from the substrate. When the structural layer B is a patterned structure, part of the structure of the structural layer a may also be located at the same physical height of the structural layer B or lower than the physical height of the structural layer B, wherein the waveguide is a height reference.

The embodiment of the disclosure provides an augmented reality display device. Referring to fig. 1 and 2, the augmented reality display device includes a waveguide WG, a superlens MLENS, and a focus modulation layer CTR. The super LENS MLENS is arranged on one side of the waveguide WG and is provided with a plurality of microstructures LENS; a focusing control layer CTR having control structures corresponding to the microstructures LENS one to one; the focus control layer CTR is for adjusting a focus position of the superlens MLENS.

In the embodiment of the disclosure, the augmented reality display device uses the superlens MLENS to focus light, rather than using an optical lens, and thus has the advantages of small thickness and light weight, thereby weakening or eliminating the restriction of the current eyepiece on the AR/VR technology. In the embodiment of the disclosure, by setting the focus control layer CTR, the focus position of the superlens MLENS can be adjusted, for example, the focus position of the superlens MLENS is dynamically adjusted according to a target picture, so that a dynamic picture is displayed outside an augmented reality display device, that is, an in-air dynamic display of AR/VR is realized, and user experience is improved.

The principles, structure and effects of the augmented reality display device according to the embodiments of the present disclosure will be further explained and illustrated below with reference to the drawings and some model devices.

FIG. 3 illustrates a model device having a waveguide and a superlens to illustrate the principle of light focusing using the waveguide and the superlens according to the model device; it is to be understood that the model device is a simplification of the display device of the embodiments of the present disclosure, and thus the general principles and laws reflected therein are consistent with those of the display device of the embodiments of the present disclosure. Referring to fig. 3, in this model device, a waveguide WG includes a waveguide transmission region AA and a coupling-out light region BB. Wherein, the light is coupled into the waveguide from the end of the waveguide transmission area AA and transmitted to the coupling-out light area BB in the waveguide transmission area AA; and a super lens MLENS is arranged on one side of the light coupling-out area BB, so that the local phase of the light coupling-out area BB is changed, light is coupled and emitted, the light is finally focused, and aerial display is realized. Similarly, in the display device of the present disclosure, a waveguide and a superlens are provided; likewise, the waveguide may have a waveguide transmission region AA and an out-coupling light region BB. The display device according to the embodiment of the disclosure mainly modulates the coupling-out light area BB, and specifically modulates the light-out angle at the microstructure in the coupling-out light area BB through the focus control layer CTR.

Referring to fig. 3, when light is coupled into the waveguide WG, the light will be transmitted along the waveguide WG. The transmission constants in the waveguide WG are different for different wavelengths of light; at the position of the superlens MLENS, because each microstructure LENS introduces extra phase, the phase of light scattered out of the microstructure LENS at each corresponding position can be calculated as

Where β is the transmission constant of the waveguide WG and d is the length of the waveguide transmission region AA of the waveguide WG; np is the distance between the nth microstructure LENS and the waveguide transmission area AA;

the phase variation additionally caused for the corresponding nth microstructure LENS. Since the light rays with different wavelengths have different transmission constants in the waveguide WG, it can be seen from the above formula that the light rays with three colors of R (red), G (green), and B (blue) can be focused at different positions without any control in the light coupling-out region BB, and a static color image display can be realized.

Fig. 4-1 shows the distribution of light at the coupling into the waveguide WG in the model device of fig. 3. Fig. 4-2 shows the light distribution of light in the waveguide transmission area AA in the model device of fig. 3. Fig. 4-3 show the light distribution of the model device of fig. 3 at the light-out-coupling region BB. As can be seen from fig. 4-1 to 4-3, light can be coupled into the waveguide WG and transmitted with low loss in the waveguide transmission region AA of the waveguide WG; in the coupling-out light region BB, the light rays can exit through the superlens MLENS and be focused.

In one embodiment of the present disclosure, light may be coupled into the waveguide WG by an optical fiber.

The analysis continues with the model device illustrated in fig. 3 as an example. The light reaches the coupling-out light region BB provided with the superlens MLENS in the waveguide transmission region AA. The waveguide WG is used for transmitting light, so that electromagnetic waves of the light can be localized in the waveguide transmission area AA, and the emergence of the electromagnetic waves is avoided (i.e., light leakage is minimized or avoided). At any position of the waveguide transmission area AA, the wave vector is k = n _eff *k ₀ . Wherein n is _eff Is the equivalent refractive index of the waveguide WG with respect to an adjacent medium (e.g., air of the external space), which is greater than 1.k is a radical of ₀ Is the wave vector in a medium (e.g. air) outside the waveguide WG. Thereby, transmitting in the waveguide WGRegion, wave vector k in waveguide WG is larger than wave vector k in external medium ₀ This allows the electromagnetic wave of the light to be transmitted in the waveguide WG without being emitted.

In the coupling-out light region BB, the superlens MLENS performs light coupling-out and focusing by adjusting the phase at each microstructure LENS. At the microstructure LENS of the superlens MLENS, the microstructure LENS performs phase modulation to generate an additional phase; this in turn introduces wave vector changes where

For phase shift, x is the light transmission direction. At the microstructure LENS, the wave vector guided in the waveguide WG decreases, the direction of the phase gradient changing opposite to the propagation direction, i.e. k = k _g - Δ k. k is a wave vector at the position of the microstructure LENS and is a wave vector modulated by the microstructure LENS; k is a radical of formula _g Is the unmodulated wave vector at the microstructure LENS. At the microstructure LENS, light needs to be emitted by coupling, so that k needs to be ensured ₀ Greater than k. Therefore, the equivalent refractive index at the microstructure LENS needs to be less than 1 to ensure that light exits from the microstructure LENS. Fig. 5 is a schematic diagram of wave vectors and emergent ray angles at any microstructure LENS. In the example of fig. 5, the exit angle (compared to the direction of travel of the light in the waveguide WG) θ of the exiting light ray satisfies the following condition: con theta = k/k ₀ . Therefore, by adjusting the phase change at the microstructure LENS, the wave vector at the microstructure LENS can be changed, and the emergent angle of the emergent light of the microstructure LENS can be further changed.

In one example, referring to fig. 3, the waveguide WG may be provided on a substrate, such as a silicon substrate. Further, the material of the waveguide WG may be selected from, but not limited to, silicon oxide and the like.

Fig. 6 presents an optimized model device to further explain and illustrate the principles and effects of the augmented reality display device of the disclosed embodiments. The optimized model device is a model device closer to the principle and effect of the display device of the embodiment of the present disclosure, and therefore the principle and general rule reflected by the optimized model device are also applicable to the display device of the embodiment of the present disclosure.

In the model device shown in fig. 6, a driver LB may be used to control an RGB three-color laser LA, synthesize three-color light into one channel through a mirror LC, couple the three-color light into an optical fiber LD, couple the three-color light into a waveguide WG through the optical fiber, and transmit the light into a superlens MLENS to realize coupled focusing output of the light. As can be seen from fig. 6, the same microstructure has a certain deviation to the coupling-out angles of the three RGB colors, which results in the phase distribution difference due to the different transmission constants β of the three different RGB colors. Such deviation of the output angle is advantageous for color mixing in space and color display. Therefore, in the embodiment of the augmented reality display device of the present disclosure, the colored light may also be coupled into the waveguide, so that the augmented reality display device realizes color display. For example, light of a plurality of different colors may be coupled into the waveguide WG at the same time, or primary colors of different colors (e.g., red, green, and blue) may be coupled into the waveguide WG sequentially at different timings.

As follows, the angle of the outgoing light ray when the superlens MLENS couples out the light ray is exemplarily explained.

Since the equivalent refractive indexes of the light rays of the three colors of RGB are different in the waveguide WG, the transmission constants of the three light rays in the waveguide WG are different, and the wave vectors of the three light rays at the same position are different. The wave vector difference of the light rays of the three colors at the same position enables the emergent angles of different light rays on the same microstructure LENS to be different.

FIG. 7-1 is a light distribution diagram of the blue light out-coupled and focused by the superlens MLENS; fig. 7-2 illustrates the exit of blue light at a microstructure LENS. In fig. 7-2, θ is the exit angle of the blue light, i.e. the angle between the exit light and the direction of propagation of the blue light within the waveguide WG; k is a radical of _b Is the wave vector, k, of blue light modulated by microstructure LENS _gb Is blue lightThe line is not a wave vector modulated by the microstructure LENS,

the wave vector change caused by the phase modulation of blue light by the microstructure LENS. k is a radical of _b0 Is the wave vector of blue light in air. The exit angle theta of the blue light at the microstructure LENS satisfies the following formula: con θ = k _b /k _b0 . The exit angles of the light rays at different microstructures LENS can be different, so that the emitted blue light rays are focused.

FIG. 8-1 is a light distribution diagram of the green light out-coupled and focused by the superlens MLENS; fig. 8-2 illustrates a schematic diagram of the emergence of green light rays at a microstructure LENS. In the case of the embodiment shown in figure 8-2,

the emergent angle of the green light ray is the included angle between the emergent light ray and the transmission direction of the green light ray in the waveguide WG; k is a radical of _g Is the wave vector, k, of green light after modulation by microstructure LENS _gg Is a wave vector of green light without microstructure LENS modulation,

the wave vector change caused by the phase modulation of green light by the microstructure LENS. k is a radical of _g0 Is the wave vector of the green light in the air. The emergent angle of the green light at the microstructure LENS

The following formula is satisfied:

the emergent angles of the light rays at different microstructures LENS can be different, so that the emergent green light rays are focused.

FIG. 9-1 is a light distribution diagram of the coupling-out and focusing of red light by the superlens MLENS; fig. 9-2 illustrates the exit of red light at a microstructure LENS. In FIG. 9-2, γ is the exit angle of the red lightI.e. the angle between the transmission directions of the outgoing light and the red light in the waveguide WG; k is a radical of _r Is the wave vector, k, of red light modulated by microstructure LENS _gr Is a wave vector of red light not modulated by the microstructure LENS,

the wave vector change due to the phase modulation of red light by the microstructure LENS. k is a radical of _r0 Is the wave vector of the red light in the air. The exit angle γ of the red light at the microstructure LENS satisfies the following formula: con gamma = k _r /k _r0 . The outgoing angles of the light rays at different microstructures LENS can be different, so that the outgoing red light rays are focused.

The principle of the exit angles of the three different colors is exemplified by taking the forward angle as an example as the exit angle schematic diagrams in fig. 7-2, fig. 8-2 and fig. 9-2. It will be appreciated that the above principle example applies not only to forward angles, but also to other angles, such as perpendicular or reverse angles. The same light has different emergent angles at different microstructures LENS, and can be focused at a focusing position. Comparing the focusing positions in fig. 7-1, 8-1 and 9-1, it can be seen that the focusing positions of the same superlens for different color light rays are different.

In the augmented reality display device of the embodiment of the present disclosure, differences in transmission constants, wave vectors, phase gradient variation amounts, and the like caused by three different colors and dispersion effects can be comprehensively considered, thereby realizing angle outgoing with slight differences in three colors through reasonable tuning, and thus realizing three-color mixing of free space to ensure color display of space.

Fig. 10 and 13 illustrate further model devices, respectively, to further approach in effect and means to the display device of the embodiments of the present disclosure, and to further explain and explain the structure, principle, and effect of the display device of the embodiments of the present disclosure.

Fig. 10 illustrates a schematic structural view of a focus position adjustable model device. The model device comprises a first common electrode layer COMA, a waveguide WG, a superlens MLENS, a liquid crystal layer LCL and a second common electrode layer COMB arranged in a stack. Wherein the individual microstructures LENS of the superlens MLENS are immersed in the liquid crystal layer LCL. The first common electrode layer COMA and the second common electrode layer COMB are all full-face electrodes, different voltages are loaded between the first common electrode layer COMA and the second common electrode layer COMB, the orientation of liquid crystals in the liquid crystal layer LCL can be changed, and then the refractive index of the liquid crystal layer LCL is changed. In other words, in the model device, the entire liquid crystal layer LCL can be controlled synchronously by the entire surface electrodes; the liquid crystal layer LCL now corresponds to a layer of a medium with a variable refractive index, and the change in refractive index remains synchronized at each location. It will be appreciated that an alignment layer may also be provided on the side adjacent to the liquid crystal layer LCL in order to preset the alignment of the liquid crystals.

Fig. 11-1 to 11-3 show the change of the focus position by changing the refractive index of the liquid crystal layer LCL. Referring to fig. 11-1 to 11-3, it can be seen that the focus position is changed by changing the refractive index of the liquid crystal layer LCL as a whole, but the focus position is not changed at will but is subject to a certain constraint. Specifically, in the examples of fig. 11-1 to 11-3, the distance between the focus position and the superlens MLENS changes, but the focus position is always located above the center position of the superlens MLENS. In other words, when the focus position is located at the center normal line of the superlens MLENS (the normal line passing through the center of the superlens MLENS and perpendicular to the waveguide WG), the focus position is moved up and down (the direction closer to or farther from the superlens MLENS) along the center normal line by changing the refractive index of the liquid crystal layer LCL as a whole, but the focus position is not deviated from the center normal line of the superlens MLENS.

Fig. 12-1 illustrates a schematic diagram in which the focus position FA changes with an overall change in refractive index of the liquid crystal layer LCL when the focus position FA is located on the center normal line LM of the superlens MLENS. When the liquid crystal layer LCL is integrally regulated and controlled, the refractive indexes of all the positions of the liquid crystal layer LCL are simultaneously changed, so that the wave vectors at all the microstructures LENS are synchronously changed, the positive and negative directions of the wave vectors at all the positions cannot be changed, the focusing position is still on the central normal line FM of the super LENS MLENS, and the focusing position FA moves up and down along the central normal line LM. This makes it possible to move the image up and down in a direction perpendicular to the superlens MLENS by changing the refractive index of the liquid crystal layer LCL as a whole.

Fig. 12-2 illustrates a schematic diagram in which the focal position FA changes with the overall change in refractive index of the liquid crystal layer LCL when the focal position FA is located on the left side of the center normal line LM (the side close to the waveguide transmission area AA) of the superlens MLENS. When the liquid crystal layer LCL is integrally regulated, the refractive indexes of the liquid crystal layer LCL at the respective positions are simultaneously changed, so that the wave vectors at the respective microstructures LENS are synchronously changed, and the positive and negative directions of the wave vectors at the respective positions are not changed, so that the focusing position is still on the left side of the center normal FM, but the focusing position can be changed. In this case, the focus position FM cannot reach the right side of the center normal FM across the center normal FM, which enables the model device to image only on the left side of the center normal FM.

Fig. 12-3 illustrate a schematic diagram in which the focal position FA changes with the overall change in refractive index of the liquid crystal layer LCL when the focal position FA is located on the right side of the center normal line LM of the superlens MLENS (the side away from the waveguide transmission area AA). In the example of fig. 12-3, when the liquid crystal layer LCL is integrally modulated, the refractive index of the liquid crystal layer LCL at each position changes simultaneously, and therefore the wave vector at each microstructure LENS changes synchronously, which causes the positive and negative directions of the wave vector at each position not to be changed, and therefore the focus position remains on the right side of the center normal FM, but the focus position may change. In this case, the focus position FM cannot reach the left side of the center normal FM across the center normal FM, which makes the model device capable of imaging only on the right side of the center normal FM.

Fig. 13 illustrates another focus position adjustable model device. The model device comprises a second common electrode layer COMB, a liquid crystal layer LCL, a first common electrode layer COMA, a waveguide WG and a microstructure LENS which are sequentially stacked. Therefore, the second common electrode layer COMB and the first common electrode layer COMA are all full-surface electrodes and are used for integrally changing the refractive index of the liquid crystal layer LCL, further changing the phase of the waveguide WG position corresponding to the microstructure LENS, and further achieving adjustment of the emergent angle of the emergent light at the microstructure LENS. The exemplary modeled device of FIG. 13 has a focal position on the central normal of the superlens MLENS. Fig. 14-1 to 14-3 illustrate the change of the focus position by synchronously changing the refractive index at each position of the liquid crystal layer LCL. As can be seen from fig. 14-1 to 14-3, in the model device of this example, the focus position can be operated up and down along the center normal line as the refractive index of the liquid crystal layer LCL changes as a whole.

It will be appreciated that in the model device illustrated in fig. 13, when the aggregate position of the model device is to the left or right of the center normal, the model device can only image to the left or right of the center normal, and cannot image across the center normal.

As described above, the focus position can be changed by changing the refractive index of the liquid crystal layer LCL as a whole whether the liquid crystal layer LCL is positioned above (on the side close to the superlens MLENS) or below (on the side far from the superlens MLENS) the waveguide, but the range of changing the focus position is limited, and free change in the display plane cannot be achieved.

In an embodiment of the present disclosure, referring to fig. 1 and 2, the augmented reality display device may be provided with a focus modulation layer CTR having a modulation structure in one-to-one correspondence with the microstructures LENS. The regulating structures are respectively and independently controlled to modulate the refractive index of the corresponding microstructure LENS or the refractive index of the surrounding structure of the microstructure LENS, so that the phase gradient change at each microstructure LENS can be freely modulated, the wave vector at the microstructure LENS can be further adjusted (the size and the direction of the wave vector can be changed), and the emergent ray angle at the microstructure LENS can be adjusted. Thus, the aim of freely adjusting the focusing position in the display plane can be achieved by matching with a preset modulation algorithm.

Thus, the augmented reality display device provided by the present disclosure can enable the focus position to realize modulation in the display space. In particular, the phase change at each microstructure LENS can be determined according to the desired focus position; the focus control layer CTR enables modulation of the phase change at each microstructure LENS, thereby bringing the focus position of the superlens MLENS to the desired focus position. In this way, by bringing the focus position to different desired focus positions at different times, it is possible to realize an in-air display (floating display) other than the superlens MLENS, for example, an in-air VR display or an in-air AR display, by virtue of the persistence of vision effect. In other words, the augmented reality display device of the present disclosure can realize free change of the focus position in a free space (two-dimensional display space), and further can display a moving image and even display video content.

Furthermore, in the related art, the optical coupling of the waveguide WG is based on a general grating design, and the angle of the display screen in the free space is limited, and the degree of freedom of design is low. In the embodiment of the disclosure, different superlenses MLENS can be designed as required, and further, an image can be emitted at any angle in the whole space, which greatly improves the degree of freedom of the waveguide WG optical coupling output technology design and expands the picture angle. In addition, the focusing control layer CTR of the augmented reality display device can also realize independent modulation on phase change of each microstructure, and can compensate design deviation of the super lens MLENS, so that the design freedom of the super lens MLENS is greatly improved, a process window is improved, the design and manufacturing difficulty is reduced, and the cost can be reduced.

In the augmented reality display device of the present disclosure, the focus control layer CTR may adopt different means such as modulating a refractive index of a medium around the microstructure LENS, modulating an equivalent refractive index of the waveguide WG at the microstructure LENS, or modulating a refractive index of the microstructure LENS itself, to implement modulation of a phase change at each microstructure LENS, thereby implementing modulation of a focus position.

In one embodiment of the present disclosure, the material of the waveguide WG may be an inorganic material, and may be, for example, silicon oxide. Illustratively, the waveguide WG is a quartz waveguide WG.

In some embodiments of the present disclosure, referring to fig. 15, 18 and 19, the focus control layer CTR includes a liquid crystal layer LCL and a driving layer, and the microstructures LENS are immersed between liquid crystals of the liquid crystal layer LCL; the driving layer comprises a regulating circuit and regulating electrodes PIX which are in one-to-one correspondence with the microstructures LENS, and the regulating electrodes PIX are used for regulating the orientation of liquid crystals around the corresponding microstructures LENS under the driving of the regulating circuit so as to regulate the focusing position of the superlens MLENS.

Therefore, when the regulating circuit loads an expected modulating voltage to the regulating electrode PIX, the regulating electrode PIX can control the orientation of the liquid crystal around the corresponding microstructure LENS, so as to control the refractive index of the liquid crystal around the microstructure LENS, further control the phase change amount at the microstructure LENS, and realize the modulation of the light outgoing direction at the microstructure LENS. The adjusting and controlling circuit can change the focusing position of the super LENS MLENS through modulating the light emitting direction of each microstructure LENS.

In one example, the driving layer may be a transparent film layer or a partially transparent film layer to facilitate the transmission of light emitted from the microstructures LENS. Illustratively, the tuning electrode PIX on the driving layer may be a transparent electrode or a grid electrode, for example, a transparent metal oxide electrode such as ITO or a magnesium-silver alloy electrode.

Optionally, the augmented reality display device further needs to be provided with a common electrode layer COM corresponding to the control electrode PIX, so as to form a control electric field between the control electrode PIX and the common electrode layer COM, so that the orientation of the liquid crystal is changed under the control of the control electric field, and the modulation of the orientation of the liquid crystal is realized.

Alternatively, the augmented reality display device may be further provided with an alignment layer in contact with the liquid crystal layer LCL, for example, an alignment layer is provided on a surface of the driving layer close to the liquid crystal layer LCL and/or on a surface of the waveguide WG to preset an alignment angle of the liquid crystal.

The common electrode layer COM and the control electrode PIX may be disposed on two sides of the liquid crystal layer LCL, respectively, so as to load voltages on the common electrode layer COM and the control electrode PIX, respectively, and control the orientation of the liquid crystal by using an electric field between the common electrode layer COM and the control electrode PIX, thereby changing the refractive index of the liquid crystal. Certainly, the common electrode layer COM and the control electrode PIX may also be disposed on the same side of the liquid crystal layer LCL, an edge electric field may be formed between the control electrode PIX and the common electrode layer COM, and the orientation of the liquid crystal is adjusted under the control of the edge electric field.

The common electrode layer COM and the modulator electrode PIX may be disposed on the same side of the waveguide WG, for example, both disposed on a side of the waveguide WG close to the superlens MLENS; of course, the common electrode layer COM and the control electrode PIX may be disposed on both sides of the waveguide WG.

In one embodiment of the present disclosure, referring to fig. 15, the augmented reality display device further includes a common electrode layer COM; the waveguide WG is arranged on the surface of the common electrode layer COM, and the super lens MLENS is arranged on the surface, far away from the surface of the common electrode layer COM, of the waveguide WG; the driving layer is arranged on one side, far away from the common electrode layer COM, of the liquid crystal layer LCL. Thus, the common electrode layer COM and the control electrode PIX are disposed on both sides of the waveguide WG, respectively.

In one example, the augmented reality display device may further include a first substrate BPA provided on a side of the driving layer away from the liquid crystal layer LCL for supporting and protecting the driving layer.

In one example, the augmented reality display device further includes a second substrate BPB, which may be disposed on a side of the common electrode layer COM away from the waveguide WG, for protecting and supporting the common electrode layer COM.

Fig. 16-1 to 16-5 are partial pictures when the light emitting direction at each microstructure LENS is changed by the focus control layer CTR to change the focus position. As can be seen from fig. 16-1 to 16-5, the augmented reality display device of the present disclosure can make the focal position move arbitrarily in the height direction (the direction of the central normal of the superlens) and the longitudinal direction (the light transmission direction), and further make it possible to perform imaging at an arbitrary position in the plane where the height direction and the longitudinal direction are located. Thus, by making the focus positions different at different times, the augmented reality display device can be made to display a dynamic picture, for example, a video picture; by coupling light of different colors to the waveguide WG at different timings, a picture displayed by the augmented reality display device can be a color picture.

Fig. 17-1 and 17-2 illustrate a schematic view of the augmented reality display device changing a focus position at different times. Referring to fig. 17-1, at some point in time, the wave vector at a portion of the microstructures LENS can be made positive and the wave vector at a portion of the microstructures LENS can be made negative by modulating the phase change at each microstructure LENS. In the example of fig. 17-2, compared to fig. 17-1, at some other time instant, the wave vector at part of the microstructures LENS can be made positive, the wave vector at part of the microstructures LENS is zero, and the wave vector at part of the microstructures LENS is negative by modulating the phase change at each microstructure LENS; at the microstructure LENS where the wave vector remains positive, the value of the wave vector itself will also change; at the microstructure LENS, where the wave vector remains negative, the value of the wave vector itself will also change. In other words, between the two moments illustrated in fig. 17-1 and fig. 17-2, the same augmented reality display device can change the focus position by changing the phase change at different microstructures LENS, and thus independently changing the wave vector at some microstructures LENS from positive to negative or from negative to positive, or changing the value of the wave vector at the microstructures LENS where the wave vector is not positive or negative. This ability to change the sign of the wave vector itself at the microstructure LENS enables the augmented reality display device to be imaged across the central normal.

In another embodiment of the present disclosure, the common electrode layer COM and the driving layer may be disposed on the same substrate. Illustratively, referring to fig. 18, the focus modulation layer CTR may include a driving substrate and a liquid crystal layer LCL covering the superlens MLENS such that the microstructures LENS are immersed in the liquid crystal. The driving substrate is arranged on one side of the liquid crystal layer LCL far away from the waveguide WG, comprises a common electrode layer COM and also comprises a driving layer, and the driving layer is provided with regulating electrodes PIX which correspond to the microstructures LENS one to one and a regulating circuit for driving the regulating electrodes PIX. Illustratively, the drive substrate includes a first substrate BPA, a common electrode layer COM, an insulating layer PVX, and a drive layer, which are sequentially stacked, the drive layer being disposed on a side of the common electrode layer COM close to the liquid crystal layer LCL. In this way, in the coupling-out light region BB, the extended reality display device includes the waveguide WG, the super lens MLENS, the liquid crystal layer LCL, the driving layer, the insulating layer PVX, the common electrode layer COM, and the first substrate BPA, which are stacked in this order.

In another embodiment of the present disclosure, referring to fig. 19, a common electrode layer COM is disposed between the waveguide WG and the superlens MLENS in the out-coupling light region BB; that is, the common electrode layer COM is disposed on the surface of the waveguide WG, and the superlens MLENS is disposed on the surface of the common electrode layer COM away from the waveguide WG; the liquid crystal layer LCL covers the superlens MLENS. The augmented reality display device further comprises a first substrate BPA arranged on a side of the driving layer remote from the liquid crystal layer LCL to provide support and protection for the driving layer. In this way, in the coupling-out light region BB, the extended reality display device includes the waveguide WG, the common electrode layer COM, the super lens MLENS, the liquid crystal layer LCL, the driving layer, and the first substrate BPA, which are stacked in this order.

In still other embodiments of the present disclosure, referring to fig. 20, 22 and 23, the focus modulation layer CTR includes a liquid crystal layer LCL provided on a side of the waveguide WG away from the superlens MLENS and a driving layer. The liquid crystal layer LCL is provided with regulating units which correspond to the microstructures LENS in a one-to-one mode, the orthographic projection of the microstructures LENS on the liquid crystal layer LCL is located on the regulating units, and the regulating units are in contact with the surface of the waveguide WG. The driving layer comprises a regulating circuit and regulating electrodes PIX which are in one-to-one correspondence with the microstructures LENS, and the regulating electrodes PIX corresponding to the microstructures LENS are used for regulating the orientation of liquid crystals of the regulating units corresponding to the microstructures LENS under the driving of the regulating circuit so as to regulate the focusing position of the superlens MLENS.

Therefore, the adjusting and controlling electrode PIX can change the equivalent refractive index of the waveguide WG at the position corresponding to the microstructure LENS under the control of the adjusting and controlling circuit, and further adjust the phase change and the wave vector at the microstructure LENS.

Furthermore, the augmented reality display device further comprises a common electrode layer COM so as to be respectively loaded with a voltage with the control electrode PIX to control the orientation of the liquid crystal, and further control the refractive index of the liquid crystal. The common electrode layer COM and the control electrode PIX may be located on the same side of the liquid crystal layer LCL, or may be respectively disposed on both sides of the liquid crystal layer LCL.

In one embodiment of the present disclosure, referring to fig. 20, the driving layer is disposed on a side of the waveguide WG away from the superlens MLENS; the augmented reality display device further comprises a common electrode layer COM; the common electrode layer COM is disposed on a side of the driving layer away from the super lens MLENS, and the liquid crystal layer LCL is sandwiched between the driving layer and the common electrode layer COM.

The augmented reality display device further comprises a first substrate BPA, and the first substrate BPA is arranged on one side of the common electrode layer COM away from the liquid crystal layer LCL so as to provide support and protection for the liquid crystal layer LCL.

Fig. 21-1 to 21-5 illustrate the augmented reality display device shown in fig. 20, with pictures of the focus position thereof changed. As can be understood by comparing fig. 21-1 to 21-5, the augmented reality display device can focus at an arbitrary position in the display plane, and thus can display an image at an arbitrary position in the display plane. In this manner, by bringing the focus position of the augmented reality display device to a desired position at different times, dynamic display in the display plane can be realized by persistence of vision.

In another embodiment of the present disclosure, referring to fig. 22, the common electrode layer COM is located on a surface of the waveguide WG away from the superlens MLENS, the driving layer is located on a side of the common electrode layer COM away from the waveguide WG, and the liquid crystal layer LCL is located between the common electrode layer COM and the driving layer.

In one example, the augmented reality display device further comprises a first substrate BPA located on a side of the drive layer remote from the liquid crystal layer LCL to provide support and protection for the drive layer.

In another embodiment of the present disclosure, referring to fig. 23, the common electrode layer COM and the driving layer are both located on a side of the liquid crystal layer LCL away from the waveguide WG; an edge electric field can be formed between the regulating electrode PIX and the common electrode layer COM to regulate the orientation of the liquid crystal, so that the refractive index of the liquid crystal is regulated. In one example, the augmented reality display device is provided with a driving back plate, and the common electrode layer COM and the driving layer are both arranged on the driving back plate; the driving backboard comprises a first substrate BPA, a common electrode layer COM, an insulating layer PVX and a driving layer which are sequentially stacked, and the driving layer is arranged on one side, close to the liquid crystal layer LCL, of the common electrode layer COM. The liquid crystal layer LCL is sandwiched between the driving backplane and the waveguide WG.

In the above embodiment, the focus control layer CTR uses liquid crystal as a refractive index variable medium to adjust the light exit angle of each microstructure LENS. In other embodiments of the present disclosure, other mediums or materials capable of changing a refractive index may also be used to adjust the refractive index of the microstructure LENS, or change the refractive index of a structure or a medium adjacent to the microstructure LENS, so as to adjust a wave vector at the microstructure LENS, and adjust an outgoing angle at the microstructure LENS.

In one embodiment of the present disclosure, referring to fig. 24, the focus modulation layer CTR includes a two-dimensional material layer GPEL between the waveguide WG and the superlens MLENS, the two-dimensional material layer having a two-dimensional material structure GPE in one-to-one correspondence with each of the micro-structures LENS; the two-dimensional material structure GPE has different refractive indices at different carrier concentrations. The focusing regulation layer CTR also comprises a regulation circuit used for modulating the carrier concentration of the two-dimensional material structure GPE; the microstructures LENS are located on the side of the corresponding two-dimensional material structure GPE remote from the waveguide WG.

In one example, referring to fig. 26, the two-dimensional material structures GPE are interconnected to form a full-faced two-dimensional material layer; the microstructure LENS is arranged on the surface of the two-dimensional material layer far away from the waveguide WG; the regulating and controlling circuit can change the carrier concentration of the local position of the whole two-dimensional material layer.

Fig. 25 illustrates a principle schematic diagram of the embodiment for changing the focus position of the superlens MLENS. In this embodiment, the control circuit has an electrode structure ETA which is matched with the two-dimensional material structure GPE, and the control circuit can change the carrier concentration of the two-dimensional material structure GPE through the electrode structure ETA; for example, an insulating layer is disposed between the electrode structure ETA and the two-dimensional material structure GPE, and a bias voltage loaded on the electrode structure ETA can form a control electric field to change the carrier concentration on the two-dimensional material structure GPE. Through the pressurization or depressurization action of the electrode structure ETA, the carrier concentration on the two-dimensional material structure GPE is changed, the refractive index of a medium adjacent to the microstructure LENS is changed, and the light emitting direction at the microstructure LENS can be changed.

Alternatively, the material of the two-dimensional material layer may be graphene or modified graphene, and may be graphene oxide, for example.

In another embodiment of the present disclosure, referring to fig. 27, the material of the microstructure LENS is a thermal phase change material; at different temperatures, the microstructure LENS has different refractive indices. The focus control layer CTR is provided with heaters HT corresponding to the respective microstructures LENS one to one and a control circuit driving the respective heaters.

The heater HT is configured to adjust the temperature of the microstructure LENS under the control of the control circuit, so as to adjust the focusing position of the superlens MLENS. In this embodiment, the focus control layer CTR may control the temperature of the microstructure LENS by whether the heater HT heats the microstructure LENS, thereby controlling the phase transition of the microstructure LENS, and further controlling the refractive index of the microstructure LENS itself; in this way, the light emitting angle of the microstructure LENS can be controlled.

In one example, the heater HT is a transparent conductive sheet (e.g., a transparent metal oxide sheet) and the microstructure LENS is located on a side of the corresponding transparent conductive sheet away from the waveguide. As such, the focus regulation layer CTR includes a transparent conductive layer HTL that is located between the superlens and the waveguide and includes transparent conductive sheets (as heaters) corresponding to the respective microstructures one to one.

In one example, referring to fig. 29, the transparent conductive sheets are connected to each other to form a full-surface transparent conductive layer HTL; the transparent conductive layer HTL is positioned at a surface of the waveguide WG, and the microstructures LENS are positioned at a surface of the transparent conductive layer away from the waveguide WG.

Fig. 28 illustrates an implementation of this embodiment, and referring to fig. 28, the regulating circuit may be provided with electrodes ETB and ETA for driving the heater HT, thereby controlling whether the heater is in an electrical path state. When the heater is in an electrical path state, the heater HT heats up to cause the microstructure LENS to be heated; when the heater HT is in the electrode off state, the heater does not heat and the microstructure LENS is cooled.

Embodiments of the present disclosure also provide a display apparatus including any one of the augmented reality display devices described in the above embodiments of the augmented reality display device. The display device may be a vehicle window projection display device, a head-mounted virtual display device, an augmented reality display device, or other display device that is suspended for display. Since the display device has any one of the augmented reality display devices described in the embodiment of the augmented reality display device, the display device has the same beneficial effects, and details are not repeated in the disclosure.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims (12)

1. An augmented reality display device comprising:

a waveguide;

the super lens is arranged on one side of the waveguide and is provided with a plurality of microstructures;

the focusing regulation layer is provided with regulation structures which correspond to the microstructures one by one; the focus regulation layer is used for regulating the focus position of the super lens.

2. The augmented reality display device of claim 1, wherein the focus modulation layer comprises a liquid crystal layer and a driving layer, and the microstructures are immersed between liquid crystals of the liquid crystal layer;

the driving layer comprises a regulating circuit and regulating electrodes which are in one-to-one correspondence with the microstructures, and the regulating electrodes are used for regulating the orientation of the liquid crystal around the corresponding microstructures under the driving of the regulating circuit so as to regulate the focusing position of the superlens.

3. An augmented reality display device according to claim 2, wherein the augmented reality display device further comprises a common electrode layer; the waveguide is arranged on the surface of the common electrode layer, and the super lens is arranged on the surface of the waveguide far away from the common electrode layer; the driving layer is arranged on one side, far away from the common electrode layer, of the liquid crystal layer.

4. An augmented reality display device according to claim 1, wherein the focus modulating layer comprises a liquid crystal layer and a driving layer, the liquid crystal layer being provided on a side of the waveguide remote from the superlens;

the liquid crystal layer is provided with regulating units which correspond to the microstructures one by one, the orthographic projection of the microstructures on the liquid crystal layer is positioned in the regulating units, and the regulating units are in contact with the surface of the waveguide;

the driving layer comprises a regulating circuit and regulating electrodes which are in one-to-one correspondence with the microstructures, and the regulating electrodes corresponding to the microstructures are used for regulating the orientation of liquid crystals of the regulating units corresponding to the microstructures under the driving of the regulating circuit so as to regulate the focusing position of the superlens.

5. An augmented reality display device according to claim 4, wherein the driving layer is provided on a side of the waveguide remote from the superlens;

the augmented reality display device further comprises a common electrode layer; the public electrode layer is arranged on one side, far away from the super lens, of the driving layer, and the liquid crystal layer is clamped between the driving layer and the public electrode layer.

6. An augmented reality display device according to claim 1, wherein the focus modulation layer comprises a two-dimensional material layer between the waveguide and the superlens, the two-dimensional material layer having a two-dimensional material structure in one-to-one correspondence with each of the microstructures; the two-dimensional material structure has different refractive indexes under different carrier concentrations;

the microstructures are positioned on one side, far away from the waveguide, of the corresponding two-dimensional material structure; the focus control layer further comprises a control circuit for modulating a carrier concentration of the two-dimensional material structure.

7. An augmented reality display device according to claim 6, wherein the two-dimensional material structures are interconnected to form a full-face two-dimensional material layer.

8. The augmented reality display device of claim 6, wherein the material of the two-dimensional material structure is graphene or graphene oxide.

9. The augmented reality display device of any one of claims 2 to 8, wherein the material of the microstructure is silicon nitride, titanium oxide, gallium nitride or silicon.

10. The augmented reality display device of claim 1, wherein the material of the microstructure is a thermal phase change material;

the focusing regulation and control layer is provided with heaters which correspond to the microstructures one by one and a regulation and control circuit for driving the heaters;

the heater is used for adjusting the temperature of the microstructure under the control of the regulating and controlling circuit so as to adjust the focusing position of the super lens.

11. The augmented reality display device of claim 10, wherein the heater is transparent conductive sheets that are connected to each other to form a transparent conductive layer;

the transparent conducting layer is located on the surface of the waveguide, and the microstructures are located on the surface, far away from the waveguide, of the transparent conducting layer.

12. A display apparatus comprising the augmented reality display device of any one of claims 1 to 11.

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