CN116224617A

CN116224617A - Display method and display structure based on asymmetric effective reflection surface optical waveguide

Info

Publication number: CN116224617A
Application number: CN202211656236.1A
Authority: CN
Inventors: 滕东东; 刘立林
Original assignee: Sun Yat Sen University
Current assignee: Sun Yat Sen University
Priority date: 2022-12-22
Filing date: 2022-12-22
Publication date: 2023-06-06

Abstract

The invention discloses a display method and a display device based on an asymmetric effective reflecting surface optical waveguide. The display method guides a light beam composed of fine light to be incident into the optical waveguide structure in a divergent state. And designing a positive integer K, guiding the light emitted by each light beam after the light beam is reflected for the Kth time in the optical waveguide, converging and projecting the light beam to the corresponding eye box through the modulation of the coupling-out device, and thus, the projection of view information carried by the light beam to eyes of an observer is realized. Further through the projection of multiple divergent beams, three-dimensional display overcoming focus-convergence conflict is finally realized based on Maxwell Wei Toushe or monocular multiple images. According to the invention, the display quality is improved by suppressing noise caused by reflection of the fine light rays larger than the Kth time, and the projection of the two-dimensional image to the eye box where the pupil of the corresponding observer is positioned is realized by combining the transmission of the divergent light beam in the two-dimensional direction in the optical waveguide.

Description

Display method and display structure based on asymmetric effective reflection surface optical waveguide

Technical Field

The invention relates to the technical field of three-dimensional display, in particular to a display method based on an asymmetric effective reflection surface optical waveguide.

Background

Three-dimensional displays are receiving more attention than two-dimensional displays due to their ability to provide information of a third dimension. The existing three-dimensional display based on the stereoscopic technology is mainly based on binocular parallax, and the three-dimensional visual presentation is realized by respectively projecting a corresponding two-dimensional image to the binocular of an observer, and triggering the depth perception of the brain by utilizing the intersection of binocular vision to the real scene. In this process, the eyes of the observer need to be focused on the display surface in order to clearly see the respective two-dimensional projection images, and the monocular focusing distance is different from the binocular convergence distance corresponding to the binocular visual intersection (the displayed screen scene), that is, the focusing-convergence conflict problem exists. In the natural environment, when an observer observes a real space scene, the monocular focusing distance and the binocular focusing distance are consistent with the space depth of interest of the observer. Therefore, the conventional optical device for performing three-dimensional display based on binocular parallax only has an inherent focusing-convergence conflict contrary to the physiological habit of natural evolution of human body, thereby causing visual discomfort of an observer, which is a bottleneck problem currently preventing the popularization and application of the three-dimensional display technology.

Monocular multiple images (PCT/CN 2017/080874, three-dimentomonal DISPLAY SYSTEM BASED ON DIVISION MULTIPLEXING OF VIEWER' SENTRANCE-PUPIL AND DISPLAY METHOD) and maxwellian view (US 2019/0204600,AUGMENTED REALITY OPTICS SYSTEM WITH PINPOINT MIRROR) are two display METHODs that can solve the focus-convergence conflict problem, also referred to as super-multiple view display and retinal projection display, respectively. The two-dimensional projection images of at least two scenes to be displayed are projected to each eye of an observer, so that the aim that at least two light beams passing through each display object point are incident into any pupil of the observer along different sagittal directions is fulfilled, and superimposed light spots are formed by superimposing the at least two light beams with different sagittal directions in space; when the light intensity distribution of the superimposed light spot is enough to draw advantage relative to the light intensity distribution of each light beam on the two-dimensional image display surface, the eyes of an observer can be drawn to naturally focus on the superimposed light spot, so that the focusing-converging conflict problem is overcome. The latter, through any display object point, only projects a light beam with small divergence to each eye of the observer, the light intensity gradient of the light beam with small divergence angle along the transmission direction is smaller, so that under the coupling driving action of the binocular convergence effect on the monocular focusing, the display scene of each eye focus of the observer in space can be pulled, the focusing-convergence conflict is overcome, and the consistency of the monocular focusing depth and the binocular convergence depth is realized.

Disclosure of Invention

The invention provides a display method based on an asymmetric effective reflecting surface optical waveguide, which is based on a corresponding light and thin optical structure to realize a three-dimensional display system without focusing-converging conflict. The display method based on the asymmetric effective reflection surface optical waveguide projects at least one divergent light beam which is constructed by fine light rays respectively carrying optical information and is divergent at least along one dimension through a projection optical machine, and utilizes two effective reflection surfaces with asymmetric sizes of the optical waveguide to guide each divergent light beam from the projection optical machine to enter a coupling-out device, and the coupling-out device modulates and converges the divergent light beam to an eye box where a pupil of a corresponding observer is positioned; in the process, a surface comprising at least one incident fine light ray and at least one normal line of an effective reflection surface of the optical waveguide is named as a vertical tangential surface, a positive integer K value larger than zero is designed and selected, each fine light ray is guided to enter a coupling-out device after being reflected for the Kth time in the optical waveguide, and then is regulated and controlled by the coupling-out device to be converged and projected to a corresponding eye box (eye-box); the control device sets light information carried by each fine light as projection information of a propagation path of a scene to be displayed when the scene is incident into a corresponding eye box along the projection information. The display method is obviously characterized in that the projection of at least one two-dimensional image to the corresponding pupil of an observer is realized based on the optical waveguide without a light transmission direction deflection structure by designing and restraining noise caused by reflection of each fine light ray for more than K times, so that the three-dimensional display for overcoming focusing-convergence conflict is realized based on Maxwell Wei Toushe or/and monocular multiple images.

The invention provides the following scheme:

the display method based on the asymmetric effective reflection surface optical waveguide uses a display structure, wherein the display structure comprises a projection optical machine, an optical waveguide comprising two effective reflection surfaces, a coupling-out device and a control device, and the display method comprises the following steps:

s1, constructing the projection optical machine into a divergent light beam which is constructed by fine light rays and is divergent along at least one dimension;

s2, guiding divergent light beams from the projection optical machine to enter an optical waveguide with two effective reflection surfaces as upper and lower surfaces;

s3, selecting a positive integer K value larger than zero, and designing that each fine light ray only reflects K times on an effective reflecting surface of the optical waveguide:

in any vertical tangential plane, the area covered by the reflection point of the K-th reflection of all the fine light is designed to be exactly covered by the effective reflection surface of the K-th reflection along the outer line of the fine light in the propagation direction of the optical waveguide, and the area covered by the reflection point of the K-1-th reflection of all the fine light is designed to be exactly covered by the effective reflection surface of the K-1-th reflection along the outer line of the fine light in the propagation direction of the optical waveguide, wherein K is equal to or greater than 1, and the vertical tangential plane refers to a plane containing at least one incident fine light and at least one normal line of the effective reflection surface of the optical waveguide;

S4, reflecting the emitted fine light rays for the Kth time, entering the coupling-out device, regulating and controlling the coupling-out device, and projecting the coupling-out device to the corresponding eye box;

s5, the control device sets light information carried by each fine light as projection information of a propagation path of a scene to be displayed along the incidence corresponding to the eye box by controlling the projection light machine, and the fine light incident to the pupil of an observer in the eye box is designed to be a reverse extension line of the fine light to cover the scene to be displayed;

each slim ray only reflects K+1 times at most, or at least part of the slim ray emits the slim ray after the reflection more than K+1 times, but does not finally enter the corresponding eye box, wherein the pupil of an observer in the eye box can receive at least one light beam passing through any display object point.

In the scheme, the projection of at least one two-dimensional image to the corresponding pupil of an observer is realized based on the optical waveguide without a light transmission direction deflection structure by designing and restraining noise caused by reflection of each fine light ray for more than K times, so that the three-dimensional display for overcoming focusing-convergence conflict is realized based on Max Wei Toushe or/and monocular multiple images

Further, the display method based on the asymmetric effective reflection surface optical waveguide further comprises the following steps: extending the surface of the optical waveguide on the surface of the effective reflecting surface where the K-1 th reflection occurs;

At most, each slim ray only reflects K+1 times, or at least part of the slim rays reflect more than K+1 times, but the slim rays emitted by the reflection more than K+1 times are not finally incident into the corresponding eye boxes.

Further, the display method based on the asymmetric effective reflection surface optical waveguide further comprises the following steps: extending the surface of the optical waveguide on the surface of the effective reflecting surface where the Kth reflection occurs;

Further, the display method based on the asymmetric effective reflection surface optical waveguide further comprises the following steps: and an auxiliary waveguide body which is connected with the optical waveguide in a coplanar manner is arranged, and the reflectivity of the thin light rays in the auxiliary waveguide body is reduced to be larger than the reflectivity of the K-th reflection by designing the lower refractive index value of the auxiliary waveguide body relative to the optical waveguide.

Further, the display method based on the asymmetric effective reflection surface optical waveguide further comprises the following steps: the coupling-out device with the angle selection characteristic is designed to prevent the incident coupling-out of the light rays emitted by the reflection for more than K+1th time or regulate and guide the light rays to propagate around the eye box.

Further, the display method based on the asymmetric effective reflection surface optical waveguide further comprises the following steps: any fine light rays emitted by the K+K 'th reflection are subjected to film coating to regulate the reflectivity of the secondary reflection or/and the last reflection under the condition that the fine light rays finally enter the eye boxes, so that the incident light intensity when the fine light rays finally enter the corresponding eye boxes is reduced, wherein K' is larger than or equal to 1.

Further, the display method based on the asymmetric effective reflection surface optical waveguide further comprises the following steps: when the light guide is incident, each light beam or the reverse extension line of each light beam is intersected with a corresponding space point, and the space point is named as the equivalent emergent point corresponding to the divergent light beam.

Further, the display structure further includes a pupil tracking unit connected to the control device, and the display method further includes: and determining the corresponding pupil position in real time by utilizing the pupil tracking unit, and controlling the projection optical machine to activate only the projection part of the divergent light beam by the control device according to the real-time position of the corresponding pupil so as to implement display.

The invention also provides the following technical scheme:

the display structure for implementing the display method based on the asymmetric effective reflection surface optical waveguide is characterized by comprising a projection optical machine, an optical waveguide comprising two effective reflection surfaces, a coupling-out device and a control device in signal connection with the projection optical machine.

Further, the display structure includes an auxiliary support structure attached to the optical waveguide.

Further, the connection area of the auxiliary support structure and the waveguide is a surface area before the first reflection occurs along the reverse direction of the transmission direction of the reflection of the fine light, or an extension area which is contained by the surface of the optical waveguide and does not generate the K+1th reflection when the fine light generates the K-1th reflection.

Further, the projection optical machine comprises a time sequence light source group formed by T light sources which can be turned on in time sequence under the driving of a control device, wherein the display device capable of loading information under the driving of the control device comprises a plurality of pixels or sub-pixels, the T light sources of the time sequence light source group provide backlight for the display device in time sequence at T time points of any time period, and T is larger than or equal to 2;

the display device is placed between the time-series light source group and the light guide, i.e. before the light guide, or after the light guide.

Further, the projection optical machine comprises a display device, a light source for providing backlight and a controllable deflection device capable of deflecting the emergent direction of incident light under the drive of the control device, and a plurality of divergent light beams are projected in time sequence through time sequence deflection of the incident light or the emergent light of the display device by the controllable deflection device;

Further, the display structure comprises a phase device and an aperture group consisting of T apertures, wherein the T time sequence light sources are respectively converged to the T apertures of the aperture group through the phase device.

Further, along the light transmission direction, a projection device that enlarges a virtual image of the display device is provided.

Further, the pixels or sub-pixels of the display device are divided into O pixel groups or sub-pixel groups, the O pixel groups or sub-pixel groups modulate the backlights with O different characteristics respectively in a one-to-one correspondence manner and emit respective modulated light beams, each pixel group or sub-pixel group prevents the backlights with other (O-1) non-corresponding characteristics from emitting, and each light source is respectively and correspondingly composed of O sub-light sources, and the O sub-light sources project the backlights with the O orthogonal characteristics respectively, wherein O is equal to 2;

The projection light machine projects O divergent light beams respectively at O sub-light sources of the light source which are turned on at each time point.

Further, the projection light machine comprises a display device, a phase device which can converge the projection light of the display device, and a time sequence aperture group which is formed by T time sequence apertures which can be opened in time sequence under the drive of a control device and allow the projection light beam of the display device to pass through, wherein T is larger than or equal to 2;

the T time sequence apertures of the time sequence aperture group are opened at T time points of any time period in time sequence, and the projection optical machine projects divergent beams by taking the T time sequence apertures as equivalent emergent points in time sequence.

Further, the projection light machine comprises a display device, a phase device for converging the projection light of the display device, a time sequence aperture for allowing the projection light of the display device to pass through, and a controllable deflection device capable of deflecting the emergent light of the time sequence aperture in time sequence under the drive of the control device, wherein a plurality of divergent beams are projected in time sequence through the time sequence deflection of the emergent light of the time sequence aperture by the controllable deflection device.

Further, the pixels or sub-pixels of the display device are divided into O pixel groups or sub-pixel groups, the O pixel groups or sub-pixel groups emit light with O different characteristics respectively in a one-to-one correspondence manner, and any time sequence aperture is composed of O sub-apertures, the O sub-apertures allow light with the O characteristics to pass through respectively in a one-to-one correspondence manner, and each sub-aperture blocks light with other (O-1) non-corresponding characteristics from passing through, wherein O is equal to 2.

Further, the projection optical machine comprises a display device constructed by pixels or sub-pixels, a microstructure regulating device and an aperture group formed by S apertures, wherein the pixels or the sub-pixels of the display device are divided into S pixel groups or sub-pixel groups, the microstructure regulating device regulates incident light or emergent light of the display device, so that the S pixel groups or the sub-pixel groups of the display device respectively project light information to the S apertures in a one-to-one correspondence manner, wherein S is equal to or larger than 2.

Further, adjacent apertures allow only light of different characteristics to pass through, respectively, and the characteristics of the light projected by the pixel group or the sub-pixel group corresponding to each aperture are consistent with the characteristics of the light allowed to pass through by the corresponding aperture.

Further, the projection light machine is a scanning projection unit composed of a scanning device and a modulated light beam generating unit, wherein light beams emitted by the modulated light beam generating unit are deflected by the scanning device in time sequence, light beams are projected along different directions, and the light beams emitted by the modulated light beam generating unit carry corresponding light information under the control of a control device.

Further, the projection light engine comprises more than one scanning projection unit.

Further, more than one optical waveguide is stacked, and each optical waveguide corresponds to a corresponding projection optical machine and coupling-out device.

Further, each optical waveguide corresponds to a respective auxiliary waveguide.

The invention also provides the following technical scheme:

the display structure for implementing the display method based on the asymmetric effective reflection surface optical waveguide is characterized by comprising a projection optical machine, an optical waveguide taking two effective reflection surfaces as surfaces, a coupling-out device, a control device connected with the projection optical machine in a signal mode and a unidirectional converging device, wherein the unidirectional converging device reduces the divergence of each divergent light beam along the vertical direction of the effective reflection surfaces before the divergent light beam enters the optical waveguide.

The invention has the following beneficial effects: the invention utilizes the reflection propagation of the light waveguide to the divergent light beam along the two-dimensional direction to implement the convergence projection of the two-dimensional distribution light beam to the eye box, and the used light waveguide does not need a pupil expansion structure and a light transmission direction deflection structure, thereby being hopeful to realize the scene presentation with monocular focusing depth clues. Wherein each of the minute rays is projected by more than the designed K reflections, and is designed not to be incident on the corresponding eye box, so as to suppress display noise due to the reflection of more than K times.

The details of embodiments of the invention are set forth in the accompanying drawings or the description below. Other features, objects, and advantages of the present invention will become more apparent from the following description and accompanying drawings.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings and description of the embodiments illustrate the principles of the invention.

Fig. 1 is a schematic structural diagram of a display structure based on an asymmetric effective reflection surface optical waveguide in embodiment 1 of the present invention.

Fig. 2 is a schematic view showing the design of the surface dimensions of an optical waveguide in a vertical section according to embodiment 1 of the present invention.

Fig. 3 is a schematic structural diagram of a concave reflective type coupling-out device in embodiment 1 of the present invention.

Fig. 4 is a schematic diagram illustrating an example of the preparation of a holographic grating type coupling-out device in embodiment 1 of the present invention.

Fig. 5 is a schematic view showing another optical waveguide surface sizing scheme illustrated in a vertical section in embodiment 2 of the present invention.

Fig. 6 is a schematic view showing still another optical waveguide surface sizing scheme illustrated in a vertical section in embodiment 2 of the present invention.

Fig. 7 is a schematic diagram showing a surface dimension design of the auxiliary waveguide in embodiment 2 of the present invention.

Fig. 8 is a schematic diagram of another surface sizing scheme of the auxiliary waveguide in embodiment 2 of the present invention.

Fig. 9 is a schematic diagram of the structure of a unidirectional converging device in example 2 of the present invention.

FIG. 10 is a schematic diagram showing the reflection and propagation of parallel fine light rays in an optical waveguide according to embodiment 2 of the present invention.

Fig. 11 is a schematic diagram of a projection optical machine employing a time-series light source group in embodiment 3 of the present invention.

Fig. 12 is a schematic diagram of an optical structure of a time-series light source group projection optical engine with a filtering structure in embodiment 3 of the present invention.

Fig. 13 is a schematic view of the structure of a projection optical machine in embodiment 3 of the present invention, where a single light source and a controllable deflection device are used.

Fig. 14 is a schematic diagram of a projection optical machine structure of the display device disposed behind the optical waveguide in embodiment 3 of the present invention.

Fig. 15 is a schematic diagram of a projection optical machine structure employing an orthogonal characteristic sub-light source in embodiment 3 of the present invention.

Fig. 16 is a schematic diagram of a projection optical engine structure employing a time-series aperture set in embodiment 3 of the present invention.

Fig. 17 is a schematic diagram of the structure of a projection optical machine in embodiment 3 of the present invention using a single time-sequential aperture and controllable deflection device.

Fig. 18 is a schematic diagram of a projection optical machine structure employing orthogonal characteristic sub-apertures in embodiment 3 of the present invention.

Fig. 19 is a schematic view of the structure of a projection optical machine using a microstructure control device and an aperture group in embodiment 3 of the present invention.

Fig. 20 is an optical structure diagram of a projection light machine using a scanning projection unit in embodiment 3 of the present invention.

Fig. 21 is a schematic diagram of a projection optical machine structure employing two scanning projection units in embodiment 3 of the present invention.

Fig. 22 is a schematic diagram illustrating an exemplary structure of a projection optical machine with more than one optical waveguide stack according to embodiment 3 of the present invention.

Detailed Description

According to the display method based on the asymmetric effective reflecting surface optical waveguide, the divergent light beam composed of fine light rays is guided through the optical waveguide, and the two-dimensional image is projected to the pupil of an observer, so that the presentation of a freely focused three-dimensional scene is realized based on a monocular multi-image or/and a Max Wei Toushe method; and by designing each fine light to be reflected by the optical waveguide, guided by the optical waveguide and modulated by the coupling-out device, the fine light is only incident on the pupil of the observer along one path, so that display noise caused by the fact that part of the fine light is incident on the pupil of the observer along more than one path due to more than one reflection is restrained and overcome.

Example 1

Fig. 1 shows a basic display structure for implementing a display method based on an asymmetric effective reflective surface optical waveguide, which comprises a projection light engine 10, an optical waveguide 20, a coupling-out device 30 and a control device 40, wherein the control device 40 is in signal connection with the projection light engine 10. The projection light machine 10 projects a divergent light beam composed of fine light rays, for exampleThe illustrated warp point S of FIG. 1 ₁ And S is ₂ Two outgoing divergent beams. At point S ₁ And S is ₂ Named equivalent exit point. Any beam projected by the projection optical machine can correspond to one equivalent emergent point, or no equivalent emergent point is needed. When an equivalent exit point exists, it corresponds to each beamlet in the diverging light beam, which passes through when entering the light guide 20, or it corresponds to each beamlet in the diverging light beam, which passes through when entering the light guide 20 in opposite extension. Fig. 1 illustrates that each divergent light beam projected by the projector 10 has a corresponding equivalent exit point. In particular, at the point of emergence S where it is equivalent ₁ The outgoing divergent light beam is incident on the light guide 20, for example, and the light guide 20 has an upper effective reflection surface, a lower effective reflection surface 201, and an effective reflection surface 202. Dielectric refractive index n of optical waveguide 20 ₁ Greater than the refractive index n of the external medium ₀ Each of the beamlets may propagate in total reflection within the optical waveguide 20. In fact, in the case where the value of K is not very large, the fine rays may also propagate wholly or partly in a non-total reflection manner. Fig. 1 illustrates that each of the fine light rays propagates by total reflection on the equivalent reflection surface of the optical waveguide 20. Defining a plane containing at least one incident fine light ray and at least one normal line of the effective reflection surface of the optical waveguide as a vertical tangential plane, as shown by a diagonal hatching in FIG. 1, containing fine

light rays

1 and 2 _θ Which is in accordance with the reference direction V _re The included angle of (2) is theta. The effective reflective surface of the optical waveguide 20 in fig. 1 is exemplified by a plane, referring to the direction V _re Plane P of _∥ Parallel to the effective reflective surface of the optical waveguide 20, the plane P _∥ Also contains equivalent exit point S ₁ . Plane P _∥ Or may coincide with the effective reflective surface 202. The effective reflective surface of the optical waveguide 20 may be curved in other implementations. Vertical section P _θ In, via equivalent exit point S ₁ Of the beamlets incident on the optical waveguide 20, the beamlet 1 has a minimum reflection angle θ _mi Reflection propagation, with the angle of maximum reflection θ for the fine light 2 _ma The reflection propagates. In FIG. 1, a thin ray 2, and a plane P _∥ The included angles of (a) are respectively denoted as alpha _ma And alpha _mi . According to the geometric relationship theta _mi +α _ma ＝θ _ma +α _mi =pi/2. In FIG. 1, point P _r1 Point P on the detail ray 1 _r2 Point P on the detail ray 2 _r3 Point P, which is the point on the effective reflective surface 202 _r4 Is a straight line P _r1 P _r2 P _r3 In plane P _∥ Upper drop foot. If P _∥ Coincides with the effective reflective surface 202, point P _r3 Sum point P _r4 And (5) overlapping. The detail ray 1 is 1 after the 1 st reflection ₁ The thin ray after the 2 nd reflection is expressed as 1 ₂ And so on; the slim ray 2 is represented as 2 after the 2 nd reflection ₁ The thin ray after the 2 nd reflection is expressed as 2 ₂ And so on.

A positive integer K greater than zero is selected, and each of the beamlets is directed onto a surface of the optical waveguide 20 in a region occupied by the kth reflection and within the region as an effective reflective surface. Namely, in any vertical section, the line covered by the reflection point of the K-th reflection of all the fine light rays in the vertical section is exactly covered by the effective reflection surface of the K-th reflection along the transmission direction of the fine light rays in the vertical section in the optical waveguide. For simplicity and clarity of illustration, fig. 1 only exemplifies k=1, and the maximum reflection angle θ is set on the effective reflection surface 201 where the kth=1st reflection occurs _ma The reflection point when the k=1st reflection occurs corresponding to the fine light 2 is the point P ₂₁ Namely, the effective reflection surface 201 is perpendicular to the tangential plane P _θ Inner and along the light transmission direction x _θ Is the outermost point M of (2) _θK . Similarly, all such outermost points in each vertical section form an outer edge line of the effective reflective surface 201 in the light reflection transmission direction, such as outer edge line M in FIG. 1 _u2 P ₂₁ M _u3 . Or, the point of the outer edge line of the effective reflecting surface with the Kth reflection in any vertical section is the outermost point when all the fine light rays in the vertical section are reflected for the Kth reflection. In the embodiment, the side line of the effective reflecting surface can be a straight line or a curve. The K-th reflection occurs on the effective reflective surface 201 whose boundary line is shown in fig. 1 as

The outer edge of another effective reflective surface is based on a similar approach: in any vertical section, the outermost reflection point when the (K-1) -th reflection occurs to all the light rays is the outer edge point of the effective reflection surface in the vertical section. In fig. 1, k=1 corresponds to K-1=0. At this time, P in any vertical section _θ In this case, the maximum reflection angle corresponds to the reflection point at which the fine light ray (K-1) =0 reflections occur. In this particular case, the area of the effective reflective surface 202 is designated as the area where no reflection (or 0 reflections) occurs, e.g., P in the vertical section as shown in FIG. 1 _θ The outer edge point of the inner effective reflective surface 202 is point P ₁₂ . Wherein point P ₁₂ The point at which the corresponding thin ray reaches the effective reflecting surface for the first time corresponds to the minimum reflection angle. The outer edge of the effective reflective surface 202 can be determined on the basis of the same principle +.>

Correspondingly, the borderline of the effective reflection surface 202 is shown in fig. 1 as +.>

More general case is K>1, where K-1 is not zero. The point of the outer edge line of the effective reflecting surface with the K-1 reflection in any vertical tangent plane is the outermost point when all the fine light rays in the vertical tangent plane are reflected for the K-1 reflection. Through equivalent exit point S ₁ All the light rays entering the optical waveguide 20, the exit light rays after the K-th reflection enter the coupling-out device 30, and are regulated and converged to a convergence point S 'by the coupling-out device 30' ₁ . Similarly, all the beamlets of any other scattered beam projected by the projector 10 are modulated and converged to other corresponding convergence points by the coupling-out device 30 after the kth reflection of the effective reflection surface of the optical waveguide 20. The light beams emitted by the K-th reflection are incident to the coupling-out device 30, and the light beams which are regulated and converged to the corresponding convergence point by the coupling-out device 30 are effective light beams; from the light beam projected by the projector 10 after being reflected by not less than the Kth reflection The other light beams exiting the optical waveguide 20 are named invalid light beams. More than one invalid beam may be projected from the same beamlets projected by the projection engine 10. For example, equivalent exit point S in FIG. 1 ₂ All the beamlets of the outgoing diverging beam converge to a further corresponding convergence point S' ₂ . All convergence points occupy the area to form an eye box. The eyebox is characterized in that an observer's pupil positioned within the eyebox receives at least one effective light beam that passes through any of the displayed object points. The term "light beam" is not strictly defined as a "line", and each "light beam" is characterized in that it is guided to modulate a corresponding effective light beam incident on the eye box via the light guide 20 and the coupling-out device 30, and the light intensity of the light beam on the pupil is not less than the light distribution linear degree of the maximum light intensity value of 1/2 and not more than the pupil diameter of the 1/2 observer. The control device 40 controls the projection optical engine 10 to load light information on any fine light: the scene to be displayed is along its projection information of the effective light beam incident on the corresponding eye box. Then, the display structure shown in fig. 1 is used as a single eyepiece, two such eyepieces build a binocular display structure, and based on the method, three-dimensional display for overcoming focusing-convergence conflict can be realized based on max Wei Toushe or/and monocular multiple images. The configuration shown in fig. 1, if designed to display a scene individually for binocular projection to an observer, requires many convergence points to form two eye boxes corresponding to both eyes of the observer.

It should be noted that the area of the effective reflection surface of the optical waveguide 20 shown in fig. 1 is only the equivalent exit point S ₁ The outgoing diverging beam corresponds to a defined area. In the case of the projection light engine 10 projecting a plurality of divergent light beams, the area of each effective reflection surface of the optical waveguide 20 should be the union of all the divergent light beams projected by the projection light engine 10, each of the areas determined as described above. Meanwhile, the coupling-out device 30 in fig. 1 is only shown with respect to the vertical section P _θ The cross lines in all the vertical tangential planes can construct the distribution area of the coupling-out devices. It is also noted that the coupling-out device 30 shown in fig. 1 also considers only the equivalent exit point S ₁ And each fine light ray is emitted, and then the incidence of the emitted fine light ray is carried out after the K-th reflection. In the case of projection light engine 10 projecting multiple divergent beams, the couplerThe dimensions of the element 30 should allow the incidence of all beamlets from the respective diverging beams that exit by the kth reflection. In fig. 1, the beamlets of each divergent beam are illustrated as passing through respective corresponding equivalent exit points (e.g., equivalent exit point S in fig. 1 ₁ And S is ₂ ) Incident on the optical waveguide 20, reflected by the effective reflection surface of the optical waveguide 20 for the Kth time, and converged by the coupling-out device to respective corresponding convergence points (e.g. point S 'in FIG. 1' ₁ And S' ₂ ). In practice, the beamlets of each divergent light beam may have no corresponding equivalent exit point before entering the optical waveguide 20, or/and no corresponding convergence point after being modulated by the coupling-out device after the K-th reflection of the effective reflection surface of the optical waveguide 20. At this time, the emitted beamlets after the kth reflection are modulated by the coupling-out device 30 to be effective beams when the beamlets are incident into the corresponding eye boxes along the unique target direction; the other light beams from the light guide 20 after the reflection of the projection light machine 10, which are projected by the light source, are not less than the kth reflection are invalid light beams. The display can be implemented as long as the requirement that "at least one effective light beam passing through any display object point can be received at the pupil of the observer positioned in the eye box" is satisfied. If each display object point passes, only one effective light beam enters any pupil of the observer, and the display is performed based on the principle of Max Wei Toushe; if each display object point is passed, an effective light beam with more than one effective light beam enters any pupil of an observer, and the display is performed based on the principle of monocular multiple images; if for any pupil of the observer, only one effective light beam is incident through part of the display object points, and more than one effective light beam is incident through the rest part of the display object points, the display is based on a mixing mechanism of Maxwell Wei Toushe and monocular multiple images.

In the above procedure, after determining the K value, all the beamlets are required to reflect the K-th time and to be incident on the outcoupling device 30. For example, as shown in fig. 1, in the case of k=1, a thin light ray 1 having a smaller reflection angle corresponds to a thin light ray 1 emitted after k=1 reflections ₁ At point P ₁₂ Upper coupling-out device 30 for coupling out the effective light beam 1' ₁ . Then slim ray 1 ₁ Corresponding to the light information, the light information is the effective light beam 1 'along the scene to be displayed' ₁ PathIs provided. At the same time, however, slim ray 1 ₁ At point P ₁₂ And may also be continuously reflected. I.e. point P on the outcoupling device 30 ₁₂ K+1=2 reflection and point P on the effective reflective surface 201 ₁₃ K+2=3 reflections as a fine ray 1 ₃ The coupling-out device 30 is again incident and the invalid beam 1 'is coupled out by the coupling-out device 30' ₃ . At the inactive beam 1' ₃ In the case of an incident eye box, the scene to be displayed carried by it is along the effective light beam 1' ₁ Projection information of the path will be referred to as noise beam 1' ₃ Exists. In FIG. 1, l ₁ Is reflected by K=1 times at point P ₁₄ A fine light ray incident on the coupling-out device 30, modulated by the coupling-out device 30, emits an effective light beam l' ₁ Carry the correct light information to propagate to the convergence point S' ₁ . In the out-coupling beam 1' ₃ And an effective light beam l' ₁ When the angle beta of the coupling-out beam is designed to be large enough, the coupling-out beam can propagate around the eyebox without affecting the display quality, which does not form a noise beam. In fig. 1, the coupling-out device 30 is, for example, a transmissive device, that is, the effective light beam coupled out by the coupling-out device 30 and the incident light corresponding to the effective light beam are located at two sides of the coupling-out device 30. The coupling-out device 30 may also be a reflective device, that is, the effective light beam coupled out by the coupling-out device 30 and the incident light corresponding to the effective light beam are located on the same side of the coupling-out device 30. When a beamlets enters the coupling-out device 30, light emitted by the coupling-out device 30 may include a beam that is finally emitted as an effective beam, and may also include a beam that is finally emitted as an ineffective beam; the light beam finally exiting the optical waveguide 20 as an inactive light beam may be reflected by the coupling-out device 30 or diffracted by the coupling-out device 30. The incident light at a point on the coupling-out device 30 may be more than 1 outgoing beam, which finally forms a noise beam, through the coupling-out device 30. It should be noted that, for the outgoing fine light beam which is reflected at a certain point on the coupling-out device 30 and finally forms the noise beam, the point is taken as a reflection point; for an outgoing beamlets that is diffraction modulated at a point on the outcoupling device 30, which ultimately forms a noise beam, the point is not taken as its reflection point, but is referred to as a pseudoreflection point for descriptive convenience. For a pair of This type of noise beam caused by the (k+k ') th reflection exemplifies three processing schemes to suppress the noise beam, where K' is ∈ 1. (1) The related parameters of the optical structure, including the K value, the reflection angle of each thin light, the thickness e of the optical waveguide, the distance a between the equivalent exit point and the effective reflection surface where the first reflection occurs, are redesigned, so as to avoid that each thin light is reflected more than the K-th reflection, or the light emitted by the reflection more than the K-th reflection is not entered into the eye box after being coupled out by the coupling-out device 30, or the light emitted by the reflection more than the K-th reflection is partially or completely entered into the eye box after being coupled out by the coupling-out device 30, but the light intensity entering the eye box is insufficient to cause influence on the display quality beyond the allowable range. (2) The coupling-out device 30 with angle selectivity is designed, and the light emitted by the reflection greater than the kth time is not allowed to be coupled out by the coupling-out device 30, or the coupled-out light is allowed to be coupled out by the coupling-out device 30, but the coupled-out light is transmitted around the corresponding eye box, or the coupled-out light is allowed to be coupled out by the coupling-out device 30, and the coupled-out light finally enters the corresponding eye box, but the incident intensity is insufficient to cause influence on the display quality beyond the allowable range. (3) When the noise beam is finally formed by the reflection of the emitted beamlets after the k+k 'th reflection, the coating is designed to reduce the noise beam intensity by designing the reflectivity of the k+k' th reflection or/and the last reflection on the surface of the optical waveguide 20 or/and the coupling-out device 30. In this patent, the light emitted by a reflection of a time greater than the K-th time enters the corresponding eye box through the coupling device 30, but when the intensity of the light entering the eye box is insufficient to affect the display quality beyond the allowable range, the light emitted by the reflection is equivalently considered as "finally not incident into the corresponding eye box". For the purpose of this patent, it is required that each of the fine light rays projected by the projection optical machine 10 is guided by the reflection of the asymmetric effective reflection surface of the optical waveguide 20 to be incident on the pupil of the observer at most only once (wherein the fine light rays emitted by a certain reflection greater than the kth time enter the pupil of the observer via the coupling-out device 30, but the intensity of the fine light rays entering the eye box is insufficient to affect the display quality beyond the allowable range The equivalent is that the fine light rays emitted by this reflection "do not ultimately strike the observer's pupil"). This also means that when each of the beamlets is reflected more than the designed number K, all of the beamlets from any one of the divergent light beams projected by the projection light engine 10 are not finally all incident on the corresponding eye box, but only the beamlets from which they are reflected the number K are modulated and guided to the corresponding eye box. In fig. 1, the divergent light beam projected by the projector 10 has a corresponding equivalent exit point. When each divergent light beam does not have an equivalent exit point, in each vertical tangential plane, the reflection angle of the corresponding fine light ray may not be the largest at the outermost reflection point where the K-th reflection occurs on the fine light ray from the same divergent light beam.

Fig. 1 illustrates only the case of k=1, in which case, in one vertical section, the maximum reflection angle θ for each ray corresponds to _ma And a minimum reflection angle theta _mi With large differences, reflections larger than the kth time may occur on both the outcoupling means 30 and the effective reflective surface. At K>At 1, reflections greater than the kth time may also occur. Meanwhile, the out-coupling device 30 requires a carrier to be fixedly placed with respect to the optical waveguide 20. On the premise of designing the carrier, further consideration needs to be given to the reflection of each fine light ray larger than the kth time, which may be caused by the introduction of the carrier. The following describes a specific example of the carrier of the coupling-out device 30, and the method for suppressing noise light beams caused by modulating the coupling-out device 30 into the eye box after each light beam is reflected more than the kth time.

Fig. 2 shows k=2 and from an equivalent exit point S ₁ For example, in the vertical section P _θ In the inside, an optical waveguide structure implementing the display method is shown. The vertical section P _θ In, via equivalent exit point S ₁ Of the thin rays incident on the

optical waveguide

20, 1 is the corresponding minimum reflection angle θ _mi 2 is the corresponding maximum reflection angle theta _ma Is a thin ray of incident light. The effective reflection surface 201 in the optical waveguide 20 in which the kth-1=1 reflection occurs is along the light transmission direction x _θ The extended, outcoupling device 30 is prepared or placed on an optical waveguide surface comprising an effective reflective surface 201 and the extended surface. Effective k=2nd reflection in the optical waveguide 20The reflective surface 202 does not stretch. The optical waveguide shown in fig. 1 is similar in structure to the optical waveguide shown in fig. 2 (the effective reflection surface on which the K-1=1 th reflection occurs extends) except that fig. 1 corresponds to k=1. Fig. 2 illustrates that the coupling-out device 30 reflects the incident minute light rays having been reflected by ∈k times, for example, again. The reflection of the incident beamlets by the outcoupling device 30 may not be the same as the reflection angle (possibly the total reflection angle) of the incident beamlets on the effective reflective surface. Point P on the surface of optical waveguide 20 ₁₁ 、P ₁₂ 、P ₁₃ …, respectively refer to reflection points of 1 st, 2 nd, 3 rd and … th reflection of the slim ray 1; point P ₂₁ 、P ₂₂ … refer to the reflection points at which the 1 st, 2 nd and … th reflections of the minute light ray 2 occur, respectively. The first subscript of each reflection point corresponds to the name of the fine light ray, and the second subscript corresponds to the serial number of the reflection times. The fine light rays 1 are respectively marked as 1 after being reflected for 1 st, 2 nd, 3 rd and … th times ₁ 、1 ₂ 、1 ₃ …; the fine light rays 2 are respectively marked as 2 after being reflected for 1 st, 2 nd, 3 rd and … th times ₁ 、2 ₂ 、2 ₃ …. The first index corresponds to the corresponding light name (e.g. incident light 1, 2) and the second index corresponds to the corresponding number of reflection times. The above nomenclature is applied to the following portions of the present embodiment, and will not be described again. Under the naming rule, if only one beam of light is considered to be incident on the vertical section P _θ The outer points of the two effective reflection surfaces of the optical waveguide 20 are P _2K And P _2(K-1) . For example, in the case of k=2, the vertical section P in fig. 2 _θ Outer edge point P of inner two effective reflection surfaces ₂₂ And P ₂₁ . The two effective reflective surfaces of the optical waveguide 20 are of different sizes, which is also referred to herein as an "asymmetric effective reflective surface optical waveguide". At the same time, the optical waveguide 20 carries the surface of the coupling-out device 30, which is in a vertical section P _θ M for the outer edge of the inner part _θK- Indicated that the outer edge of the other face is M _θK And (3) representing. Wherein subscripts θ and K represent vertical cuts P _θ The outer edge point of the optical waveguide surface where the kth reflection occurs, subscript θk-, denotesVertical section P _θ The outer points of the surface of the optical waveguide where the K-1 th reflection occurs. It should be noted that considering the incidence of more than one divergent light beam, the outer edge point of each effective reflecting surface in a vertical tangential plane needs to be determined by the outermost reflecting point when all the beamlets in the vertical tangential plane reflect at the kth or kth-1 th time. When each effective reflection surface of the optical waveguide 20 is extended, reflection generated in each extended area needs to be suppressed, or the emergent fine light is designed to be transmitted around the corresponding eye box after being emergent through the coupling-out device 30. In contrast, each reflection occurring on the effective reflective surface no greater than the kth time is optimally a high reflectance reflection, such as total reflection. According to the principle of determining the effective reflecting surface area, only the equivalent emergent point S is passed ₁ In the case of divergent light beam incidence, a vertical tangential plane P _θ In the light transmission direction x, the effective reflection surface 201 _θ The directional edge point is the corresponding maximum reflection angle theta _ma Reflection point P at which fine light ray 2 of (1) is reflected K-1=1 times ₂₁ The method comprises the steps of carrying out a first treatment on the surface of the The effective reflective surface 202 is along the light transmission direction x _θ The directional edge point is the corresponding maximum reflection angle theta _ma Reflection point P at which fine light ray 2 of (2) is reflected k=2 times ₂₂ . In order to modulate all the thin light rays incident after the k=2nd reflection, the two edge points of the coupling-out device 30 are respectively corresponding to the minimum reflection angle θ _mi Fine ray 1 of (2) and corresponding maximum reflection angle θ _ma Reflection point P at which k+1=3 th reflection occurs for fine light ray 2 of (2) ₁₃ And P ₂₃ . If the extension of the effective reflective surface 201 is designed to comprise exactly the coupling-out device 30, the outer edge M of the optical waveguide surface with the extension _θK And an outer edge point P of the out-coupling device 30 prepared on the surface ₂₃ Superposition, optical waveguide surface outer edge point M without extension surface _θK And the edge point P of the effective reflection surface on the surface ₂₂ And (5) overlapping. When the projection light machine 10 projects more scattered light beams, the edge points of the coupling-out device 30 can be correspondingly changed to ensure that all the emitted light beams projected by the projection light machine 10 after the kth reflection are incident on the corresponding coupling-out device 30. In the following, a case where only one divergent light beam is incident on the optical waveguide 20 will be described as an example, and the details of the divergent light beam are used as a basisThe effective reflective surface edge points and the edge points of the outcoupling means 30 are determined and will not be described in a similar additional way for the case of incidence of more than one divergent light beam. It should be noted that in the above process, the same K values are taken in different vertical tangential planes. In fact, in order to obtain a regularly shaped beam exit area on the outcoupling device 30, the angles of maximum and minimum reflection corresponding to the beamlets of the same diverging beam in each vertical tangential plane may be different; the fine light of the divergent light beam can also select different K values in different vertical tangential planes. In this case, the surface of the optical waveguide may be divided into different regions, each region corresponding to the same number of times K, and the regions may be processed according to the above-described rule based on the respective K values. In fig. 2, the beamlets that are incident on the coupling-out device 30 by reflection + K times may also exit by diffraction (rather than reflection) and eventually form invalid beams. For example, in FIG. 2 (c), point P ₁₃ Outgoing light ray 1 ₃ It is also possible to rely on diffractive exit of the outcoupling means 30. In this case, point P ₁₃ No longer is the k+1=3 actual reflection point, point P ₁₄ It is the k+1=3 actual reflection points, i.e. the beamlets I ₄ Is formed by the exit of the k+k' =2+1=3 reflections. But for convenience of explanation, point P is referred to ₁₃ Is a pseudo-reflection point P ₁₃ Refer to emergent light 1 ₃ To emit a beamlet 1 by the 3 rd pseudoreflection ₃ 、1 ₄ The subscript of (2) indicates the number of reflections corresponding to it, including the pseudoreflection. In fig. 1, the coupling-out device 30 is, for example, a transmissive device, and after the incident light beam reflected by the kth time is modulated, the light beam exits from the other side of the corresponding effective light beam; the coupling-out device 30 may also be a reflective device, and after the incident light beam reflected by the kth time is modulated, the light beam exits corresponding to the same side of the effective light beam. When a reflective outcoupling device 30 is used, an incident beamlets may be based on reflected and outgoing beamlets that ultimately form noise, or on diffracted and outgoing beamlets that ultimately form noise. The out-coupling device 30 may be a variety of micro-nano structured devices such as super surface structures, holographic gratings, wiener grating structures, etc. In the figures of this patent, the out-coupling device 30 is shown as a planar structure, and light The waveguide 20 surfaces are disposed coplanar. It may also be disposed out of plane with optical waveguide 20, if possible. For example, the out-coupling device 30 may also be designed as a concave structure for reflection regulation of the incident light, as shown in fig. 3. The situation shown in fig. 3 (a) and (b) is similar to that of fig. 2 (a) and (b), only the out-coupling device 30 being changed. The coupling-out device of concave structure modulates the fine light from each divergent light beam, and converges toward the corresponding eye box along the corresponding direction, such as from the equivalent divergence point S in FIG. 3 ₁ Is modulated and converged to a convergence point S 'by the coupling-out device 30' ₁ . Obviously, in this case, the equivalent reflecting surface 201 is extended along a curved surface. Also in this case, reflection of each minute light ray more than the kth time causes occurrence of noise, and suppression of such noise is required. For example, in FIG. 3 (b), the thin ray 1 is at point P ₁₃ After 4 th reflection more than K=2, the emergent fine light ray 1 ₄ Modulated by the out-coupling device 30 at point P ₁₅ Where the noise beam is emitted. However, the coupling-out device with such a curved structure may have a smaller viewing angle of the modulated exit area to the eye box than a coupling-out device placed parallel to the optical waveguide. The following example structures are all exemplified by planar coupling-out devices, and curved coupling-out devices may be employed.

FIGS. 2 (a) to (c) correspond to θ _ma -θ _mi Gradually increasing. In the case of the design shown in FIG. 2 (a), the minimum reflection angle θ _mi And a maximum reflection angle theta _ma The difference is smaller, and (a+ (K+1) e) tan (theta) _mi )>(a+(K-1)e)tan(θ _ma ) Each beamlet does not diverge more than the kth reflection at the effective reflective surface. Where e is the thickness of the optical waveguide 20 and a is the distance between the equivalent exit point and the effective reflective surface where the first reflection occurs. That is, a, e, θ can be designed by _ma -θ _mi The value of (2) satisfies the condition (a+ (K+1) e) tan (θ) _mi )>(a+(K-1)e)tan(θ _ma ) To avoid more than K reflections from occurring at the effective reflective surface. With theta _ma -θ _mi An increase in the value when (a+ (K+1) e) tan (θ _mi )≦(a+(K-1)e)tan(θ _ma ) When the reflection of the fine light is greater than the K-th reflection, the light emitted by the reflection is incident on the coupling-out device 30Conditions may occur. As illustrated in fig. 2 (b), a point P on the outcoupled device 30 ₁₃ The k+1=3 th reflection emits a fine light ray 1 ₃ Then passes through point P on the effective reflecting surface 202 ₁₄ K+2=4 reflection exit beamlets 1 ₄ . Light ray 1 ₄ At point P ₁₅ The outcoupling device 30 is in-coupled. If the design of the optical structure parameters can ensure the fine light 1 ₄ The outgoing light modulated by the coupling-out device 30 does not enter the eye box, and the k+2=4 th reflected and outgoing light 1 ₄ No noise is introduced. Otherwise, it will introduce noise. Similar situations exist for other beams that exit through greater than the designed kth reflection. When the minimum reflection angle theta _mi And a maximum reflection angle theta _ma The difference is relatively large, i.e., (a+ (K-1) e) tan (θ) _ma ) Far greater than (a+ (K+1) e) tan (θ) _mi ) At this time, as shown in fig. 2 (c), a portion of the slim rays will be reflected more than the kth time on the coupling-out device 30 and the effective reflective surface 202. For example, the fine light 1 is coupled out through the point P on the device 30 ₁₃ K+1=3 th reflection of emitted light ray 1 ₃ Point P on the effectively reflecting surface 202 ₁₄ K+2=4 reflection of emitted beamlets 1 ₄ Point P on the coupled-out device 30 ₁₅ The k+3=5 th reflection of the emitted light ray 1 ₅ Point P on the effectively reflecting surface 202 ₁₆ K+4=6 reflection of emitted beamlets 1 ₆ Point P on the coupled-out device 30 ₁₇ The k+5=7 th reflection of the emitted beamlets 1 ₇ Point P on the effectively reflecting surface 202 ₁₈ K+6=8 reflection of emitted beamlets 1 ₈ . At this time, at a certain point on the coupling-out device 30, the incident light beam emitted after the kth reflection and the light beam emitted after the reflection greater than the kth reflection are incident as noise light beams into the eye box at the same time, and if the included angle is not large enough, the light beam emitted after the reflection greater than the kth reflection is coupled out by the coupling-out device 30. Here as shown in fig. 2 (c) at point P ₁₅ A light ray 1 incident from the position ₄ For example, it sums the minutiae ray 3 after the k=2nd reflection, which is incident on the point ₂ Under the condition that the included angle of the light beam is smaller than a certain value, the fine light beam 1 ₄ The coupled-out light beam is modulated again by the coupling-out device 30 and will be incident on the eye as a noise light beamA box. The suppression of the noise beam can design the modulation characteristic of the coupling-out device 30, and the coupling-out efficiency is zero or very low for the incident beamlets after being reflected for more than the Kth time, so that the influence of the noise beam finally formed on the target display quality is within the allowable range; and then, or for the incident beamlets after being more than the Kth reflection, guiding the corresponding invalid beams not to be incident into the corresponding eye boxes. Another method may suppress such noise by coating the surface of the optical waveguide. The optical structure shown in fig. 2 is specifically exemplified as follows.

For any beamlet emitted by the K+K 'th reflection, under the condition that a noise beam is finally formed, the reflectivity of the K+K' th reflection or/and the last reflection of the beamlet can be designed through coating so as to inhibit corresponding noise. Wherein K' > 1. In FIG. 2, a fine ray 1 ₂ At point P ₁₃ Is coupled out by the coupling-out device 30, but at the same time has part of the energy reflected as a fine light ray 1 ₃ At this time, if the fine light ray 1 ₃ Reflection with little or no energy loss via the effective reflective surface 202 to provide a fine light ray 1 of a certain energy ₄ The outcoupling device 30 is in-coupled. At this time, if the light ray 1 ₄ The coupled-out light beam modulated by the coupling-out device 30 is then incident on the eyebox as a noise beam, and its energy affects the display quality beyond the allowable range of the target display quality, which can have a destructive effect on the display. Such noise beams may be suppressed by coating the surface of the optical waveguide 20. Taking the transmissive outcoupling device 30 as an example, the fine light 1 ₄ The corresponding k+k' =2+2=4 reflections, the 4 th and 3 rd reflections being required to be avoided (with zero reflectivity) to block the slim ray 1 ₄ Is present; or wherein the reflectivity of at least one reflection is reduced to reduce the beamlets 1 ₄ Thereby making the fine light 1 ₄ Noise caused by the light beam coupled out via the coupling-out device 30 is within the allowable range of display quality. Here, the reflectance reduction of the 3 rd or/and 4 th reflection may be achieved by plating. Other, greater number of reflections, if eventually forming a noise beam, which in turnThe reflectivity on the out-coupling device is expected to have a large value (optimally total reflection), and the reflectivity on the reflective surface of the optical waveguide 20, where K reflections occur, is expected to have a small value, which can be achieved by plating. In this process, the outgoing beamlets that are emitted on the outcoupling device 30, which ultimately form the noise beam, are exemplified by reflection. The outgoing beamlets exiting the outcoupling device 30, which ultimately form a noise beam, may also be diffraction-exiting. For example, if detail ray 1 of FIG. 2 (c) ₃ Is a slim ray 1 ₂ Is transmitted through point P ₁₄ K+k' =2+1=3 reflection exit beamlets 1 ₄ . If beamlets 1 ₄ Noise beam is coupled out by the coupling-out device 30, and the fine light 1 can be reduced by coating ₃ At point P ₁₄ Reflectivity at the spot (increasing its transmissivity) to suppress beamlets 1 ₄ Noise is coupled out via the coupling-out device 30. Each beamlet is reflected by other greater numbers, and if a noisy beam is ultimately formed, its reflectivity on the coupling-out device is expected to be greater, its reflectivity on the reflective surface of the optical waveguide 20 where K reflections occur, which is expected to be smaller, and the corresponding coating is based on this requirement. All the fine light rays emitted by reflection larger than the Kth time and finally forming noise beams to be incident to the corresponding eye boxes have similar requirements under the condition that the corresponding noise beams cause noise exceeding the allowable range. In fact, in the case of a transmissive outcoupling device, the reflection of the k+1 and/or k+2 reflection of a thin line is effectively suppressed, and the k+3 or more reflections (if present) of the outgoing beam, the beam being coupled out by the outcoupling device, may not take into account the effect of the k+3 or more reflections if no noise is introduced or is within the target display quality tolerance. But if this is not the case, the k+3, k+5, k+7, … reflections occurring on the out-coupling device 30 are continued, and if the corresponding areas on the out-coupling device 30 are coated, the reflectivity of these reflections not less than the k+3 reflections needs to be increased. Whereas the k+4, k+6, k+8, … reflections occurring on the effective reflective surface 202 require a reduction in the reflectivity of these reflections greater than the k+3 reflections if the corresponding areas on the effective reflective surface 202 are coated.

In contrast, in the case of the reflective coupling-out device 30, any fine light is reflected on the coupling-out device 30 more than the kth time, and when the reflected light beam finally forms a noise beam, the coating film needs to reduce the reflectivity of the reflection, and the reflection more than the kth time on the other optical waveguide surface is designed to have a larger reflectivity. If the out-coupling device 30 diffracts the outgoing light beam, which eventually forms a noise light beam, the diffracted outgoing light beam needs to be reflected by a large reflectivity when entering the other optical guide surface, and the outgoing light reflected by the large reflectivity is designed to have a small reflectivity when entering the out-coupling device 30 again, or/and is modulated by the out-coupling device 30 to be an inactive light beam outgoing without forming a noise light beam.

In the region where the Kth reflection and the reflection greater than the Kth reflection occur simultaneously, as shown in FIG. 2 (c)

The layer design of the coating should optimally be designed so as not to significantly affect the reflectivity of the no greater than the kth reflection in this region. Specifically, if the reflectivity of the minute light ray 4, at which the kth-1=1 reflection occurs, is significantly reduced, it will have a portion of the energy emitted through the coupling-out device 30, and if the emitted light beam enters the eyebox, noise will also be introduced, it is necessary to design it to bypass the eyebox, or noise brought about while entering the eyebox is within the display quality allowable range. Similarly, on the optical waveguide surface on which the kth reflection occurs, a coating may also be performed to reduce the reflectivity of the reflection on the optical waveguide surface that is greater than the kth reflection; at the same time, however, the film design of the coating should be optimally designed at the same time so that the reflectivity of the optical waveguide surface is not greater than the K-th reflection, in order to avoid excessive loss of display brightness or the introduction of noise. Because of the different conditions of the incident beamlets at each reflection point (e.g., the angles of reflection corresponding to the incident beamlets at different reflection points are different; e.g., the first incidence of each beamlet is optimally designed to be reflected with a small reflectivity on the outcoupling device 30 to increase the outcoupling efficiency; greater than the first incidence optimally requires a large reflectivity with the transmissive outcoupling device 30 and a reflection is used) The low reflectivity is optimally required in the case of the injection-type coupling-out device 30, and the design requirements on the coating film layer are different; the film design can be performed based on different characteristics of incident fine light at each reflection point in combination with ray tracing, even a film whose characteristics vary significantly with the region. The reflection on the surface of the optical waveguide 20, which is not greater than the K-th reflection, is optimally designed to be total reflection. In the vertical section shown in FIG. 2, M is used _θK- Marking the outer edge point of the optical waveguide surface where the K-1 th reflection occurs, as M _θK The outer points of the surface of the optical waveguide where the kth reflection occurs are marked. I.e.)>

For the optical waveguide 20 in the vertical section P _θ A vertical edge in the inner part, which is optimally designed to have a high transmittance so as to avoid noise caused by reflection. Vertical side line->

In fig. 2 is shown as a straight line, which may also be a broken line, a curved line, etc. In each of the optical structures shown in the figures below, such vertical edges are present in each vertical tangential plane, and the discussion will not be repeated.

The angle selective out-coupling device 30 does not allow for incident out-coupling of light greater than the K-th reflection of the exiting beamlets; or although the incidence coupling-out of the emergent light rays larger than the Kth reflection is allowed, the emergent direction of the coupling-out light beam can be controlled to ensure that the coupling-out light beam bypasses the corresponding eye box, or the coupling-out efficiency of the emergent light rays larger than the Kth reflection is reduced, so that the noise brought by the coupling-out light rays does not exceed the allowable range of the target display quality. Specifically, for example, a volume hologram grating prepared based on optical hologram, which has angular selectivity in diffraction, and when the incident angle of the incident beam deviates from the design incident angle, the coupling-out efficiency is rapidly reduced, and the volume hologram grating can be used as the coupling-out device 30 with angular selectivity. Specifically, taking the coupling-out grating 30 corresponding to the optical structure shown in fig. 2 (b) as an example, the preparation method based on optical holography is shown in fig. 4: from point I _S12 Diverging light and equivalent exit point S ₁ Corresponding convergence point S' ₁ The converging light, which is converged, interferes with the optical recording medium disposed in the spatial region occupied by the outcoupling device 30, with the recorded volume grating as the outcoupling device 30. Wherein in case of k=2, the equivalent divergence point S ₁ Mirror image of the effective reflective surface 201 with respect to the first reflection is point I _S11 Point I _S11 The mirror image of the effective reflective surface 202 with respect to the second reflection is point I _S12 . In the recording process, at the point I _S12 Is not able to use the light emitted from the equivalent exit point S ₁ The outgoing light distribution transmitted by reflection through the light guide 20 is replaced. If it is from equivalent exit point S ₁ The outgoing light guided by the light guide 20 is distributed and converged to a convergence point S' ₁ Is recorded from the equivalent exit point S ₁ Light emitted by reflection greater than the kth time is also recorded to form a corresponding grating profile. Then, during the display process, the projection light machine 10 projects the equivalent exit point S ₁ More than K times of reflected light rays are generated, the light rays emitted after being reflected by the Kth, the K+1th and the … th are modulated by the coupling-out device 30 to be converged to a convergence point S 'after being coupled out of the coupling-out device 30' ₁ Thereby creating noise that the patent would otherwise attempt to suppress. Another exemplary noise suppression scheme is to coat the surface of the optical waveguide 20 with a film design to reduce the reflectivity of each of the beamlets for the k+1 and/or k+2 reflections, and even to reduce the reflectivity of other reflections greater than the k+3 reflections in addition to the k+3, k+5, k+7, … reflections (if any) that occur on the outcoupling device 30. It is also desirable to reduce the noise described above to have greater reflectivity for the k+3, k+5, k+7, … th reflections that occur on the out-coupling device 30. Specifically, taking fig. 2 (c) as an example, a reflection occurrence area causing the noise generation is determined on the surface of the optical waveguide 20 based on ray tracing, and a film structure is designed with a specific requirement for reflectivity, and the film may have a characteristic change with a position change.

Example 2

Fig. 5 shows k=2 and from an equivalent exit point S ₁ For example, in the vertical section P _θ In this, another example of an optical structure for implementing the display method is shown. The vertical section P _θ In, via equivalent exit point S ₁ Of the thin rays incident on the

optical waveguide

20, 1 is the corresponding minimum reflection angle θ _mi Is 2 is the corresponding maximum reflection angle theta _ma Is a fine light ray of (2). The structure includes an auxiliary support structure 60, the auxiliary support structure 60 being secured together by a connection and an optical waveguide, the coupling-out device 30 being fabricated on the auxiliary support structure 60. In case the out-coupling device 30 needs to cover part of the active reflective surface, the out-coupling device 30 may be partly prepared on the active reflective surface and partly prepared with the auxiliary support structure 60. FIGS. 5 (a) to (c), θ _ma -θ _mi Gradually increasing. Unlike FIG. 2, the effective reflection surface for K-1 reflection in FIGS. 5 (a) and (b) may be 1 in the light transmission direction x _θ There is no more than K reflections in the extended regions, and the extended regions serve as connection regions for the optical waveguide 20 and the auxiliary support structure 60. In fig. 4 (c), neither effective reflective surface of the optical waveguide extends. In FIG. 5 (a), design (a+ (K+1) e) tan (θ) _mi )>(a+(K-1)e)tan(θ _ma ) No more than K reflections occur at the reflecting surface. Similar to fig. 2, e is the thickness of the optical waveguide 20, and a is the distance between the equivalent exit point and the effective reflective surface where the first reflection occurs. Also, with θ _ma -θ _mi When (a+ (K+1) e) tan (θ) _mi )≦(a+(K-1)e)tan(θ _ma ) When there are more than K reflections of the fine light. At (a+Ke) tan (θ _mi )<atan(θ _ma ) When the outcoupling means 30 occupies part of the effective reflective surface, as shown in FIG. 4 (c)

An area. In this case the out-coupling device 30 may be connected by an area on the active reflective surface before the 1 st reflection occurs. Similar to the discussion related to fig. 2, in the case of fig. 5, the angular selective out-coupling device 30 may be similarly designed, or the noise caused by reflection of each of the beamlets greater than the kth time may be avoided or suppressed by coating the surface of the optical waveguide or/and coating the out-coupling device.

Fig. 6 at k=2 and from one equivalent exit point S ₁ For example, in the vertical section P _θ In the interior, an optical structure is shown for implementing the display method. The vertical section P _θ In, via equivalent exit point S ₁ Of the thin rays incident on the

optical waveguide

20, 1 is the corresponding minimum reflection angle θ _mi Is 2 is the corresponding maximum reflection angle theta _ma Is a fine light ray of (2). The difference from the structure shown in fig. 2 is that in the structure shown in fig. 6, both effective reflection surfaces of the optical waveguide 20 are extended, and the coupling-out device 30 is prepared on the surface of the optical waveguide 20 where the K-1 th reflection of the fine light occurs. FIGS. 6 (a) to (c), θ _ma -θ _mi Gradually increasing. FIG. 6 (a) shows a vertical section P _θ On, (a+ (K+1) e) tan (θ) _mi )>(a+(K-1)e)tan(θ _ma ) Respectively by P ₂₁ And P ₂₂ No reflection greater than the kth time occurs on the effective reflective surface, which is the outer edge point, but a reflection greater than the kth time occurs on each extended surface. Similar to fig. 2, e is the thickness of the optical waveguide 20, and a is the distance between the equivalent exit point and the effective reflective surface where the first reflection occurs. Also, with θ _ma -θ _mi When (a+ (K+1) e) tan (θ) _mi )≦(a+(K-1)e)tan(θ _ma ) When the reflection is greater than the kth time on the effective reflection surface, as shown in fig. 6 (b) and 6 (c). At (a+Ke) tan (θ _mi )<atan(θ _ma ) When the outcoupling means 30 occupies part of the effective reflective surface, as shown in FIG. 4 (c)

An area. Similar to the discussion related to fig. 2, in the case of fig. 6, the angular selective out-coupling device 30 may be similarly designed, or by coating the optical waveguide surfaces (including the effective reflective and extended surfaces) to avoid or suppress noise caused by reflection of each thin ray greater than the kth time.

The optical structure shown in fig. 7 is based on the optical structure shown in fig. 2, and further comprises an auxiliary waveguide 70, wherein the auxiliary waveguide 70 and the upper and lower surfaces of the optical waveguide 20 are respectively connected in a coplanar manner, and the refractive index of the auxiliary waveguide 70 is smaller than that of the optical waveguide 20,to reduce the reflectivity of the reflections occurring within the auxiliary waveguide 70 that are greater than the kth time. FIGS. 7 (a) to (c), θ _ma -θ _mi Gradually increasing, similar to the case of fig. 2 (a) to (c). In FIG. 7 (a), (a+ (K+1) e) tan (θ) _mi )>(a+(K-1)e)tan(θ _ma ) No reflection greater than the kth time occurs on the effective reflective surface of the optical waveguide 20. Also, with θ _ma -θ _mi When (a+ (K+1) e) tan (θ) _mi )≦(a+(K-1)e)tan(θ _ma ) More than K reflections may also occur at the effective reflective surface. At (a+Ke) tan (θ _mi )<atan(θ _ma ) When the outcoupling means 30 occupies part of the effective reflective surface, as shown in FIG. 4 (c)

An area. Similar to the discussion related to fig. 2, in the case of fig. 7, the angular selective out-coupling device 30 may be similarly designed, or noise caused by reflections of each of the beamlets greater than the kth time may be avoided or suppressed by coating the surface of the optical waveguide with a coating. Further, each of the plating films may be further designed on the surface of each auxiliary waveguide. In FIG. 7, the refractive index of the optical waveguide 20 is shown as the same value n ₁ The refractive index of the auxiliary waveguide 70 is shown as the same value n ₂ . In practice, the refractive index of the auxiliary waveguide 70 may be graded, or non-uniform with spatial position; even the refractive index of optical waveguide 20 may be graded or non-uniform with spatial position. For example, the optical waveguide structure shown in FIG. 6 has a refractive index lower than that of the vertical section P _θ Inner edge x _θ The direction is distributed in a changing manner. The refractive index change distribution may be a refractive index stepwise change, a refractive index continuously graded, or a combination of both. The optical waveguide 20 or the auxiliary waveguide body 70 may be made of optical glass, resin, plastic, polymer, or the like, or a combination of these materials. The design of the optical waveguide with the refractive index changing along with the spatial position meets the following requirements: under the condition that any fine light rays emitted by the K+K' th reflection finally form noise light beams, the reflectivity of the secondary reflection or/and the last reflection is regulated and controlled through a coating film so as to reduce the corresponding pair of the fine light rays The incident light intensity of the eye box. With respect to the optical structure shown in fig. 7, the effective reflection surfaces in the optical structure shown in fig. 8 are not extended, and both surfaces of the auxiliary waveguide 70 and both effective reflection surfaces of the optical waveguide 20 are directly connected in a coplanar manner, respectively. The connection may be in the form of a glue, a split bond or the like, which optimally does not affect the incidence of external ambient light.

In each of the above optical structures, each divergent light beam projected by the projector may first pass through the unidirectional converging device 50 shown in fig. 9 and then enter the optical waveguide 20. The unidirectional converging means 50 compresses the divergence of the diverging light beam in a vertical direction parallel to the effective reflective surface. FIG. 8 shows a cylindrical lens with a long axis O' parallel to the effective reflection surface of the optical waveguide 20 as the unidirectional converging device 50, and the projection light machine 10 projects through a spatial point S ₁ For example, and defines the O' O "axis as the divergent direction. Due to the introduction of the unidirectional converging device 50, when each thin light ray of the divergent light beam shown in fig. 9 enters the optical waveguide 20 through the unidirectional converging device 50, the reverse extension line of each thin light ray is no longer converged at a certain spatial point, that is, the divergent light beam no longer has a corresponding equivalent exit point. The diverging light beam without the corresponding equivalent exit point can also be determined to be a sideline of the effective reflecting surface based on the rule. After passing through the unidirectional converging device 50, the fine light rays in each vertical tangential plane enter the optical waveguide 20 after the difference between the maximum reflection angle and the minimum reflection angle corresponding to the unidirectional converging device 50 becomes smaller due to the vertical converging function. At the most extreme, there is a vertical section, as shown in FIG. 8, vertical section P ₀ In the vertical section, each thin light ray exits the unidirectional converging device 50 in parallel. The introduction of the unidirectional converging device 50 can ensure that each divergent light beam projected by the projector 10 propagates in the optical waveguide 20 along the two-dimensional direction; and by reducing the divergence of each diverging beam from the projection light engine 10 in the vertical direction (the vertical direction of the effective reflective surface of the optical waveguide), the following is achieved: the beamlets of the same diverging beam, after the kth reflection, are located to exit the beamlets at modulated exit points on the outcoupling device 30 with a more uniform pitch along the light transport direction. In this patent, each minute ray from the same divergent beam after the K-th reflectionAt each exit point on the out-coupling device 30, which is functionally equivalent to a display pixel, a relatively good uniformity is desired. The uniformity of the arrangement pitch of the exit points on the coupling-out device 30 after the kth reflection of each fine light of the same divergent light beam can also be improved by designing different angular pitches between the fine light of the same divergent light beam, and the respective maximum reflection angle and minimum reflection angle in each vertical tangential plane, and even the first reflection point position of each fine light on the equivalent reflection surface.

FIG. 10 is a vertical section P of FIG. 9 ₀ In the optical waveguide 20, the thin light rays which are parallel to the optical waveguide 20 after passing through the unidirectional converging device 50 are reflected in the optical waveguide 20 at an angle of theta _m The reflections that are made propagate. The outcoupling device 30 receives exactly all the beamlets emitted by the kth reflection in its entirety. At this time, incidence of the coupling-out device by the fine light emitted by the reflection larger than the kth time does not occur. However, considering that the projector 10 projects a plurality of divergent light beams, the size of the coupling-out device 30 needs to be enlarged to receive all the fine light rays emitted from all the divergent light beams by the kth reflection. At this time, incidence of the coupling-out device by the fine light rays emitted by the kth reflection may occur more than that, especially, θ corresponding to each divergent light beam projected by the projection optical machine 10 _m Let b/cos (θ) _m ) Near or even equal to 2etan (θ) _m ) When (1). At this time, attention is also paid to suppression of the corresponding noise. Wherein b is a vertical tangential plane P ₀ Internal reflection angle theta _m Corresponding to the vertical dimension of the beam formed by the parallel beamlets in the propagation direction when the parallel beamlets are incident on the optical waveguide 20.

In the

above embodiments

1, 2, the divergent light beam projected by the projector 10 is shown as being directly incident on the optical waveguide 20 or being incident on the optical waveguide 20 only through the unidirectional converging device 50. In practice, it is also possible to enter the optical waveguide 20 via various guiding optical devices, such as mirrors, prisms, etc. that deflect the direction of propagation of the incident light. After entering the optical waveguide 20, the incident light may be guided to propagate along a specific reflection angle by a coupling structure (not shown in this patent) of the optical waveguide 20, for example, a reflection surface, which is formed in the optical waveguide and deflects the transmission direction of the incident light, or a diffraction device structure. These are conventional methods in the optical waveguide display technology, and although not shown, those skilled in the art will readily recognize these devices or structures and not create new innovations based on this patent due to the introduction of these structures or devices. Note that the reflection of each minute light ray before the first reflection on the surface of the optical waveguide 20 is not counted in the K reflections described in this patent.

In the above embodiments, the pupil tracking unit 80 may be further introduced, as shown in fig. 1. By using the pupil tracking unit 80, the position of the corresponding pupil is determined in real time, and the control device 40 controls the projector 10 to activate only part of the corresponding divergent light beams to display according to the real-time position of the corresponding pupil, so as to reduce the requirement on the time division multiplexing degree of the display structure or the requirement on the data quantity under the condition of spatial multiplexing.

Example 3

Fig. 11 shows an example of a projection light engine 10, which includes a display device 101 and a time-sequential light source set 102. The time-series light source group 102 is composed of t+.2 light sources, wherein the T light sources can be turned on in time series under the driving of the control device 40. Fig. 11 is an example of t=3 light sources, S ₁ ，S ₂ ，S ₃ . The display device 101 comprises a plurality of pixels or sub-pixels, which may be driven by the control device 40 to load light information. At T time points of each time period, the T light sources of the time-sequence light source group 102 are turned on in time sequence, the display device 101 synchronously loads corresponding light information, and time sequence projection of three divergent light beams with the point where the three light sources are located as an equivalent exit point can be realized. Fig. 11 illustrates a transmissive display device, which may also be a reflective display device. The light from each light source is reflected by the reflective display device 101 and then enters the light guide, which may also be guided by the coupling-in device (typically a conventional light guide). The structure shown in fig. 11 may further include a phase device 104 and an aperture group 106 consisting of T apertures, as shown in fig. 12. Wherein the phase device 104 can be used for t=3 light sources S ₁ ，S ₂ ，S ₃ Separately imaged, such as a lens. The T light sources are respectively converged to T apertures of the aperture set 106 via the phase device 104. The T aperturesActing as a filtering function, the divergence of each thin ray of incident light guide 20 can be constrained. The function of a plurality of light sources may also be performed by one controllable deflection device 102. As shown in fig. 13. The projection light engine 10 comprises a display device 101 and a light source 1020 for projecting backlight. A controllable deflection device 103, which is driven by the control device 40 and is capable of deflecting the outgoing direction of the incident light, is used for time-sequentially deflecting the backlight from the light source 1020, equivalently realizing the projection of a plurality of divergent light beams. The display device 101 in fig. 13 may be an active light emitting device or a passive light emitting device carrying a backlight. In fig. 11 to 13, the display device 101 is disposed between the light source and the optical waveguide 20, i.e., before the optical waveguide 20. It may also be placed after the light guide, guided by the light guide, emitted by the light source, and modulated by the out-coupling device 30 as a backlight, as shown in fig. 14. In this case, information corresponding to each beamlet is loaded under the control of control device 40 by display device 101 disposed behind optical waveguide 20. The display device 101 shown in fig. 14 is a transmissive device, which may also be a reflective device. In addition, the projection device 90 may be further introduced in the light transmission direction to magnify the display device 101 into a virtual image. In the optical structures shown in fig. 11 to 14, the pixels or sub-pixels of the display device 101 may be divided into o+.2 pixel groups or sub-pixel groups, where the O pixel groups or sub-pixel groups modulate the O different characteristic backlights respectively in a one-to-one correspondence manner and emit the respective modulated light beams, and each pixel group or sub-pixel group prevents the backlight of the other (O-1) non-corresponding characteristics from emitting. At this time, each light source is designed to be composed of O sub-light sources, respectively, which project backlights each having the O characteristics. The pixels or sub-pixels of the O ≡ 2 pixel groups or sub-pixel groups are optimally arranged or arranged. The O species should have mutually distinguishable characteristics. For example, a pixel corresponding to one characteristic modulates only incident light having the corresponding characteristic; for other (O-1) non-corresponding characteristics, the pixel does not allow its incidence and then does not emit modulated light. The different characteristics may be a line bias in which bias directions are perpendicular to each other, a timing characteristic in which different times are activated respectively, a combination of both, or the like. FIG. 15 shows polarization directions perpendicular to each other O=2 distinct properties are exemplified, which are denoted by "·" and "-" respectively. Each light source is composed of sub-light sources for emitting light of the two characteristics, for example, sub-light source OS of light source S1 ₁₁ And OS (operating system) ₁₂ The "·" light and "-" light are emitted, respectively. The pixels of the display 101 are divided into o=2 groups, modulating outgoing "·" light and "-" light, respectively. Specifically, pixel p _nm ,p _nm+2 ,…；p _n+1m+1 ,p _n+1m+3 …; … the pixel group only allows the incident "-" light to be modulated and then emitted, and prevents "·"; pixel p _nm+1 ,p _nm+3 ,…；p _n+1m ,p _n+1m+2 The group of … pixels only allows the incident "·" light to be modulated and then emitted, preventing the "-". The attached polarizer may be used to achieve "·" and "-" characteristics for each sub-light source, or each pixel, or each sub-pixel. Then, the sub-light sources OS are turned on at the same time ₁₁ And OS (operating system) ₁₂ The outgoing backlights are respectively modulated by the corresponding pixel groups, and project O=2 scattered light beams. When the sub-light sources corresponding to the other light sources are designed in a similar way, the projection of the scattered light beams of the T x O beams can be implemented at T time points with each O=2 sub-light sources which are opened in time sequence. Here, the case where the projection light machine 10 includes only O sub-light sources of one time series light source is also allowed, corresponding to the case where there is no time series multiplexing.

The projection light machine 10 shown in fig. 16 includes a display device 101, a phase device 104 for converging light projected from the display device 101, and a time-series aperture group 105 which is formed by T ∈2 time-series apertures capable of being opened in time series under the drive of the control device 40 to allow the light beam projected from the display device 101 to pass through. With the timings of the T timing apertures open, the display device 101 synchronously loads the light information of the divergent light beams corresponding to the open timing apertures, respectively, so that the timing projection of the T divergent light beams can be realized. Fig. 16 has a lens as the phase device 104 and the timing aperture set 105 is placed in its focal plane. The temporal aperture set 105 may also be placed in a non-focal plane of the phase device 104. The display device 101 of fig. 16 may be an active light emitting device or a passive light emitting device with a backlight. The function of the timing aperture group 105 may also be to exit from one timing aperture 1050 and deflect the timing aperture 1050The controllable deflection device 103 of the light propagation direction is realized as shown in fig. 17. The control device 40 drives the controllable deflection device 103 to deflect the emergent light from the time sequence aperture 1050 in time sequence, and the display device 101 synchronously loads light information under the control of the control device 40, so that the projection of a plurality of divergent light beams to the optical waveguide 20 can be realized. In the optical structures shown in fig. 16 to 17, the pixels or sub-pixels of the display device 101 may be divided into o+ 2 pixel groups or sub-pixel groups, and the O pixel groups or sub-pixel groups respectively emit O kinds of different characteristic lights in a one-to-one correspondence manner. At this time, each of the timing apertures is designed to be composed of O sub-apertures having the O characteristics, respectively, each of which allows only light of the corresponding characteristic to pass therethrough, blocking light of other (O-1) non-corresponding characteristics. The pixels or sub-pixels of the O ≡ 2 pixel groups or sub-pixel groups are optimally arranged or arranged. The O species should have mutually distinguishable characteristics. The different characteristics may be a line bias in which bias directions are perpendicular to each other, a timing characteristic in which different times are activated respectively, a combination of both, or the like. Fig. 18 exemplifies o=2 different characteristics with polarization directions perpendicular to each other, which are denoted by "·" and "-" respectively. Each of the timing apertures is composed of sub-apertures allowing light of the two characteristics, respectively, e.g. sub-aperture A of timing aperture A1 ₁₁ And A ₁₂ Allowing "·" light and "-" light to pass through, respectively. The pixels of the display 101 are divided into o=2 groups, and emit "·" light and "-" light, respectively. Specifically, pixel p _nm ,p _nm+2 ,…；p _n+1m+1 ,p _n+1m+3 …; … the pixel group emits "-" light; pixel p _nm+1 ,p _nm+3 ,…；p _n+1m ,p _n+1m+2 … make up the pixel set exit "·". Preventing the emergence of "-". Then, the sub-aperture A is opened at the same time ₁₁ And A ₁₂ The distribution allows the light information projected by the two pixel groups to pass. If the sub-apertures corresponding to the time sequence apertures are designed in the same way, the projection of the scattered beam of the T x O beam can be implemented at T time points with each o=2 sub-apertures opened in the time sequence. Here, the case where the projection optical machine 10 includes only O sub-apertures of one sequential aperture is also allowed, corresponding to the case where there is no sequential multiplexing.

In fig. 19, the microstructure controlling device 107 is disposed corresponding to the display device 101, and modulates the propagation direction of the outgoing light or the incoming light of each pixel or sub-pixel of the display device 101, so that S > 2 pixel groups or sub-pixel groups of the display device 101 project light information to S apertures respectively in a one-to-one correspondence. The projector 10 shown in fig. 19 can project S divergent light beams based on spatial multiplexing. Further, adjacent apertures may be designed to allow only light of different characteristics to pass therethrough, respectively, and the characteristics of the light projected by the pixel group or sub-pixel group corresponding to each aperture correspond to the characteristics of the light allowed to pass therethrough by the corresponding aperture, so as to reduce crosstalk of information between the adjacent apertures. Obviously, in the structure of the projection optical engine 10 shown in fig. 19, if the display device 101 adopts a backlight device, and the corresponding backlight structure can be used for time-sequence incidence of T beams in T different directions, more t×s beams can be projected by combining spatial multiplexing and time-sequence multiplexing.

The functions of projector 10 may also be implemented by scanning projection unit 108. As shown in fig. 20, the projection unit 108 includes a scanning device 1081, and a modulated beam generating unit 1082. The light beam generating unit 1082 includes R (red), G (green), and B (blue)

light sources

1082R, 1082G, 1082B, and the light beams projected by the light sources are collectively referred to as a light beam through the reflecting mirror 1082MR, the half mirror 1082G, and the half mirror 1082B. The resultant beamlets are scanned by scanning device 1081 at a two-dimensional angle to form a divergent beam projection. Wherein each light source synchronously loads corresponding information under the control of the control device 40. The scanning projection unit 108 can flexibly control the reflection angle corresponding to each fine light in any vertical tangential plane, including the angular interval between adjacent fine light, so as to improve the uniformity of the distribution of the emitting points of each emitting light beam on the coupling-out device 30 through the flexible control of the angular interval. The projection engine 10 may further comprise more than one scanning projection unit, such as the scanning projection units 108 and 108' of fig. 21.

In addition, the display structure may also be placed by more than one optical waveguide stack, such as optical waveguides 20 and 20' of FIG. 22. Each optical waveguide 20 corresponds to a respective projection light engine 10, 10 'and coupling-out device 30, 30'. In fig. 22, the optical waveguides 20 and 20 'are shown as being each designed with a corresponding auxiliary waveguide 70 and 70'.

The invention uses divergent light beam to enter the light waveguide, uses the light waveguide to reflect and spread the thin light rays contained in the incident light beam along the two-dimensional direction, designs each thin light ray to be reflected for K times in preset, modulates the thin light rays by the coupling-out device, two-dimensionally distributes and emits the thin light rays on the coupling-out device, and projects a two-dimensional image to the pupil of an observer in the eye box. The beamlets are designed to have no reflections greater than K or to be directed away from the eyebox for propagation by reflections greater than K to suppress display noise introduced by reflections greater than K. The display method can realize three-dimensional display for overcoming focusing-convergence conflict based on Maxwell Wei Toushe or monocular multiple images in a light and thin optical structure. The adopted optical waveguide does not need pupil expansion or a turning structure, and the requirements on the preparation process of the optical waveguide are greatly reduced.

The foregoing is merely a preferred embodiment of the present invention, but the design concept of the present invention is not limited thereto, and any insubstantial modifications made by using the concept fall within the scope of the present invention. For example, various conventional optical waveguide structures can be used as the optical waveguide of the present patent; for example, an existing optical waveguide structure formed by stacking three monochromatic optical waveguides and capable of projecting color light information may be used, for example, various micro-nano structures capable of modulating the emitting direction of each pixel or sub-pixel of the display device may be used as the micro-structure control device of the present patent, and for example, various other optical structures capable of projecting at least one diverging light beam (including a diverging light beam without a corresponding equivalent emitting point) may be used as the projection light machine of the present patent. Accordingly, all such related embodiments are intended to fall within the scope of the present invention.

Claims

1. Display method based on asymmetric effective reflective surface optical waveguides, characterized in that it uses a display structure comprising a projection light engine (10), an optical waveguide (20) comprising two effective reflective surfaces, a coupling-out device (30) and a control device (40), comprising:

s1, constructing the projection optical machine (10) into a beam which is constructed by fine light rays and is divergent at least along one dimension;

s2, guiding divergent light beams from the projection optical machine to enter an optical waveguide (20) with two effective reflection surfaces as upper and lower surfaces;

s3, selecting a positive integer K value larger than zero, and designing that each fine light ray only reflects K times on an effective reflecting surface of the optical waveguide (20):

in any vertical tangential plane, the area covered by the reflection point of the K-th reflection of all the fine light is designed to be exactly covered by the effective reflection surface of the K-th reflection along the outer line of the fine light in the propagation direction of the optical waveguide (20), and the area covered by the reflection point of the K-1 th reflection of all the fine light is designed to be exactly covered by the effective reflection surface of the K-1 th reflection along the outer line of the fine light in the propagation direction of the optical waveguide (20), wherein K is not less than 1, and the vertical tangential plane refers to a plane containing at least one incident fine light and at least one normal line of the effective reflection surface of the optical waveguide;

S4, reflecting the emitted fine light rays for the Kth time, entering the coupling-out device (30), regulating and controlling the coupling-out device (30), and projecting the fine light rays to the corresponding eye boxes;

s5, the control device (40) sets light information carried by all the fine lights as projection information of a propagation path of a scene to be displayed when the scene is incident into a corresponding eye box by controlling the projection optical machine (10), and the fine lights incident into pupils of an observer in the eye box are designed to be reverse extension lines of the fine lights so as to cover the scene to be displayed;

2. The method for displaying an optical waveguide based on an asymmetric effective reflective surface of claim 1, further comprising: extending the surface of the optical waveguide on the surface of the effective reflecting surface where the K-1 th reflection occurs;

3. The method for displaying an optical waveguide based on an asymmetric effective reflective surface of claim 2, further comprising: further extending the surface of the optical waveguide on the surface of the effective reflecting surface where the Kth reflection occurs;

4. A display method based on an asymmetric effective reflective surface optical waveguide according to any one of claims 1-2, further comprising: an auxiliary waveguide (70) is provided in coplanar connection with the optical waveguide (20), and the reflectivity of the fine light rays in the auxiliary waveguide (70) is reduced to be greater than the reflection of the Kth time by designing a smaller refractive index value of the auxiliary waveguide (70) relative to the optical waveguide (20).

5. A display method based on an asymmetric effective reflective surface optical waveguide according to any one of claims 1-3, further comprising: the coupling-out device (30) with angle-selective properties is designed to prevent the incident coupling-out of light rays emitted by reflections greater than the K+1st time, or to regulate the guiding of light rays around the eyebox.

6. The method of displaying an optical waveguide based on an asymmetric effective reflective surface of claim 4, further comprising: the coupling-out device (30) with angle-selective properties is designed to prevent the incident coupling-out of light rays emitted by reflections greater than the K+1st time, or to regulate the guiding of light rays around the eyebox.

7. A display method based on an asymmetric effective reflective surface optical waveguide according to any one of claims 1-3, further comprising: any fine light rays emitted by the K+K 'th reflection are subjected to film coating to regulate the reflectivity of the secondary reflection or/and the last reflection under the condition that the fine light rays finally enter the eye boxes, so that the incident light intensity when the fine light rays finally enter the corresponding eye boxes is reduced, wherein K' is larger than or equal to 1.

8. The method of displaying an optical waveguide based on an asymmetric effective reflective surface of claim 4, further comprising: any fine light rays emitted by the K+K 'th reflection are subjected to film coating to regulate the reflectivity of the secondary reflection or/and the last reflection under the condition that the fine light rays finally enter the eye boxes, so that the incident light intensity when the fine light rays finally enter the corresponding eye boxes is reduced, wherein K' is larger than or equal to 1.

9. The method of displaying an optical waveguide based on an asymmetric effective reflective surface of claim 1, further comprising: when the light guide (20) is incident, each light ray or the reverse extension line of each light ray of the light beam projected by the projection light machine (10) is intersected with a corresponding space point, and the space point is named as an equivalent emergent point corresponding to the divergent light beam.

10. The method of displaying an asymmetric effective reflective surface optical waveguide according to claim 1, wherein the display structure further comprises a pupil tracking unit (80) connected to the control device (40), the method of displaying further comprising: the corresponding pupil position is determined in real time by using the pupil tracking unit (80), and the control device (40) controls the projection optical machine (10) to activate only the projection part of the divergent light beam according to the real-time position of the corresponding pupil so as to implement display.

11. A display structure for implementing a display method based on an asymmetric effective reflective surface optical waveguide according to any of the claims 1-10, characterized in that it comprises a projection optics (10), an optical waveguide (20) comprising two effective reflective surfaces, a coupling-out device (30) and a control device (40) in signal connection with the projection optics (10).

12. A display structure for implementing a display method based on an asymmetric effective reflective surface optical waveguide according to any one of claims 1-10, characterized in that it comprises a projection light engine (10), an optical waveguide (20) with two effective reflective surfaces as surfaces, a coupling-out device (30), a control device (40) in signal connection with the projection light engine (10) and a unidirectional converging device (50), wherein the unidirectional converging device (50) reduces the divergence of each diverging light beam in the vertical direction of the effective reflective surfaces before each diverging light beam enters the optical waveguide (20).

13. A display structure according to claim 11 or 12, further comprising an auxiliary support structure (60) attached to the optical waveguide (20).

14. A display structure according to claim 13, characterized in that the connection area of the auxiliary support structure (60) and the waveguide (20) is a surface area before the first reflection occurs in the reverse direction of the transmission direction of the reflection of the fine light or an extended area which is included in the surface of the optical waveguide (20) where the K-1 th reflection occurs by the fine light and which does not occur the k+1 th reflection.

15. The display structure according to claim 11 or 12, wherein the projection light machine (10) comprises a display device (101) and a time sequence light source group (102) consisting of T light sources capable of being turned on in time sequence under the driving of the control device (40), wherein the display device (101) capable of loading information under the driving of the control device (40) comprises a plurality of pixels or sub-pixels, the T light sources of the time sequence light source group (102) provide backlight to the display device (101) in time sequence at T time points of any time period, and T is equal to or greater than 2;

The display device (101) is placed between the time-series light source group (102) and the light guide (20), i.e. before the light guide (20), or after the light guide (20).

16. The display structure according to claim 11 or 12, characterized in that the projection light machine (10) comprises a display device (101), a light source (1020) providing a backlight and a controllable deflection device (103) capable of deflecting the outgoing direction of the incoming light under the drive of the control device (40), the time-sequential deflection of the incoming or outgoing light of the display device (101) by the controllable deflection device (103) projecting a plurality of diverging light beams time-sequentially;

17. The display structure of claim 16, further comprising a phase device (104) and an aperture group (106) of T apertures, wherein the T time-sequential light sources are respectively converged to the T apertures of the aperture group (106) via the phase device (104).

18. A display structure according to claim 16 or 17, characterized in that a projection device (90) is arranged to enlarge the virtual image of the display device (101) in the light transmission direction.

19. A display structure according to claim 16 or 17, characterized in that the pixels or sub-pixels of the display device (101) are divided into O pixel groups or sub-pixel groups, which modulate respectively O different characteristic backlights in a one-to-one correspondence and emit respectively corresponding modulated light beams, each pixel group or sub-pixel group preventing the exit of other (O-1) non-corresponding characteristic backlights, and each light source respectively consisting of O sub-light sources projecting respectively backlights with said O orthogonal characteristics, wherein O is ∈ 2;

The projection light machine (10) projects O divergent light beams respectively at O sub-light sources of the light source which are turned on at each time point.

20. The display structure according to claim 11 or 12, wherein the projection light machine (10) comprises a display device (101), a phase device (104) for converging light projected from the display device (101), and a time-series aperture group (105) formed by T time-series apertures capable of being opened in time series under the driving of the control device (40) to allow the light beam projected from the display device (101) to pass therethrough, wherein t+.2;

t time sequence apertures of the time sequence aperture group (105) are opened at T time points of any time period in time sequence, and the projection optical machine (10) takes the T time sequence apertures as equivalent emergent points to project divergent beams in time sequence.

21. A display structure according to claim 11 or 12, characterized in that the projection light machine (10) comprises a display device (101), a phase device (104) for converging the light projected by the display device (101), a time-sequential aperture (1050) for allowing the light projected by the display device (101) to pass through, and a controllable deflection device (103) capable of time-sequentially deflecting the light exiting from the time-sequential aperture (1050) under the drive of the control device (40), the time-sequential deflection of the light exiting from the time-sequential aperture (1050) by the controllable deflection device (103) projecting a plurality of diverging light beams time-sequentially.

22. A display structure according to claim 20 or 21, wherein the pixels or sub-pixels of the display device (101) are divided into O pixel groups or sub-pixel groups, which respectively emit O different characteristic lights in a one-to-one correspondence, and wherein any timing aperture is composed of O sub-apertures, which respectively allow the O characteristic lights to pass in a one-to-one correspondence, each sub-aperture blocking the other (O-1) non-corresponding characteristic lights to pass, wherein O is ∈2.

23. The display structure according to claim 11 or 12, wherein the projection light machine (10) comprises a display device (101) constructed by pixels or sub-pixels, a microstructure control device (107), and an aperture group (106) formed by S apertures, the pixels or sub-pixels of the display device (101) are divided into S pixel groups or sub-pixel groups, and the microstructure control device (107) controls the incident light or the emergent light of the display device (101) so that the S pixel groups or sub-pixel groups of the display device (101) respectively project light information to the S apertures in a one-to-one correspondence manner, wherein S is ∈2.

24. A display structure as claimed in claim 23, characterized in that adjacent apertures each allow only light of a different characteristic to pass through, and the characteristics of the light projected by the group of pixels or sub-groups of pixels corresponding to each aperture correspond to the characteristics of the light allowed to pass through by the corresponding aperture.

25. A display structure according to claim 11 or 12, characterized in that the projection light machine (10) is a scanning projection unit (108) comprising a scanning device (1081) and a modulated light beam generating unit (1082), wherein the light beam emitted by the modulated light beam generating unit (1082) is deflected by the scanning device (1081) in time sequence, the light beams are projected in different directions, and the light beam emitted by the modulated light beam generating unit (1082) carries corresponding light information under the control of the control device (40).

26. The display structure of claim 25, wherein the projection engine (10) comprises more than one scanning projection unit (108).

27. A display structure according to claim 11 or 12, characterized in that more than one light guide (20) is arranged in a stack, each light guide (20) corresponding to a respective projection light engine (10) and coupling-out device (30).

28. A display structure according to claim 27, wherein each optical waveguide (20) further corresponds to a respective auxiliary waveguide body (70).