CN114911001A

CN114911001A - Diffraction light waveguide for improving light-emitting uniformity and application thereof

Info

Publication number: CN114911001A
Application number: CN202110168421.5A
Authority: CN
Inventors: 张雅琴; 楼歆晔; 胡雪蕾; 黄河; 林涛
Original assignee: Shanghai Kunyou Technology Co ltd
Current assignee: Shanghai Kunyou Technology Co ltd
Priority date: 2021-02-07
Filing date: 2021-02-07
Publication date: 2022-08-16

Abstract

The invention mainly provides a coupling-in component, a diffraction optical waveguide for improving light-emitting uniformity and a projection method thereof, wherein the diffraction optical waveguide for improving light-emitting uniformity is used for projecting light to at least one light ray. In the diffractive optical waveguide for improving the uniformity of the emitted light, the incoupling component can be used in cooperation with the outcoupling part, so that the light rays with different field angles can reach the outcoupling part after being diffracted by the incoupling component and uniformly cover the outcoupling part, thereby improving the utilization rate of the light rays.

Description

Diffraction light waveguide for improving light-emitting uniformity and application thereof

Technical Field

The invention belongs to the field of optical elements, and particularly relates to a diffraction optical waveguide capable of improving light-emitting uniformity and a projection method thereof.

Background

Augmented Reality (AR) is a technology that integrates the real world with virtual information, and an AR display system generally includes a micro-projector and an optical display screen through which pixels on the micro-projector are projected into the human eye, and at the same time, a user can see the real world through the optical display screen. The pico-projector provides virtual content to the device and the optical display screen is typically a transparent optical component.

Optical waveguides are one way of achieving optical display screens. When the refractive index of the transmission medium is larger than that of the surrounding medium and the incident angle in the waveguide is larger than the critical angle of total reflection, light can be transmitted in the waveguide without leakage, and total reflection occurs. After light from the projector is coupled into the waveguide, the light continues to propagate the image within the waveguide without loss until it is coupled out by subsequent structures. At present, optical waveguides on the market are generally divided into geometric array waveguides and diffraction optical waveguides, wherein the diffraction optical waveguides are divided into volume holographic waveguides and surface relief grating waveguides, and the essence is that incident light is coupled into the waveguides for transmission through grating diffraction.

Regarding technical parameters and technical indexes of the AR waveguide, the technical parameters of the AR waveguide mainly include a field angle FOV, a viewing distance eye relief, an orbit size eye box, and the like. The field of view is typically indicated by diagonal angles, e.g., 40 °, corresponding to a field of view of about 35 ° (H) 20 ° (V) for a 16:9 scale frame; the visual distance is usually about 20-25mm, and the wearing requirements of most users can be basically met, including the user wearing myopia glasses; the orbit size determines the range of free movement of the user's eye, and larger sizes are less likely to lose images and are therefore more adaptable. The horizontal size of the orbit needs to be able to adapt to the range of the exit pupil distance of the human eye and give the user different horizontal wearing references foot margins, and the vertical size of the orbit needs to be adapted to the vertical wearing references of the user. It is generally believed that orbital size 15mm (h) x 10mm (v) may meet the basic requirements of the user experience.

The AR waveguide takes high efficiency and good uniformity as optimization targets, and the high efficiency aims to realize higher brightness output under the same micro-projection input, so that a picture is bright enough when a human eye sees; the uniformity includes FOV uniformity, i.e. the full-field picture seen by human eyes has better brightness and color uniformity, and eyebox uniformity, i.e. the brightness difference received by human eyes at different positions of the eyebox (or when worn by users with different pupil distances and different heights of nose bridge) is as small as possible, and it is expected that the FOV uniformity is better at different positions.

More specifically, to ensure comfort, the opto-mechanical position of the waveguide glasses usually needs to be kept at a certain distance from the human eye, and to obtain the same size orbital range, there are two ways: mode 1 as shown in fig. 1A, 1B, which show the optical paths of (0 ° ) and (17 °, 10 °) respectively when the spacing between the incoupling grating 1 and the outcoupling grating 2 is small, fig. 1C shows the effective outcoupling means 3. When the coupling-out grating area 3 is large and the distance between the coupling-in grating 1 and the coupling-out grating 2 is small, the arrangement can ensure that the full-field light can reach and cover the whole range of the orbit, so as to achieve better field angle uniformity and orbit range uniformity, however, the light under the structure is diffracted for many times before reaching the range of the orbit, each time the light is diffracted by the two-dimensional grating at the moment means energy loss to a certain degree, and part of the light beam reaches an invalid area which does not contribute to the overall efficiency, so that the overall efficiency is low. Therefore, in order to improve efficiency, the incoupling grating 1 is usually designed as a sawtooth grating, an inclined grating, or an additional coating is required, which greatly increases the process difficulty and cost.

Mode 2 is shown in fig. 2A and 2B, which show the optical paths when the distance between the incoupling grating 1 and the outcoupling grating 2 is large (0 ° ) and (17 °, 10 °), respectively. The coupling-out grating area 3 is smaller, and the distance between the coupling-in grating 1 and the coupling-out grating 2 is larger, which can reduce the efficiency loss, as shown in fig. 2C, the whole two-dimensional grating area is the "effective coupling-out part 3", but in a large field of view, the light cannot cover the whole orbit range, so that the field angle uniformity in some areas of the orbit range is very poor. Fig. 3A shows a diagram of pupil position detection when the distance between the incoupling grating 1 and the outcoupling grating 2 is relatively long, and fig. 3B shows a diagram of full-field picture brightness distribution when detecting in the upper right of the orbit range.

Disclosure of Invention

One advantage of the present invention is to provide a coupling-in member, which is suitable for coupling in a light ray and can diffract the coupled-in light ray along a plurality of expected directions, so as to change the projection direction of the light ray.

Another advantage of the present invention is to provide a coupling-in element, which is suitable for coupling in a light ray and can expand the diffraction width of the coupled-in light ray and diffract the coupled-in light ray toward the same direction, thereby improving the diffraction efficiency and diffraction effect of the light ray.

Another advantage of the present invention is to provide an incoupling assembly, which is suitable for cooperating with an outcoupling component, so that the light rays with different angles of view can reach the outcoupling component after being diffracted by the incoupling assembly and uniformly cover the outcoupling component, thereby improving the utilization rate of the light rays.

Another advantage of the present invention is to provide a diffractive light waveguide for improving uniformity of light output, which can reduce energy loss caused by diffraction of light by a two-dimensional grating each time, so as to prevent a part of light beams from reaching an ineffective area that does not contribute to overall efficiency, thereby improving overall efficiency of light action.

Another advantage of the present invention is to provide a diffractive light waveguide for improving uniformity of output light, which can improve uniformity of diffraction of light without increasing process steps or process difficulty, thereby improving diffraction efficiency of light.

Another advantage of the present invention is to provide a diffractive light guide for improving uniformity of light extraction that can cover as much as possible the entire orbital range, thereby improving field angle uniformity in all areas of the orbital range over a large field of view.

Another advantage of the present invention is to provide a diffractive light waveguide for improving uniformity of light output, in which an independent deflection grating is disposed between an incoupling grating and an outcoupling grating and spaced apart from the incoupling grating and the outcoupling grating, so as to reduce the diffraction order of light, reduce loss of output efficiency of light, and thus improve the output efficiency of light.

Another advantage of the present invention is to provide a diffractive light waveguide for improving uniformity of light output, which can enable light rays with different angles of view to better cover an effective outcoupling means, thereby improving uniformity of light output.

Another advantage of the present invention is to provide a diffractive light waveguide for improving uniformity of emitted light, in which three one-dimensional gratings with different periodic directions or two-dimensional gratings equivalent to the one-dimensional gratings with three directions and two turning gratings are disposed to realize diffraction of incident light with different angles, and the light with different angles is diffracted and guided to different areas, so that the light with different angles of view can better cover an effective outcoupling component.

Another advantage of the present invention is to provide a diffractive light waveguide for improving uniformity of light output, which is suitable for different types of gratings, thereby improving applicability and convenience of use of the diffractive light waveguide for improving uniformity of light output.

Another advantage of the present invention is to provide a diffractive light waveguide for improving uniformity of emitted light, which can achieve better balance and improvement of the overall uniformity of emitted light by optimizing the position and area ratio of the incoupling grating and the sizes and shapes of the two turning gratings.

Another advantage of the present invention is to provide a diffractive light waveguide for improving uniformity of light output, which can further improve light utilization efficiency and uniformity of light output by optimizing microscopic parameters, such as depth, duty ratio, and tilt angle, of each grating.

Another advantage of the present invention is to provide a diffractive light waveguide for improving uniformity of output light, which can further improve the balance between the overall uniformity of output light and the light utilization efficiency by optimizing the incoupling grating microstructure to concentrate the diffraction efficiency in different three directions and by further optimizing the efficiency ratio of distributing the three directions.

Another advantage of the present invention is to provide a diffractive light waveguide for improving uniformity of light output, which can design the incoupling grating and the outcoupling grating to have different microstructure parameters according to practical situations, so that the diffractive light waveguide for improving uniformity of light output further meets specific application requirements.

Another advantage of the present invention is to provide a method of projecting a diffractive optical waveguide for improving uniformity of light extraction, which can uniformly cover light projected from a incoupling part to an outcoupling part, thereby improving light extraction efficiency.

Another advantage of the present invention is to provide a method for projecting a diffractive optical waveguide for improving uniformity of outgoing light, which is capable of adapting a diffractive optical waveguide structure in which an incoupling member is a one-dimensional grating or a two-dimensional grating, thereby improving an application range of the method for projecting a diffractive optical waveguide for improving uniformity of outgoing light.

To achieve at least the above advantages, the present invention provides a coupling-in component for coupling in a light beam, where the coupling-in component includes three one-dimensional gratings, and the grating directions of the three one-dimensional gratings are along the first axis direction and the direction forming a predetermined included angle with the first axis, respectively.

In some embodiments, the coupling-in component comprises a first grating, a second grating, and a third grating, wherein the first grating, the second grating, and the third grating are each an embossed grating or a holographic grating.

In some embodiments, the first grating, the second grating and the third grating respectively include a plurality of protrusions and a plurality of grooves, wherein the protrusions and the grooves are alternately and uniformly arranged.

In some of these embodiments, the first, second and third gratings are periodic alternating light and dark fringes formed within the material by holographic exposure.

In some embodiments, the grating direction of the first grating is along the first axis, the grating direction of the second grating is 60 ° to the first axis, and the grating direction of the third grating is-60 ° to the first axis.

The invention further provides a coupling-in component, which is arranged as a two-dimensional grating.

In some of these embodiments, the two-dimensional grating is a second two-dimensional grating, which can be equivalent to a ninth grating disposed along a second axis, a tenth grating disposed along a grating direction at 60 ° to the second axis, and an eleventh grating disposed along a grating direction at-60 ° to the second axis.

The present invention further provides an incoupling assembly for incoupling a light ray, comprising an incoupling part and a turning part, wherein the turning part is arranged at the light exit area of the incoupling part to be adapted to diffract the light ray emitted from the incoupling part.

In some of these embodiments, the coupling-in component includes a first grating, a second grating, and a third grating, wherein the first grating, the second grating, and the third grating are disposed along a first axis and grating directions that are 60 ° and-60 ° from the first axis, respectively.

In some embodiments, the turning component includes a fourth grating and a fifth grating, wherein the fourth grating is disposed on the left side of the second grating, and the fifth grating is disposed on the right side of the third grating, so that the light diffused from the second grating and the third grating can be deflected by the fourth grating and the fifth grating, respectively.

In some embodiments, the grating direction and period of the fourth grating are the same as those of the third grating, and the grating direction and period of the fifth grating are the same as those of the second grating.

In some embodiments, directions and periods of the fourth grating and the third grating are the same, and directions and periods of the fifth grating and the second grating are the same, so that a direction of a light ray passing through the second grating and being turned by the fourth grating is parallel to a direction of a light ray passing through the third grating element and being turned by the fifth grating, and is parallel to a light ray passing through the first grating.

In some of these embodiments, the incoupling means is implemented as a two-dimensional grating, and the two-dimensional grating can be equivalent to a ninth grating, a tenth grating and an eleventh grating, wherein the ninth grating, the tenth grating and the eleventh grating are respectively one-dimensional gratings and the grating directions of the ninth grating, the tenth grating and the eleventh grating are respectively arranged along the second axis and at 60 ° or-60 ° to the second axis.

In some of these embodiments, the period of the ninth grating, the tenth grating, and the eleventh grating is the same as the period of the fourth grating and the fifth grating, respectively.

In some embodiments, the turning component includes a fourth grating and a fifth grating, wherein the direction and period of the fourth grating and the eleventh grating are the same, and the direction and period of the fifth grating and the tenth grating are the same, so that the direction of the light passing through the tenth grating and turned by the fourth grating is parallel to the direction of the light passing through the eleventh grating and turned by the fifth grating, and is parallel to the light passing through the ninth grating.

The invention further provides a diffractive light waveguide for improving the uniformity of light output, which is used for projecting light to at least one light ray, and the diffractive light waveguide for improving the uniformity of light output comprises an incoupling component and an outcoupling component, wherein the incoupling component is suitable for diffracting the light rays with different field angles to the outcoupling area and uniformly covering the outcoupling component.

In some embodiments, the coupling-in component includes at least one coupling-in part and a turning part, and the turning part is disposed at two sides of the coupling-in part and can further diffract the light diffracted by the coupling-in part and make the diffracted light reach the coupling-out part.

In some of these embodiments, the coupling-in means comprises a first grating, a second grating and a third grating, the first, second and third gratings being respectively one-dimensional gratings and the first, second and third gratings being respectively arranged along the first axis and grating directions at 60 ° and-60 ° to the first axis.

In some of these embodiments, the outcoupling means is arranged as a plurality of one-dimensional gratings or as a first two-dimensional grating.

In some embodiments, the first two-dimensional grating can be equivalent to a sixth grating, a seventh grating and an eighth grating, the sixth grating, the seventh grating and the eighth grating are all one-dimensional gratings and the sixth grating is disposed along the second axis in a grating direction, the seventh grating is disposed along the second axis in a grating direction of 60 °, and the eighth grating is disposed along the second axis in a grating direction of-60 °.

In some of these embodiments, the incoupling component is arranged as a second two-dimensional grating.

In some of these embodiments, the second two-dimensional grating can be equivalent to a ninth grating, a tenth grating, and an eleventh grating, wherein the ninth grating is disposed along the second axis, the tenth grating is disposed along a grating direction at 60 ° to the second axis, and the eleventh grating is disposed along a grating direction at-60 ° to the second axis.

In some of these embodiments, the ninth grating, the tenth grating, the eleventh grating and the fourth grating, the fifth grating and the sixth, seventh and eighth gratings have the same period.

In some embodiments, the waveguide substrate further comprises at least transparent parallel waveguide substrates, and the coupling-in part, the turning part and the coupling-out part are respectively disposed on the waveguide substrates.

In some embodiments, the waveguide substrate has a front surface and a back surface, and the coupling-in member, the turning member and the coupling-out member are disposed on the front surface or the back surface of the waveguide substrate, respectively.

In some of these embodiments, the coupling-in component and the coupling-out member are respectively disposed on different surfaces of the waveguide substrate.

The invention further provides a method for projecting the diffraction optical waveguide for improving the uniformity of the emergent light, which is used for projecting a light ray, and the method for projecting the diffraction optical waveguide for improving the uniformity of the emergent light comprises the following steps:

1001: projecting the light to a coupling-in component for diffraction; and

1002: the light diffracted by the coupling-in component can enter a coupling-out part for coupling out, and the light entering the coupling-in part can uniformly cover the coupling-out part.

In some embodiments, the step 1001 further comprises the steps of:

10011: the coupling-in component comprises a coupling-in part and a turning part, wherein the light is projected to the coupling-in part for diffraction, and the diffracted light can be respectively diffracted along the first axis and directions which respectively form 60 degrees and-60 degrees with the first axis; and

10012: this light, which is directed at 60 deg. and-60 deg. to the first axis, can enter the turning part and be further diffracted to reach the coupling-out part, respectively.

In some embodiments, in step 1001, the coupling-in component is configured to include a first grating, a second grating, and a third grating, wherein the first grating, the second grating, and the third grating are one-dimensional gratings and the first grating, the second grating, and the third grating are disposed along the first axis and a grating direction of 60 ° and-60 ° from the first axis, respectively.

In some embodiments, in step 1001, the coupling-in component is configured as a second two-dimensional grating, which can be equivalent to a ninth grating, a tenth grating and an eleventh grating, wherein the ninth grating is configured along the second axis, the tenth grating is configured along the grating direction at 60 ° with respect to the second axis, and the eleventh grating is configured along the grating direction at-60 ° with respect to the second axis.

Further objects and advantages of the invention will be fully apparent from the ensuing description and drawings.

These and other objects, features and advantages of the present invention will become more fully apparent from the following detailed description, taken in conjunction with the accompanying drawings.

Drawings

Fig. 1A and 1B are schematic diagrams of optical paths when the incoupling and outcoupling distances are short in a conventional diffractive optical waveguide.

Fig. 1C is a schematic diagram of an effective coupling-out component in a conventional diffractive optical waveguide when the light coupling-in and coupling-out distance is short.

Fig. 2A and 2B are schematic diagrams of optical paths when the coupling-in and coupling-out distances are long in the conventional diffractive optical waveguide.

Fig. 2C is a schematic diagram of an effective coupling-out component in a conventional diffractive optical waveguide when the light coupling-in and coupling-out distance is long.

Fig. 3A is a schematic diagram illustrating a pupil position detection when the light in-out coupling distance is long in the conventional diffractive optical waveguide.

Fig. 3B is a diagram illustrating a full-field-angle luminance distribution when the light coupling-in and coupling-out distance in the conventional diffractive optical waveguide is long.

Fig. 4A is a schematic structural diagram of a first embodiment of a diffractive light waveguide for improving uniformity of light output according to the present invention.

Fig. 4B is a side view and a top view of the first embodiment of the diffractive light waveguide for improving uniformity of light output in fig. 4A with an enlarged structure at D.

Fig. 4C is a side view and a top view of the first embodiment of the diffractive light waveguide at E in fig. 4A for improving uniformity of light output.

Fig. 5A to 5C are schematic diagrams of optical paths at different angles of the first embodiment of the diffractive light waveguide for improving uniformity of light output in fig. 4A.

Fig. 6A to 6C are schematic perspective views of the first embodiment of the diffractive light waveguide for improving uniformity of light output of fig. 4A, illustrating a case where the incoupling member, the turning member, and the outcoupling member are respectively disposed on the front and rear surfaces of the diffractive substrate.

Fig. 7A to 7D are schematic perspective views of optical paths at different angles of the first embodiment of the diffractive light waveguide for improving uniformity of light output in fig. 4A.

Fig. 8 is a K-domain analysis diagram of the first embodiment of the diffractive light waveguide for improving light exit uniformity of fig. 4A before reaching the two-dimensional grating.

Fig. 9 is a K-domain analysis diagram of the first embodiment of the diffractive light waveguide for improving light exit uniformity of fig. 4A after reaching the two-dimensional grating.

Fig. 10 is a schematic structural diagram of a second embodiment of a diffractive optical waveguide for improving uniformity of outgoing light according to the present invention.

Fig. 11 is a schematic step diagram of a method for projecting a diffractive optical waveguide for improving uniformity of light output according to the present invention.

Detailed Description

The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. The basic principles of the invention, as defined in the following description, may be applied to other embodiments, variations, modifications, equivalents, and other technical solutions without departing from the spirit and scope of the invention.

It will be understood by those skilled in the art that in the present disclosure, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for ease of description and simplicity of description, and do not indicate or imply that the referenced devices or components must be in a particular orientation, constructed and operated in a particular orientation, and thus the above terms are not to be construed as limiting the present invention.

It is understood that the terms "a" and "an" should be interpreted as meaning that a number of one element or element is one in one embodiment, while a number of other elements is one in another embodiment, and the terms "a" and "an" should not be interpreted as limiting the number.

The invention mainly provides a coupling-in component, a coupling-in assembly, a diffraction light waveguide for improving light-emitting uniformity and a projection method thereof, which are used for coupling-out projection of a light ray 20. Fig. 4A to 9 are schematic structural diagrams, partial perspective enlarged schematic diagrams, and K-domain analysis diagrams of the light 20 before and after reaching the first two-dimensional grating 130 of the incoupling component 11, the incoupling component 100, and the diffractive light waveguide 10 for improving light-emitting uniformity according to the first embodiment of the present invention. The diffractive light guide 10 enables the light 20 to be diffused already before reaching the effective outcoupling means 13, so that the light of different field angles can cover the orbital range for better uniformity.

More specifically, in the first embodiment of the diffractive light waveguide 10 for improving uniformity of emitted light according to the present invention, the diffractive light waveguide 10 for improving uniformity of emitted light includes a coupling-in component 11, a turning component 12, a coupling-out component 13 and a waveguide substrate 15, wherein the coupling-in component 11, the turning component 12 and the coupling-out component 13 are all disposed on the waveguide substrate 15, the turning component 12 is disposed in the light-emitting region of the coupling-in component 11 and can diffract the light 20 emitted from the coupling-in component 11 to enter the coupling-out component 13, and the coupling-in component 11 and the turning component 12 form a coupling-in component 100, so that the light 20 reaches the coupling-out component 13 through diffraction of the coupling-in component 100.

As shown in fig. 4A, the coupling-in component 11 includes a first grating 111, a second grating 112, and a third grating 113, where the first grating 111, the second grating 112, and the third grating 113 are all one-dimensional gratings, a grating direction of the first grating 111 is set along a first axis, i.e., a y-axis direction in the drawing, and the second grating 112 and the third grating 113 are respectively at 60 ° and-60 ° with respect to the y-axis, i.e., 60 ° included angles are respectively set between the first grating 111, the second grating 112, and the third grating 113.

The turning part 12 includes a fourth grating 121 and a fifth grating 122, wherein the fourth grating 121 is disposed on the left side of the second grating 112, and the fifth grating 122 is disposed on the right side of the third grating 113, so that the light 20 diffused from the second grating 112 and the third grating 113 is deflected downward to reach the coupling-out part 13, and is uniformly covered on the coupling-out part 13.

In detail, in the first embodiment of the present invention, the first grating 111, the second grating 112, and the third grating 113 have different periodic directions, wherein the grating direction of the first grating 111 is along the y-axis direction, the grating direction of the second grating 112 is a direction forming an angle of 60 ° with the y-axis, and the grating direction of the third grating 113 is a direction forming an angle of-60 ° with the y-axis. The fourth grating 121 and the fifth grating 122 are also one-dimensional gratings, directions and periods of the fourth grating 121 and the third grating 113 are the same, and directions and periods of the fifth grating 122 and the second grating 112 are the same, so that the direction of the light ray 20 after the light ray 20 passes through the second grating 112 and is turned by the fourth grating 121 is parallel to the direction of the light ray 20 after passing through the third grating 113 and is turned by the fifth grating 122, and is parallel to the light ray 20 after passing through the first grating 111.

As shown in fig. 4B, the first grating 111, the second grating 112 and the third grating 113 are surface relief gratings, which respectively have at least one protrusion 1111 and one groove 1112, wherein the protrusion 1111 and the groove 1112 are uniformly arranged, and the protrusion 1111 and the groove 1112 of the first grating 111 have different directions from the protrusion 1111 'and the groove 1112' of the second grating 112 and the protrusion and the groove of the third grating 113, so that the first grating 111, the second grating 112 and the third grating 113 have different periodic arrangements. Wherein the protrusions 1111 and the grooves 1112 in the first grating 111 are uniformly arranged along the y-axis, the protrusions 1111 'and the grooves 1112' in the second grating 112 are uniformly arranged along the y-axis at 60 °, and the protrusions and the grooves 113 in the third grating 113 are uniformly arranged along the y-axis at-60 °, so that the first, second and

third gratings

111, 112 and 113 form an angle of 60 ° with each other.

As shown in fig. 4C, in the first embodiment of the present invention, the coupling-out component 13 is configured as at least one first two-dimensional grating 130, and the first two-dimensional grating 130 can be equivalent to a sixth grating 131, a seventh grating 132 and an eighth grating 133 in three directions, wherein the directions of the sixth grating 131, the seventh grating 132 and the eighth grating 133 are staggered to form an included angle of 60 ° therebetween, so that the light 20 can be diffracted toward the directions corresponding to the sixth grating 131, the seventh grating 132 and the eighth grating 133.

As shown in the figure, in the first embodiment of the present invention, the first two-dimensional grating 130 is implemented as a surface relief grating, which includes a plurality of cylindrical protrusions 1311, and the cylindrical protrusions 1311 are periodically arranged between the cylindrical protrusions 1311, so that the light 20 can be diffracted toward the directions corresponding to the sixth grating 131, the seventh grating 132, and the eighth grating 133.

In addition, the directions of the first grating 111, the second grating 112, and the third grating 113 may be set according to actual conditions, and the directions of the sixth grating 131, the seventh grating 132, and the eighth grating 133 may be set in other directions, for example, determined according to the directions of the first grating 111, the second grating 112, and the third grating 113.

Moreover, a person skilled in the art can optimize the positions, area ratios and sizes and shapes of the first grating 111, the second grating 112 and the third grating 113, so as to balance the overall uniformity and efficiency of the incoupling component 100.

Furthermore, microscopic parameters such as the depth, duty cycle, and/or tilt angle of the first grating 111, the second grating 112, the third grating 113, the fourth grating 121, the fifth grating 122, the sixth grating 131, the seventh grating 132, and/or the eighth grating 133 may also be optimized.

In addition, the types of the gratings in the coupling-in part 11, the turning part 12 and the coupling-out part 13 can be adjusted according to specific situations, for example, a holographic grating is adopted, that is, the first grating 111, the second grating 112 and the third grating 113 are set to form periodic light and dark stripes in the material through holographic exposure, and the like. In other words, as long as the technical solutions identical or similar to the present invention are adopted on the basis of the above disclosure of the present invention, the technical problems identical or similar to the present invention are solved, and the technical effects identical or similar to the present invention are achieved, all of which are within the protection scope of the present invention, and the specific embodiments of the present invention are not limited thereto.

As shown in fig. 5A to 7D, in the first embodiment of the present invention, the waveguide substrate 15 is a transparent parallel waveguide having a certain thickness and having a front surface 151 and a rear surface 152, and the coupling-in member 11, the turning member 12 and the coupling-out member 13 may be respectively disposed on the front surface 151 and/or the rear surface 152 of the waveguide substrate 15. As shown in fig. 6A, the coupling-in member 11, the turning member 12, and the coupling-out member 13 are respectively provided on the front surface 151 of the waveguide substrate 15. As shown in fig. 6B, the coupling-in member 11 is disposed on the rear surface 152 of the waveguide substrate 15, and the turning member 12 and the coupling-out member 13 are disposed on the front surface 151 of the waveguide substrate 15. As shown in fig. 6C, the coupling-out member 13 is disposed on the rear surface 152 of the waveguide substrate 15, and the coupling-in member 11 and the turning member 12 are disposed on the front surface 151 of the waveguide substrate 15, respectively.

However, the specific embodiment of the present invention is not limited thereto, and those skilled in the art can also adjust the arrangement of the coupling-in member 11, the turning member 12 and the coupling-out member 13 in the diffractive optical waveguide according to the present invention according to specific situations. As long as the technical solutions identical or similar to the present invention are adopted on the basis of the above disclosure, the technical problems identical or similar to the present invention are solved, and the technical effects identical or similar to the present invention are achieved, all of which are within the protection scope of the present invention, and the specific embodiments of the present invention are not limited thereto.

Further, as a variation of the first embodiment of the present invention, the out-coupling part 13 may include two sets of one-dimensional gratings, which are respectively located on the front surface 151 and the back surface 152 of the waveguide substrate 15, and the directions of the two sets of one-dimensional gratings are respectively 60 ° and-60 ° from the direction of the first grating 111 in the in-coupling part 11.

When the light 20 enters the coupling-in part 11, the light 20 passing through the first grating 111 in the coupling-in part 11 reaches the coupling-out part 13 through diffraction of the first grating 111 and is coupled out by the coupling-out part 13 to reach the orbital range.

Similarly, the light 20 passing through the second grating 112 in the coupling-in part 11 reaches the fourth grating 121 in the turning part 12 by diffraction of the second grating 112, is turned by the fourth grating 121 to reach the coupling-out part 13, and is coupled out by the coupling-out part 13 to reach the movable eye socket range. Unlike the light 20 diffracted by the first grating 111 and directly reaching the coupling-out part 13, the light 20 refracted by the second grating 112 and the fourth grating 121 can cover the left region of the first two-dimensional grating 130 in the coupling-out part 13.

Similarly, the light 20 passing through the third grating 113 in the coupling-in part 11 reaches the fifth grating 122 in the turning part 12 by diffraction of the third grating 113, is turned by the fifth grating 122 to reach the coupling-out part 13, and is coupled out by the coupling-out part 13 to reach the movable eyebox range. Unlike the light 20 diffracted by the first grating 111 and directly reaching the coupling-out part 13, the light 20 turned by the third grating 113 and the fifth grating 122 can cover the right area of the first two-dimensional grating 130 in the coupling-out part 13.

Therefore, as shown in fig. 7D, the light 20 of the coupling-in component 11 passes through the coupling-in component 11, the turning component 12 and the coupling-out component 13, so that the range of the coupled-out light 20 can reach the range of the desired light 20, and therefore, the diffractive optical waveguide of the present invention can improve the uniformity and the light extraction efficiency of the light extraction, so that the human eye can see the complete field of view in the desired area and the light 20 entering from the coupling-in component 11 can uniformly cover the coupling-out component 13.

As shown in fig. 8 and 9, K-domain analysis graphs before the light 20 with different field angles reaches the first two-dimensional grating 130 of the outcoupling means 13 and K-domain analysis graphs after the light reaches the first two-dimensional grating 130 of the outcoupling means 13.

As shown in fig. 8, in the coupling-in part 11, the diffraction 1 order is totally reflected within the waveguide substrate 15 by the diffraction of the first grating 111, the second grating 112, and the third grating 113, and the regions a in the corresponding K domains pass through the grating vector respectively

Then translated to a region B, a region D and a region C between the inner and outer circles; then, the reflected light meets the fourth grating 121 and the fifth grating 122 in the turning component 12, and correspondingly reflects 0 order when the reflected light is totally reflected, the wave vector is unchanged, meanwhile, a part of the light is diffracted by the fourth grating 121 and the fifth grating 122 in the turning component 12, the diffracted 1 order is deflected in the waveguide substrate 15 and then propagates along the y direction, and the region D and the region C in the corresponding K domain respectively pass through the grating vector

Then translated to a region B, and still totally reflected in the waveguide substrate 15 between the inner circle and the outer circle; then meets the coupling grating 130, the 1-order diffraction is coupled out into the human eye, corresponding to the grating vector of the region B in the K domain

Or

Or

And then translated back to area a within the inner circle, i.e. the beam travels back into the air and is in the same direction as the incident light. It is noted that a necessary condition for the coupling-out direction and the coupling-in direction of the light beam to be the same is that the grating vector has to satisfy that the vector sum of the grating vectors is zero, e.g. the grating vector sum is zero

The vector diagram eventually closes itself.

In the light ray 20After reaching the first two-dimensional grating 130 of the coupling-out part 13, as shown in fig. 9, the light 20 is diffracted by the coupling-in part 11 and the turning part 12, is totally reflected in the waveguide, and propagates in the + y direction, and corresponds to the area a in the K domain via the grating vector

And then translated to the region B between the inner and outer circles until encountering the first two-dimensional grating 130, the beam is divided into four parts: a part of the light is directly coupled out by diffraction of the sixth grating 131, and corresponds to the region B in the K domain via a grating vector

Then translated back to the area A in the inner circle, namely the light beam is transmitted back to the air; a part of the light beams are respectively diffracted and transmitted towards the left lower side and the right lower side under the action of the seventh grating 132 and the eighth grating 133, and when the light beams respectively encounter the first two-dimensional grating 130 again, the part of the light beams are continuously totally reflected along the original direction, the wave vectors are unchanged, the part of the light beams are coupled out after being diffracted by the eighth grating 133 and the seventh grating 132, and the corresponding part of the region B in the K domain is respectively diffracted and transmitted by the grating vectors

Then translated to the region C, D between the inner and outer circles and then rasterized back to vector

Translating to an area A in the inner circle, and enabling the light beam to return to the air for propagation; and a part of the light is continuously reflected in the + y direction, the wave vector in the K domain is unchanged, and the light is divided into four parts again when meeting the first two-dimensional grating 130 again.

As shown in fig. 10, a second preferred embodiment of the diffractive light waveguide 10' for improving uniformity of light output according to the present invention is different from the first embodiment in that the coupling-in component 14 is implemented as a second two-dimensional grating 140, the second two-dimensional grating 140 can be equivalent to three-directional one-dimensional gratings, that is, the coupling-in component 14 can be equivalent to a ninth grating 141, a tenth grating 142 and an eleventh grating 143, the ninth grating 141, the tenth grating 142 and the eleventh grating 143 are respectively one-dimensional gratings, and grating directions of the ninth grating 141, the tenth grating 142 and the eleventh grating 143 form an angle of 60 ° with each other.

In addition, in the second embodiment of the diffractive light waveguide 10 'for improving the uniformity of the emitted light according to the present invention, the periods of the ninth grating 141, the tenth grating 142 and the eleventh grating 143 in the coupling-in part 14 are the same as the periods of the fourth grating 121', the fifth grating 122 'in the turning part 12', and the sixth grating 131 ', the seventh grating 132' and the eighth grating 133 'in the coupling-out part 13', and the microstructures of the ninth grating 141, the tenth grating 142 and the eleventh grating 143 in the coupling-in part 14 are optimized, so that the diffraction efficiency is concentrated in the direction along the y-axis and the three directions of 60 ° and-60 ° respectively with the y-axis in a second axis, i.e., the figure.

In addition, the skilled person can further optimize the distribution of the efficiency ratios in the three directions, so as to achieve a certain balance between the overall uniformity and efficiency of the light emitted from the outcoupling means 13'.

It is emphasized that, in the second embodiment of the diffractive light waveguide 10 ' for improving the uniformity of the output light according to the present invention, although both the coupling-in part 14 and the coupling-out part 13 ' are implemented as two-dimensional gratings, the grating structure parameters of the second two-dimensional grating 140 of the coupling-in part 14 and the first two-dimensional grating 130 of the coupling-out part 13 ' are independent. That is, the grating microstructure of the second two-dimensional grating 140 of the coupling-in part 14 and the grating microstructure of the first two-dimensional grating 130 of the coupling-out part 13' are not necessarily the same, and those skilled in the art can design the two-dimensional gratings according to actual situations.

In addition, the micro-structural shape of the coupling-in component 14, and the positions, sizes and shapes of the two turning gratings can be determined by those skilled in the art according to practical situations, so as to achieve a better balance between the overall uniformity and efficiency of the coupling-in component 100'.

Further, the present invention provides a method for projecting a diffraction light waveguide 10 for improving uniformity of light output, which is used for projecting a light 20, as shown in fig. 11, and is a schematic diagram illustrating the steps of the first embodiment of the method for projecting a diffraction light waveguide 10 for improving uniformity of light output, and the method for projecting a diffraction light waveguide 10 for improving uniformity of light output includes the following steps:

1001: projecting the light 20 to an incoupling component 100 for diffraction; and

1002: the light 20 diffracted by the incoupling component 100 can enter an outcoupling part 13 for outcoupling, wherein the light 20 entering the outcoupling part 11 can uniformly cover the outcoupling part 13.

Further, in the step 1001, the method further includes the steps of:

10011: the coupling-in component 100 comprises at least one coupling-in part 11 and one turning part 12, wherein the light 20 is projected to the coupling-in part 11 for diffraction, and the diffracted light 20 irradiates along the y-axis and in the directions of 60 degrees and-60 degrees respectively with the y-axis; and

10012: this light ray 20, which is at 60 deg. and-60 deg. to the y-axis, respectively, can enter the turning part 12 for further diffraction and reach the outcoupling part 13.

Preferably, in the first embodiment of the projection method of the diffractive light waveguide 10 for improving uniformity of light output according to the present invention, the coupling-in component 11 in the step 10011 includes a first grating 111, a second grating 112, and a third grating 113, wherein the grating direction of the first grating 111 is along the y-axis direction, the grating direction of the second grating 112 is a direction forming an angle of 60 ° with the y-axis, and the grating direction of the third grating 113 is a direction forming an angle of-60 ° with the y-axis.

Preferably, in the step 10012, the turning component 12 includes a fourth grating 121 and a fifth grating 122, wherein the direction of the fourth grating 121 is the same as the direction of the third grating 113, and the direction of the fifth grating 122 is the same as the direction of the second grating 112.

Preferably, in the step 1002, the coupling grating is implemented as a first two-dimensional grating 130, the first two-dimensional grating 130 can be equivalent to three one-dimensional gratings, the three one-dimensional gratings include a sixth grating 131, a seventh grating 132 and an eighth grating 133, wherein the grating directions of the sixth grating 131, the seventh grating 132 and the eighth grating 133 are along the y-axis direction and the directions of 60 ° and-60 ° with the y-axis, respectively.

As a variation of the first embodiment of the projection method of the diffractive light waveguide 10 for improving the uniformity of the emitted light according to the present invention, in the step 10011, the coupling component 11 is implemented as a second two-dimensional grating 140, and the second two-dimensional grating 140 can be equivalent to a ninth grating 141, a tenth grating 142 and an eleventh grating 143, wherein the grating direction of the ninth grating 141 is along the y-axis direction, the grating direction of the tenth grating 142 is 60 ° with respect to the y-axis, and the grating direction of the eleventh grating 143 is-60 ° with respect to the y-axis.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Moreover, various embodiments or examples and features of various embodiments or examples described in this specification can be combined and combined by one skilled in the art without being mutually inconsistent.

It will be appreciated by persons skilled in the art that the embodiments of the invention described above and shown in the drawings are given by way of example only and are not limiting of the invention. The objects of the present invention have been fully and effectively accomplished. The functional and structural principles of the present invention have been shown and described in the embodiments, and any variations or modifications may be made to the embodiments of the present invention without departing from the principles described.

Claims

1. An incoupling component for incoupling a light ray, characterized in that, the incoupling component comprises an incoupling part and a turning part, wherein the turning part is arranged in the light-out region of the incoupling part to diffract the light ray emitted from the incoupling part.

2. A coupling-in assembly according to claim 1, wherein the coupling-in member comprises a first grating, a second grating and a third grating, wherein the first grating, the second grating and the third grating are arranged along the first axis and grating directions at 60 ° and-60 ° to the first axis, respectively.

3. The coupling-in assembly of claim 2, wherein the turning member comprises a fourth grating and a fifth grating, wherein the fourth grating is disposed on the left side of the second grating and the fifth grating is disposed on the right side of the third grating, such that the light rays diffused from the second grating and the third grating can be deflected by the fourth grating and the fifth grating, respectively.

4. The incoupling assembly of claim 3, wherein the fourth and third gratings have the same direction and period, and the fifth and second gratings have the same grating direction and period.

5. The incoupling component of claim 3, wherein the direction and period of said fourth grating and said third grating are the same, and the direction and period of said fifth grating and said second grating are the same, so that the direction of the light passing through said second grating and turned by said fourth grating is parallel to the direction of the light passing through said third grating element and turned by said fifth grating, and is parallel to the light passing through said first grating.

6. A coupling-in assembly according to claim 1, wherein the coupling-in member is implemented as a two-dimensional grating and the two-dimensional grating can be equivalent to a ninth grating, a tenth grating and an eleventh grating, wherein the ninth grating, the tenth grating and the eleventh grating are respectively one-dimensional gratings and the grating directions of the ninth grating, the tenth grating and the eleventh grating are respectively arranged along the second axis and at 60 ° or-60 ° to the second axis.

7. The coupling-in assembly of claim 6, wherein the turning member comprises a fourth grating and a fifth grating, wherein the period of the ninth grating, the tenth grating and the eleventh grating is the same as the period of the fourth grating and the fifth grating, respectively.

8. The coupling-in assembly of claim 6, wherein the turning component comprises a fourth grating and a fifth grating, wherein the direction and period of the fourth grating are the same as those of the eleventh grating, and the direction and period of the fifth grating are the same as those of the tenth grating, so that the direction of the light passing through the tenth grating and turned by the fourth grating is parallel to the direction of the light passing through the eleventh grating and turned by the fifth grating, and is parallel to the light passing through the ninth grating.

9. A diffraction light waveguide for improving the uniformity of light output is used for projecting at least one light ray, and is characterized in that the diffraction light waveguide for improving the uniformity of light output comprises an incoupling component and an outcoupling component, wherein the incoupling component is suitable for diffracting the light rays with different angles of view to the outcoupling area and uniformly covering the outcoupling component.

10. The diffractive optical waveguide according to claim 9, wherein the incoupling component comprises at least one incoupling component and a turning component, the turning component is disposed on two sides of the incoupling component and can further diffract the light diffracted by the incoupling component and make the diffracted light reach the outcoupling component.

11. The diffractive optical waveguide for improving uniformity of output light according to claim 10, wherein said coupling-in component comprises a first grating, a second grating, and a third grating, said first grating, said second grating, and said third grating are each one-dimensional gratings and said first grating, said second grating, and said third grating are each disposed along a first axis and grating directions that are 60 ° and-60 ° from said first axis.

12. The diffractive optical waveguide for improving uniformity of output light according to claim 11, wherein said turning component includes a fourth grating and a fifth grating, wherein said fourth grating is disposed on the left side of said second grating and said fifth grating is disposed on the right side of said third grating, such that the light rays diffused from said second grating and said third grating can be deflected by said fourth grating and said fifth grating, respectively.

13. The diffractive optical waveguide for improving uniformity of extracted light according to claim 12, wherein said outcoupling means is configured as a plurality of one-dimensional gratings or a first two-dimensional grating.

14. The diffractive optical waveguide for improving uniformity of extracted light according to claim 13, wherein said first two-dimensional grating can be equated to a sixth grating, a seventh grating, and an eighth grating, said sixth grating, said seventh grating, and said eighth grating are all one-dimensional gratings and said sixth grating is disposed along a grating direction of a second axis, said seventh grating is disposed along a grating direction at 60 ° to said second axis, said eighth grating is disposed along a grating direction at-60 ° to said second axis.

15. The diffractive optical waveguide for improving uniformity of extracted light according to claim 10, wherein said incoupling component is configured as a second two-dimensional grating.

16. The diffractive optical waveguide for improving uniformity of output light according to claim 15, wherein said second two-dimensional grating can be equated to a ninth grating, a tenth grating and an eleventh grating, wherein said ninth grating is disposed along a second axis with a grating direction, said tenth grating is disposed along a grating direction at 60 ° to said second axis, and said eleventh grating is disposed along a grating direction at-60 ° to said second axis.

17. The diffractive optical waveguide for improving uniformity of light extraction according to claim 16, wherein said ninth, tenth, eleventh and fourth, and sixth, seventh and eighth gratings have the same period.

18. The diffractive optical waveguide according to any one of claims 10 to 16 for improving uniformity of extracted light, further comprising at least one transparent parallel waveguide substrate, wherein said coupling-in component, said turning component and said coupling-out component are disposed on said waveguide substrate, respectively.

19. The diffractive optical waveguide for improving uniformity of light extraction according to claim 18, wherein said waveguide substrate has a front surface and a back surface, said incoupling component, said turning component and said outcoupling component being disposed on the front surface or the back surface of said waveguide substrate, respectively.

20. The diffractive optical waveguide for improving uniformity of extracted light according to claim 18, wherein said incoupling component and said outcoupling means are respectively disposed on different surfaces of said waveguide substrate.

21. A method for projecting a diffractive optical waveguide for improving uniformity of light output is used for projecting a light ray, and is characterized in that the method for projecting the diffractive optical waveguide for improving uniformity of light output comprises the following steps:

1001: projecting the light to an incoupling component for diffraction; and

22. The method for projecting a diffractive optical waveguide for improving uniformity of extracted light according to claim 21, wherein said step 1001 further comprises the steps of:

10011: the coupling-in component comprises a coupling-in part and a turning part, wherein the light is projected to the coupling-in part for diffraction, and the diffracted light can be respectively diffracted along a first axis and directions which respectively form 60 degrees and-60 degrees with the first axis; and

10012: the light rays in the directions of 60 ° and-60 ° to the first axis can enter the turning part and further diffract to reach the coupling-out part respectively.

23. The method for projecting diffractive optical waveguide according to claim 21 or 22 for improving uniformity of extracted light, wherein in step 1001, the incoupling component is configured to include a first grating, a second grating, and a third grating, wherein the first grating, the second grating, and the third grating are respectively one-dimensional gratings and the first grating, the second grating, and the third grating are respectively disposed along a first axis and a grating direction of 60 ° and-60 ° from the first axis.

24. The method of claim 21 or 22, wherein in step 1001, the coupling-in component is configured as a second two-dimensional grating, and the second two-dimensional grating can be equivalent to a ninth grating, a tenth grating and an eleventh grating, wherein the ninth grating is arranged along a second axis, the tenth grating is arranged along a direction 60 ° from the second axis, and the eleventh grating is arranged along a grating direction-60 ° from the second axis.