CN217846686U - Graded-refractive-index optical waveguide AR glasses - Google Patents

Abstract

The utility model discloses a graded index optical waveguide AR glasses, the AR glasses include light source, coupling-in grating, graded optical waveguide, coupling-out grating; the coupling grating is connected with the light incidence side of the optical waveguide and is used for coupling the light emitted by the light source into the optical waveguide; the gradual change optical waveguide is arranged on the AR glasses or in the interlayer of the glasses and is used for automatically converging the coupled light on the light emergent side; the light coupling grating is connected with the light emitting side of the light waveguide and used for coupling the self-converged light out to human eyes. Implement the utility model discloses, effectively alleviated the problem of RGB separation among the prior art under the condition that does not influence the light efficiency, the cost is reduced has avoided the emergence of "rainbow effect" phenomenon.

Description

Gradient index optical waveguide AR glasses

Technical Field

The utility model relates to an augmented reality technical field, in particular to graded index optical waveguide AR glasses.

Background

The existing AR augmented reality technology is a near-eye display system, and a pixel picture on a display is projected into a human eye through a series of optical imaging elements to form a distant virtual image.

AR glasses require perspective (see-through) to see both the real outside world and virtual information, so the imaging system cannot be kept in front of the line of sight. In order to achieve the effect, one or a group of optical elements or devices are additionally added to fuse the virtual information image and the scene of the real world into a whole in an overlapping mode, namely augmented reality.

Existing AR glasses based on RGB three-color display have different wavelength bands because of the three colors of red, green and blue (RGB) from the light engine. When they are diffracted by the incident grating, as shown in fig. 1, it is assumed that we optimize the +1 st order diffracted light, i.e., T +1, and the diffraction angle θ +1T is different for different wavelengths, i.e., R > G > B.

Due to the difference of the angle, the path length of the light which passes through each time of completing total reflection is also different, the number of times of total reflection of red is less than that of green, and the number of times of total reflection of blue is the largest. Due to this difference, when the light in fig. 1 finally encounters the exit grating (please see the arrow pointing to the glasses), in the certain size outcoupling region, the RGB outcoupling times are different and the positions are different, resulting in non-uniform RGB color ratio at a certain specific position. In addition, even the diffraction efficiency of the same color fluctuates depending on the incident angle, which results in that the distribution ratio of three colors of red, green and blue may be different in the entire field angle (FOV), that is, a so-called "rainbow effect" occurs.

In order to improve the dispersion problem, red, green and blue can be respectively coupled into three layers of waveguides as shown in fig. 2, and the diffraction grating of each layer is optimized only for a certain color, so that the color uniformity at the exit pupil position can be improved, and the rainbow effect can be reduced.

However, the effect of fig. 2 for solving the rainbow effect is not obvious, the lighting effect is poor, and the cost is high.

SUMMERY OF THE UTILITY MODEL

Because the RGB three colors include different wavelength bands, after the three colors are coupled into the waveguide, the angles are different, so that the distribution ratios of the red, green and blue three colors of light in the whole field of view (FOV) range are also different, that is, a so-called "rainbow effect" occurs, and the existing scheme for alleviating the problem of the "rainbow effect" has unobvious effect, relatively poor light efficiency and higher cost.

Aiming at the problems, the AR glasses with the graded index optical waveguides are provided, and the light is enabled to be self-converged during transmission by adopting the single-layer graded optical waveguides, so that the phenomenon that the angles of different wavelengths of light are different, and the RGB colors are separated due to the separation of each wavelength in the process of multiple waveguide reflections is avoided, the problem of RGB separation in the prior art is effectively solved under the condition that the light efficiency is not influenced, the cost is reduced, and the rainbow effect phenomenon is avoided.

In a first aspect, graded index optical waveguide (AR) eyewear comprises:

a light source;

coupling in a grating;

a graded optical waveguide;

coupling out the grating;

the incoupling grating is connected with the light incidence side of the optical waveguide and is used for coupling light emitted by the light source into the optical waveguide;

the gradual change optical waveguide is arranged on the AR glasses or in the interlayer of the glasses and is used for automatically converging the coupled light on one light emergent side;

the coupling-out grating is connected with the light emitting side of the optical waveguide and is used for coupling out the self-converged light to human eyes.

Combine the utility model discloses first aspect graded index optical waveguide AR glasses, in the first possible mode, the graded optical waveguide includes:

a graded layer;

a step layer;

the step layer and the gradual change layer are integrally formed;

the gradient layer is used for self-converging light coupled in from different angles in the step layer;

the step layer is arranged on one side of the optical waveguide facing to human eyes and used for generating steps for the self-converged light so as to carry out total reflection.

Combine the utility model discloses the first possible mode of first aspect, in the second possible mode, the gradient layer material refracting index radially steadilys decrease from the step layer.

Implement a graded index optical waveguide AR glasses, through adopting individual layer graded optical waveguide for light is when the transmission, has gone on from assembling, has avoided different wavelength light angle difference, the phenomenon of the RGB color separation that each wavelength separation produced in many times waveguide reflection process has effectively alleviated the problem of RGB separation among the prior art under the condition that does not influence the light efficiency, the cost is reduced has avoided the emergence of "rainbow effect" phenomenon.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic illustration of the transmission of light in a waveguide according to the prior art;

FIG. 2 is a schematic representation of the transmission of light in a layered waveguide according to the prior art;

FIG. 3 is a schematic view of the medium GI waveguide AR glasses of the present invention;

FIG. 4 is a schematic diagram of a medium graded index optical waveguide structure according to the present invention;

description of the part symbols: 10-light source, 20-coupling-in grating, 30-graded optical waveguide, 31-graded layer, 32-step layer.

Detailed Description

The technical solutions of the present invention will be described more clearly and completely with reference to the drawings of the present invention, and it should be understood that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, other embodiments obtained by a person of ordinary skill in the art without creative efforts all belong to the protection scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Because the RGB three colors include different wavelength bands, after the three colors are coupled into the waveguide, the angles are different, so that the distribution ratios of the red, green and blue three colors of light are also different in the whole field angle (FOV) range, that is, a so-called "rainbow effect" occurs, and the existing scheme for alleviating the problem of the "rainbow effect" has an unobvious effect, a poor light efficiency and a high cost.

In order to solve the above problems, graded index optical waveguide AR glasses are proposed.

In a first aspect, as shown in fig. 3, fig. 3 is a schematic view of the medium graded index optical waveguide AR glasses of the present invention;

FIG. 4 is a schematic diagram of a medium graded index optical waveguide structure according to the present invention;

a kind of gradual change refractive index optical waveguide AR glasses, including the light source 10, couple into the grating 20, gradual change optical waveguide 30, couple out the grating; the in-coupling grating 20 is connected to a light incident side of the optical waveguide, and is configured to couple light emitted from the light source 10 into the optical waveguide; the gradual change optical waveguide 30 is arranged on AR glasses or in a glass interlayer of the glasses and is used for automatically converging the coupled light 10 on the light emergent side; the coupling grating is connected to the light exit side of the optical waveguide for coupling out the self-converged light 10 to human eyes.

Further, graded optical waveguide 30 includes graded layer 31, stepped layer 32; the step layer 32 and the gradual change layer 31 are integrally formed; the graded layer 31 is used for self-converging light coupled in from different angles in the step layer 32; the step layer 32 is disposed on a side of the optical waveguide facing human eyes, and is used for generating a step for self-converged light to perform total reflection.

Further, the refractive index of the material of the graded layer 31 decreases radially from that of the stepped layer 32.

Emergent light of the light source 10 is coupled into the graded optical waveguide 30 through the coupling grating 20, the refractive index of the material of the graded optical waveguide 30 is gradually changed from the radial direction of the step layer 32, and the graded optical waveguide has a strong constraint effect on light and effectively converges the light.

The graded layer 31 concentrates the light to the stepped layer 32 to cause the light to be totally reflected, and the total reflection propagation in the graded optical waveguide 30 is realized.

By adopting the single-layer gradual change optical waveguide, light is automatically converged during transmission, the phenomenon of RGB color separation caused by the separation of wavelengths in the multiple waveguide reflection process due to the fact that the light angles of different wavelengths are different is avoided, the problem of RGB separation in the prior art is effectively solved under the condition that the light efficiency is not influenced, the cost is reduced, and the rainbow effect phenomenon is avoided.

An AR imaging method, comprising the steps of: coupling-in grating 20 is used to couple the outgoing light of light source 10 into graded optical waveguide 30; the graded optical waveguide 30 self-converges the coupled-in light 10; totally reflecting the self-converged light through the stepped layer 32 of the graded optical waveguide 30; coupling the totally reflected and self-converged light out to human eyes by using an out-coupling grating; the graded optical waveguide 30 comprises a graded layer 31 and a step layer 32; the step layer 32 and the gradual change layer 31 are integrally formed; the graded layer 31 is used for self-converging light coupled in from different angles in the stepped layer 32; the step layer 32 is disposed on a side of the optical waveguide facing the human eye, and is used for generating a step for the self-converged light to perform total reflection. The refractive index of the material of the graded layer 31 is reduced from that of the stepped layer 32 in the radial direction.

Implement the utility model discloses a graded index optical waveguide AR glasses through adopting individual layer graded optical waveguide for light is when transmitting, carries out from assembling, and it is different to have avoided different wavelength light angle, and the phenomenon of the RGB color separation that each wavelength separation produced in many times waveguide reflection process has effectively alleviated the problem of RGB separation among the prior art under the condition that does not influence the light efficiency, and the cost is reduced has avoided the emergence of "rainbow effect" phenomenon.

The above is merely a preferred embodiment of the present invention, and not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims (3)

1. Graded index optical waveguide (AR) eyewear comprising:

a light source;

coupling in a grating;

a graded optical waveguide;

coupling out a grating;

the incoupling grating is connected with the light incidence side of the optical waveguide and is used for coupling light emitted by the light source into the optical waveguide;

the gradual change optical waveguide is arranged on the AR glasses or in the interlayer of the glasses and is used for automatically converging the coupled light on the light emergent side;

the coupling-out grating is connected with the light emitting side of the optical waveguide and is used for coupling out the self-converged light to human eyes.

2. The graded-index optical waveguide AR glasses according to claim 1, wherein the graded optical waveguide comprises:

a graded layer;

a step layer;

the step layer and the gradual change layer are integrally formed;

the gradient layer is used for self-converging light coupled in from different angles in the step layer;

the step layer is arranged on one side of the optical waveguide facing to human eyes and used for generating steps for the self-converged light so as to carry out total reflection.

3. The AR eyewear of claim 2, wherein the graded-index optical waveguide material has a refractive index that decreases radially from the stepped layer.

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