Waveguide display device
By employing a tilted coupling end face and dispersion compensation elements in the waveguide display device, the problem of insufficient clarity in waveguide display devices has been solved, achieving high-definition display of projected images and improving the user experience.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- LIGHTIN INC
- Filing Date
- 2025-06-19
- Publication Date
- 2026-04-28
Smart Images
Figure CN224176818U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of optical display technology, and in particular to a waveguide display device. Background Technology
[0002] Augmented Reality (AR) is an emerging technology that overlays virtual images onto real-world scenes, providing users with more intuitive information and a richer experience. Currently, AR technology is mostly implemented using waveguide display devices. This involves using waveguide elements to transmit projected light to the human eye, allowing the eye to receive and view the virtual projected image while simultaneously viewing the real-world scene through the waveguide element. In other words, it achieves the overlay display of the virtual projected image and the real-world scene within the human eye's field of vision.
[0003] With the widespread application of AR technology in fields such as medicine, sports, and assisted driving, users have increasingly higher requirements for the clarity of the projected images output by waveguide display devices. Therefore, improving the clarity of the projected images output by waveguide display devices to achieve good imaging effects is one of the important development directions for waveguide display devices. Utility Model Content
[0004] The purpose of this invention is to provide a waveguide display device that improves the display effect of projected images to a certain extent, which is conducive to the widespread application of AR technology.
[0005] To solve the above-mentioned technical problems, this utility model provides a waveguide display device, including a waveguide element; the coupling end of the waveguide element has a coupling end face that is inclined relative to the plane on which the waveguide element is located; the coupling end of the waveguide element is provided with a coupling out diffraction element; a projection light source is used to output projection light to the coupling end face on the waveguide element, so that the projection light is coupled into the waveguide element through the coupling end face, conducted through the waveguide element, and coupled out through the coupling out diffraction element;
[0006] It also includes a dispersion compensation element disposed in the optical path between the projection light source and the coupled-out diffraction element, the dispersion compensation element having opposite dispersion characteristics to the coupled-out diffraction element.
[0007] In an optional embodiment of this application, both the coupled-out diffraction element and the dispersion compensation element are diffractive optical elements selected from holographic volume gratings and surface relief gratings.
[0008] In an optional embodiment of this application, the coupling end face is a convex curved surface; the waveguide element includes a waveguide body and a compensation mirror located at the coupling end of the waveguide element; the first inclined surface of the waveguide body and the second inclined surface of the compensation mirror are parallel to each other and are connected in a cooperative manner, so that the waveguide body and the compensation mirror together form a waveguide element that is flat and has a uniform thickness;
[0009] The coupled-out diffraction element is disposed in the gap between the first inclined surface and the second inclined surface, and the coupled-out diffraction element is inclined relative to the plane on which the waveguide element is located.
[0010] In one optional embodiment of this application, a shaping lens group is further provided between the projection light source and the coupling end face; the projection light source is an image source chip.
[0011] In an optional embodiment of this application, the dispersion compensation element is disposed on the waveguide element and located between the coupling end face and the coupling out diffraction element.
[0012] In an optional embodiment of this application, the dispersion compensation element is disposed on the surface of a predetermined region on the waveguide element, so that when the projected light is incident on the predetermined region by the waveguide element, the dispersion compensation element performs reflective diffraction transmission of the projected light.
[0013] In an optional embodiment of this application, the dispersion compensation element includes a first dispersion compensation element and a second dispersion compensation element respectively disposed on opposite sides of the waveguide element, so that after the projected light is coupled into the waveguide element through the coupling end face, it undergoes two reflection diffraction propagations through the first dispersion compensation element and the second dispersion compensation element in sequence, and then is incident on the coupling out diffraction element.
[0014] In an optional embodiment of this application, the dispersion compensation element is embedded in the waveguide element at an angle relative to the plane in which the waveguide element is located, so that the projected light is totally internally reflected at the optical interface of the waveguide element and undergoes transmission diffraction through the dispersion compensation element.
[0015] In one optional embodiment of this application, the dispersion compensation element is disposed in the optical path between the coupling end face and the projection light source.
[0016] In one optional embodiment of this application, the dispersion compensation element is a reflective diffraction element disposed in the output optical path of the projection light source, so that the projection light output by the projection light source is reflected and diffracted by the dispersion compensation element and then incident on the coupling end face.
[0017] Alternatively, the dispersion compensation element may be a transmission diffraction element attached to the coupling end face.
[0018] The present invention provides a waveguide display device, comprising a waveguide element; the coupling end of the waveguide element has a coupling end face inclined relative to the plane of the waveguide element; the coupling end of the waveguide element is provided with a coupling out diffraction element; a projection light source for outputting projection light to the coupling end face on the waveguide element, so that the projection light is coupled into the waveguide element through the coupling end face, conducted through the waveguide element and coupled out through the coupling out diffraction element; and further comprising a dispersion compensation element disposed in the optical path between the projection light source and the coupling out diffraction element, the dispersion characteristics of the dispersion compensation element and the coupling out diffraction element being opposite.
[0019] In this application, to simplify the structure of the waveguide display device, the coupling end of the waveguide element is set as an inclined coupling end face. This allows the projection light output from the projection light source to be directly transmitted and coupled into the waveguide element from the coupling end face, without the need for other optical elements, reducing the coupling loss of the projection light and the dispersion introduced by the projection light coupling into the waveguide element. In addition, a coupling-out diffraction element is set at the coupling-out end of the waveguide element to couple the projection light out, so as to project the projected image to the human eye. On this basis, a dispersion compensation element is further set between the projection light source and the coupling-out diffraction element. The dispersion characteristics of the dispersion compensation element and the coupling-out diffraction element are opposite, so that the dispersion compensation element can compensate and correct the dispersion of the projection light caused by the coupling-out diffraction element to a certain extent. This results in the projection image formed by the projection light diffracted by the coupling-out diffraction element having good clarity, improving the display effect of the projection image, and thus improving the user experience. Attached Figure Description
[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of a first optical path structure of the waveguide display device provided in the embodiments of this application;
[0022] Figure 2 A schematic diagram of a second optical path structure for the waveguide display device provided in this application embodiment:
[0023] Figure 3 This is a schematic diagram of a third optical path structure for the waveguide display device provided in the embodiments of this application;
[0024] Figure 4 This is a schematic diagram of a fourth optical path structure for the waveguide display device provided in the embodiments of this application;
[0025] Figure 5 This is a schematic diagram of the fifth optical path structure of the waveguide display device provided in the embodiments of this application;
[0026] Figure 6 A schematic diagram of the sixth optical path structure of the waveguide display device provided in the embodiments of this application:
[0027] Figure 7 This is a schematic diagram of the seventh optical path structure of the waveguide display device provided in the embodiments of this application;
[0028] In the attached figure: 1 is a waveguide element, 10 is a coupling end face, 11 is a waveguide body, 12 is a compensation mirror, 2 is a coupling grating, 3 is a projection light source, 4 is a shaping lens, 5 is a dispersion compensation element, 51 is a first dispersion compensation element, and 52 is a second dispersion compensation element. Detailed Implementation
[0029] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0030] like Figure 1 and Figure 2 As shown, Figure 1 This is a schematic diagram of a first optical path structure of the waveguide display device provided in the embodiments of this application; Figure 2 This is a schematic diagram of a second optical path structure for a waveguide display device provided in an embodiment of this application.
[0031] In one optional embodiment of this application, the waveguide display device may include:
[0032] Waveguide element 1; the coupling end of waveguide element 1 has a coupling end face 10 that is inclined relative to the plane on which waveguide element 1 is located; the coupling end of waveguide element 1 is provided with a coupling out diffraction element 2; projection light source 3 is used to output projection light to the coupling end face 10 on waveguide element 1, so that the projection light is coupled into waveguide element 1 through the coupling end face 10, conducted through waveguide element 1 and coupled out through coupling out diffraction element 2;
[0033] It also includes a dispersion compensation element 5 disposed in the optical path between the projection light source 3 and the coupled diffraction element 2, the dispersion compensation element 5 and the coupled diffraction element 2 having opposite dispersion characteristics.
[0034] like Figure 1 As shown, the waveguide element 1 in this application can be a light-transmitting plate structure with a certain thickness, such as a light-transmitting glass plate; of course, the waveguide element 1 can also be a curved light-transmitting plate with a certain curvature. However, it is understood that whether the waveguide element 1 is a flat plate structure or a curved plate structure, it will not affect the implementation of its subsequent embodiments.
[0035] Based on this, the projection light source 3 is positioned on one side near the coupling end of the waveguide element 1. This projection light source 3 can be any image source chip among DMD, LCD, OLED, DLP, LBS, and LCoS, used to input projection light to the coupling end of the waveguide element 1. One end of the waveguide element 1 is the coupling end of the projection light, and the other end is the coupling end of the projection light.
[0036] In this embodiment, to simplify the optical structure of the coupling end of the waveguide element 1, a coupling end face 10 inclined relative to the plane of the waveguide element 1 is provided at the coupling end of the waveguide element 1. This allows the projection light to be incident on the coupling end face 10 in a direction perpendicular to or approximately perpendicular to the coupling end face 10, and then transmitted through the coupling end face 10 into the waveguide element 1. Because the coupling end face 10 is inclined relative to the surface of the waveguide element 1, the incident angle of the projection light when it first enters the optical interface of one side surface of the waveguide element 1 should not be less than its total reflection angle. Thus, total reflection can occur within the waveguide element 1. After at least one total reflection within the waveguide element 1, the projection light is transmitted to the coupling end of the waveguide element 1 and is coupled out of the waveguide element 1 by the diffraction of the coupling diffraction element 2, and then received by the human eye, so that the human eye can see the projected image formed by the projection light.
[0037] like Figure 1As shown, in this embodiment, the coupled diffraction element 2 can be installed in the waveguide element 1 in an inclined embedded manner. Specifically, the waveguide element 1 includes a waveguide body 11 and a compensation mirror 12 located at the coupled end of the waveguide element 1. The first inclined surface of the waveguide body 11 and the second inclined surface of the compensation mirror 12 are parallel to each other and are connected to each other so that the waveguide body 11 and the compensation mirror 12 together form a waveguide element 1 with a flat plate shape and uniform thickness. The coupled diffraction element 2 is disposed in the gap between the first inclined surface and the second inclined surface, and the coupled diffraction element 2 is inclined relative to the plane of the waveguide element 1. In practical applications, the waveguide body 11 and the compensation mirror 12 can be two separate structures connected by bonding or other means; however, the waveguide body 11 and the compensation mirror 12 can also be integrally formed to form the waveguide element 1, which is equivalent to processing a flat gap in the plate-shaped waveguide element 1 to accommodate the coupled diffraction element 2, and the flat gap is inclined relative to the plane of the waveguide element 1, which can also realize that the coupled diffraction element 2 is inside the waveguide element and is inclined relative to the waveguide element 1.
[0038] Based on this, Figure 1 The coupled-out diffraction element 2 shown is a reflective diffraction element; however, it is understood that this application does not exclude embodiments where the coupled-out diffraction element 2 is a transmission diffraction element, as long as the reflective coupled-out diffraction element 2 and the transmission coupled-out diffraction element 2 have opposite tilt directions within the waveguide element 1. Compared to the coupled-out diffraction element 2 being directly attached to the surface of one side of the waveguide element 1, the coupled-out diffraction element 2 being tilted and embedded in the waveguide element 1 can, to a certain extent, reduce the incident angle of the projected light rays incident on the coupled-out diffraction element 2, and can also, to a certain extent, reduce the dispersion generated during the diffraction of the projected light rays by the coupled-out diffraction element 2.
[0039] Furthermore, the position directly in front of the viewer's line of sight on waveguide element 1 is the position of the coupling diffraction element 2 on waveguide element 1. Therefore, after the coupling diffraction element 2 is embedded at the coupling end of waveguide element 1, the uniformity of the thickness of the coupling end of waveguide element 1 should not be disrupted. Figure 1 As shown, the main structure on the right side of the coupled diffraction element 2 and the compensation structure on the right side of the coupled diffraction element 2 on the waveguide element 1 are both inclined surfaces that are in contact with the coupled diffraction element 2. The thickness of the waveguide element 1 as a whole in the direction of human eye line of sight is uniform, thereby ensuring that the real scene seen by human eye through the waveguide element 1 will not be distorted.
[0040] Of course, the waveguide element 1 in this application can also be a nearsighted waveguide lens or a farsighted waveguide lens with a certain optical power. In this case, the embedding of the coupled diffraction element 2 will not affect the overall optical power of the waveguide element 1. This will not be described in detail in this application.
[0041] Based on the above discussion, in order to improve the display effect of the projected image, a shaping lens 4 can be further provided between the projection light source 3 and the coupling end face 10. The shaping lens 4 is used to distort and shape the projection light output from the projection light source 3, thereby improving the display effect of the projected image to a certain extent. In addition, the coupling end face 10 on the waveguide element 1 can be further made into a convex curved surface, so that the projection light is essentially incident into the waveguide element 1 through a convex lens, which can reduce the divergence angle of the projection light.
[0042] Based on this, this application further considers that the coupled-out diffraction element 2 is wavelength sensitive. When light of different wavelengths is incident on the diffraction optical element at the same angle, it will be diffracted into light of different angles, resulting in dispersion. Obviously, the projection light in this embodiment is a mixed beam containing multiple different wavelengths. The diffraction angles of the incident light of different wavelengths after being diffracted by the coupled-out diffraction element 2 are different. Therefore, when the projection light is diffracted and coupled out by the coupled-out diffraction element 2, dispersion will inevitably occur, which will affect the display effect of the projected image to a certain extent.
[0043] Therefore, in order to ensure the display effect of the projected image output by the waveguide display device, a dispersion compensation element 5 is further provided in the optical path between the projection light source 3 and the coupled diffraction element 2. This dispersion compensation element 5 can be a diffraction optical element with dispersion characteristics opposite to or complementary to those of the coupled diffraction element 2, meaning that the color difference is canceled out by the dispersion compensation element 5 and the coupled diffraction element 2. Taking a projection light containing three different wavelengths (RGB) as an example, when the three different colored light waves are incident on the same coupled diffraction element 2 at the same incident angle, the diffraction angles of the red, green, and blue light after being diffracted and coupled out by the coupled diffraction element 2 are respectively θ. 1R θ 1G and θ 1B If the relationship between the three diffraction angles satisfies: θ 1R <θ 1G <θ 1B Correspondingly, a dispersion compensation element 5 with opposite dispersion characteristics can be configured. When red, green, and blue light rays are incident on the dispersion compensation element 5 at the same incident angle, the dispersion compensation element 5 diffracts the red, green, and blue light rays respectively, and the diffraction angles output by the element are θ. 2R θ 2G and θ 2B Furthermore, the dispersion compensation element 5 can make θ 2R >θ 2G >θ 2BTherefore, the dispersion compensation element 5 and the coupled diffraction element 2 work together to modulate the projected light, which can eliminate the dispersion of the projected image to the greatest extent, thereby improving the display effect of the projected image. Furthermore, in practical applications, the dispersion compensation element 5 and the coupled diffraction element 2 in this application can both be any diffraction optical element selected from holographic gratings and surface relief gratings; and the dispersion compensation element 5 and the coupled diffraction element 2 can be the same type of diffraction grating or different types of diffraction gratings, which is not specifically limited in this application. In addition, how to design the dispersion parameters of the dispersion compensation element 5 and the coupled diffraction element 2 to achieve color difference correction can be determined based on common sense in the field of optics, and will not be elaborated here.
[0044] Based on the above discussion, the dispersion compensation element 5 in this application has a variety of different configuration methods, which will be described below with specific embodiments.
[0045] In an optional embodiment of this application, the dispersion compensation element 5 may be disposed on the waveguide element 1 and located in the optical path between the coupling end face 10 and the coupling out diffraction grating.
[0046] like Figure 1 , Figure 2 and Figure 3 As shown, the dispersion compensation element 5 in this embodiment may contain only one monolithic diffractive optical element or two diffractive optical elements.
[0047] exist Figure 1 and Figure 2 In the embodiments shown, the dispersion compensation element 5 contains only a single monolithic diffractive optical element. The dispersion compensation element 5 is disposed on the surface of a set area on the waveguide element 1 so that when the projected light is incident on the set area by the waveguide element 1, the dispersion compensation element 5 performs reflective diffraction transmission of the projected light.
[0048] like Figure 1 and Figure 2 As shown, after the projected light rays are incident into the waveguide element 1 through the coupling end face 10, they are first incident on the optical interface of one side surface of the waveguide element 1 for a first reflection, and then incident on the optical interface of the other side surface of the waveguide element 1 for a second reflection before being incident on the coupling out diffraction element 2.
[0049] like Figure 1As shown, in this embodiment, the optical interface region where the projected light undergoes its first reflection within the waveguide element 1 can be designated as the set region. The dispersion compensation element 5 can then be disposed within the set region on one side surface of the waveguide element 1. Thus, after the projected light is coupled into the waveguide element 1, it first enters the optical interface region where the dispersion compensation element 5 is located. Obviously, at this time, the dispersion compensation element 5 can perform reflective diffraction on the projected light. After reflective diffraction, the projected light can enter the optical interface on the side of the waveguide element 1 facing away from the dispersion compensation element 5, so that after the projected light undergoes total internal reflection at the optical interface, it can be coupled out and output by the diffraction element 2.
[0050] like Figure 2 As shown, in this embodiment, the optical interface region where the projected light undergoes a second reflection within the waveguide element 1 can also be used as the set region, and the dispersion compensation element 5 is set in the set region. When the projected light is coupled into the waveguide element 1, it first enters the optical interface on one side of the waveguide element 1 for total internal reflection and then enters the dispersion compensation element 5 on the other side of the waveguide element 1. After the reflection diffraction of the dispersion compensation element 5, it is output to the coupling diffraction element 2, and after the diffraction of the coupling diffraction element 2, it is coupled out from the waveguide element 1.
[0051] exist Figure 1 and Figure 2 In the optical path shown, the dispersion compensation element 5 is respectively placed on two different optical interfaces on both sides of the waveguide element 1. This allows the projection light to undergo diffraction once through the dispersion compensation element 5 before entering the coupled diffraction element 2 inside the waveguide element 1, and then undergo diffraction once through the coupled diffraction element 2. The dispersion produced in the two diffractions is opposite, thereby eliminating the dispersion of the final projection image output by the projection light, thus forming a projection image with good clarity.
[0052] Based on this, such as Figure 3 As shown, the dispersion compensation element 5 in this application may further include a first dispersion compensation element 51 and a second dispersion compensation element 52 respectively disposed on opposite sides of the waveguide element 1, so that the projected light rays are coupled into the waveguide element 1 through the coupling end face 10, and then undergo two reflection diffraction propagations through the first dispersion compensation element 51 and the second dispersion compensation element 52 before being incident on the coupling out diffraction element 2.
[0053] like Figure 3 As shown, in Figure 3In the embodiment shown, the first dispersion compensation element 51 is disposed in the optical interface region of the surface of the waveguide element 1 after the projection light is incident on the waveguide element 1. Thus, the projection light can be incident on the optical interface on the other side of the waveguide element 1 after the first reflection diffraction of the first dispersion compensation element 51. The optical interface region where the projection light is incident is also the region where the second dispersion compensation element 52 is located. After the second dispersion compensation element 52 performs a second reflection diffraction on the projection optics, it can be incident on the coupling diffraction element 2 and diffracted out by the coupling diffraction element 2.
[0054] In this embodiment, after the projected light is coupled into the waveguide element 1, it is diffracted three times in sequence by the first dispersion compensation element 51, the second dispersion compensation element 52 and the coupled-out diffraction element 2 before being coupled out from the waveguide element 1. Obviously, in this embodiment, the first dispersion compensation element 51 and the second dispersion compensation element 52 together play the role of compensating for the dispersion of the coupled-out diffraction element 2.
[0055] exist Figures 1 to 3 In the illustrated embodiments, the projection light is described as undergoing two reflections or reflective diffractions within the waveguide element 1 before entering the coupling diffraction element 2. However, it is understood that in practical applications, the projection light may undergo more than two reflections or reflective diffractions before entering the coupling diffraction element 2 within the waveguide element 1. In this case, a greater number of dispersion compensation elements 5 can be sequentially attached to both sides of the waveguide element 1 to maximize dispersion compensation of the projection light and ensure a better display effect for the final projected image after diffraction and coupling through the waveguide element 1. Of course, this application does not exclude embodiments where the projection light undergoes only one reflective diffraction after coupling into the waveguide element 1 before entering the coupling diffraction element 2.
[0056] And such Figure 4 As shown, in Figure 4 In the embodiment shown, the projection light source 3 is located near the coupling end of the waveguide element 1 and is also located on the side of the waveguide element 1 away from the human eye (i.e., the side from which the projection light is coupled out of the waveguide element 1). At this time, the dispersion compensation element 5 is also a monolithic diffraction grating element and is located on the surface of the waveguide element 1 near the human eye. After the projection light is coupled into the waveguide element 1, it can be incident on the dispersion compensation element 5 and diffracted by reflection to the coupling out diffraction element 2. Finally, after being diffracted by the coupling out diffraction element 2, the dispersion compensation element 5 and the coupling out diffraction element 2 can also achieve mutual compensation of dispersion, and finally output a projection image with good display effect.
[0057] exist Figures 1 to 4In the embodiments shown, the dispersion compensation element 5 is described using the example of being attached to at least one surface of the waveguide element 1. In practical applications, the dispersion compensation element 5 is not necessarily disposed on both surfaces of the waveguide element 1. Figure 5 As shown, in another optional embodiment of this application, the dispersion compensation element 5 may further include:
[0058] The dispersion compensation element 5 is embedded in the waveguide element 1 at an angle relative to the plane of the waveguide element 1, so that the projected light is totally internally reflected at the optical interface of the waveguide element 1 and then undergoes transmission diffraction through the dispersion compensation element 5.
[0059] It should be noted that when the dispersion compensation element 5 is tilted and embedded in the waveguide element 1, the dispersion compensation element 5 should mainly adopt a transmission diffraction optical element; and when the coupled diffraction element 2 is a reflection diffraction optical element tilted and embedded in the waveguide element 1, the embedded tilt directions of the coupled diffraction element 2 and the dispersion compensation element 5 in the waveguide element 1 should be exactly opposite, and the tilt angles can be exactly complementary.
[0060] like Figure 5 As shown, in Figure 5 In the illustrated embodiment, the dispersion compensation element 5 is positioned after the first total internal reflection and before the second total internal reflection within the waveguide element 1. That is, after the projection light is coupled into the waveguide element 1, it undergoes a first total internal reflection at the optical interface on one side of the waveguide element 1. Then, in the light path incident on the optical interface on the other side of the waveguide element 1, it undergoes a transmission diffraction through the dispersion compensation element 5 before further incident on the optical interface of the waveguide element 1, undergoes a second total internal reflection, and is output to the coupled-out diffraction optical element. Thus, during the total internal reflection transmission of the projection light in the waveguide element 1, it also passes through the dispersion compensation element 5 and the coupled-out diffraction element 2 for two diffractions in sequence. The dispersion in the two diffraction processes is complementary, thereby effectively reducing the dispersion problem of the final output projection image and improving the display effect of the projection image.
[0061] In the above embodiments, the dispersion compensation element 5 is mainly described as being disposed on the waveguide element 1; however, the dispersion compensation element 5 in this embodiment is not necessarily disposed on the waveguide element 1, but can also be disposed in the optical path between the coupling end face 10 of the waveguide element 1 and the projection light source 3.
[0062] like Figure 6 As shown, in an optional embodiment of this application, the dispersion compensation element 5 may also be a reflective diffraction element disposed in the output optical path of the projection light source 3, so that the projection light output by the projection light source 3 is reflected and diffracted by the dispersion compensation element 5 and then incident on the coupling end face 10.
[0063] It is understood that the dispersion compensation element 5, which is disposed between the coupling end face 10 and the projection light source 3 in this embodiment and can reflectively diffract the projected light, can not only adjust the dispersion of the projected light, but also deflect the transmission direction of the projected light. Based on this, waveguide display devices are generally worn on the user's head, similar to helmets or glasses; therefore, optical components such as the projection light source 3 generally need to be encapsulated inside structures such as the temples connected to the waveguide element 1. Thus, by placing the dispersion compensation element 5 with the function of deflecting the optical path between the projection light source 3 and the coupling end face 10 on the waveguide unit, the optical components such as the edge projection light source 3 and the shaping lens 4 can be better adapted to the installation environment inside the temples.
[0064] like Figure 7 As shown, in another optional embodiment of this application, the dispersion compensation element 5 may also be a transmission diffraction element attached to the coupling end face 10.
[0065] In this embodiment, the dispersion compensation element 5 is a transmission diffraction element. The dispersion compensation element 5 is directly disposed on the coupling end face 10. Compared with the surface attached to one side of the waveguide element 1 or embedded in the waveguide element 1, in this embodiment, there is no need to specifically determine the specific placement position of the dispersion compensation element 5 on the waveguide element 1, and the placement of the dispersion compensation element 5 is relatively easier.
[0066] Based on any of the above embodiments, regardless of whether the dispersion compensation element 5 is disposed on the waveguide element 1 or between the waveguide element 1 and the projection light source 3, in practical applications, the dispersion compensation element 5 in this application can not only be complementary to the dispersion characteristics of the coupled diffraction element 2, but it can also be a diffraction element with optical power, which can correct the distortion of the projected image formed by the projected light to a certain extent, or modulate the divergence angle of the projected light during the transmission process. In short, it can only improve the display effect of the projected image as much as possible.
[0067] In this application, to simplify the structure of the waveguide display device, the coupling end of the waveguide element is set as an inclined coupling end face. This allows the projection light output from the projection light source to be directly transmitted and coupled into the waveguide element from the coupling end face without the need for other optical components. Furthermore, a coupling-out diffraction element is set at the coupling-out end of the waveguide element to couple the projection light out, so as to project the projected image onto the human eye. On this basis, a dispersion compensation element is further set between the projection light source and the coupling-out diffraction element. The dispersion characteristics of the dispersion compensation element and the coupling-out diffraction element are opposite, so that the dispersion compensation element can compensate and correct the dispersion of the projection light generated by the coupling-out diffraction element to a certain extent. This results in the projection image formed by the projection light diffracted and output by the coupling-out diffraction element having good clarity, improving the display effect of the projection image, and thus improving the user experience.
[0068] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that the elements inherent in a process, method, article, or apparatus that includes a list of elements are included. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Additionally, portions of the technical solutions provided in the embodiments of this application that are consistent with the implementation principles of corresponding technical solutions in the prior art have not been described in detail to avoid excessive elaboration.
[0069] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of this utility model.
Claims
1. A waveguide display device, characterized in that, The system includes a waveguide element; the waveguide element has a coupling end face that is inclined relative to the plane in which the waveguide element is located; the waveguide element has a coupling end diffraction element at its coupling end; and a projection light source for outputting projection light to the coupling end face on the waveguide element, so that the projection light is coupled into the waveguide element through the coupling end face, conducted through the waveguide element, and coupled out through the coupling end diffraction element. It also includes a dispersion compensation element disposed in the optical path between the projection light source and the coupled-out diffraction element, the dispersion compensation element having opposite dispersion characteristics to the coupled-out diffraction element.
2. The waveguide display device as described in claim 1, characterized in that, Both the coupled-out diffraction element and the dispersion compensation element are either holographic volume gratings or surface relief gratings, which are diffractive optical elements.
3. The waveguide display device as described in claim 1, characterized in that, The coupling end face is a convex curved surface; The waveguide element includes a waveguide body and a compensating mirror located at the coupling end of the waveguide element; the first inclined surface of the waveguide body and the second inclined surface of the compensating mirror are parallel to each other and are connected to each other so that the waveguide body and the compensating mirror together form a waveguide element with a flat plate shape and uniform thickness. The coupled-out diffraction element is disposed in the gap between the first inclined surface and the second inclined surface, and the coupled-out diffraction element is inclined relative to the plane on which the waveguide element is located.
4. The waveguide display device as described in claim 1, characterized in that, A shaping lens group is also provided between the projection light source and the coupling end face; the projection light source is an image source chip.
5. The waveguide display device according to any one of claims 1 to 4, characterized in that, The dispersion compensation element is disposed on the waveguide element and is located between the coupling end face and the coupling out diffraction element.
6. The waveguide display device as described in claim 5, characterized in that, The dispersion compensation element is disposed on the surface of a designated area on the waveguide element so that when the projected light is incident on the designated area by the waveguide element, the dispersion compensation element performs reflective diffraction and transmission of the projected light.
7. The waveguide display device as described in claim 5, characterized in that, The dispersion compensation element includes a first dispersion compensation element and a second dispersion compensation element respectively disposed on opposite sides of the waveguide element, so that the projected light rays are coupled into the waveguide element through the coupling end face, and then undergo two reflection diffraction propagations through the first dispersion compensation element and the second dispersion compensation element before being incident on the coupling out diffraction element.
8. The waveguide display device as described in claim 5, characterized in that, The dispersion compensation element is embedded in the waveguide element at an angle relative to the plane of the waveguide element, so that the projected light is totally internally reflected at the optical interface of the waveguide element and then undergoes transmission diffraction through the dispersion compensation element.
9. The waveguide display device according to any one of claims 1 to 4, characterized in that, The dispersion compensation element is disposed in the optical path between the coupling end face and the projection light source.
10. The waveguide display device as described in claim 9, characterized in that, The dispersion compensation element is a reflective diffraction element disposed in the output optical path of the projection light source, so that the projection light output by the projection light source is reflected and diffracted by the dispersion compensation element and then incident on the coupling end face. Alternatively, the dispersion compensation element may be a transmission diffraction element attached to the coupling end face.