Optical display device

Abstract

The present invention discloses an optical display device, in which a coupling device couples light output from an image generating device into an optical extension waveguide. The optical extension waveguide includes at least a first reflective surface array and a second reflective surface array, and the light entering the optical extension waveguide passes through the first reflective surface array and the second reflective surface array in sequence, and each reflective surface array expands the light propagated through the optical extension waveguide in a one-dimensional direction, and realizes the expansion of the light entering the optical extension waveguide in a two-dimensional direction, and emits the light out of the optical extension waveguide to form an image. At least one of the first reflective surface of the first reflective surface array and the second reflective surface of the second reflective surface array is at least partially curved, and the first reflective surface and / or the second reflective surface change the light emission angle so that the image distance formed from the light emitted by the optical extension waveguide meets a predetermined requirement. Therefore, the present invention can change the image distance, is suitable for users with visual impairments, and has a thin and light structure.

Description

cross reference

[0001] This application claims priority from a Chinese patent application filed with the China Patent Office on January 20, 2022, bearing application number 202210065963.4 and entitled "Optical Display Device," the entire contents of which are incorporated herein by reference. [Technical Field]

[0002] The present invention relates to the field of optical devices, and more particularly to optical display devices. [Background technology]

[0003] Near-eye display is a hot technology field, and its optical system includes microdisplays and optical elements. Currently, there are many optical solutions for near-eye display on the market.

[0004] The arrayed waveguide solution uses semi-transparent and semi-reflective optical surfaces to achieve light expansion and exit pupil, and follows the law of reflection that the angle of incidence is equal to the angle of reflection, so there is no dispersion effect on the incident light of the three primary colors forming a full-color display, and the formed image can be guaranteed to have no obvious color shift, meeting the most basic requirements of a display device and providing clear advantages for optimizing the design of head-mounted devices and improving aesthetics.

[0005] However, due to the characteristic of this solution that focuses an image at infinity, the display device according to this solution is applicable to people with visual acuity of about 1.2, while the visual acuity of an average person (including visual correction) is about 1.0, so when using such a display device, the wearer cannot see a clear and good image, which causes great inconvenience to the user. To solve this problem, the mainstream solution uses an external device for assistance and adjustment, which not only increases the volume and weight of the display device but also reduces the comfort and perception experience of the user. Summary of the Invention [Problem to be solved by the invention]

[0006] In view of this, an object of the present invention is to provide an optical display device that can change the image distance, is suitable for users with visual impairments, and has a thin and lightweight structure. [Means for solving the problem]

[0007] To achieve the above objectives, the present invention provides the following technical solutions: An optical display device, comprising: an image generating device; a coupling device; and an optical extension waveguide, wherein the coupling device is associated with the image generating device and couples light output from the image generating device to the optical extension waveguide; the optical expansion waveguide includes at least a first reflective surface array and a second reflective surface array, and the light entering the optical expansion waveguide passes through the first reflective surface array and the second reflective surface array in order, and the first reflective surface array and the second reflective surface array respectively expand the light propagated through the optical expansion waveguide in a one-dimensional direction, and realize the expansion of the light entering the optical expansion waveguide in a two-dimensional direction, and emit the light out of the optical expansion waveguide to form an image; By making at least a portion of at least one of the first reflecting surface of the first reflecting surface array and the second reflecting surface of the second reflecting surface array curved, the image distance formed from the light emitted by the optical extension waveguide satisfies a specified requirement.

[0008] Preferably, at least a portion of the first reflecting surface of the first reflecting surface array is a curved surface, and the first reflecting surface diverges the light reflected by the first reflecting surface; Alternatively, at least a local portion of the second reflecting surface of the second reflecting surface array is curved, and the second reflecting surface diverges the light reflected by the second reflecting surface.

[0009] Preferably, the first reflecting surface array expands the light propagated through the optical expansion waveguide in a first dimensional direction, and each of the first reflecting surfaces forms an inclined angle with respect to the first dimensional direction.

[0010] Preferably, the optically enhanced waveguide includes a first waveguide base, the first reflective surface array is disposed within the first waveguide base, the first waveguide base includes at least a first set of opposing surfaces, and light entering the first waveguide base is reflected by each of the first set of opposing surfaces and propagates forward.

[0011] Preferably, at least one of the first set of opposing surfaces is curved at least locally to change the angle at which the reflected light from that surface strikes the first reflecting surface, thereby helping to ensure that the image distance formed from the light emitted by the optical expansion waveguide meets a predetermined requirement.

[0012] Preferably, at least one surface of the first set of opposing surfaces is divergent in the light reflected therefrom.

[0013] Preferably, the optically extended waveguide includes a second waveguide base, the second reflective surface array is disposed within the second waveguide base, the second waveguide base includes at least a third set of opposing surfaces, and light entering the second waveguide base is reflected by each of the third set of opposing surfaces and propagated forward.

[0014] Preferably, each of the second reflecting surfaces forms an inclined angle with respect to one of the opposing surfaces of the third set.

[0015] Preferably, the inclination angle formed by the second reflecting surface with respect to one surface of the third set of opposing surfaces as a coupling output surface is greater than 0° and less than 45°, and when the second reflecting surface rotates counterclockwise with respect to the one surface, the inclination angle formed by the second reflecting surface with respect to the surface is positive.

[0016] Preferably, at least one of the third set of opposing surfaces is curved at least locally to change the angle at which the reflected light from that surface strikes the second reflecting surface, thereby helping to ensure that the image distance formed from the light emitted by the optical expansion waveguide meets a predetermined requirement.

[0017] Preferably, at least one surface of the third set of opposing surfaces diverges light reflected by that surface.

[0018] Preferably, the optically extended waveguide includes a first waveguide base and a second waveguide base, the first reflective surface array is disposed in the first waveguide base, and the second reflective surface array is disposed in the second waveguide base; The first waveguide base further includes a first coupling output surface that causes the reflected light from the first reflecting surface to be emitted outside the first waveguide base, and the second waveguide base further includes a second coupling input surface that causes the light emitted from the first waveguide base to enter the second waveguide base, and the first coupling output surface and the second coupling input surface are optically coaxial.

[0019] Preferably, the coupling device splits the light output from the image generating device into a first beam and a second beam having different polarization states, and couples the first beam and the second beam into the optical extension waveguide, respectively.

[0020] Preferably, the coupling device includes a polarization splitting unit, an optical conversion unit, a collimating unit, and a spectral selection unit, wherein the polarization splitting unit performs polarization splitting on the light output from the image generating device, the optical conversion unit realizes mutual conversion of two lights with different polarization states, the collimating unit collimates the light to uniformly distribute the light energy, and the spectral selection unit inputs the light corresponding to the polarization state of the light that has passed through the spectral selection unit into the optical extension waveguide. [Effects of the Invention]

[0021] As can be seen from the above technical solution, in the optical display device provided by the present invention, a coupling device couples light output from an image generating device into an optical extension waveguide. The optical extension waveguide includes at least a first reflective surface array and a second reflective surface array. The light entering the optical extension waveguide passes through the first reflective surface array and the second reflective surface array, respectively. Each reflective surface array expands the light propagating through the optical extension waveguide in one dimension and expands the light entering the optical extension waveguide in two dimensions, and the light exits the optical extension waveguide to form an image. At least one of the first reflective surface of the first reflective surface array and the second reflective surface of the second reflective surface array is at least partially curved, thereby changing the light output angle through the first reflective surface and / or the second reflective surface, so that the image distance formed from the light emitted from the optical extension waveguide meets a predetermined requirement. Therefore, the optical display device of the present invention can change the image distance, is suitable for users with visual impairments, and has a thin and lightweight structure. [Brief explanation of the drawings]

[0022] In order to more clearly explain the technical solutions in the embodiments of the present invention or the prior art, the following briefly introduces the drawings necessary for the description of the embodiments or the prior art, and the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings on the premise that they do not make efforts worthy of inventive step. [Figure 1] 1 is a schematic diagram of ray propagation in an optical display device provided by an embodiment of the present invention, in which a coupling device couples output light from an image generating device into an optical extension waveguide. [Figure 2] FIG. 2 is a schematic diagram of light propagation on a first reflecting surface in one embodiment of the present invention. [Figure 3-1] FIG. 3-3 is a left side view of the optical extension waveguide of FIG. [Figure 3-2] 1 is a front view of an optical extension waveguide provided by one embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram of a first waveguide-based ray propagation in one embodiment of the present invention. [Figure 5]3 is a schematic diagram of ray propagation at one surface of a first set of opposing surfaces and at a first reflecting surface in one embodiment of the present invention. [Figure 6] FIG. 10 is a schematic diagram of a second waveguide-based ray propagation in one embodiment of the present invention. [Figure 7] FIG. 10 is a schematic diagram illustrating a light ray propagating through a second waveguide base to form a corresponding effective light passage aperture in one embodiment of the present invention. [Figure 8] 1 is a schematic diagram of a waveguide-based, curved reflecting surface and surface structure parameters in one embodiment of the present invention; FIG. [Figure 9-1] 10 is a schematic diagram of a curved surface used for one of the opposing surfaces of the waveguide base in one of the embodiments of the present invention. FIG. [Figure 9-2] 10A and 10B are schematic diagrams of other curved surfaces used on either of the opposing surfaces of the waveguide base in any of the embodiments of the present invention. [Figure 10-1-10-4] 3A-3C are schematic diagrams of four embodiments of a first waveguide-based first coupling output surface and a second waveguide-based second coupling input surface according to an embodiment of the present invention; [Figure 11-1-11-3] 3A to 3C are schematic diagrams of three embodiments of the arrangement positions of the first waveguide base and the second waveguide base in an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] In order to make those skilled in the art better understand the technical solutions of the present invention, the following clearly and completely describes the technical solutions of the embodiments of the present invention in combination with the drawings of the embodiments of the present invention, and the described embodiments are not all embodiments but only some embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without any inventive efforts are also within the protection scope of the present invention.

[0024] This embodiment provides an optical display device, including an image generating device, a coupling device, and an optical extension waveguide, wherein the coupling device corresponds to the image generating device and couples light output from the image generating device into the optical extension waveguide; the optical expansion waveguide includes at least a first reflective surface array and a second reflective surface array, and the light entering the optical expansion waveguide passes through the first reflective surface array and the second reflective surface array in order, and the first reflective surface array and the second reflective surface array respectively expand the light propagated through the optical expansion waveguide in a one-dimensional direction, and realize the expansion of the light entering the optical expansion waveguide in a two-dimensional direction, and emit the light out of the optical expansion waveguide to form an image; By making at least a portion of at least one of the first reflecting surface of the first reflecting surface array and the second reflecting surface of the second reflecting surface array curved, the image distance formed from the light emitted by the optical extension waveguide satisfies a specified requirement.

[0025] The light entering the optical expansion waveguide propagates through the optical expansion waveguide, passing through the first reflective surface array and the second reflective surface array in order, expanding the light entering the optical expansion waveguide in two dimensions, and then exiting the optical expansion waveguide, where the exiting light enters the user's eye, allowing the user to view an image.

[0026] The image distance formed from the light emitted by the optical expansion waveguide is the distance from the viewing position to the corresponding virtual image of the image formed from the light emitted by the optical expansion waveguide.

[0027] Furthermore, if at least a portion of the first reflecting surface is curved, the curved surface can change the reflection angle of the light at the first reflecting surface, thereby changing the output angle of the light from the optical extension waveguide. If at least a portion of the second reflecting surface is curved, the curved surface can change the reflection angle of the light at the second reflecting surface, thereby changing the output angle of the light from the optical extension waveguide. Therefore, by using a curved surface for at least one of the first reflecting surface and the second reflecting surface, the optical extension waveguide can change the output angle of the light, thereby changing the image distance formed from the output light of the optical display device, so that the image distance meets a predetermined requirement.

[0028] Therefore, the optical display device of this embodiment can change the image distance, which is suitable for users with visual impairments, allowing them to see clear and sharp images, and the structure of the optical extension waveguide in the optical display device of this embodiment is thin and light.

[0029] The image generating device outputs light carrying image information. In this embodiment, the type and structure of the image generating device are not specifically limited. Preferably, considering the weight and volume of the entire optical display device, the image generating device may use a miniaturized display chip, and may use, but is not limited to, a Liquid Crystal on Silicon (LOCS) display screen, a Liquid Crystal Display (LCD) display screen, an Organic Light-Emitting Diode (OLED) display screen, a Micro LED display screen, a Mini LED display screen, or a Digital Light Processing (DLP) display screen.

[0030] In actual applications, depending on different application scenarios, the lightness and size of the head-mounted display device should be considered, and factors such as the uniformity of brightness at each point of the image source, output light effect, brightness requirements, resolution and size limitations should be taken into consideration to select an image generating device with an appropriate volume, uniform brightness and high resolution.

[0031] Preferably, the coupling device splits the light output from the image generating device into a first beam and a second beam having different polarization states, and couples the first beam and the second beam into the optical extension waveguide, respectively. The coupling device polarizes and splits the light output from the image generating device, and couples the beams into the optical extension waveguide, respectively, and propagates and expands the light through the optical extension waveguide, thereby making the brightness of the image formed from the output light uniform.

[0032] Preferably, the coupling device includes a polarization splitting unit, a light conversion unit, a collimating unit, and a light selection unit, wherein the polarization splitting unit performs polarization splitting on the light output from the image generating device, the light conversion unit realizes mutual conversion of two light beams having different polarization states, the collimating unit collimates the light to uniformly distribute the light energy, and the light selection unit inputs light corresponding to the polarization state of the light that has passed through the light selection unit into the optical extension waveguide. In this way, the coupling device performs polarization splitting on the light output from the image generating device and couples it into the optical extension waveguides respectively, so that the portions of the light energy coupled into the input optical extension waveguides are uniformly distributed.

[0033] In this embodiment, the specific optical structure of the coupling device is not limited, as long as the light output from the image generating device is coupled into the optical extension waveguide. For example, refer to FIG. 1, which is a schematic diagram of light propagation in an optical display device provided by one embodiment, in which the coupling device couples the light output from the image generating device into the optical extension waveguide. As shown in the drawing, the coupling device 301 includes a polarization splitting unit 401, a first light converting unit 402, a first collimating unit 403, a second light converting unit 404, a second collimating unit 405, a first light selecting unit 406, and a second light selecting unit 407.

[0034] The polarization splitting unit 401 splits the output light of the image generating device 300 into light of a first polarization state and light of a second polarization state, the light of the first polarization state is reflected and passes through the first light converting unit 402 and the first collimating unit 403 in order, the first collimating unit 403 collimates and reflects the light, and this part of the light passes through the first light converting unit 402 twice before being converted into light of the second polarization state. The light of the second polarization state formed by the conversion passes through the polarization splitting unit 401 and enters the first light selecting unit 406, where it is reflected and enters the optical extension waveguide 302.

[0035] The light of the second polarization state separated by the polarization splitting unit 401 is transmitted and sequentially enters the second optical conversion unit 404 and the second collimating unit 405. The second collimating unit 405 collimates and reflects the light, so that this portion of the light passes through the second optical conversion unit 404 twice and is converted to light of the first polarization state. The light of the first polarization state formed by the conversion is reflected when passing through the polarization splitting unit 401, and is reflected when entering the second optical splitting selection unit 407, and enters the input optical extension waveguide 302. The vibration directions of the light of the first polarization state and the light of the second polarization state are perpendicular to each other, and are P light and S light, respectively.

[0036] Here, the coupling device of FIG. 1 is merely an exemplary description of an embodiment, and in other embodiments, other optical structures may be used for the coupling device, all of which are within the protection scope of the present invention.

[0037] Hereinafter, an embodiment of the optical extension waveguide of the optical display device will be described.

[0038] In this embodiment, as long as at least a portion of the first reflecting surface of the first reflecting surface array is curved, the shape and size of the curved surface included in the first reflecting surface are not specifically limited, as long as the emission angle of the light emitted from the optical extension waveguide is changed and the image distance formed from the light emitted from the optical extension waveguide meets a predetermined requirement. The curved surface included in the first reflecting surface may be a curved surface with a constant curvature or a free-form surface. Preferably, the curved surface is used for the first reflecting surface to diverge or converge the light reflected by the first reflecting surface.

[0039] In this embodiment, as long as at least a portion of the second reflecting surface of the second reflecting surface array is curved, the shape and size of the curved surface included in the second reflecting surface are not specifically limited, as long as the emission angle of the light emitted from the optical extension waveguide is changed and the image distance formed from the light emitted from the optical extension waveguide meets a predetermined requirement. The curved surface included in the second reflecting surface may be a curved surface with a constant curvature or a free-form surface. Preferably, the curved surface is used for the second reflecting surface to diverge or converge the light reflected by the second reflecting surface.

[0040] For example, FIG. 2 shows a schematic diagram of ray propagation at a first reflecting surface in one embodiment. As shown in the drawing, rays L1 and L2 reflected by waveguide surface 100 are incident on first reflecting surface 101, which is a curved surface. They form reflected rays L1′ and L2′ through first reflecting surface 101. Rays L1 and L2 are reflected by reference plane 102 of first reflecting surface 101, forming reflected rays L1″ and L2″ through reference plane 102 of first reflecting surface 101. The reflected rays L1′ and L2′ diverge. This reduces the distance of the image formed from the light emitted by the optically enhanced waveguide. For a visually impaired user, the image can be focused on the retina of the visually impaired user.

[0041] The above explains the principle of using a curved surface for the first reflecting surface to change the image distance, taking the propagation of light rays on the first reflecting surface as an example, based on Figure 2. Similarly, using a curved surface for the second reflecting surface to change the image distance also follows the same principle.

[0042] The first reflective surface array expands the light propagated through the optical expansion waveguide in a first dimensional direction, and each of the first reflective surfaces forms an inclination angle with respect to the first dimensional direction. The inclination angle of the first reflective surface with respect to the first dimensional direction means that the chord of the first reflective surface and the first dimensional direction are neither parallel nor perpendicular. Correspondingly, the inclination angle formed by the first reflective surface with respect to the first dimensional direction is the included angle between the chord of the first reflective surface and the first dimensional direction. When the light propagated through the optical expansion waveguide is incident on a first reflective surface, a portion of the light energy is transmitted through the first reflective surface and continues to propagate, and another portion of the light energy is reflected, and the first reflective surface array expands the light propagated through the optical expansion waveguide in the first dimensional direction.

[0043] In this embodiment, the magnitude of the inclination angle formed by each of the first reflecting surfaces with respect to the first dimension is not limited, as long as the expansion of the light propagating through the optical expansion waveguide in the first dimension is realized. In practical application, the requirement for expanding the light in the first dimension is set based on the size of the optical expansion waveguide, and preferably, the structure of the optical expansion waveguide is thin and light while meeting the requirement for expanding the light.

[0044] For the projection plane of the first reflecting surface on a plane parallel to the first-dimensional direction, the plane parallel to the first-dimensional direction is located on the light-reflecting side of the first reflecting surface and determines the light passing aperture of the output light of the optical expansion waveguide in the first-dimensional direction. For the optical display device, the light passing aperture of the output light of the optical expansion waveguide in the first-dimensional direction must ensure that the image from the image generating device is fully expanded, i.e., the image formed by the output light of the optical expansion waveguide contains the complete information of the image in the first-dimensional direction.

[0045] Preferably, the optically enhanced waveguide includes a first waveguide base, the first reflective surface array is disposed within the first waveguide base, the first waveguide base includes at least a first set of opposing surfaces, and light entering the first waveguide base is reflected by each of the first set of opposing surfaces and propagates forward. Specifically, when light is incident on each of the first set of opposing surfaces, the total internal reflection condition is satisfied. The first set of opposing surfaces may or may not be parallel to each other, as long as the light is reflected by each of the first set of opposing surfaces and propagates forward.

[0046] Preferably, the first waveguide base further includes a second set of opposing surfaces, the second set of opposing surfaces and the first set of opposing surfaces forming a closed cross section, and light entering the first waveguide base is reflected by each of the first set of opposing surfaces and the second set of opposing surfaces to propagate forward. Specifically, when light is incident on each of the second set of opposing surfaces, the total internal reflection condition is satisfied. The second set of opposing surfaces may or may not be parallel to each other, as long as the light is reflected by each of the second set of opposing surfaces to propagate forward.

[0047] 3-1, 3-2, and 4 are combined for illustrative purposes. FIG. 3-1 is a left-side view of the optical extension waveguide of FIG. 3-2, FIG. 3-2 is a front view of the optical extension waveguide provided in one embodiment, and FIG. 4 is a schematic diagram of light propagation in a first waveguide base in one embodiment. As shown in the drawings, within a cross section formed by four surfaces 1-A, 1-B, 1-C, and 1-D of the first waveguide base 1, light entering the first waveguide base 1 is reflected by each surface and propagates forward. During propagation, when the light encounters the first reflecting surface 101, it reflects a portion of the light energy at a certain energy ratio, thereby coupling the light into the second waveguide base 2.

[0048] In the first waveguide base 1 of Fig. 4, the first set of opposing surfaces 1-A and 1-B are parallel to each other, and the second set of opposing surfaces 1-C and 1-D are parallel to each other, for illustrative purposes only. In other embodiments, the first set of opposing surfaces may not be parallel, and the second set of opposing surfaces may not be parallel.

[0049] In one preferred embodiment, at least one surface of the first set of opposing surfaces is curved at least locally to change the angle of incidence of light reflected from that surface onto the first reflecting surface, thereby helping to ensure that the image distance formed from the light emitted from the optical expansion waveguide meets a predetermined requirement. At least one surface of the first set of opposing surfaces is curved at least locally to change the angle of reflection of light after passing through that surface and the angle of incidence of the light reflected from that surface onto the first reflecting surface, thereby helping to change the image distance formed from the light emitted from the optical expansion waveguide in combination with the first reflecting surface using a curved surface or the second reflecting surface using a curved surface.

[0050] In this embodiment, the shape and area of ​​the curved surface included in any of the first set of opposing surfaces are not specifically limited, as long as the emission angle of the light emitted from the optical extension waveguide is changed and the image distance formed from the light emitted from the optical extension waveguide meets the predetermined requirement. The curved surface included in any of the first set of opposing surfaces may be a curved surface with a constant curvature or a free-form surface. Preferably, the curved surface included in any of the first set of opposing surfaces diverges or converges the reflected light from that surface.

[0051] For example, as shown in FIG. 5, FIG. 5 is a schematic diagram of ray propagation on one surface of the first set of opposing surfaces and the first reflecting surface in one embodiment. As shown in the drawing, surface 100 is one of the first set of opposing surfaces of the first waveguide base 1, and surface 100 is a curved surface (its reference plane is surface 103). The reflected rays of incident rays L3 and L4 on surface 100 become divergent, and the reflected rays L3' and L4' after the rays are reflected by the first reflecting surface 101 become divergent. As a result, the image distance formed from the light emitted by the optical expansion waveguide becomes smaller.

[0052] Preferably, the optically enhanced waveguide includes a second waveguide base, the second reflective surface array is disposed within the second waveguide base, the second waveguide base includes at least a third set of opposing surfaces, and light entering the second waveguide base is reflected by each of the third set of opposing surfaces and propagates forward. Specifically, when light is incident on each of the third set of opposing surfaces, the total internal reflection condition is satisfied. The third set of opposing surfaces may or may not be parallel to each other, as long as the light is reflected by each of the third set of opposing surfaces and propagates forward.

[0053] Preferably, each second reflecting surface forms an inclination angle with one of the third set of opposing surfaces. The inclination angle of the second reflecting surface with a surface refers to the fact that the chord of the second reflecting surface is neither parallel nor perpendicular to the surface. Correspondingly, the inclination angle of the second reflecting surface with a surface is the included angle between the chord of the second reflecting surface and the surface. If the surface is curved, the inclination angle of the second reflecting surface with the surface is the included angle between the chord of the second reflecting surface and the surface. When the light propagating through the second waveguide base is incident on the second reflecting surface, a portion of the light energy is transmitted through the second reflecting surface and continues to propagate, and another portion of the light energy is reflected and emitted out of the second waveguide base, forming an output light of the optical extension waveguide.

[0054] 3-1, 3-2, and 6, which are illustrative diagrams of light propagation in a second waveguide base in one embodiment. As shown in the drawing, light coupled from the first waveguide base 1 to the second waveguide base 2 is reflected by surfaces 2-A and 2-B of the second waveguide base 2 and propagates forward. During propagation, when the light encounters the second reflecting surface 201, a portion of the light energy is reflected at a certain energy ratio, causing a portion of the light to exit the second waveguide base 2.

[0055] In this embodiment, the magnitude of the inclination angle formed by each second reflecting surface with respect to any of the third set of opposing surfaces is not limited, as long as at least a portion of the light propagating within the second waveguide base is reflected and emitted out of the second reflecting surface when the light is incident on the second reflecting surface. In practical application, the size of the first waveguide base and the size of the second waveguide base may be determined to determine the expansion requirement for the light in the second dimension.

[0056] 7, which is a schematic diagram of light rays propagating through the second waveguide base 2 and correspondingly forming an effective light aperture in one embodiment, where the light propagating through the second waveguide base 2 encounters each of the second reflective surfaces S1, S2, S3, S4, and S5, respectively, and is reflected, causing at least a portion of the light to exit the second waveguide base 2. The total projection area S of each of the second reflective surfaces S1, S2, S3, S4, and S5 on surface 2-A determines the effective light aperture of the optical expansion waveguide. For an optical display device, the effective light aperture of the optical expansion waveguide must fully expand the image from the image source, i.e., ensure that the image formed by the output light of the optical expansion waveguide contains complete image information in both the first and second dimensional directions.

[0057] Preferably, the tilt angle formed by the second reflecting surface with respect to one of the surfaces of the third set as the coupling output surface is greater than 0° and less than 45°, where β is 0°<β≦45°, and when the second reflecting surface rotates counterclockwise with respect to the one surface, the tilt angle formed by the second reflecting surface with respect to the one surface is positive. With respect to one of the surfaces of the third set as the coupling output surface, the light reflected by the second reflecting surface exits the second waveguide base through the surface. In this way, the light is expanded by the second reflecting surface, and the thickness of the second waveguide base can be reduced, making the entire waveguide thinner and lighter.

[0058] In one preferred embodiment, at least one surface of the third set of opposing surfaces is curved at least partially to change the angle of incidence of light reflected from that surface onto the second reflecting surface, thereby helping to ensure that the image distance formed from the light emitted from the optical expansion waveguide meets a predetermined requirement. By curved at least one surface of the third set of opposing surfaces, the angle of reflection of light after passing through that surface can be changed, and the angle of incidence of light reflected from that surface onto the second reflecting surface can be changed, thereby, in combination with the first reflecting surface using a curved surface or the second reflecting surface using a curved surface, realizing a change in the image distance formed from the light emitted from the optical expansion waveguide.

[0059] In this embodiment, the shape and area of ​​the curved surface included in any of the third set of opposing surfaces are not specifically limited, as long as the emission angle of the light emitted from the optical extension waveguide is changed and the image distance formed from the light emitted from the optical extension waveguide meets the predetermined requirement. The curved surface included in any of the third set of opposing surfaces may be a curved surface with a fixed curvature or a free-form surface. Preferably, the curved surface included in any of the third set of opposing surfaces diverges or converges the reflected light from that surface.

[0060] In optical design, if a curved surface is used for the first reflecting surface of the first waveguide base and at least one surface of the first set of opposing surfaces, in order to ensure that the resolution, contrast, clarity, etc. of the generated image meets the requirements, the curved surface parameters of the first reflecting surface of the first waveguide base and any surface of the first set of opposing surfaces should satisfy a certain relationship. If a curved surface is used for the second reflecting surface of the second waveguide base and at least one surface of the third set of opposing surfaces, the curved surface parameters of the second reflecting surface of the second waveguide base and any surface of the third set of opposing surfaces should satisfy a certain relationship. Referring to Figure 8 in conjunction with this, Figure 8 is a schematic diagram of the structural parameters of a reflecting surface and surface using a curved surface of any waveguide base in one embodiment. The optical design is based on a collimated main axis beam emitted from an on-axis object point. When the main axis beam is perpendicularly incident on the coupling input surface of the waveguide base, the corresponding relationships of each parameter are as follows: αR2=α R1 -β o ; αR1=π / 2-β i ; β i is the angle between the coupling input plane and the horizontal reference plane of the waveguide base surface, and β o is the angle between the plane on which the chord of the curved reflecting surface is located and the horizontal reference plane of the waveguide base surface, and α R1 is the angle between the principal axis ray and the horizontal reference plane normal of the waveguide base surface, and α R2 is the angle between the principal axis ray and the reference surface normal of the coupling output surface.

[0061] h s =h r =N*(λ / 2); H r =H / (sin(β o )); H s =H / (tan(β o )); h s is the local curved arrow height of the curved waveguide corresponding to a single reflecting surface, and H s is the local chord length of the curved waveguide corresponding to a single reflecting surface, and h ris the local curved arrow height corresponding to the curved reflecting surface itself, and H r is the local chord length corresponding to the curved reflective surface itself; N is the number of apertures according to the image distance adjustment needs; λ is the reference wavelength selected during optical design. Based on the specific image distance adjustment needs, the required local curvature of the curved reflective surface and the local curvature radius of the waveguide-based curved surface can be obtained by calculating the corresponding arrow height and chord length.

[0062] For example, refer to Figures 9-1 and 9-2, which are schematic diagrams of using a curved surface for one of the opposing surfaces of one of the waveguide bases in this embodiment, and as shown in the drawings, one of the opposing surfaces of the waveguide base may be a free-form surface, a concave surface, or a convex surface.

[0063] Furthermore, the first waveguide base further includes a first coupling output surface that causes the reflected light from the first reflecting surface to be emitted outside the first waveguide base, and the second waveguide base further includes a second coupling input surface that causes the light emitted from the first waveguide base to enter the second waveguide base, and the first coupling output surface and the second coupling input surface are optically coaxial. The first coupling output surface and the second coupling input surface being optically coaxial means that the first coupling output surface and the second coupling input surface are parallel to each other corresponding to a local optical axis.

[0064] In this embodiment, the shape of the first coupling output surface of the first waveguide base and the shape of the second coupling input surface of the second waveguide base are not limited, as long as the first coupling output surface and the second coupling input surface are optically coaxial. The first coupling output surface may be, but is not limited to, a flat surface, an inclined surface, a sawtooth surface, or a curved surface. The second coupling input surface may be, but is not limited to, a flat surface, an inclined surface, a sawtooth surface, or a curved surface. As an example, refer to Figures 10-1 to 10-4, which respectively show four embodiments of the first coupling output surface of the first waveguide base and the second coupling input surface of the second waveguide base in this embodiment.

[0065] In this embodiment, the relative positions of the first waveguide base and the second waveguide base are not limited, as long as the light coupled out from the first waveguide base enters the second waveguide base. For example, see Figures 11-1 to 11-3, which respectively show three embodiments of the arrangement positions of the first waveguide base and the second waveguide base in this embodiment. As shown in the drawings, the first waveguide base 1 is provided in front of, behind, or above the second waveguide base 2.

[0066] The optical display device of this embodiment may be a near-eye display device, such as a head-mounted device, which can change the image distance, is suitable for users with visual impairments, has a thin and light structure, and improves the user's comfort and perception experience.

[0067] The above is a detailed introduction to the optical display device provided by the present invention. Specific examples are used in this specification to describe the principles and embodiments of the present invention, and the description of the above examples is merely used to understand the method and spirit of the present invention. It should be noted that those skilled in the art may make some improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An optical display device, comprising: an image generating device; a coupling device; and an optical extension waveguide, wherein the coupling device is configured to couple light output from the image generating device to the optical extension waveguide, the coupling device being configured to correspond to the image generating device; the optical expansion waveguide includes at least a first reflective surface array and a second reflective surface array, and the light entering the optical expansion waveguide passes through the first reflective surface array and the second reflective surface array in order, and the first reflective surface array and the second reflective surface array respectively expand the light propagated through the optical expansion waveguide in a one-dimensional direction, and realize the expansion of the light entering the optical expansion waveguide in a two-dimensional direction, and emit the light out of the optical expansion waveguide to form an image; An optical display device characterized in that at least a portion of the first reflecting surface of the first reflecting surface array is curved, and at least a portion of the second reflecting surface of the second reflecting surface array is curved, so that the image distance formed from the light emitted by the optical extension waveguide meets a specified requirement.

2. At least a portion of a first reflecting surface of the first reflecting surface array is curved, and the first reflecting surface diverges the light reflected by the first reflecting surface; Alternatively, the optical display device according to claim 1, characterized in that at least a portion of the second reflective surface of the second reflective surface array is curved, and the second reflective surface diverges the light reflected by the second reflective surface.

3. 2. The optical display device of claim 1, wherein the first reflective surface array expands the light propagated through the optical expansion waveguide in a first dimensional direction, and each of the first reflective surfaces forms an inclination angle with respect to the first dimensional direction.

4. 2. The optical display device of claim 1, wherein the optically extended waveguide includes a first waveguide base, the first reflective surface array is disposed within the first waveguide base, the first waveguide base includes at least a first set of opposing surfaces, and light entering the first waveguide base is reflected by each of the first set of opposing surfaces and propagates forward.

5. 5. The optical display device according to claim 4, wherein at least one surface of the first set of opposing surfaces is curved at least partially, thereby changing the angle at which the reflected light from that surface enters the first reflecting surface, thereby helping to ensure that the image distance formed from the light emitted by the optical expansion waveguide meets a predetermined requirement.

6. 6. The optical display device of claim 5, wherein at least one surface of the first set of opposing surfaces diverges light reflected from that surface.

7. 2. The optical display device of claim 1, wherein the optically extended waveguide includes a second waveguide base, the second reflective surface array is disposed within the second waveguide base, the second waveguide base includes at least a third set of opposing surfaces, and light entering the second waveguide base is reflected by each of the third set of opposing surfaces and propagates forward.

8. 8. The optical display device according to claim 7, wherein each of the second reflecting surfaces forms an inclination angle with respect to one of the opposing surfaces of the third set.

9. 9. The optical display device according to claim 8, wherein the inclination angle formed by the second reflective surface with respect to one surface of the third set of opposing surfaces as a coupling output surface is greater than 0° and less than 45°, and when the second reflective surface rotates counterclockwise with respect to the one surface, the inclination angle formed by the second reflective surface with respect to the surface is positive.

10. 8. The optical display device according to claim 7, wherein at least one surface of the third set of opposing surfaces is curved at least partially, thereby changing the angle at which the reflected light from that surface enters the second reflecting surface, thereby helping to ensure that the image distance formed from the light emitted by the optical expansion waveguide meets a predetermined requirement.

11. 11. The optical display device of claim 10, wherein at least one surface of the third set of opposing surfaces diverges light reflected by that surface.

12. the optically extended waveguide includes a first waveguide base and a second waveguide base, the first reflective surface array is disposed within the first waveguide base, and the second reflective surface array is disposed within the second waveguide base; 2. The optical display device of claim 1, wherein the first waveguide base further includes a first coupling output surface that causes the reflected light from the first reflecting surface to be emitted outside the first waveguide base, and the second waveguide base further includes a second coupling input surface that causes the light emitted from the first waveguide base to enter the second waveguide base, and the first coupling output surface and the second coupling input surface are optically coaxial.

13. The optical display device described in any one of claims 1 to 12, characterized in that the coupling device separates the light output from the image generating device into a first beam and a second beam having different polarization states, and couples the first beam and the second beam into the optical extension waveguide, respectively.

14. 14. The optical display device of claim 13, wherein the combining device includes a polarization splitting unit, a light conversion unit, a collimating unit, and a light selection unit, wherein the polarization splitting unit polarizes and splits the light output from the image generating device, the light conversion unit converts two lights having different polarization states into each other, the collimating unit collimates the light to uniformly distribute the light energy, and the light selection unit inputs the light corresponding to the polarization state of the light passing through the light selection unit into the optical extension waveguide.

Images