Projection modules and head-mounted displays

Abstract

This application discloses a projection module and a head-mounted display. The projection module includes multiple light-emitting panels, a color-combining prism, and a light deflector. The multiple light-emitting pixels of the light-emitting panels include edge pixels located at the edges of the light-emitting panels and a central pixel in a central area surrounded by multiple edge pixels. The color-combining prism includes an incident surface and an exit surface, with the incident surface and the light-emitting panel corresponding one-to-one. The light deflector is disposed between the light-emitting panel and the corresponding incident surface. The light deflector deflects incident light rays from the light-emitting panel toward the corresponding incident surface. The deflection angle of the incident light rays corresponding to the edge pixels is greater than the deflection angle of the incident light rays corresponding to the central pixels, so that the incident light rays exit from the exit surface. This avoids light loss, ensures that all light rays from each light-emitting pixel can be used for imaging, and provides good brightness consistency among the light-emitting pixels, thereby improving the brightness consistency of the displayed image and resulting in better imaging performance.

Description

Technical Field

[0001] This application relates to the field of head-mounted display technology, and more specifically, to a projection module and a head-mounted display. Background Technology

[0002] Currently, in head-mounted displays, due to size limitations, the light emission angle of the light-emitting panel is generally large, usually greater than 40 degrees half-width and height. This causes the light emitted by some pixels to easily escape from the designated area and cannot be used for imaging, resulting in obvious brightness differences in different imaging areas and poor imaging effect. Summary of the Invention

[0003] This application provides a projection module and a head-mounted display that can avoid light loss, ensure that all light from each light-emitting pixel can be used for imaging, and achieve good brightness consistency among the light-emitting pixels, thereby improving the brightness consistency of the displayed image and resulting in better imaging effect.

[0004] The projection module of this application includes multiple light-emitting panels, a color-combining prism, and a light deflector. Each light-emitting panel includes multiple light-emitting pixels, including edge pixels located at the edges of the light-emitting panels and a central pixel located in the central region enclosed by the edge pixels. The color-combining prism includes an incident surface and an exit surface, with the incident surface corresponding to a light-emitting panel. The light deflector is disposed between the light-emitting panel and the corresponding incident surface, and is used to deflect incident light rays from the light-emitting panel toward the corresponding incident surface. The deflection angle of the incident light rays corresponding to the edge pixels is greater than the deflection angle of the incident light rays corresponding to the central pixels, so that the incident light rays exit from the exit surface.

[0005] In some embodiments, the divergence angle of the light emitted by each of the light-emitting pixels is less than or equal to 40 degrees after passing through the light deflector, and the deflection direction of the incident light corresponding to the edge pixel is from the edge of the light-emitting panel toward the center.

[0006] In some embodiments, the distance between the light-emitting pixel and the center of the light-emitting panel is proportional to the deflection angle of the incident light corresponding to the light-emitting pixel.

[0007] In some embodiments, the light deflector includes a deflecting lens, the deflecting lens including a convex lens, and the curvature of the lens portion of the deflecting lens facing the light-emitting pixel is proportional to the distance between the light-emitting pixel and the center of the light-emitting panel.

[0008] In some embodiments, the deflecting lens includes opposing convex surfaces and flat surfaces, the flat surfaces being disposed on the corresponding incident surfaces.

[0009] In some embodiments, the light deflector includes a microlens array, the microlens array including a plurality of microlenses, the plurality of microlenses including at least an edge microlens disposed corresponding to each of the edge pixels.

[0010] In some embodiments, the plurality of microlenses include an intermediate microlens corresponding one-to-one with each of the intermediate pixels. The deflection angle of the principal optical axis of the microlens relative to the optical axis of the corresponding light-emitting pixel is proportional to the distance between the microlens and the center of the microlens array. The deflection direction of the principal optical axis of the microlens is from the center of the light-emitting panel to the edge.

[0011] In some embodiments, the light deflector includes a holographic grating, wherein the grating period of the grating portion facing the light-emitting pixel is inversely proportional to the distance between the light-emitting pixel and the center of the light-emitting panel.

[0012] In some embodiments, the light deflector includes a metasurface in which the phase change gradient of the region directly opposite the light-emitting pixel is proportional to the distance between the light-emitting pixel and the center of the light-emitting panel.

[0013] In some embodiments, the light deflector includes a Fresnel diffraction lens, wherein the phase change gradient of the lens portion facing the light-emitting pixel is proportional to the distance between the light-emitting pixel and the center of the light-emitting panel.

[0014] In some embodiments, the projection module further includes an aberration compensator disposed between the light deflector and the corresponding incident surface, and the aberration compensator is used to compensate for aberrations in the incident light after it has been deflected by the light deflector.

[0015] In some embodiments, the aberration compensator includes at least one of a lens, a microlens array, a diffractive optical component, a metasurface, a Fresnel diffractive lens, and a holographic grating.

[0016] The head-mounted display of this application includes a projection module, a lens module, and a waveguide according to any of the above embodiments. The lens module and the projection module are arranged opposite to each other, and all light emitted from the projection surface is received by the lens module. The waveguide is used to conduct the light emitted from the lens module to the display area for display.

[0017] The projection module and head-mounted display of this application embodiment, by setting a light deflector between the color combining prism and the light-emitting panel, deflects the light emitted by the light-emitting panel. The light deflection angle of the edge pixels, which are prone to light loss, is larger than that of the middle pixels. This ensures that all the light emitted by the light-emitting panel can be emitted from the exit surface of the color combining prism, avoiding light loss from other surfaces. The light emitted from the exit surface is then processed by a corresponding lens module to ensure that all emitted light is used for imaging. This allows all the light from each light-emitting pixel of the light-emitting panel to be used for imaging, resulting in better brightness consistency among the light-emitting pixels and thus improving the brightness consistency of the displayed image, resulting in better imaging effect.

[0018] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0019] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein:

[0020] Figure 1 This is a schematic diagram of a projection module without a light deflector.

[0021] Figure 2 This is a first structural schematic diagram of a projection module according to certain embodiments of this application;

[0022] Figure 3 This is a second structural schematic diagram of a projection module according to certain embodiments of this application;

[0023] Figure 4 This is a third structural schematic diagram of a projection module according to certain embodiments of this application;

[0024] Figure 5 This is a fourth structural schematic diagram of the projection module according to certain embodiments of this application;

[0025] Figure 6 This is a fifth structural schematic diagram of the projection module according to certain embodiments of this application;

[0026] Figure 7 This is a sixth structural schematic diagram of the projection module according to certain embodiments of this application;

[0027] Figure 8 This is a seventh structural schematic diagram of a projection module according to certain embodiments of this application;

[0028] Figure 9 This is a schematic diagram of the internal structure of a head-mounted display according to certain embodiments of this application;

[0029] Figure 10 This is an overall schematic diagram of a head-mounted display according to certain embodiments of this application. Detailed Implementation

[0030] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of this application, and should not be construed as limiting the embodiments of this application.

[0031] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one feature. In the description of this application, "multiple" means at least two, such as two or three, unless otherwise explicitly specified.

[0033] Please see Figure 1 Currently, the applicant has discovered that in head-mounted displays, the projection optical engine typically uses a color-combining prism 105 paired with RGB three-color light-emitting panels (such as the three light-emitting panels 101 to 103) to project light. However, when the light beam is combined, the prism's volume is limited. Furthermore, the current light-emitting panels have a relatively large emission angle, typically greater than 40 degrees (°) at half-width. Therefore, some of the light rays 106 emitted by pixels located at the edge of the light-emitting panel 101 cannot be collected by the optical lens group 104 (generally designed for the exit surface). Consequently, this light cannot exit the optical engine, resulting in pixels in the center of the panel receiving more light from the lens group 104 and the color-combining prism 105 compared to pixels at the edges. This leads to a brightness difference between the center and edges of the displayed image.

[0034] To resolve the above technical issues, please refer to [link / reference]. Figure 2 This application provides a projection module 10.

[0035] The projection module 10 includes multiple light-emitting panels 11, a color-combining prism 12, and a light deflector 13. Each light-emitting panel 11 includes multiple light-emitting pixels 111, comprising edge pixels located at the edges of the light-emitting panels 11 and center pixels located in the central area enclosed by the edge pixels. The color-combining prism 12 includes an incident surface 121 and an exit surface 122, with the incident surface 121 corresponding to a light-emitting panel 11. The light deflector 13 is disposed between the light-emitting panel 11 and the corresponding incident surface 121. The light deflector 13 deflects incident light rays from the light-emitting panel 11 toward the corresponding incident surface 121. The deflection angle of the incident light rays corresponding to the edge pixels is greater than the deflection angle of the incident light rays corresponding to the center pixels, so that the incident light rays exit from the exit surface 122.

[0036] The projection module 10 of this application sets a light deflector 13 between the color combining prism 12 and the light-emitting panel 11. The light deflector 13 deflects the light emitted by the light-emitting panel 11, and the light deflection angle of the edge pixels that are prone to light loss is larger than that of the middle pixels. This ensures that all the light emitted by the light-emitting panel 11 can be emitted from the exit surface 122 of the color combining prism 12, avoiding light loss from other surfaces. The light emitted from the exit surface 122 is used for imaging by setting a corresponding lens module, so that all the emitted light is used for imaging. This ensures that all the light from each light-emitting pixel of the light-emitting panel 11 can be used for imaging, and the brightness consistency of each light-emitting pixel is good, thereby improving the brightness consistency of the displayed image and the imaging effect.

[0037] The projection module 10 of this application will be described in detail below.

[0038] Please continue reading. Figure 2 The projection module 10 includes multiple light-emitting panels 11, a color-combining prism 12, and a light deflector 13.

[0039] Here, the light-emitting panel 11 refers to a device for emitting light to form an image.

[0040] Optionally, the light-emitting panel 11 may include three, corresponding to red (R), green (G), and blue (B) respectively. The three light-emitting panels 11 emit light of different colors respectively, and then the light at the corresponding positions is combined to synthesize light of a specific color, thereby generating a display image of pixels with different colors.

[0041] Optionally, the light-emitting panel 11 includes a plurality of light-emitting pixels 111. Each light-emitting pixel 111 is used to emit light.

[0042] The light-emitting pixels 111 of different colored light-emitting panels 11 can emit light of the corresponding color. The light emitted by the light-emitting pixels 111 at the corresponding position is combined by the color-combining prism 12 to synthesize light of a specific color, thereby realizing the generation of light of different colors and thus generating a display image of pixels with different colors.

[0043] Optionally, after the light emitted by each light-emitting pixel 111 passes through the light deflector 13, the divergence angle of the light is less than or equal to 40 degrees, and the deflection direction of the incident light corresponding to the edge pixel is from the edge of the light-emitting panel towards the center.

[0044] Thus, by deflecting the light through the light deflector 13, the incident light emitted by each light-emitting pixel 111, after passing through the deflecting lens, has a divergence angle of less than or equal to 40 degrees. Furthermore, the light emitted by the edge pixels is deflected in the direction from the edge of the light-emitting panel towards the center. This ensures that the light emitted by the edge pixels can all enter the exit surface, thus avoiding the problem of excessively large light emission angles preventing the light emitted by the edge pixels from being used for subsequent imaging. It can be understood that 40 degrees is an empirical value; the specific design of the divergence angle after deflection can be based on the parameters of the exit surface 122 and the lens module, ensuring that all light emitted from the exit surface 122 is received by the lens module.

[0045] Optionally, the distance between the center of the light-emitting pixel 111 and the center of the light-emitting panel 11 is proportional to the deflection angle of the incident light corresponding to the light-emitting pixel 111. Thus, the closer the light-emitting pixel 111 is to the edge of the light-emitting panel 111, the larger the deflection angle of the incident light; that is, the larger the deflection angle of the light-emitting pixel 111 that is more prone to light loss. This ensures that the light from all light-emitting pixels 111 exits from the exit surface 122 of the color-combining prism 12, guaranteeing the light efficiency of the projection module 10.

[0046] Among them, the color-combining prism 12 is an optical element mainly used to combine light of different colors (wavelengths) into one or more beams of light.

[0047] The color combining prism 12 includes multiple incident surfaces 121 and exit surfaces 122. The incident surfaces 121 correspond one-to-one with the light-emitting panels 11, that is, each light-emitting panel 11 is provided with an incident surface 121.

[0048] If the color-combining prism 12 is a rectangle, the three light-emitting panels 11 correspond to three adjacent side surfaces, and the remaining side surface serves as the exit surface 122. The light emitted by each light-emitting panel 11 is directed toward the corresponding incident surface 121, and then, after being combined by the color-combining prism 12, it is emitted from the exit surface 122.

[0049] Optionally, the three light-emitting panels 11 include a light-emitting panel R that emits red light, a light-emitting panel G that emits green light, and a light-emitting panel B that emits blue light.

[0050] Among them, the wavelength of red light can be 630±16nm, the wavelength of blue light can be 463±9nm, and the wavelength of green light can be 538±17nm.

[0051] Please see Figure 3 Optionally, the light-emitting panel G is the light-emitting panel 11 facing the emission surface 122. Therefore, the color-combining prism 12 may also include a red light reflective film and a blue light reflective film. The red light reflective film can reflect the red light emitted by the light-emitting panel R and transmit light of other wavelengths. The blue light reflective film can reflect the blue light emitted by the light-emitting panel B and transmit light of other wavelengths.

[0052] Because a red light reflector 123 and a blue light reflector 124 are provided in the color combining prism 12, red light is reflected to the exit surface 122 after it propagates to the red light reflector 123, and blue light is reflected to the exit surface 122 after it propagates to the blue light reflector 124. Green light is not reflected by the red light reflector 123 and the blue light reflector 124. The red light, blue light and green light are combined and emitted from the exit surface 122.

[0053] Optionally, the light emitted by each light-emitting panel 11 overlaps within the coverage area of ​​the emission surface 122, thereby causing the light emitted by the light-emitting pixels 111 at corresponding positions of each light-emitting panel 11 to converge at the same position on the emission surface 122.

[0054] It is understandable that the principle of light deflection by the light deflector 13 set for different incident surfaces 121 is the same. Therefore, the following explanation only focuses on the incident surface 121 facing the exit surface 122, and will not elaborate on other incident surfaces 121.

[0055] The light deflector 13 is disposed between the light-emitting panel 11 and the incident surface 121. Since each light-emitting panel 11 may have technical problems, multiple light deflectors 13 can be provided, with one light deflector 13 corresponding to each light-emitting panel 11, thereby ensuring that the light from each light-emitting panel 11 can be used for imaging.

[0056] The light deflector 13 is a device used to deflect light to change the angle of light propagation. For example, the light deflector 13 can be a lens, a microlens array, a grating, a metasurface, etc.

[0057] Optionally, the light deflector 13 is used to deflect the light emitted by the light source towards the central axis of the light-emitting panel 11, thereby reducing the divergence angle of each light-emitting pixel 111, so that the light emitted by the light-emitting pixel 111 can be emitted from the exit surface 122, thereby reducing light loss and improving light efficiency.

[0058] In some embodiments, the light deflector 13 includes a lens. The lens may be a convex lens or a Fresnel diffraction lens.

[0059] For example, the light deflector 13 includes a deflecting lens 131, which includes a convex lens.

[0060] It is understood that a convex lens can converge light rays, specifically by deflecting the light rays along the optical axis of the lens, thereby achieving convergence. Therefore, a convex lens can be used to deflect the light rays from the light-emitting panel 11, so that all the light rays emitted by the light-emitting panel 11 are emitted from the exit surface 122.

[0061] Optionally, the curvature of the lens portion of the deflecting lens 131 (such as a convex lens) opposite the light-emitting pixel 111 is proportional to the distance of the light-emitting pixel 111 relative to the central axis of the light-emitting panel 11. In this way, the deflection angle of the incident light corresponding to the light-emitting pixel 111 is proportional to the distance of the light-emitting pixel 111 relative to the central axis of the light-emitting panel 11.

[0062] Please see Figure 4 Optionally, the deflecting lens 131 can be a Fresnel diffraction lens 135, in which the phase change gradient of the lens portion directly opposite the light-emitting pixel 111 is proportional to the distance between the center of the light-emitting pixel 111 and the center of the light-emitting panel 11. This ensures that the deflection angle of the incident light corresponding to the light-emitting pixel 111 is proportional to the distance between the center of the light-emitting pixel 111 and the center of the light-emitting panel 11.

[0063] Fresnel lenses are a special type of optical element that divides the curved refractive surface of a traditional lens into a series of concentric rings (or rings), each of which is equivalent to an independent refractive surface. This allows the lens to retain its basic functions such as focusing or imaging while significantly reducing its thickness and weight.

[0064] The phase gradient of a Fresnel lens refers to the rate at which the phase changes with position on the surface of the Fresnel lens or along a specific direction.

[0065] Optionally, the deflecting lens 131 includes opposing convex and flat surfaces, with the flat surfaces disposed on the corresponding incident surface 121.

[0066] Thus, by setting the surface of the deflecting lens 131 opposite to the incident surface 121 to be flat, the deflecting lens 131 can be easily mounted on the incident surface 121 of the color combining prism 12. And because it has a convex surface opposite to the flat surface, it ensures that the deflecting lens 131 can deflect the light so that the light emitted by the light-emitting panel 11 is emitted from the exit surface 122.

[0067] For example, the light deflector 13 includes a Fresnel lens.

[0068] Among them, the Fresnel lens is a special lens design that achieves light focusing by dividing the curved surface of a traditional lens into a series of annular strip structures. This design greatly reduces the thickness and weight of the lens while retaining the focusing function of a traditional lens.

[0069] Therefore, by using a Fresnel lens, while retaining the light deflection capability similar to that of a convex lens, the thickness and weight of the light deflector 13 are reduced, which is beneficial to the miniaturization of the projection module 10.

[0070] Please see Figure 5 In some embodiments, the light deflector 13 includes a microlens array 132, which includes a plurality of microlenses. The light-emitting panel 11 includes a plurality of light-emitting pixels 111, which includes edge pixels located at the edge of the light-emitting panel 11. The plurality of microlenses includes at least an edge microlens corresponding to each edge pixel.

[0071] Microlens array 132 (MLA) is an array structure composed of tiny lenses (microlenses) and is widely used in optics, imaging, and display technologies. The design and application of microlens array 132 can greatly improve the performance of optical systems, especially in applications requiring high-precision beam control and light field manipulation.

[0072] Since only edge pixels of the light-emitting panel 11 typically fail to emit light from the emission surface 122, a microlens array 132 can be used to reduce the cost of the light deflector 13. However, when setting up the microlens array 132, only corresponding microlenses are set for each edge pixel. That is, only the light emitted from the edge pixels is deflected, while the light emitted from the center pixels that are not on the edge is not deflected, thereby reducing the number of microlenses in the microlens array 132 and reducing its cost.

[0073] Microlenses based on edge pixels can deflect the light emitted by the edge pixels toward the central axis of the light-emitting panel 11, so that all the light emitted by the light-emitting panel 11 is emitted from the exit surface 122.

[0074] Of course, a corresponding microlens can also be provided for each luminous pixel 111 to achieve light control and improve imaging effect. For example, multiple luminous pixels 111 include a central pixel located in the central region surrounded by multiple edge pixels, and multiple microlenses include a central microlens corresponding to each central pixel. The light deflection angle of the edge microlenses is greater than that of the central microlenses. In this way, it can be ensured that the edge pixels have a larger deflection angle, ensuring that the light emitted by the edge pixels is used for imaging, and avoiding excessive deflection that would affect the imaging effect of the central pixels.

[0075] The central and edge regions can be determined based on empirical values, such as by testing based on the image to determine the dark areas with low imaging brightness, and then by determining the corresponding luminous pixel 111 area based on the dark areas, thereby determining the edge regions and the central region surrounded by the edge regions.

[0076] Optionally, the deflection angle of the main optical axis of the microlens relative to the optical axis of the corresponding light-emitting pixel 111 is proportional to the distance of the microlens relative to the center line of the microlens array 132, and the deflection direction of the main optical axis of the microlens is from the center of the light-emitting panel to the edge.

[0077] For example, the deflection direction of the principal optical axis of a microlens satisfies the following relationship:

[0078]

[0079] Among them, L x and L y These represent the horizontal and vertical distances from the microlens to the center of the microlens array 132, respectively, and L is the length of the color combining prism 12. The reference axis for the rotation of the principal optical axis of the microlens is the line passing through the center of the microlens and perpendicular to the line connecting the light-emitting pixel 111 to the center of the light-emitting panel 11.

[0080] Please see Figure 6 In some embodiments, the light deflector 13 includes a holographic grating 133, the light-emitting panel 11 includes a plurality of light-emitting pixels 111, the plurality of light-emitting pixels 111 includes edge pixels located at the edge of the light-emitting panel 11, and the holographic grating 133 includes at least a grating portion corresponding to the edge pixel, the direction of the grating vector of the grating portion is toward the central axis of the light-emitting panel 11.

[0081] Among them, the holographic grating 133 is a grating manufactured using holographic technology, and its manufacturing process differs from that of traditional gratings. The main features of the holographic grating 133 are:

[0082] Fabrication process: The holographic grating 133 is manufactured by recording the fringe pattern formed by the interference of two coherent laser beams in a material. These fringes create periodic changes in refractive index within the material, thus functioning as a grating.

[0083] Structural features: The holographic grating 133 can be volumetric, that is, it forms a periodic change in refractive index in the three-dimensional space of the material.

[0084] Diffraction efficiency: The holographic grating 133 can achieve very high diffraction efficiency, especially at specific wavelengths and incident angles.

[0085] Tunability: By changing the fabrication conditions of the holographic grating 133 (such as laser wavelength, exposure time, etc.), gratings with different diffraction characteristics can be fabricated.

[0086] Nonlinear optics applications: The holographic grating 133 can also be used for the study of nonlinear optical processes, such as second harmonic generation and optical parametric amplification.

[0087] Holographic gratings 133 generally have higher diffraction efficiency and can achieve high diffraction efficiency over a wider wavelength range.

[0088] Similarly, the holographic grating 133 can also be configured only for edge pixels, such as by configuring only the grating portion corresponding to the edge pixels to diffract the light emitted by the edge pixels, thereby deflecting the light emitted by the edge pixels and ensuring that all the light emitted by the edge pixels is used for imaging. This eliminates the need to configure the grating portion corresponding to the center pixels, reducing the cost of the holographic grating 133.

[0089] Optionally, the grating vector direction of the grating portion of the holographic grating 133 corresponding to the edge pixels is oriented towards the central axis of the light-emitting panel 11. That is, the grating portion can deflect the light rays of the corresponding edge pixels towards the central axis of the light-emitting panel 11.

[0090] Optionally, in the holographic grating 133, the grating period of the grating portion opposite the light-emitting pixel 111 is inversely proportional to the distance between the light-emitting pixel 111 and the central axis of the light-emitting panel 11. This allows the deflection angle of the incident light corresponding to the light-emitting pixel 111 to be directly proportional to the distance between the light-emitting pixel 111 and the central axis of the light-emitting panel 11.

[0091] The grating period of the holographic grating 133 refers to the distance between two adjacent grating fringes, usually represented by the symbol "Λ" (uppercase Greek letter Lambda). Physically, it reflects the periodic variation of the characteristic scale in the structure of the holographic grating 133.

[0092] Please see Figure 7In some embodiments, the light deflector 13 includes a metasurface 134, the light-emitting panel 11 includes a plurality of light-emitting pixels 111, the plurality of light-emitting pixels 111 includes edge pixels located at the edge of the light-emitting panel 11, and the metasurface 134 includes at least a surface portion disposed corresponding to the edge pixels.

[0093] Among them, Metasurfaces 134 are two-dimensional planar structures composed of subwavelength scale artificially designed units (called "meta-atoms" or "meta-units") that can precisely control the phase, amplitude, polarization and other properties of electromagnetic waves.

[0094] Metasurface 134 controls light waves by altering properties such as the phase, amplitude, and polarization of incident light. Each elementary atom can be considered an independent phase modulator, and precise control of the output light waves from the entire metasurface 134 can be achieved through the design of each elementary atom.

[0095] Similarly, metasurface 134 can also be configured only for edge pixels, such as configuring only the surface portion corresponding to the edge pixels (this surface portion includes the meta-atoms corresponding to each edge pixel) to modulate the light emitted by the corresponding edge pixels, thereby deflecting the light emitted by the edge pixels and ensuring that the light emitted by the edge pixels is used for imaging. This eliminates the need to configure the surface portion corresponding to the center pixels, reducing the cost of metasurface 134.

[0096] Optionally, in the metasurface 134, the phase change gradient of the region directly opposite the light-emitting pixel 111 is proportional to the distance of the light-emitting pixel 111 relative to the central axis of the light-emitting panel 11. This allows the deflection angle of the incident light corresponding to the light-emitting pixel 111 to be proportional to the distance of the light-emitting pixel 111 relative to the central axis of the light-emitting panel 11.

[0097] The phase change gradient of metasurface 134 refers to the rate at which the phase changes with position on the two-dimensional plane of metasurface 134.

[0098] Please see Figure 8 In some embodiments, the projection module 10 further includes an aberration compensator 14, which is disposed between the light deflector 13 and the corresponding incident surface 121. The aberration compensator 14 is used to compensate for aberrations in the incident light after it has been deflected by the light deflector 13.

[0099] The aberration compensator 14 is an optical device specifically designed to compensate for aberrations. For example, the aberration compensator 14 includes at least one of a lens, a microlens array, a diffractive optical component, a metasurface, a Fresnel diffraction lens, and a holographic grating.

[0100] Specifically, since the light deflector 13 deflects the light, it will inevitably cause some aberration loss, thus affecting the subsequent imaging effect. Therefore, a phase aberration compensator can be set between the light deflector 13 and the corresponding incident surface 121 to compensate for the aberration of the imaging light while ensuring the light deflection effect (i.e., both can be used for imaging), thereby improving the final imaging effect.

[0101] Aberration is a common problem in optical systems, which can lead to decreased image quality and problems such as blurring and distortion. The aberration compensator 14 can compensate for or correct aberrations through proper design, thereby improving the image quality of the optical system.

[0102] For example, spherical aberration can be corrected by combining lenses with different radii of curvature. As another example, the surface shape of aspherical lenses can be specially designed to more precisely control the light path, reducing spherical and coma. Furthermore, designing freeform lenses can better correct astigmatism and other aberrations.

[0103] Please see Figure 9 This application also provides a head-mounted display 100, which includes a projection module 10, a lens module 20, and a waveguide 30 as described in any of the above embodiments. The lens module 20 is disposed opposite to the emission surface 122 of the projection module 10, and all light emitted from the emission surface 122 is received by the lens module 20; the waveguide 30 is used to conduct the light emitted from the lens module 20 to the display area for display.

[0104] The projection module 10 emits projection light, and the lens module 20 is designed for the exit surface 122 of the projection module 10 to receive all the light emitted from the exit surface 122 for subsequent imaging. The lens module 20 can adjust the projection light so that it smoothly enters the waveguide 30 through the inlet (such as the coupling grating), propagates through the waveguide 30, and exits from the waveguide 30 through the outlet (such as the output grating), finally reaching the user's eye from the display area facing the user's eye for imaging.

[0105] The waveguide 30 is a conduit or structure used to guide and confine electromagnetic waves (such as microwaves and light waves) along a specific path. The waveguide 30 enables the propagation of light, allowing projected light to exit the display area for display. The waveguide 30 features efficient light transmission with minimal scattering or energy loss.

[0106] Please see Figure 10In one embodiment, the head-mounted display 100 includes a left-eye display 110 and a right-eye display 120. Both the left-eye display 110 and the right-eye display 120 include the projection module 10, lens module 20, and waveguide 30 described in the above embodiment. Thus, by displaying images through the left-eye display 110 and the right-eye display 120 respectively, the differences between the left and right eyes can be addressed, resulting in better imaging performance.

[0107] In the description of this specification, the references to terms such as "some embodiments," "in one example," "exemplarily," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0108] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A projection module, characterized in that, include: Multiple light-emitting panels, each light-emitting panel including multiple light-emitting pixels, the multiple light-emitting pixels including edge pixels located at the edge of the light-emitting panel and middle pixels located in the middle area surrounded by the multiple edge pixels; A color-combining prism, comprising an incident surface and an exit surface, wherein the incident surface and the light-emitting panel are respectively configured in a one-to-one correspondence; A light deflector is disposed between the light-emitting panel and the corresponding incident surface. The light deflector is used to deflect the incident light rays emitted by the light-emitting panel toward the corresponding incident surface. The deflection angle of the incident light rays corresponding to the edge pixels is greater than the deflection angle of the incident light rays corresponding to the middle pixels, so that the incident light rays are emitted from the exit surface.

2. The projection module according to claim 1, characterized in that, The light emitted by each of the light-emitting pixels has a divergence angle of less than or equal to 40 degrees after passing through the light deflector, and the incident light rays corresponding to the edge pixels are deflected in the direction from the edge of the light-emitting panel toward the center.

3. The projection module according to claim 1, characterized in that, The deflection angle of the incident light corresponding to the light-emitting pixel is proportional to the distance of the light-emitting pixel relative to the central axis of the light-emitting panel.

4. The projection module according to claim 1, characterized in that, The light deflector includes a deflecting lens, which includes a convex lens. The curvature of the lens portion of the deflecting lens facing the light-emitting pixel is proportional to the distance of the light-emitting pixel relative to the central axis of the light-emitting panel.

5. The projection module according to claim 4, characterized in that, The deflecting lens includes opposing convex surfaces and flat surfaces, the flat surfaces being disposed on the corresponding incident surfaces.

6. The projection module according to claim 1, characterized in that, The light deflector includes a microlens array, which includes multiple microlenses, and the multiple microlenses include at least an edge microlens corresponding to each of the edge pixels.

7. The projection module according to claim 6, characterized in that, The plurality of microlenses include an intermediate microlens corresponding one-to-one with each of the intermediate pixels. The deflection angle of the principal optical axis of the microlens relative to the optical axis of the corresponding light-emitting pixel is proportional to the distance of the microlens relative to the center line of the microlens array. The deflection direction of the principal optical axis of the microlens is from the center of the light-emitting panel to the edge.

8. The projection module according to claim 1, characterized in that, The light deflector includes a holographic grating, wherein the grating period of the portion of the grating directly opposite the light-emitting pixel is inversely proportional to the distance of the light-emitting pixel relative to the central axis of the light-emitting panel.

9. The projection module according to claim 1, characterized in that, The light deflector includes a metasurface in which the phase change gradient of the region directly opposite the light-emitting pixel is proportional to the distance of the light-emitting pixel relative to the central axis of the light-emitting panel.

10. The projection module according to claim 1, characterized in that, The light deflector includes a Fresnel diffraction lens, wherein the phase change gradient of the lens portion facing the light-emitting pixel is proportional to the distance of the light-emitting pixel relative to the central axis of the light-emitting panel.

11. The projection module according to any one of claims 1-10, characterized in that, Also includes: An aberration compensator is disposed between the light deflector and the corresponding incident surface. The aberration compensator is used to compensate for aberrations in the incident light after it has been deflected by the light deflector.

12. The projection module according to claim 11, characterized in that, The aberration compensator includes at least one of a lens, a microlens array, a diffractive optical component, a metasurface, a Fresnel diffractive lens, and a holographic grating.

13. A head-mounted display, characterized in that, include: The projection module according to any one of claims 1 to 12; A lens module is provided, with its exit surface facing the projection module, and all light emitted from the exit surface is received by the lens module. and A waveguide is used to guide the light emitted from the lens module to the display area for display.

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