Display module and head-mounted display device

Abstract

The embodiment of the application provides a display module and a head-mounted display device, and belongs to the technical field of head-mounted display products. The display module comprises an image source, a lens group and a polarized light path assembly. The image source is used for emitting first linearly polarized light. The lens group is located on the light emitting side of the image source and is used for transmitting the first linearly polarized light emitted by the image source. The polarized light path assembly comprises a first optical element, a second optical element and a third optical element, the first optical element is located on the light emitting side of the lens group, the second optical element and the third optical element are arranged at intervals along a first direction, and the second optical element and the third optical element are both arranged at intervals with the lens group in a second direction. By folding the light path between the lens group and the second optical element, the lens group is away from the third optical element, and the eyebox in the vertical direction remains unchanged after myopia adjustment.

Description

Technical Field

[0001] This application relates to the field of head-mounted display products technology, and in particular to an electronic device. Background Technology

[0002] Head-mounted display devices, such as augmented reality (AR) devices, can generate virtual images superimposed on the real world. In related technologies, the optical scheme for head-mounted display devices is the Birdbath (BB) scheme, which consists of a screen, polarizer, lens, concave beam splitter, and planar beam splitter. The polarizer converts the light emitted from the screen into linearly polarized light. After passing through the lens, the linearly polarized light is first reflected by the planar beam splitter, then reflected again by the concave beam splitter, and finally reaches the eye through the planar beam splitter. Simultaneously, ambient light passes through both the concave and planar beam splitters to reach the eye, allowing the eye to simultaneously see the virtual image and the real environment for an AR experience. However, after myopia accommodation, the lens moves a certain distance vertically towards the planar beam splitter, causing interference between the reflected light from the concave beam splitter and the lens, resulting in a smaller vertical eyebox. Summary of the Invention

[0003] This application provides a display module and a head-mounted display device. The lens group and the third optical element of the display module are arranged at intervals in the vertical direction, so that the eye box in the vertical direction will not change after myopia adjustment.

[0004] In a first aspect, embodiments of this application provide a display module, which includes an image source, a lens group, and a polarization optical path assembly. The image source emits first linearly polarized light. The lens group is located on the light-emitting side of the image source and transmits the first linearly polarized light emitted by the image source. The polarization optical path assembly includes a first optical element, a second optical element, and a third optical element. The first optical element is located on the light-emitting side of the lens group. The second and third optical elements are arranged at intervals along a first direction, and both the second and third optical elements are spaced apart from the lens group in a second direction, which is perpendicular to the second direction. Specifically: the first optical element reflects the first linearly polarized light transmitted by the lens group to the second optical element. The second optical element reflects the first linearly polarized light and transmits second linearly polarized light to the human eye, wherein the polarization direction of the first linearly polarized light is perpendicular to the polarization direction of the second linearly polarized light. The third optical element converts a portion of the first linearly polarized light reflected by the second optical element into second linearly polarized light emitted to the second optical element.

[0005] Compared to existing technologies where the lens partially overlaps with the concave beam splitter in the thickness direction after myopia adjustment, causing interference between the reflected light from the lens and the concave beam splitter, thus reducing the vertical eye box size, this embodiment addresses this issue by placing a first optical element in the optical path between the second optical element and the lens group. This folds the optical path between the second optical element and the lens group, allowing the lens group and the third optical element to be spaced apart in the vertical direction (second direction). After myopia adjustment, the reflected light from the lens group and the third optical element will not interfere, thus not obstructing the display image. The vertical (second direction) eye box size remains unchanged and does not obstruct the display image. The eye box refers to the area where the eye can be placed and still receive a clear image.

[0006] Furthermore, in existing technologies, the reflected light from a concave beam splitter is incident on the bottom of the lens, forming an arc-shaped stray light. This arc-shaped stray light then passes through a planar beam splitter and enters the human eye, resulting in an arc-shaped stray light appearing above the displayed image, thus reducing the display effect. However, in this application, by folding the optical path between the lens group and the second optical element, the lens group and the third optical element are spaced apart in the second direction. The reflected light from the third optical element does not incident on the bottom of the lens group, avoiding the generation of arc-shaped stray light. Therefore, no arc-shaped stray light is seen above the displayed image, improving the display effect.

[0007] Furthermore, in existing technologies, linearly polarized light is transmitted to a planar beam splitter via a lens group. The angle between the normal of the planar beam splitter and the thickness direction (first direction) is 45°, resulting in a relatively large thickness of the entire BB module. Therefore, this embodiment of the application incorporates an optical element that reflects the first linearly polarized light between the lens group and the second optical element. This folds the optical path between the lens group and the second optical element, reducing the tilt angle of the second optical element. In other words, the angle between the normal of the second optical element and the thickness direction can be reduced, thereby reducing the thickness of the display module in the thickness direction. Simultaneously, the lens group and the third optical element are spaced apart in the second direction. This prevents the lens group from getting stuck between the second and third optical elements after myopia adjustment, and the distance between the second and third optical elements in the thickness direction can also be reduced, further reducing the thickness of the display module in the thickness direction. Therefore, by folding the optical path between the lens group and the second optical element, the thickness of the display module can be reduced, achieving a thinner and lighter design.

[0008] In one possible implementation, the polarization path assembly further includes a fourth optical element located in the optical path between the first and second optical elements, for reflecting the first linearly polarized light reflected by the first optical element to the second optical element.

[0009] In this implementation, by reflecting the first linearly polarized light reflected by the first optical element through the fourth optical element, the optical path between the first and second optical elements can be folded. This further reduces the angle between the normals of the first and second optical elements and the thickness direction, thereby further reducing the thickness of the display module. Simultaneously, the distance between the lens group and the second and third optical elements in the second direction can be further increased, further ensuring that reflected light from the third optical element does not incident on the lens group, ensuring that the vertical eye box remains unchanged, and avoiding the generation of arc-shaped stray light.

[0010] In one possible implementation, a fourth optical element is positioned close to the third optical element in a second direction. The fourth optical element includes a first reflective polarizer and a first polarizer, wherein: the first polarizer is used to transmit second linearly polarized light from ambient light; and the first reflective polarizer is used to reflect the first linearly polarized light and transmit the second linearly polarized light transmitted through the first polarizer to the second optical element.

[0011] In this implementation, ambient light enters the eye not only after passing through the third and second optical elements sequentially, but also after passing through the fourth and second optical elements sequentially. Therefore, both the third and fourth optical elements can receive the ambient light incident on the eye. Compared to existing technologies that use concave mirrors to receive ambient light, using both the third and fourth optical elements to receive ambient light increases the vertical eyebox size.

[0012] In one possible implementation, the fourth optical element further includes a first light-transmitting substrate, wherein: the first polarizer and the first reflective polarizer are respectively connected to opposite sides of the first light-transmitting substrate, or the first reflective polarizer and the first light-transmitting substrate are respectively connected to opposite sides of the first polarizer.

[0013] In this implementation, the first polarizer and the first reflective polarizer can be integrated into a single structure through a first transparent substrate, which helps to reduce the thickness of the display module.

[0014] In one possible implementation, the third optical element includes a first quarter-wave plate and a transmission-reflecting mirror arranged along a first direction. The first quarter-wave plate is located between the transmission-reflecting mirror and the second optical element and is connected to the transmission-reflecting mirror. The first quarter-wave plate is used to convert first linearly polarized light from the second optical element into first circularly polarized light, and to convert second circularly polarized light from the transmission-reflecting mirror into second linearly polarized light. The transmission-reflecting mirror is used to transmit a portion of the first circularly polarized light emitted from the first quarter-wave plate, and a portion of the first circularly polarized light reflected from the first quarter-wave plate is reflected by the transmission-reflecting mirror and becomes second circularly polarized light.

[0015] In this implementation, the first quarter-wave plate and the mirror work together to transform the first linearly polarized light reflected by the second optical element into second linearly polarized light that enters the human eye, allowing the viewer to see the virtual image formed by the first linearly polarized light emitted from the image source. Additionally, ambient light passes sequentially through the mirror, the first quarter-wave plate, and the second optical element, becoming second linearly polarized light before entering the human eye, allowing the viewer to see the real image formed by the ambient light.

[0016] In one possible implementation, the third optical element further includes a second quarter-wave plate and a second polarizer. The second quarter-wave plate is located between the mirror and the second polarizer along a first direction and is connected to both the mirror and the polarizer. The second quarter-wave plate converts the first circularly polarized light emitted by the mirror into second linearly polarized light. The second polarizer absorbs the second linearly polarized light emitted by the second quarter-wave plate and transmits the first linearly polarized light.

[0017] In this implementation, the second quarter-wave plate converts the first circularly polarized light transmitted by the mirror into second linearly polarized light. The second polarizer absorbs the second linearly polarized light from the second quarter-wave plate, thus preventing light leakage inside the display module. Furthermore, ambient light from the outside world becomes first linearly polarized light after passing through the second polarizer, then becomes second circularly polarized light after passing through the second quarter-wave plate, then becomes second linearly polarized light after passing through the first quarter-wave plate, and finally enters the human eye through the second optical element, achieving optical transmission.

[0018] In one possible implementation, the transflector includes a second transparent substrate and a semi-transparent semi-reflective film, the semi-transparent semi-reflective film being located between a first quarter-wave plate and the second transparent substrate, and being connected to the second transparent substrate and the first quarter-wave plate respectively.

[0019] In one possible implementation, the mirror is a concave mirror.

[0020] In this implementation, a concave mirror magnifies the image by reflecting and focusing light. Compared to a planar mirror, the concave design better corrects certain types of optical aberrations, resulting in sharper, clearer image quality. The concave mirror allows light to fold along its path, reducing the overall size of the optical system and making the device lighter, more compact, and more suitable for extended wear. Due to its curvature, the concave mirror more effectively collects and guides light into the user's eye, contributing to improved image brightness and contrast, especially in bright environments.

[0021] In one possible implementation, the first optical element is a total reflection mirror, which can reflect all the first linearly polarized light from the lens group, thereby improving image quality.

[0022] In one possible implementation, the first optical element is a concave total internal reflection mirror.

[0023] In this implementation, the image can be magnified or reduced while reflecting all the first linearly polarized light from the lens group, thus achieving image focusing. Additionally, it can reduce aberrations, improve brightness and contrast, and enable a more compact design.

[0024] In one possible implementation, a first optical element is positioned close to a third optical element in a second direction. The first optical element includes a third reflective polarizer and a fourth polarizer. The fourth polarizer transmits second linearly polarized light from ambient light. The third reflective polarizer reflects first linearly polarized light and transmits the second linearly polarized light transmitted through the fourth polarizer to the second optical element.

[0025] In this implementation, ambient light enters the eye not only after passing through the third and second optical elements sequentially, but also after passing through the first and second optical elements sequentially. Therefore, both the third and first optical elements can receive the ambient light incident on the eye. Compared to existing technologies that use concave mirrors to receive ambient light, using both the third and first optical elements to receive ambient light increases the vertical eyebox size.

[0026] In one possible implementation, the second optical element includes a third light-transmitting substrate and a second reflective polarizer, the second reflective polarizer being fixedly connected to the third light-transmitting substrate, and the second reflective polarizer being used to reflect the first linearly polarized light and transmit the second linearly polarized light.

[0027] In one possible implementation, the image source includes a display device and a third polarizer. The display device is used to emit image light. The third polarizer is located between the display device and the lens group and is used to transmit first linearly polarized light through the image light emitted from the display device.

[0028] In one possible implementation, the lens group includes at least one lens, and the lens group is used to move along the optical axis of the lens group.

[0029] In this implementation, there can be one, two, three, or more lenses; this application does not impose any limitation. Furthermore, by moving the lens group, the diopter of the display module can be adjusted, aberrations can be compensated, and the focus can be improved, thereby enhancing the user experience. Additionally, increasing the number of lenses can improve image clarity.

[0030] In one possible implementation, the first linearly polarized light is S-polarized light and the second linearly polarized light is P-polarized light.

[0031] Secondly, embodiments of this application provide a head-mounted display device, which includes a display module as described in any of the first aspects. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of a display module in related technologies;

[0033] Figure 2 for Figure 1 A schematic diagram of the interference between the reflected light from the lens and the concave beam splitter.

[0034] Figure 3 for Figure 1 A schematic diagram showing how the reflected light from the concave beam-splitter in the lens forms an arc-shaped stray light.

[0035] Figure 4 This is a schematic diagram of the structure of a display module provided in Embodiment 1 of this application;

[0036] Figure 5 This is a schematic diagram of the structure of a display module provided in Embodiment 2 of this application;

[0037] Figure 6 This is a schematic diagram of the structure of a display module provided in Embodiment 3 of this application;

[0038] Figure 7 This is a schematic diagram of another display module provided in Embodiment 3 of this application.

[0039] Explanation of reference numerals in the attached figures:

[0040] 100. Image source; 110. Display device; 120. Third polarizer;

[0041] 200. Lens group;

[0042] 300. Polarization optical path assembly;

[0043] 310. First optical element;

[0044] 320. Second optical element; 321. Third light-transmitting substrate; 322. Second reflective polarizer;

[0045] 330. Third optical element; 331. First quarter-wave plate; 332. Transmitting mirror; 3321. Semi-transmitting and semi-reflecting film; 3322. Second transparent substrate; 333. Second quarter-wave plate; 334. Second polarizer;

[0046] 340. Fourth optical element; 341. First reflective polarizer; 342. First polarizer; 343. First light-transmitting substrate;

[0047] X, third direction; Y, second direction; Z, first direction. Detailed Implementation

[0048] The terminology used in the implementation section of this application is for the purpose of explaining specific embodiments of this application only, and is not intended to limit this application.

[0049] To facilitate understanding, the technical terms used in this application will be explained and described below.

[0050] A polarizer (POL), also known as a light polarizer, is an optical filter. Polarizers are used to absorb or reflect light with one polarization direction and transmit light with another orthogonally polarized direction. The transmittance of light is directly related to its polarization state. Polarizers are generally classified into absorptive polarizers and reflective polarizers (RP). Absorptive polarizers strongly absorb one of the orthogonally polarized components of incident linearly polarized light, while absorbing the other component weakly. Reflective polarizers can transmit linearly polarized light in a certain direction and reflect light with a polarization direction perpendicular to the transmitted direction. Absorptive polarizers can be, for example, dichroic polarizers, while reflective polarizers can be, for example, birefringence-based polarizing beam splitters.

[0051] Light waves are electromagnetic waves, composed of both electric and magnetic fields. Both are vectors perpendicular to the direction of light wave propagation. Light waves are deflected in these electric and magnetic fields, becoming polarized. When the light vector vibrates in only one fixed direction, this light is called linearly polarized light, also known as plane-polarized light. When both vectors rotate around themselves, the light wave is circularly polarized. Circularly polarized light is characterized by its light vector rotating at a certain frequency (left-handed or right-handed) within a plane perpendicular to the direction of light propagation. If the trajectory of the endpoint of the light vector is a circle, this light is called circularly polarized light.

[0052] When natural light (or unpolarized light) is incident on a polarizer, the outgoing light becomes linearly polarized. When linearly polarized light is incident on a polarizer, the outgoing light remains linearly polarized.

[0053] S-polarized light, also called S-beam or vertically polarized light, has an electric field vibration direction perpendicular to the plane of incidence.

[0054] P-polarized light, also called P-beam or horizontally polarized light, has an electric field vibration direction parallel to the plane of incidence.

[0055] The polarization direction is also called the polarization direction or the polarization initiation direction. This is because there is a certain characteristic direction in the polarizer, called the polarization direction. The polarizer only allows light parallel to the polarization direction to pass through, while absorbing or reflecting light perpendicular to that direction.

[0056] A quarter-wave plate (QWP) can also be called a 90° phase retardation plate. A quarter-wave plate is made of a birefringent material. When the light vector of linearly polarized light forms a ±45° angle with the fast or slow axis of the quarter-wave plate, the light passing through the quarter-wave plate is circularly polarized; conversely, when circularly polarized light passes through the quarter-wave plate, it becomes linearly polarized. The direction of the slower-propagating light vector in the quarter-wave plate is called the slow axis direction.

[0057] A semi-transparent and semi-reflective film is a film that allows incident light to partially pass through and partially reflect. For example, a film with both 50% transmittance and 50% reflectance. Transmission is the phenomenon where incident light, after refraction, exits through an object. The object through which light is transmitted is transparent or translucent, such as glass or a color filter. If the transparent object is colorless, most light passes through it, except for a small amount reflected. To represent the degree to which light passes through an object, the ratio of the intensity of the transmitted light to the intensity of the incident light is typically used to characterize transmissivity. The ratio of the intensity of the reflected light to the intensity of the incident light is used to characterize reflectivity.

[0058] A semi-transparent and semi-reflective mirror, also known as a beam splitter, is an optical element that alters the transmission and reflection ratio of an incident light beam by coating a semi-reflective film on optical glass or on one optical surface of a lens. The coating can increase transmission (increasing light intensity) or decrease reflection (reducing light intensity). For example, a semi-transparent and semi-reflective mirror can transmit and reflect incident light in a 50:50 ratio, meaning its transmittance and reflectance are each 50%. When incident light passes through the mirror, the transmitted and reflected light intensities are each 50%. Of course, the reflectance and transmittance can be selected according to specific needs; for example, the reflectance can be higher than 50% and the transmittance lower than 50%, or vice versa.

[0059] This application provides a head-mounted display device, which is wearable on a user's head and can be used to display images in front of the user's line of sight. This head-mounted display device may include, but is not limited to, a virtual reality (VR) device, an augmented reality (AR) device, or a mixed reality (MR) device. This application uses an AR device as an example for illustration; for instance, the head-mounted display device can be AR glasses.

[0060] In this embodiment, the head-mounted display device includes a display module and a fixing member. The display module is fixedly mounted on the fixing member and can display virtual images to the user as well as allow the user to view the real-world environment. The fixing member is used to wear the head-mounted display device on the user's head. For example, the fixing member can be a glasses frame, including a front frame and two temples respectively disposed at both ends of the front frame in a first direction. The two temples can be hooked onto the user's ears, and the front frame can be placed on the user's nose to wear the head-mounted display device on the user's head.

[0061] In some examples, the temples can be fixed to the front frame. For instance, the temples can be an integral part of the front frame.

[0062] In other examples, the temples can be hinged to the front frame via a hinge assembly, allowing the temples to fold away from the front frame for easy storage of the head-mounted display device.

[0063] Figure 1 This is a structural diagram of a display module in related technologies. Figure 2 for Figure 1 A schematic diagram of the interference between the reflected light from the lens and the concave beam-splitter. Figure 3 for Figure 1 A schematic diagram showing how the reflected light from the concave beam splitter in the lens forms an arc-shaped stray light.

[0064] In related technologies, such as Figure 1 As shown, the display module is a Birdbath (BB) optical system, including a screen 410, a polarizer 420 (POL), a lens 430, a planar beam splitter 440, and a concave beam splitter 450. The screen 410 emits image light to form a virtual image. The polarizer 420 converts the image light into linearly polarized light. The planar beam splitter 440 is tilted and positioned on the visual axis in front of the viewer's eye, with its normal intersecting the visual axis. The planar beam splitter 440 includes a translucent plate 441 and a reflective polarizer 442 (RP) stacked together. The concave beam splitter 450 includes a quarter-wave plate 451, a semi-transparent and semi-reflective film 452, and a concave translucent substrate 453 stacked together, with the quarter-wave plate 451 close to the reflective polarizer 420.

[0065] In this system, light emitted from screen 410 is polarized (S) by polarizer 420, then transmitted through lens 430 to reflective polarizer 442. Reflective polarizer 442 reflects the S-polarized light to quarter-wave plate 451, which converts it to right-handed polarization. A portion of this right-handed polarization is reflected by semi-reflective film 452, becoming left-handed polarization. This left-handed polarization then passes through quarter-wave plate 451 and becomes p-polarized light. Reflective polarizer 442 transmits this p-polarized light into the viewer's eye, creating a virtual image. Ambient light from the real environment passes sequentially through concave beam splitter 450 and planar beam splitter 440, allowing p-polarized light from the ambient light to enter the viewer's eye, thus enabling optical vision.

[0066] like Figure 1 As shown, a portion of lens 430 is located between planar beam splitter 440 and concave beam splitter 450, such that planar beam splitter 440 and concave beam splitter 450 are in the thickness direction (e.g., Figure 1 The spacing in the Z-direction is relatively large, resulting in the entire BB module having a larger thickness in the thickness direction (e.g., Figure 1 The thickness is relatively thick in the Z-direction. The normal of the planar beam splitter 440 is different from the thickness direction (e.g., Figure 1 The angle between the two directions (Z-direction) is typically 45° so that the light transmitted through the lens 430 is deflected by 45°. The planar beam splitter 440 is in the thickness direction (e.g., Figure 1 It also occupies a large size in the Z-direction, causing the entire BB module to have a large thickness in the thickness direction (e.g., Figure 1 The thickness is relatively large in the Z-direction. Therefore, it can be seen that the existing BB module is quite thick, occupying a large space in the head-mounted display module, which is not conducive to the thinning design of head-mounted display devices.

[0067] Additionally, lens 430 is along the vertical direction (e.g.) Figure 2 The lens 430 moves downwards towards the planar beam splitter 440 (in the Y direction) to perform myopia accommodation. This increases the overlap between the lens 430 and the concave beam splitter 450 in the thickness direction, causing interference between the reflected light from the concave beam splitter 450 and the lens 430 (e.g., ...). Figure 2 As shown in the image, the vertical eye box becomes smaller, making it easier to obstruct the display. The eye box refers to the area where the eye can rest and still receive a clear image.

[0068] In addition, such as Figure 3As shown, the reflected light from the concave beam splitter 450 is incident on the bottom of the lens 430 and reflected by the lens 430. The reflected light then passes through the planar beam splitter 440 and enters the human eye, forming an arc-shaped stray light superimposed on the display screen, resulting in a decrease in image quality. Finally, the semi-transparent film transmits the right-handed polarized light transmitted by the quarter-wave plate 451 to the concave light-transmitting substrate 453. The right-handed polarized light then enters the real environment through the concave light-transmitting substrate 453, resulting in light leakage.

[0069] In view of this, this application provides a display module that uses linearly polarized light emitted from a multi-reflection lens to fold the optical path between the lens and the planar beam splitter at least once. This decouples the relative positions of the lens and the planar beam splitter, ensuring that the lens position does not limit the thickness of the display module. After myopia adjustment, the reflected light from the lens and the concave beam splitter will not interfere with each other, preventing a reduction in the vertical eyebox and avoiding the formation of arc-shaped stray light. Furthermore, by providing a light-leakage prevention structure on the concave beam splitter that absorbs right-handed polarized light transmitted through a semi-transparent, semi-reflective film, right-handed polarized light is prevented from entering the real environment.

[0070] The display module provided in this application will be described in detail below with reference to specific embodiments.

[0071] Example 1

[0072] Figure 4 This is a schematic diagram of the structure of a display module provided in Embodiment 1 of this application. Figure 4 The positional relationships between the components do not constitute a limitation on the specific structure of each optical element. Furthermore, in this embodiment, the thickness direction is defined as the first direction Z, the vertical direction as the second direction Y, and the horizontal direction as the third direction X.

[0073] like Figure 4 As shown, the display module provided in this embodiment includes an image source 100, a lens group 200, and a polarization optical path assembly 300. The image source 100 emits first linearly polarized light to form a virtual image. The lens group 200 is located on the light-emitting side of the image source 100 and transmits the first linearly polarized light emitted by the image source 100. The polarization optical path assembly 300 is used to fold the polarization optical path, reducing the thickness of the display module, achieving a thinner and lighter design, and reducing the vertical eyebox after myopia adjustment, while also preventing the generation of arc-shaped stray light entering the eye.

[0074] like Figure 4As shown, the image source 100 includes a display device 110 and a third polarizer 120. The display device 110 emits image light. The third polarizer 120 (POL) is located between the display device 110 and the lens group 200 and transmits first linearly polarized light through the image light emitted from the display device 110. However, in some embodiments, besides filtering the image light into first linearly polarized light through the third polarizer 120, the image source 100 may also omit the third polarizer 120, in which case the display device 110 directly emits the first linearly polarized light.

[0075] For example, the third polarizer 120 can be attached to the light-emitting surface of the display device 110, thus avoiding the impact of the spacing between the third polarizer 120 and the display device 110 on the thickness of the display module. Of course, in some embodiments, the third polarizer 120 and the display device 110 can also be spaced apart.

[0076] For example, the display device 110 may be a liquid crystal display (LCD), an organic light-emitting diode (OLED), a micro light-emitting diode (micro-LED), an active-matrix organic light-emitting diode (AMOLED), a flexible light-emitting diode (FLED), or a quantum dot light-emitting diode (QLED). OLEDs have high luminous efficiency and high contrast; mini-LED displays have high luminous brightness and can be applied to scenarios requiring strong luminous brightness.

[0077] For example, the display device 110 can also be a reflective display screen. For instance, a liquid crystal on silicon (LCOS) display screen, or a reflective display screen based on a digital micromirror device (DMD). LCOS and DMD, being reflective structures, have higher resolution or aperture ratios.

[0078] Lens group 200 includes at least one lens, for example Figure 4As shown, the number of lenses is one, although the number of lenses can exceed one. Lens group 200 is used to move along the optical axis of lens group 200. By moving lens group 200, the diopter of the display module can be adjusted, aberrations can be compensated, and the focus can be adjusted, thus improving the user experience. Furthermore, increasing the number of lenses can improve image clarity.

[0079] The surface structure of the lens can be spherical, aspherical, freeform, etc.

[0080] In this embodiment, the polarization optical path assembly 300 includes at least three optical elements, such as... Figure 4 As shown, there are three optical elements: a first optical element 310, a second optical element 320, and a third optical element 330. The first optical element 310 is located on the light-emitting side of the lens group 200. The second and third optical elements 320 and 330 are arranged at intervals along the first direction Z and at intervals with the lens group 200 along the second direction Y. The first optical element 310 reflects the first linearly polarized light transmitted from the lens group 200 to the second optical element 320. The second optical element 320 is tilted and positioned on the visual axis in front of the eye, with its normal intersecting the visual axis. The second optical element 320 reflects the first linearly polarized light and transmits the second linearly polarized light to the eye. The third optical element 330 converts a portion of the first linearly polarized light reflected by the second optical element 320 into second linearly polarized light emitted to the second optical element 320 and receives ambient light. The ambient light passes sequentially through the third optical element 330 and the second optical element 320 before entering the eye.

[0081] In this embodiment, the polarization direction of the first linearly polarized light is perpendicular to the polarization direction of the second linearly polarized light. One of the first and second linearly polarized lights is S-polarized light, and the other is P-polarized light. For example, in this embodiment, the first linearly polarized light is S-polarized light, and the second linearly polarized light is P-polarized light.

[0082] In this embodiment, one of the first and second circularly polarized lights is right-handed polarized light and the other is left-handed polarized light. For example, in this application embodiment, the first circularly polarized light is right-handed polarized light and the second circularly polarized light is left-handed polarized light.

[0083] For example, the first optical element 310 can be a total reflection mirror, capable of reflecting all the first linearly polarized light from the lens group 200, thereby improving image quality. Of course, in some embodiments, the first optical element 310 can also be a non-total reflection mirror, such as a partial reflection mirror or a polarizing mirror.

[0084] In some embodiments, such as Figure 4As shown, the first optical element 310 can be a concave total internal reflection mirror, which can magnify or reduce the image while reflecting all the first linearly polarized light from the lens group 200, thus achieving image focusing. Additionally, it can reduce aberrations, improve brightness and contrast, and enable a more compact design.

[0085] Of course, the first optical element 310 can also be a total reflection mirror of the type such as a planar total reflection mirror, a convex total reflection mirror, an aspherical reflection mirror, or a freeform surface non-total reflection mirror. Therefore, the surface structure of the first optical element 310 can be, but is not limited to, a planar surface, a spherical surface, an aspherical surface, or a freeform surface.

[0086] In order to reflect the first linearly polarized light and transmit the second linearly polarized light, for example, as follows: Figure 4 As shown, the second optical element 320 includes a third light-transmitting substrate 321 and a second reflective polarizer 322 (RP). The second reflective polarizer 322 is fixedly connected to the third light-transmitting substrate 321 and is located on the side of the third light-transmitting substrate 321 close to the third optical element 330. The second reflective polarizer 322 is used to reflect the first linearly polarized light and transmit the second linearly polarized light.

[0087] The third light-transmitting substrate 321 is made of a light-transmitting material, such as glass. Furthermore, the third light-transmitting substrate 321 has a flat plate structure, and the second reflective polarizer 322 is attached to one side of the flat plate structure.

[0088] To convert the first linearly polarized light into the second linearly polarized light, for example, as follows: Figure 4 As shown, the third optical element 330 includes a first quarter-wave plate 331 and a transmission mirror 332 arranged along a first direction Z. The first quarter-wave plate 331 is located between the transmission mirror 332 and the second optical element 320 and is connected to the transmission mirror 332. The first quarter-wave plate 331 is used to convert first linearly polarized light from the second optical element 320 into first circularly polarized light, and to convert second circularly polarized light from the transmission mirror 332 into second linearly polarized light. The transmission mirror 332 is used to transmit a portion of the first circularly polarized light emitted from the first quarter-wave plate 331, and a portion of the first circularly polarized light reflected from the first quarter-wave plate 331 is reflected by the transmission mirror 332 and becomes second circularly polarized light.

[0089] Through the interaction of the first quarter-wave plate 331 and the transmission-reflecting mirror 332, the first linearly polarized light reflected by the second optical element 320 is transformed into second linearly polarized light that enters the human eye, allowing the viewer to see the virtual image formed by the first linearly polarized light emitted by the image source 100. Additionally, ambient light sequentially passes through the transmission-reflecting mirror 332, the first quarter-wave plate 331, and the second optical element 320, transforming into second linearly polarized light before entering the human eye, allowing the viewer to see the real image formed by the ambient light.

[0090] For example, such as Figure 4 As shown, the transflector 332 includes a second transparent substrate 3322 and a semi-transparent and semi-reflective film 3321. The semi-transparent and semi-reflective film 3321 is located between the first quarter-wave plate 331 and the second transparent substrate 3322, and is connected to the second transparent substrate 3322 and the first quarter-wave plate 331, respectively. Therefore, the transflector 332 is a semi-transparent and semi-reflective mirror.

[0091] Of course, in addition to using a semi-transparent and semi-reflective film 3321 with both 50% transmittance and 50% reflectance, the transflective mirror 332 can also use transflective films with other transmittance and reflectance ratios, such as a film with 30% transmittance and 70% reflectance.

[0092] The material of the second light-transmitting substrate 3322 is a light-transmitting material, for example, the material of the second light-transmitting substrate 3322 is optical glass.

[0093] For example, such as Figure 4 As shown, the transflector 332 is a concave transflector, which magnifies the image by reflecting and focusing light. Compared to the planar transflector 332, the concave design can better correct certain types of optical aberrations, thus providing clearer and sharper image quality. The concave transflector allows the light path to be folded, thereby reducing the size of the entire optical system, making the device lighter and more compact, and more suitable for prolonged wear. Due to its curvature, the concave transflector can more effectively collect and guide light into the user's eye.

[0094] like Figure 4 As shown, ambient light from the outside world passes through the third optical element 330 and the second optical element 320 in sequence before entering the human eye, achieving optical transmission. The ambient light, after passing through the semi-transparent and semi-reflective film 3321, is divided into a transmission part and a reflection part; part is reflected, and part passes through the semi-transparent and semi-reflective film 3321. After the transmission part passes through the first quarter-wave plate 331, the second reflective polarizer 322 transmits the P-polarized light (second linearly polarized light) transmitted by the first quarter-wave plate 331 to the human eye.

[0095] like Figure 4As shown, for the image light emitted by the display device 110, the image light passes through the third polarizer 120 to generate first transmitted light, which is S-polarized light (first linearly polarized light). The first transmitted light passes through the lens group 200 to generate second transmitted light, which is also S-polarized light (first linearly polarized light). The second transmitted light is reflected by the first optical element 310 to form first reflected light, which is also S-polarized light (first linearly polarized light). The first reflected light is reflected by the second reflective polarizer 322 of the second optical element 320 to form second reflected light, which is also S-polarized light (first linearly polarized light). The second reflected light is processed by the first quarter-wave plate 331 to generate third transmitted light, which is right-handedly polarized light (first circularly polarized light). The third transmitted light is partially reflected by the transflector 332 to form third reflected light, which is left-handedly polarized light (second circularly polarized light), and the remaining portion is transmitted to form fourth transmitted light, which is right-handedly polarized light (first circularly polarized light). The third reflected light is processed by the first quarter-wave plate 331 to generate the fifth transmitted light, which is P-polarized light (second linearly polarized light). The fifth transmitted light is transmitted through the second reflective polarizer 322 of the second optical element 320 and then enters the human eye.

[0096] As described above, in existing BB modules, the lens interferes with the reflected light from the concave beam splitter, causing the vertical eyebox to shrink. To address this, this embodiment of the application arranges a first optical element 310 in the optical path between the second optical element 320 and the lens group 200, thus folding the optical path between them. This results in the lens group 200 and the third optical element 330 being spaced apart in the second direction Y (vertical direction). Regardless of whether the lens group 200 moves, the reflected light from the third optical element 330 will not be incident on the lens group 200. Therefore, during or after the movement of the lens group 200, the reflected light from the third optical element 330 will not interfere with the lens group 200, the lens group 200 will not obstruct the display screen, and the vertical (second direction Y) eyebox will not change.

[0097] As described above, in existing BB modules, the bottom of the lens reflects the reflected light from the concave beam splitter to the planar beam splitter and into the human eye, forming an arc-shaped stray light. Therefore, in this embodiment, by folding the optical path between the lens group 200 and the second optical element 320, the lens group 200 and the third optical element 330 are always spaced apart in the vertical direction. The reflected light from the third optical element 330 will not be incident on the lens group 200, thus preventing the lens group 200 from reflecting the reflected light from the third optical element 330 to the second optical element 320, preventing it from entering the human eye and fundamentally avoiding the generation of arc-shaped stray light. No arc-shaped stray light is visible above the displayed image, improving the display effect.

[0098] As described above, in existing BB modules, the angle between the normal of the planar beam splitter and the thickness direction (or the visual axis of the human eye) is 45 degrees, and the lens portion is located between the planar beam splitter and the concave beam splitter, resulting in a relatively large module thickness. Therefore, in this embodiment, a first optical element 310 is placed between the lens group 200 and the second optical element 320. Thus, from the lens group 200 to the third optical element 330, the first linearly polarized light emitted by the lens group 200 undergoes two reflections, folding the optical path between the lens group 200 and the third optical element 330 twice. This reduces the tilt angle of the second optical element 320, meaning the angle between the normal of the second optical element 320 and the thickness direction can be reduced, thereby reducing the thickness of the module in the thickness direction. Meanwhile, the first optical element 310 is located outside the gap between the third optical element 330 and the second optical element 320. The lens group 200 and the third optical element 330 are spaced apart in the second direction Y. After myopia adjustment, the lens group 200 will not get stuck between the second optical element 320 and the third optical element 330. The distance between the second optical element 320 and the third optical element 330 in the thickness direction can also be reduced, thereby reducing the thickness of the display module in the thickness direction. Therefore, by folding the optical path between the lens group 200 and the second optical element 320, the thickness of the display module can be reduced, achieving a thinner and lighter design.

[0099] Example 2

[0100] Figure 5 This is a schematic diagram of the structure of a display module provided in Embodiment 2 of this application.

[0101] Figure 5 and Figure 4The difference lies in that the third optical element 330 further includes a second quarter-wave plate 333 and a second polarizer 334. The second quarter-wave plate 333 is located between the transflector 332 and the second polarizer 334 along the first direction Z, and is connected to both the transflector 332 and the second polarizer 334. Specifically: the second quarter-wave plate 333 converts the first circularly polarized light emitted by the transflector 332 into second linearly polarized light. The second polarizer 334 absorbs the second linearly polarized light emitted by the second quarter-wave plate 333 and transmits the first linearly polarized light. The second quarter-wave plate 333 converts the first circularly polarized light transmitted by the transflector 332 into second linearly polarized light, and the second polarizer 334 absorbs the second linearly polarized light from the second quarter-wave plate 333, thus preventing light leakage inside the display module. In addition, ambient light from the outside world becomes linearly polarized light after passing through the second polarizer 334, then becomes circularly polarized light after passing through the second quarter-wave plate 333, then becomes linearly polarized light after passing through the first quarter-wave plate 331, and finally enters the human eye through the second optical element 320 to achieve optical vision.

[0102] like Figure 5 As shown, ambient light from the outside world passes through the third optical element 330 and the second optical element 320 in sequence before entering the human eye, achieving optical transmission. Specifically, the ambient light becomes S-polarized light (first linearly polarized light) after passing through the second polarizer 334, then becomes left-handedly polarized light (second circularly polarized light) after passing through the second quarter-wave plate 333. The reflective mirror 332 transmits a portion of the left-handedly polarized light to the first quarter-wave plate 331, which then converts a portion of the left-handedly polarized light (second circularly polarized light) transmitted through the reflective mirror 332 into P-polarized light (second linearly polarized light). Finally, the light passes through the second reflective polarizer 322 of the second optical element 320 before entering the human eye.

[0103] like Figure 5As shown, for the image light emitted by the display device 110, the image light passes through the third polarizer 120 to generate first transmitted light, which is S-polarized light (first linearly polarized light). The first transmitted light passes through the lens group 200 to generate second transmitted light, which is also S-polarized light (first linearly polarized light). The second transmitted light is reflected by the first optical element 310 to form first reflected light, which is also S-polarized light (first linearly polarized light). The first reflected light is reflected by the second reflective polarizer 322 of the second optical element 320 to form second reflected light, which is also S-polarized light (first linearly polarized light). The second reflected light is processed by the first quarter-wave plate 331 to generate third transmitted light, which is right-handedly polarized light (first circularly polarized light). The third transmitted light is partially reflected by the transflector 332 to form third reflected light, which is left-handedly polarized light (second circularly polarized light), and the remaining portion is transmitted to form fourth transmitted light, which is right-handedly polarized light (first circularly polarized light). The third reflected light is processed by the first quarter-wave plate 331 to generate the fifth transmitted light, which is P-polarized light (second linearly polarized light). After being transmitted through the second reflective polarizer 322 of the second optical element 320, the fifth transmitted light enters the human eye. The fourth transmitted light is processed by the second quarter-wave plate 333 to form the sixth transmitted light, which is also P-polarized light (second linearly polarized light). The sixth transmitted light is absorbed by the second polarizer 334, preventing it from entering the outside world and achieving the purpose of preventing light leakage.

[0104] In the above description, an optical element for reflecting the first linearly polarized light is disposed in the optical path between the lens group 200 and the second optical element 320. Alternatively, at least two optical elements capable of reflecting the first linearly polarized light can be disposed. For example, as shown in the figure, a first optical element 310 and a fourth optical element 340 can be disposed in the optical path between the lens group 200 and the second optical element 320. The more lenses there are between the lens group 200 and the second optical element 320, the greater the number of folds in the optical path between them, the smaller the tilt angle of the second optical element 320, the smaller the space occupied by the second optical element 320 in the thickness direction, and the smaller the thickness of the display module. Simultaneously, the vertical distance between the lens group 200 and the third optical element 330 is also greater.

[0105] Example 3

[0106] Figure 6 This is a schematic diagram of the structure of a display module provided in Embodiment 3 of this application.

[0107] Figure 6 and Figure 4The difference lies in that the polarization optical path assembly 300 also includes a fourth optical element 340, which is located in the optical path between the first optical element 310 and the second optical element 320. The fourth optical element 340 is used to reflect the first linearly polarized light reflected by the first optical element 310 to the second optical element 320. By reflecting the first linearly polarized light reflected by the first optical element 310 through the fourth optical element 340, the optical path between the first optical element 310 and the second optical element 320 can be folded, thereby further reducing the angle between the normals of the first optical element 310 and the second optical element 320 and the thickness direction, and further reducing the thickness of the display module. At the same time, the spacing between the lens group 200 and the second optical element 320 and the third optical element 330 in the second direction Y can be further increased, further ensuring that the reflected light reflected by the third optical element 330 will not enter the lens group 200, ensuring that the vertical eye box does not change during myopia accommodation, and avoiding the generation of arc-shaped stray light.

[0108] For example, such as Figure 6 As shown, the fourth optical element 340 includes a first reflective polarizer 341 and a first transparent substrate 343. The first reflective polarizer 341 is located on one side of the first transparent substrate 343 and is fixedly connected to the first transparent substrate 343. Of course, in addition to the first reflective polarizer 341 and the first transparent substrate 343, the fourth optical element 340 can also be a reflector in some embodiments.

[0109] The first light-transmitting substrate 343 is made of a light-transmitting material, such as glass. Figure 6 As shown, the first light-transmitting substrate 343 is a flat plate structure. Of course, the first light-transmitting substrate 343 can also be other structures. For example, the surface structure of the first light-transmitting substrate 343 can be a spherical surface, an aspherical surface, or a free-form surface.

[0110] like Figure 6 As shown, ambient light from the outside world passes through the third optical element 330 and the second optical element 320 in sequence before entering the human eye, achieving optical transmission. Specifically, the ambient light becomes S-polarized light (first linearly polarized light) after passing through the second polarizer 334, then becomes left-handedly polarized light (second circularly polarized light) after passing through the second quarter-wave plate 333. The reflective mirror 332 transmits a portion of the left-handedly polarized light to the first quarter-wave plate 331, which then converts a portion of the left-handedly polarized light (second circularly polarized light) transmitted through the reflective mirror 332 into P-polarized light (second linearly polarized light). Finally, the light passes through the second reflective polarizer 322 of the second optical element 320 before entering the human eye.

[0111] like Figure 6As shown, for the image light emitted by the display device 110, the image light passes through the third polarizer 120 to generate first transmitted light, which is S-polarized light (first linearly polarized light). The first transmitted light passes through the lens group 200 to generate second transmitted light, which is also S-polarized light (first linearly polarized light). The second transmitted light is reflected by the first optical element 310 to form first reflected light, which is also S-polarized light (first linearly polarized light). The first reflected light is reflected by the fourth optical element 340 to form second reflected light, which is also S-polarized light (first linearly polarized light). The second reflected light is reflected by the second reflective polarizer 322 of the second optical element 320 to form third reflected light, which is also S-polarized light (first linearly polarized light). The third reflected light is processed by the first quarter-wave plate 331 to generate third transmitted light, which is right-handedly polarized light (first circularly polarized light). The third transmitted light, after being processed by the reflective mirror 332, is partially reflected to form the fourth reflected light, which is left-handedly polarized (second circularly polarized light). The remaining portion is transmitted to form the fourth transmitted light, which is right-handedly polarized (first circularly polarized light). The fourth reflected light, after being processed by the first quarter-wave plate 331, generates the fifth transmitted light, which is P-polarized (second linearly polarized light). This fifth transmitted light, after being transmitted through the second reflective polarizer 322 of the second optical element 320, enters the human eye. The fourth transmitted light, after being processed by the second quarter-wave plate 333, forms the sixth transmitted light, which is also P-polarized (second linearly polarized light). This sixth transmitted light is absorbed by the second polarizer 334, preventing it from entering the outside world and achieving the purpose of preventing light leakage.

[0112] Figure 7 This is a schematic diagram of another display module provided in Embodiment 3 of this application.

[0113] To further improve the vertical eyebox, some possible implementations include, for example... Figure 7 As shown, the third optical element 330 and the fourth optical element 340 are used together to receive ambient light. Part of the ambient light passes through the third optical element 330 and the second optical element 320 in sequence and enters the human eye. Part of the ambient light passes through the fourth optical element 340 and the second optical element 320 in sequence and enters the human eye. At this time, part of the boundary of the eye box is the side of the fourth optical element 340 that is away from the third optical element 330 in the vertical direction.

[0114] Specifically, such as Figure 7As shown, the fourth optical element 340 is close to the third optical element 330 in the second direction Y. In this case, the fourth optical element 340 and the third optical element 330 are arranged side-by-side in the vertical direction, spliced ​​together, and the gap between the fourth optical element 340 and the third optical element 330 in the vertical direction is zero. Alternatively, in some embodiments, a portion of the fourth optical element 340 and a portion of the third optical element 330 are disposed opposite each other in the thickness direction; that is, the fourth optical element 340 is located on the side of the third optical element 330 away from the second optical element 320 and partially overlaps the third optical element 330 in the thickness direction.

[0115] In order for ambient light to enter the human eye through the fourth optical element 340, such as Figure 7 As shown, the fourth optical element 340 includes a first reflective polarizer 341, a first transparent substrate 343, and a first polarizer 342. The first polarizer 342 transmits second linearly polarized light from ambient light. The first reflective polarizer 341 transmits both the first linearly polarized light and the second linearly polarized light transmitted through the first polarizer 342 to the second optical element 320. The first reflective polarizer 341 is located near the reflective side of the first optical element 310, and the first polarizer 342 and the first reflective polarizer 341 are respectively connected to opposite sides of the first transparent substrate 343. Of course, in some embodiments, the first reflective polarizer 341 and the first transparent substrate 343 are respectively connected to opposite sides of the first polarizer 342; that is, the first polarizer 342 is located between the first transparent substrate 343 and the first reflective polarizer 341.

[0116] like Figure 7 As shown, ambient light from the outside world passes through the fourth optical element 340 and the second optical element 320 in sequence before entering the human eye, achieving optical vision. Specifically, the ambient light becomes P-polarized light (second linearly polarized light) after passing through the first polarizer 342, and then enters the human eye in sequence through the first reflective polarizer 341 and the second reflective polarizer 322.

[0117] It should be noted that when an optical element capable of reflecting first linearly polarized light is disposed in the optical path between the lens group 200 and the second optical element 320, as shown in the figure, and only the first optical element 310 is disposed in the optical path between the lens group 200 and the second optical element 320, the structure of the first optical element 310 is similar to that of the fourth optical element 340. The first optical element 310 is close to the third optical element 330 in the second direction Y. The first optical element 310 may include a third reflective polarizer and a fourth polarizer. The third reflective polarizer is used to reflect the first linearly polarized light and transmit the second linearly polarized light transmitted by the fourth polarizer to the second optical element 320. The fourth polarizer is used to transmit the second linearly polarized light from ambient light. In this way, the first optical element 310 can also transmit ambient light to the second optical element 320, which ultimately enters the human eye, achieving the purpose of increasing the vertical eye box.

[0118] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances. The terms "first," "second," "third," "fourth," etc. (if present) are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them. Although the embodiments of this application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A display module, characterized in that, include: Image source (100) for emitting first linearly polarized light; A lens group (200) is located on the light-emitting side of the image source (100) and is used to transmit the first linearly polarized light emitted by the image source (100); A polarizing optical path assembly (300) includes a first optical element (310), a second optical element (320), and a third optical element (330). The first optical element (310) is located on the light-emitting side of the lens group (200). The second optical element (320) and the third optical element (330) are arranged at intervals along a first direction (Z). Both the second optical element (320) and the third optical element (330) are spaced apart from the lens group (200) in a second direction (Y). The first direction (Z) is perpendicular to the second direction (Y). The first optical element (310) is used to reflect the first linearly polarized light transmitted by the lens group (200) to the second optical element (320). The second optical element (320) is used to reflect the first linearly polarized light and transmit the second linearly polarized light to the human eye, wherein the polarization direction of the first linearly polarized light is perpendicular to the polarization direction of the second linearly polarized light; The third optical element (330) is used to convert a portion of the first linearly polarized light reflected by the second optical element (320) into second linearly polarized light emitted to the second optical element (320).

2. The display module according to claim 1, characterized in that, The polarization optical path assembly (300) further includes: A fourth optical element (340) is located in the optical path between the first optical element (310) and the second optical element (320) and is used to reflect the first linearly polarized light reflected by the first optical element (310) to the second optical element (320).

3. The display module according to claim 2, characterized in that, The fourth optical element (340) is located close to the third optical element (330) in the second direction (Y). The fourth optical element (340) includes a first reflective polarizer (341) and a first polarizer (342), wherein: The first polarizer (342) is used to transmit second linearly polarized light from ambient light; The first reflective polarizer (341) is used to reflect the first linearly polarized light and transmit the second linearly polarized light transmitted by the first polarizer (342) to the second optical element (320).

4. The display module according to claim 3, characterized in that, The fourth optical element (340) further includes a first light-transmitting substrate (343), wherein: The first polarizer (342) and the first reflective polarizer (341) are respectively connected to opposite sides of the first light-transmitting substrate (343), or the first reflective polarizer (341) and the first light-transmitting substrate (343) are respectively connected to opposite sides of the first polarizer (342).

5. The display module according to any one of claims 1 to 4, characterized in that, The third optical element (330) includes a first quarter-wave plate (331) and a transmission mirror (332) arranged along the first direction (Z). The first quarter-wave plate (331) is located between the transmission mirror (332) and the second optical element (320) and is connected to the transmission mirror (332). The first quarter-wave plate (331) is used to convert the first linearly polarized light from the second optical element (320) into first circularly polarized light, and to convert the second circularly polarized light from the mirror (332) into second linearly polarized light; The transflector (332) is used to transmit a portion of the first circularly polarized light emitted from the first quarter-wave plate (331), and the portion of the first circularly polarized light reflected from the first quarter-wave plate (331) is reflected by the transflector (332) and becomes second circularly polarized light.

6. The display module according to claim 5, characterized in that, The third optical element (330) further includes a second quarter-wave plate (333) and a second polarizer (334). The second quarter-wave plate (333) is located between the mirror (332) and the second polarizer (334) along the first direction (Z), and is connected to the mirror (332) and the second polarizer (334) respectively, wherein: The second quarter-wave plate (333) is used to convert the first circularly polarized light emitted by the mirror (332) into a second linearly polarized light; The second polarizer (334) is used to absorb the second linearly polarized light emitted by the second quarter-wave plate (333) and transmit the first linearly polarized light.

7. The display module according to claim 5 or 6, characterized in that, The transflector (332) includes a second transparent substrate (3322) and a semi-transparent and semi-reflective film (3321). The semi-transparent and semi-reflective film (3321) is located between the first quarter-wave plate (331) and the second transparent substrate (3322), and is connected to the second transparent substrate (3322) and the first quarter-wave plate (331) respectively.

8. The display module according to any one of claims 5 to 7, characterized in that, The reflective mirror (332) is a concave reflective mirror (332).

9. The display module according to any one of claims 1 to 8, characterized in that, The first optical element (310) is a total reflection mirror.

10. The display module according to claim 9, characterized in that, The first optical element (310) is a concave total reflection mirror.

11. The display module according to claim 1, characterized in that, The first optical element (310) is close to the third optical element (330) in the second direction (Y). The first optical element (310) includes a third reflective polarizer and a fourth polarizer, wherein: The fourth polarizer is used to transmit second linearly polarized light from ambient light; The third reflective polarizer is used to reflect the first linearly polarized light and transmit the second linearly polarized light transmitted by the fourth polarizer to the second optical element (320).

12. The display module according to any one of claims 1 to 11, characterized in that, The second optical element (320) includes a third light-transmitting substrate (321) and a second reflective polarizer (322). The second reflective polarizer (322) is fixedly connected to the third light-transmitting substrate (321). The second reflective polarizer (322) is used to reflect the first linearly polarized light and transmit the second linearly polarized light.

13. The display module according to any one of claims 1 to 12, characterized in that, The image source (100) includes: Display device (110) for emitting image light; A third polarizer (120) is located between the display device (110) and the lens group (200) and is used to transmit first linearly polarized light into the image light emitted from the display device (110).

14. The display module according to any one of claims 1 to 13, characterized in that, The lens group (200) includes at least one lens, and the lens group (200) is movable along the optical axis of the lens group (200).

15. The display module according to any one of claims 1 to 14, characterized in that, The first linearly polarized light is S-polarized light, and the second linearly polarized light is P-polarized light.

16. A head-mounted display device, characterized in that, Includes the display module as described in any one of claims 1 to 15.

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