Near-eye display module and head-mounted display device

Abstract

The embodiment of the present application provides a near-eye display module and a head-mounted display device; the near-eye display module comprises an imaging lens group, a light splitting element, a first phase retarder and a polarization reflection element arranged in the imaging lens group; the imaging lens group comprises a first lens, a second lens and a third lens in sequence along the same optical axis, the light splitting element is arranged on either side of the second lens, and the first phase retarder and the polarization reflection element are arranged between the second lens and the third lens; the outer diameter of the second lens > the outer diameter of the third lens > the outer diameter of the first lens, so as to form an accommodation space at the outer periphery of the third lens and the first lens; the near-eye display module further comprises an eyeball tracking assembly, the eyeball tracking assembly comprises an illuminating device and an imaging device, the illuminating device is arranged at the outer periphery of the third lens, and the imaging device is arranged above the outer periphery of the first lens. The embodiment of the present application reserves space for the eyeball tracking assembly, and does not additionally increase the volume of the module.

Description

Technical Field

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

[0002] Virtual reality (VR) devices need to track the user's eyes to perform specific functions. Currently, eye-tracking modules are typically used to achieve real-time eye position tracking. However, introducing eye-tracking modules into VR devices increases their size, which contradicts users' preference for compact VR devices and affects the user's wearing comfort. Furthermore, existing placement schemes for eye-tracking modules may obstruct the user's view. Summary of the Invention

[0003] The purpose of this application is to provide a new technical solution for a near-eye display module and a head-mounted display device.

[0004] In a first aspect, this application provides a near-eye display module. The near-eye display module includes an imaging lens group and a beam splitter, a first phase retarder, and a polarization reflection element disposed within the imaging lens group, wherein the first phase retarder is located between the beam splitter and the polarization reflection element;

[0005] The imaging lens group includes a first lens, a second lens, and a third lens sequentially along the same optical axis. The beam splitter is located on either side of the second lens, and the first phase retarder and the polarization reflection element are located between the second lens and the third lens. The outer diameter D2 of the second lens is greater than the outer diameter D3 of the third lens, which is greater than the outer diameter D1 of the first lens, so as to form an accommodating space on the outer periphery of the third lens and the first lens.

[0006] The near-eye display module further includes an eye-tracking component, which includes an illumination device and an imaging device. The illumination device is located on the outer periphery of the third lens, and the imaging device is located above the outer periphery of the first lens. The light emitted from the illumination device is reflected by the human eye and passes through the third lens and the second lens, and then enters the imaging device to form an eye-tracking light path.

[0007] Optionally, the absolute value of the difference between the outer diameter D3 of the third lens and the outer diameter D2 of the second lens is greater than 1 mm.

[0008] Optionally, the absolute value of the difference between the outer diameter D1 of the first lens and the outer diameter D2 of the second lens is greater than 1 mm.

[0009] Optionally, the combined optical power of the second lens and the third lens is positive.

[0010] Optionally, the combined optical power of the second lens and the third lens is 0.019.

[0011] Optionally, the lighting device includes an infrared light source, and the imaging device includes an infrared camera.

[0012] Optionally, the imaging device further includes a reflective structure located on the light emission path of the infrared light source, wherein at least a portion of the light emitted by the infrared light source can be reflected by the reflective structure to the infrared camera.

[0013] Optionally, the near-eye display module further includes a display screen located on the side of the first lens opposite to the second lens;

[0014] The display screen is configured to emit either circularly polarized light or natural light;

[0015] When the light emitted by the display screen is natural light, a superimposed sheet is provided between the display screen and the first lens to convert the natural light into circularly polarized light before it enters the imaging lens group.

[0016] Optionally, the laminating sheet is disposed on the surface of the first lens near the display screen;

[0017] The laminate includes a second phase retarder, a second polarizing element, and a third phase retarder, wherein the second polarizing element is located between the second phase retarder and the third phase retarder.

[0018] Optionally, the imaging lens group is further provided with a first polarizing element, and the first polarizing element, the polarizing reflection element and the first phase retarder are stacked in sequence to form a composite film;

[0019] The beam splitter is disposed on the surface of the second lens near the first lens, and the composite film is disposed on the surface of the third lens near the second lens.

[0020] Optionally, the optical power of the first lens is positive.

[0021] Secondly, this application provides a head-mounted display device, the head-mounted display device comprising:

[0022] Casing; and

[0023] The near-eye display module as described in the first aspect.

[0024] According to an embodiment of this application, a near-eye display module is provided, which is a folded optical path structure design. By adjusting the difference in the outer diameter of different lenses in the imaging lens group, accommodating spaces can be formed on the outer periphery of the two lenses on both sides. In this way, the introduced eye-tracking component can be arranged in different accommodating spaces, so that no increase in size is introduced in the optical axis direction (lateral) and the direction perpendicular to the optical axis (longitudinal), that is, no additional increase in the volume of the entire near-eye display module is introduced. The position of the imaging device in the eye-tracking component is reasonably arranged so as not to obstruct the user's line of sight.

[0025] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0027] Figure 1 This is one of the structural schematic diagrams of the near-eye display module provided in the embodiments of this application;

[0028] Figure 2 This is a schematic diagram of the composite film structure of the near-eye display module provided in the embodiments of this application;

[0029] Figure 3 This is a schematic diagram of the structure of the overlay sheet of the near-eye display module provided in the embodiments of this application;

[0030] Figure 4 for Figure 1 The diagram shows a dot matrix of a near-eye display module.

[0031] Figure 5 for Figure 1 The MTF curve of the near-eye display module is shown below;

[0032] Figure 6 for Figure 1 The field curvature distortion diagram of the near-eye display module is shown;

[0033] Figure 7 for Figure 1 The diagram showing the vertical chromatic aberration of the near-eye display module is shown.

[0034] Figure 8 This is a second schematic diagram of the near-eye display module provided in the embodiments of this application.

[0035] Explanation of reference numerals in the attached figures:

[0036] 10. First lens; 11. First surface; 12. Second surface; 20. Second lens; 21. Third surface; 22. Fourth surface; 30. Third lens; 31. Fifth surface; 32. Sixth surface; 40. Display screen; 50. Illumination device; 51. Infrared light source; 60. Imaging device; 61. Infrared camera device; 62. Reflective structure; 70. Composite film; 71. First polarizing element; 72. Polarizing reflective element; 73. First phase retarder; 74. First anti-reflective film; 80. Lamination sheet; 81. Second anti-reflective film; 82. Second phase retarder; 83. Second polarizing element; 84. Third phase retarder; 90. Beam splitter; 100. Screen protection glass; 01. Human eye. Detailed Implementation

[0037] Various exemplary embodiments of this application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this application.

[0038] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0039] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0040] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0041] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0042] According to one aspect of the embodiments of this application, a near-eye display module is provided, which is suitable for use in head-mounted display devices (HMDs), such as VR head-mounted devices. The VR head-mounted device may include, for example, VR glasses or VR helmets, etc., and the embodiments of this application do not impose specific limitations on this.

[0043] This application provides a near-eye display module, such as... Figure 1As shown, the near-eye display module includes an imaging lens group and a beam splitter 90, a first phase retarder 73, and a polarization reflection element 72 disposed within the imaging lens group. The first phase retarder 73 is located between the beam splitter 90 and the polarization reflection element 72. The imaging lens group includes a first lens 10, a second lens 20, and a third lens 30 sequentially along the same optical axis. The beam splitter 90 is located on either side of the second lens 20, and the first phase retarder 73 and the polarization reflection element 72 are located between the second lens 20 and the third lens 30. The outer diameter D2 of the second lens 20 is greater than the outer diameter D3 of the third lens 30, which is greater than the outer diameter D1 of the first lens 10, thus forming an accommodating space around the third lens 30 and the first lens 10.

[0044] The near-eye display module also includes an eye-tracking component, which includes an illumination device 50 and an imaging device 60. The illumination device 50 is disposed on the outer periphery of the third lens 30, and the imaging device 60 is located above the outer periphery of the first lens 10. The light emitted from the illumination device 50 is reflected by the human eye 01 and passes through the third lens 30 and the second lens 20, and then enters the imaging device 60 to form an eye-tracking light path.

[0045] The near-eye display module provided in this application embodiment incorporates an eye-tracking component into its optical path structure. (See also...) Figure 1 The eye-tracking component structurally includes an illumination device 50 and an imaging device 60. Light emitted from the illumination device 50 is reflected by the user's eye 01 on one side, then passes sequentially through the third lens 30 and the second lens 20 in the imaging lens group before being incident on the imaging device 60. The imaging device 60 receives the light to capture an image of the user's eye. This eye-tracking component enables the acquisition of the user's eye position, achieving real-time tracking of the eye position within the user's eye 01. This provides the near-eye display module with eye-tracking functionality.

[0046] By adding an eye-tracking component to the near-eye display module, the specific position of the user's eyes can be tracked. This has two benefits: First, based on the tracked eye position, the user's interpupillary distance (IPD) can be obtained, enabling the near-eye display module to activate a precise IPD adjustment function. This ensures that the near-eye display module accurately matches the user's IPD during use, avoiding discomfort caused by mismatch between the user's IPD and the device being worn. Second, based on the tracked eye position, the gaze point (fixation point) can also be rendered. This means the module can capture the angle of the eye's gaze to find the gaze point, allowing for detailed rendering near the gaze point, which improves image quality and provides the user with a better visual experience.

[0047] It should be noted that in optical display modules without eye tracking, rendering the image typically involves rendering the entire screen, which places high demands on the rendering computer hardware and increases production costs. In reality, the optimal approach to image rendering is to render the area near the user's gaze point. This is because the image is clearer near the gaze point, becoming increasingly blurry towards the periphery. This application achieves image rendering near the user's gaze point.

[0048] In the embodiments of this application, the illumination device 50 in the eye-tracking assembly is located on the outer periphery of the third lens 30, and the imaging device 60 in the eye-tracking assembly is located above the first lens 10. In the imaging lens assembly provided in this embodiment, the outer diameter of the second lens 20 is the largest, the outer diameter of the third lens 30 is the second largest, and the outer diameter of the first lens 10 is the smallest. This design ensures that the outer diameters of both the third lens 30 and the first lens 10 differ from the outer diameter of the second lens 20 by a certain amount. This provides space for accommodating the illumination device 50 and the imaging device 60 in the eye-tracking assembly without introducing any increase in size in the horizontal or vertical direction of the near-eye display module. This effectively solves the problem of increased overall module size caused by adding an eye-tracking assembly to the near-eye display module.

[0049] In the embodiments of this application, the illumination device 50 is disposed on the periphery of the third lens 30, that is, the illumination device 50 of the eye-tracking component is disposed on the third lens 30 and located in the edge region of the third lens 30; at the same time, the imaging device 60 is disposed on the light-emitting path of the illumination device 50 and designed to be located above the first lens 10. With this layout, the illumination device 50 is located outside the imaging area of ​​the third lens 30, and the imaging device 60 is located outside the imaging area of ​​the first lens 10, which will not obstruct the user's line of sight at all. In other words, in this application, the illumination device 50 and the imaging device 60 of the eye-tracking component are reasonably arranged by utilizing the difference in the outer diameter of the different lenses in the imaging lens group.

[0050] The near-eye display module provided in this application embodiment is a folded optical path, which, in addition to including an imaging lens group, also includes a beam splitter 90, a first phase delayer 73, and a polarization reflection element 72. These optical elements (optical films) can be used to form a folded optical path between the imaging lens group, so that light is reflected back in it, which is beneficial to the final clear imaging.

[0051] In the near-eye display module of this application embodiment, the number of lenses includes, but is not limited to, the three mentioned above, and the number of lenses can be flexibly adjusted according to specific needs. While increasing the number of lenses in the folded optical path can improve the imaging quality of the near-eye display module, it can also affect the dimensions of the near-eye display module along the optical axis (longitudinal direction), resulting in a larger volume and increased weight. In the embodiments of this application, considering factors such as the volume, weight, imaging quality, and production cost of the near-eye display module, a design including three lenses is incorporated into the optical path.

[0052] The beam splitter 90 is, for example, a semi-transmissive and semi-reflective film.

[0053] The beam splitter 90 allows a portion of the light to be transmitted and another portion to be reflected.

[0054] It should be noted that the reflectivity of the beam splitter 90 can be flexibly adjusted according to specific needs, and this application embodiment does not impose any restrictions on it.

[0055] The first phase delayer 73 is, for example, a quarter-wave plate. Of course, it can also be configured as other phase delay plates as needed.

[0056] In the folded optical path located near the human eye 01, the first phase delayer 73 can be used to change the polarization state of light. For example, it can be used to convert linearly polarized light into circularly polarized light, or circularly polarized light into linearly polarized light.

[0057] The polarization reflective element 72 is, for example, a polarization reflective film.

[0058] The polarization reflector 72 is a polarization reflector that reflects horizontally linearly polarized light and transmits vertically linearly polarized light, or any other polarization reflector that reflects linearly polarized light at a specific angle and transmits linearly polarized light in a direction perpendicular to that angle.

[0059] In embodiments of this application, the first phase retarder 73 cooperates with the polarization reflective element 72 to resolve and transmit light. The polarization reflective element 72 has a transmission axis, and the direction of the transmission axis of the polarization reflective element 72 forms a 45° angle with either the fast or slow axis of the first phase retarder 73.

[0060] It should be noted that the positions of the beam splitter 90, the first phase delayer 73 and the polarization reflection element 72 within the imaging lens group are relatively flexible, but it is necessary to ensure that the first phase delayer 73 is located between the beam splitter 90 and the polarization reflection element 72.

[0061] Optionally, the beam splitter 90 can be disposed at a suitable position on the side of the second lens 20 close to the first lens 10; the first phase delayer 73 and the polarization reflection element 72 can be mounted together and disposed at a suitable position between the second lens 20 and the third lens 30; in this way, the beam splitter 90 is separated from the first phase delayer 73 and the polarization reflection element 72 by the second lens 20, which provides greater freedom in optical path design and does not increase the assembly difficulty of the module.

[0062] Optionally, such as Figure 1 and Figure 2 As shown, the beam splitter 90 is disposed on the surface of the second lens 20 near the first lens 10, and the first phase retarder 73 is attached together with the polarization reflection element 72 and disposed on the surface of the third lens 30 near the second lens 20. This assembly method is relatively simple.

[0063] Of course, the beam splitter 90, the first phase delayer 73 and the polarization reflection element 72 can also be disposed on the flat glass as independent devices in the optical path.

[0064] like Figure 1 As shown, the optical path diagram of the near-eye display module in this embodiment of the application has the following two lines:

[0065] The virtual reality optical path is as follows: Circularly polarized light is transmitted through the first lens 10 and the second lens 20, and then converted into linearly polarized light (such as S-light) by the first phase delayer 73 between the third lens 30 and the second lens 20. After being reflected by the polarization reflection element 72, it is converted into circularly polarized light again by the first phase delayer 73. After being reflected by the beam splitter 90 on one side of the second lens 20, it is converted into linearly polarized light (such as P-light) by the first phase delayer 73. After being transmitted through the third lens 30, it enters the human eye O1 to form an image.

[0066] The eye-tracking optical path is as follows: the light emitted by the illumination device 50 enters the human eye 01, is reflected by the human eye 01, passes through the third lens 30 and the second lens 20, and then enters the imaging device 60. The imaging device 60 is used to capture images of the user's eyes.

[0067] The near-eye display module provided in this application embodiment is a folded optical path structure design. By adjusting the difference in the outer diameter of different lenses in the imaging lens group, accommodating spaces can be formed on the outer periphery of the two lenses on both sides. In this way, the introduced eye-tracking components can be arranged in different accommodating spaces. This avoids introducing an increase in size in the optical axis direction (lateral) and the direction perpendicular to the optical axis (longitudinal), that is, it does not increase the volume of the entire near-eye display module. The position of the imaging device in the eye-tracking component is reasonably arranged so as not to obstruct the user's line of sight.

[0068] In some examples of this application, the absolute value of the difference between the outer diameter D3 of the third lens 30 and the outer diameter D2 of the second lens 20 is greater than 1 mm.

[0069] This parameter range design allows for a larger accommodating space on the outer side of the third lens 30 in the imaging lens assembly, providing sufficient space for the illumination device 50 in the eye-tracking component without increasing the overall size of the module in both the longitudinal and lateral directions.

[0070] Optionally, the absolute value of the difference between the outer diameter D1 of the first lens 10 and the outer diameter D2 of the second lens 20 is greater than 1 mm.

[0071] In the imaging lens assembly provided in this application embodiment, the second lens 20 is located between the first lens 10 and the third lens 30, and its outer diameter is the largest. Because the illumination device 50 of the eye-tracking assembly needs to be installed around the third lens 30, a certain amount of space is reserved, thus the outer diameter D3 of the third lens 30 is designed to be smaller than the outer diameter D2 of the second lens 20. Simultaneously, the imaging device 60 of the eye-tracking assembly is also installed above and to the outside of the first lens 10. Since the imaging device 60 is slightly larger, the outer diameter D1 of the first lens 10 can be designed to be smaller, that is, smaller than the outer diameter D2 of the second lens 20. In the embodiment of this application, the difference in outer diameter between the second lens 20 and the first lens 10 is also greater than 1 mm.

[0072] In other words, the outer diameter D1 of the first lens 10 and the outer diameter D3 of the third lens 30 are both designed to be smaller than the outer diameter D2 of the second lens 20; wherein, the outer diameter D1 of the first lens 10 only needs to be smaller than the outer diameter D3 of the third lens 30. In this embodiment of the application, there is no specific numerical limit on the difference between the outer diameter D1 of the first lens 10 and the outer diameter D3 of the third lens 30, which can be flexibly adjusted according to the size requirements of the assembly space.

[0073] In some examples of this application, the combined optical power of the second lens 20 and the third lens 30 is positive.

[0074] The near-eye display module of this application embodiment is described in [reference]. Figure 1 The light reflected from the human eye 01 passes through the imaging device 60 in the eye-tracking assembly via the transmission of the third lens 30 and the second lens 20. When the combined optical power of the third lens 30 and the second lens 20 is set to positive, the incident angle of the light reflected from the human eye 01 relative to the imaging device 60 will decrease accordingly after passing through the third lens 30 and the second lens 20 in sequence. This can improve the accuracy of eye positioning.

[0075] Preferably, the combined optical power of the second lens 20 and the third lens 30 is 0.019, resulting in higher accuracy in eye positioning.

[0076] The optical power of the second lens 20 is positive.

[0077] For example, the optical power range of the second lens 20 is

[0078] The center thickness T2 of the second lens 20 ranges from 3mm to 8mm, and it comprises two optical surfaces. (See attached image.) Figure 1 These are the third surface 21 near the first lens 10 and the fourth surface 22 near the third lens 30, respectively.

[0079] Optionally, the beam splitter 90 is disposed on the third surface 21, which is, for example, an aspherical surface.

[0080] Optionally, an anti-reflective film may be selectively provided on the fourth surface 22. The fourth surface 22 may be planar or aspherical.

[0081] Anti-reflective coatings reduce reflection, lower reflected energy, and improve light efficiency. These coatings can be applied to optical components via adhesive or coating to create interfaces that increase transmittance and reduce reflectivity, thereby reducing image distortion and providing users with clearer image quality, thus minimizing glare.

[0082] The optical power of the third lens 30 is positive.

[0083] For example, the optical power range of the third lens 30 is

[0084] The center thickness T3 of the third lens 30 is in the range of 3mm < T3 < 6mm, and it comprises two optical surfaces. See [link / reference needed]. Figure 1These are the fifth surface 31, which is close to the second lens 20, and the sixth surface 32, which is far away from the second lens 20.

[0085] Optionally, the fifth surface 31 and the sixth surface 32 can be designed as aspherical.

[0086] Optionally, the first phase delayer 73 and the polarization reflection element 72 forming the folded optical path can be stacked and disposed on the fifth surface 31 of the third lens 30.

[0087] Optionally, an anti-reflective film may also be selectively provided on the sixth surface 32.

[0088] See some examples in this application. Figure 1 As shown, the lighting device 50 includes an infrared light source 51, and the imaging device 60 includes an infrared camera 61.

[0089] The lighting device 50 includes an infrared light source that emits infrared light. In this embodiment, the infrared light is reflected by the human eye 01 and passes through the third lens 30 and the second lens 20 before entering the imaging device 60. Since the infrared light is invisible to the human eye, it does not affect the image formed in the human eye 01 by the virtual reality optical path.

[0090] Optionally, see Figure 1 and Figure 8 As shown, the imaging device 60 also includes a reflective structure 62, which is located on the light emission path of the infrared light source 51. At least a portion of the light emitted by the infrared light source 51 can be reflected by the reflective structure 62 to the infrared camera device 61.

[0091] In other words, for the eye-tracking component introduced in the near-eye display module, a reflective structure 62 can be added to the imaging device 60. The reflective structure 62 reflects the infrared light passing through the third lens 30 and the second lens 20 into the infrared camera device 61, which can appropriately increase the optical path length and receive more infrared light, which also helps to improve the accuracy of eye tracking to a certain extent.

[0092] The reflective structure 62 is, for example, a reflector.

[0093] See some examples in this application. Figure 1 and Figure 8 As shown, the near-eye display module also includes a display screen 40, which is located on the side of the first lens 10 that is away from the second lens 20;

[0094] The display screen 40 is configured to emit circularly polarized light or natural light;

[0095] When the light emitted by the display screen 40 is natural light, a superimposed sheet 80 is provided between the display screen 40 and the first lens 10, which can be used to convert the natural light into circularly polarized light before it enters the imaging lens group.

[0096] In other words, the light entering the imaging lens group should be circularly polarized light.

[0097] When the display screen 40 emits natural light, the natural light needs to be converted into circularly polarized light before entering the imaging lens group on the left. Finally, the light emitted from the imaging lens group enters the human eye 01 to form an image.

[0098] Optionally, the overlay sheet 80 is disposed on the surface of the first lens 10 near the display screen 40; the overlay sheet 80 includes a second phase delayer 82, a second polarizing element 83 and a third phase delayer 84, wherein the second polarizing element 83 is located between the second phase delayer 82 and the third phase delayer 84.

[0099] In the embodiments of this application, the device for converting natural light into circularly polarized light is the aforementioned composite sheet 80. The composite sheet 80 includes two phase retarders and a polarizing element disposed between the two phase retarders. Specifically, the display screen 40 emits natural light, which remains natural light after passing through the third phase retarder 84, becomes linearly polarized light after passing through the second polarizing element 83, and becomes circularly polarized light after passing through the second phase retarder 82.

[0100] In the composite plate 80, both phase retarders are, for example, quarter-wave plates; one quarter-wave plate can be used to adjust the polarization state of light, and the other quarter-wave plate is located on the outermost side and can be used to block a portion of the incident light. Specifically, this portion of light is unwanted light in imaging. If this portion of light is not blocked, it will be reflected back through the light-emitting surface of the display screen 40 and enter the human eye 01, which is detrimental to the final imaging.

[0101] See Figure 1 The first lens 10 is located on the side close to the display screen 40. The center thickness T1 of the first lens 10 is in the range of 1mm < T1 < 6mm. It includes two optical surfaces, namely a first surface 11 close to the display screen 40 and a second surface 12 away from the display screen 40.

[0102] Optionally, the first surface 11 and the second surface 12 are aspherical or planar.

[0103] The overlapping sheet 80 is designed to be located on the first surface 11 of the first lens 10, see [reference]. Figure 3 The laminate 80 includes a second anti-reflective film 81, a second phase delayer 82, a second polarizing element 83 and a third phase delayer 84 stacked sequentially, with the second anti-reflective film 81 bonded to the first surface 11.

[0104] Specifically, the laminate 80 is a composite film structure formed by sandwiching a polarizing film between two quarter-wave plates. In this application, the laminate 80 is designed to be directly attached to the first surface 11 using, for example, optical adhesive. This assembly method is simple, reduces production costs, and improves product yield.

[0105] The optical power of the first lens 10 is positive.

[0106] For example, the optical power range of the first lens 10 is

[0107] In the near-eye display module provided in this application embodiment, by setting a superimposed sheet 80 between the display screen 40 and the first lens 10, the polarization state transformation of natural light is realized. This transforms the natural light emitted from the display screen 40 into circularly polarized light, which then enters the folded optical path structure on the near-eye side for light reflection. Finally, the light is emitted through the third lens 30 to form a clear image. This improves the display effect of the near-eye display module, resulting in better final image quality. Thus, it enhances the user's viewing experience.

[0108] Optionally, the light-emitting surface of the display screen 40 is provided with a screen protective glass 100.

[0109] The light emitted by the display screen 40 is transmitted through the screen protection glass 100 on the surface and then enters the laminate 80 to undergo a polarization state transformation.

[0110] See some examples in this application. Figure 1 and Figure 2 The imaging lens group is further provided with a first polarizing element 71, and the first polarizing element 71, the polarizing reflection element 72 and the first phase delayer 73 are stacked in sequence to form a composite film 70; the beam splitting element 90 is disposed on the surface of the second lens 20 near the first lens 10, and the composite film 70 is disposed on the surface of the third lens 30 near the second lens 20.

[0111] The first polarizing element 71 can be used to reduce stray light.

[0112] Optionally, such as Figure 2As shown, the composite film 70 may further include a first anti-reflective film 74, wherein the first anti-reflective film 74, the first phase retarder 73, the polarization reflection element 72, and the first polarizing element 71 are stacked sequentially. The composite film 70 is attached to the surface of the third lens 30 near the second lens 20. In this case, an anti-reflective film may also be provided on the surface of the third lens 30 away from the second lens 20.

[0113] Anti-reflective coatings can be applied to optical components to create interfaces that increase transmittance and reduce reflectivity, thereby reducing image distortion and allowing users to enjoy clearer image quality, thus reducing glare.

[0114] In the near-eye display module of this application embodiment, the beam splitter 90 and the first phase delayer 73 are arranged at intervals. For example, the beam splitter 90 is disposed on the side of the second lens 20 near the first lens 10, and the first phase delayer 73 is disposed between the second lens 20 and the third lens 30. In this way, the beam splitter 90 and the first phase delayer 73 are disposed on opposite sides of the second lens 20, that is, the second lens 20 separates the beam splitter 90 from the first phase delayer 73.

[0115] Of course, the beam splitter 90 and the first phase delayer 73 can be mounted together and disposed on either side of the second lens 20, and this application embodiment does not impose specific restrictions on this.

[0116] Optionally, the polarizing reflective element 72 is attached to the first phase delayer 73 and then disposed on the surface of the third lens 30 near the second lens 20.

[0117] Furthermore, the polarization reflection element 72 and the first phase delayer 73 can also be set independently.

[0118] The near-eye display module of this application includes a first lens 10, a second lens 20, and a third lens 30. The refractive index n of the first lens 10, the second lens 20, and the third lens 30 ranges from 1.4 to 1.7; the dispersion coefficient v of the first lens 10, the second lens 20, and the third lens 30 ranges from 20 to 75. By adjusting the refractive index and dispersion coefficient of the three lenses to match them, the imaging quality of the near-eye display module can be improved.

[0119] In a specific example of this application, the first lens 10 has a refractive index of 1.54 and a dispersion coefficient of 56.3; the second lens 20 has a refractive index of 1.54 and a dispersion coefficient of 56.3; and the third lens 30 has a refractive index of 1.54 and a dispersion coefficient of 55.7.

[0120] The near-eye display module provided in this application is described in detail below through three embodiments.

[0121] Example 1

[0122] like Figures 1 to 3 As shown, the near-eye display module includes an imaging lens group and a beam splitter 90, a first phase retarder 73, a polarization reflection element 72, and a first polarizing element 71 disposed within the imaging lens group; the first polarizing element 71, the polarization reflection element 72, and the first phase retarder 73 are sequentially stacked to form a composite film 70, and the first phase retarder 73 is located between the beam splitter 90 and the polarization reflection element 72;

[0123] The imaging lens group includes a first lens 10, a second lens 20, and a third lens 30 along the same optical axis. The first lens 10 has a positive optical power, and the combined optical power of the second lens 20 and the third lens 30 is 0.019. The beam splitter 90 is located on the third surface 21 of the second lens 20, and the composite film 70 is disposed on the fifth surface 31 of the third lens 30.

[0124] The outer diameter D2 of the second lens 20 is greater than the outer diameter D3 of the third lens 30, which is greater than the outer diameter D1 of the first lens 10, so as to form an accommodating space on the outer periphery of the third lens 30 and the first lens 10; wherein, the absolute value of the difference between the outer diameter D3 of the third lens 30 and the outer diameter D2 of the second lens 20 is greater than 1 mm, and the absolute value of the difference between the outer diameter D1 of the first lens 10 and the outer diameter D2 of the second lens 20 is greater than 1 mm.

[0125] The near-eye display module further includes an eye-tracking component, which includes an illumination device 50 and an imaging device 60. The illumination device 50 is disposed on the outer periphery of the third lens 30, and the imaging device 60 is located above the outer periphery of the first lens 10. The illumination device 50 includes an infrared light source 51, and the imaging device 60 includes an infrared camera device 61. The infrared light emitted from the infrared light source 51 is reflected by the human eye 01 and passes through the third lens 30 and the second lens 20, and then enters the infrared camera device 61 to form an eye-tracking light path.

[0126] The near-eye display module also includes a display screen 40, which is located on the side of the first lens 10 away from the second lens 20. The display screen 40 is capable of emitting natural light. The first surface 11 of the first lens 10 is provided with a superimposed sheet 80 to convert the natural light into circularly polarized light before it enters the imaging lens group. The superimposed sheet 80 includes a second phase retarder 82, a second polarizing element 83, and a third phase retarder 84, wherein the second polarizing element 83 is located between the second phase retarder 82 and the third phase retarder 84.

[0127] Table 1 shows the optical parameters of each lens in the near-eye display module provided in Example 1.

[0128] Table 1

[0129]

[0130] Based on the near-eye display module shown in the example above, please continue as follows: Figure 1 As shown, the propagation of virtual imaging light can be understood as follows: natural light emitted from display screen 40 is converted into natural light through third phase delayer 84, then into linearly polarized light through second polarizing element 83, then into circularly polarized light through second phase delayer 82, transmitted through second lens 20, converted into linearly polarized light (S-light) through first phase delayer 73, reflected by polarizing reflection element 72, converted into circularly polarized light through first phase delayer 73, reflected by beam splitter 90, converted into linearly polarized light (P-light) through first phase delayer 73, and finally transmitted through third lens 30 and enters human eye 01.

[0131] The optical performance of the near-eye display module provided in Embodiment 1 above is as follows: Figures 4 to 7 As shown: Figure 4 This is a dot diagram of a near-eye display module. Figure 5 This is the MTF curve of the near-eye display module. Figure 6 This is a field curvature distortion diagram of a near-eye display module. Figure 7 It is the vertical axis chromatic aberration diagram of the near-eye display module.

[0132] A dot matrix pattern refers to the diffuse pattern formed by numerous rays emanating from a single point after passing through a near-eye display module. Due to aberrations, the rays no longer converge at a single point on the image plane, but instead create a scattered pattern over a certain area. This pattern can be used to evaluate the imaging quality of a near-eye display module. For example... Figure 4 As shown in this embodiment 1, the maximum value of the image point in the point array corresponds to the maximum field of view, and the maximum value of the image point in the point array is less than 19μm.

[0133] The MTF curve is a modulation transfer function graph, which characterizes the imaging sharpness of the near-eye display module through the contrast of black and white line pairs. For example... Figure 5As shown, in this embodiment 1, the MTF is >0.4 at 60 lp / mm, resulting in clear imaging.

[0134] The distortion diagram reflects the difference in the position of the image plane that produces a sharp image at different fields of view. In this embodiment 1, for example... Figure 6 As shown, the maximum distortion occurs in the field of view 1, with an absolute value of less than 30%.

[0135] Transverse chromatic aberration, also known as magnification chromatic aberration, mainly refers to the difference in focal positions between blue and red light on the image plane when a single polychromatic principal ray from the object side is emitted as multiple rays due to dispersion in the refraction system. In Example 1, as... Figure 7 As shown, the maximum color difference value of the near-eye display module is less than 120μm.

[0136] Example 2

[0137] The near-eye display module provided in Example 2, see [link / reference]. Figure 8 As shown, the difference between this and the near-eye display module provided in Embodiment 1 is that the imaging device 60 in the eye-tracking component is equipped with a reflective structure 62. The reflective structure 62 is a reflector. The infrared light emitted by the infrared light source 51 passes through the third lens 30 and the second lens 20 and is reflected by the reflective structure 62 into the infrared camera device 61.

[0138] Table 2 shows the optical parameters of each lens in the near-eye display module provided in Example 2.

[0139] Table 2

[0140]

[0141] The optical performance of the near-eye display module provided in Embodiment 2 is not significantly different from that of the near-eye display module shown in Embodiment 1. Further details can be found therein. Figures 4 to 7 .

[0142] According to another aspect of the embodiments of this application, a head-mounted display device is also provided, the head-mounted display device including a housing and a near-eye display module as described above.

[0143] The head-mounted display device is, for example, a VR head-mounted device, including VR glasses or VR helmets, etc., and this application embodiment does not impose specific limitations on it.

[0144] The specific implementation of the head-mounted display device in this application can refer to the above-described near-eye display module embodiments, and therefore has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0145] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0146] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A near-eye display module, characterized in that, It includes an imaging lens assembly and a beam splitter (90), a first phase retarder (73) and a polarization reflection element (72) disposed within the imaging lens assembly, wherein the first phase retarder (73) is located between the beam splitter (90) and the polarization reflection element (72); The imaging lens group includes a first lens (10), a second lens (20), and a third lens (30) sequentially along the same optical axis. The beam splitter (90) is located on either side of the second lens (20). The first phase retarder (73) and the polarization reflection element (72) are located between the second lens (20) and the third lens (30). The outer diameter D2 of the second lens (20) is greater than the outer diameter D3 of the third lens (30) and the outer diameter D1 of the first lens (10), so as to form an accommodating space on the outer periphery of the third lens (30) and the first lens (10). The near-eye display module further includes an eye-tracking component, which includes an illumination device (50) and an imaging device (60). The illumination device (50) is disposed in the accommodating space on the outer periphery of the third lens (30), and the imaging device (60) is located in the accommodating space above the outer periphery of the first lens (10). The light emitted from the illumination device (50) is reflected by the human eye (01) and passes through the third lens (30) and the second lens (20), and then enters the imaging device (60) to form an eye-tracking light path. The absolute value of the difference between the outer diameter D3 of the third lens (30) and the outer diameter D2 of the second lens (20) is greater than 1 mm; The absolute value of the difference between the outer diameter D1 of the first lens (10) and the outer diameter D2 of the second lens (20) is greater than 1 mm; The combined optical power of the second lens (20) and the third lens (30) is positive. The incident angle of the light reflected by the human eye (01) relative to the imaging device (60) will decrease accordingly after passing through the third lens (30) and the second lens (20) in sequence. It also includes a composite film (70) disposed on the surface of the third lens (30) near the second lens (20), the composite film (70) including a first polarizing element (71), the polarizing reflection element (72) and the first phase delayer (73) stacked in sequence.

2. The near-eye display module according to claim 1, characterized in that, The combined optical power of the second lens (20) and the third lens (30) is 0.

019.

3. The near-eye display module according to claim 1, characterized in that, The lighting device (50) includes an infrared light source (51), and the imaging device (60) includes an infrared camera (61).

4. The near-eye display module according to claim 3, characterized in that, The imaging device (60) further includes a reflective structure (62) located on the light emission path of the infrared light source (51), and at least a portion of the light emitted by the infrared light source (51) can be reflected by the reflective structure (62) to the infrared camera (61).

5. The near-eye display module according to claim 1, characterized in that, The near-eye display module also includes a display screen (40), which is located on the side of the first lens (10) away from the second lens (20); The display screen (40) is configured to emit circularly polarized light or natural light; When the light emitted by the display screen (40) is natural light, a superimposed sheet (80) is provided between the display screen (40) and the first lens (10), which can be used to convert the natural light into circularly polarized light before it enters the imaging lens group.

6. The near-eye display module according to claim 5, characterized in that, The laminate (80) is disposed on the surface of the first lens (10) near the display screen (40); The composite sheet (80) includes a second phase retarder (82), a second polarizing element (83) and a third phase retarder (84), wherein the second polarizing element (83) is located between the second phase retarder (82) and the third phase retarder (84).

7. The near-eye display module according to claim 1, characterized in that, The optical power of the first lens (10) is positive.

8. A head-mounted display device, characterized in that, include: case; as well as The near-eye display module as described in any one of claims 1-7.

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