Near-eye display system, head-mounted display device, and near-eye display method

Abstract

The present disclosure relates to a near-eye display system, a head-mounted display device, and a near-eye display method. The near-eye display system includes: an objective lens having a distortion rate determined according to a desired field of view angle to collect a barrel-shaped distortion pattern with the field of view angle; an image sensor configured to sense the barrel-shaped distortion pattern and convert it into image data; a processing unit configured to obtain image data from the image sensor and transmit it to a display unit; a display unit configured to display the barrel-shaped distortion pattern according to the image data; and a near-eye optical unit configured to optically correct the displayed barrel-shaped distortion pattern to obtain a distortion-free pattern with an angular resolution that gradually decreases from the center to the periphery for human eye observation. Through the system, device, and method, it is possible to obtain a larger field of view angle while still enabling the human eye to observe a high-definition image.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular, to a near-eye display system, a head-mounted display device including the near-eye display system, and a near-eye display method. Background Art

[0002] With the continuous development of display technology, near-eye display has received more and more attention. Near-eye display technology is a technology that provides images within the visual area of ​​the human eye to create an immersive visual experience. This technology is currently mainly used in head-mounted display devices such as virtual reality (VR) devices, augmented reality (AR) devices, and mixed reality (MR) devices.

[0003] Generally, in order to achieve a better immersive visual experience, a larger field of view and higher angular resolution are required. However, in the current technical context, the image detection resolution of image sensors and the display resolution of displays are not high enough to achieve a larger field of view and a higher angular resolution. Or, even if there are image sensors and displays that meet the high-resolution requirements, their costs are too high, making them difficult to be widely used in engineering. Summary of the invention

[0004] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0005] The object of the present disclosure is to provide a near-eye display system, a head-mounted display device, and a near-eye display method that can achieve a larger field of view while still enabling the human eye to observe high-definition images.

[0006] In order to achieve the above objective, according to one aspect of the present disclosure, a near-eye display system is provided, comprising:

[0007] an objective lens having a distortion rate determined according to a desired field angle so as to capture a barrel distortion pattern having the field angle;

[0008] an image sensor configured to sense the barrel distortion pattern and convert it into image data;

[0009] a processing unit configured to acquire image data from the image sensor and transmit the image data to a display unit;

[0010] A display unit configured to display a barrel distortion pattern based on the image data; and

[0011] The near-eye optical unit is configured to perform optical correction on the displayed barrel-shaped distortion pattern to obtain a distortion-free pattern with an angular resolution gradually decreasing from the center to the periphery for human eye observation.

[0012] In some embodiments, the distortion rate may be -30% to -100%.

[0013] In some embodiments, the objective lens may be a fisheye lens.

[0014] In some embodiments, the processing unit may also be configured to correct distortion introduced by optical processing tolerances and / or assembly errors of the objective lens and the near-eye optical unit.

[0015] In some embodiments, the near-eye optical unit may be an aspherical lens.

[0016] In some embodiments, the field of view angle of the non-distorted image after correction by the near-eye optical unit may be equal to the field of view angle of the barrel-shaped distorted image collected by the objective lens.

[0017] In some embodiments, the angular resolution of the center of the distortion-free image may remain unchanged before and after optical correction and may reach the angular resolution of the retina of the human eye.

[0018] In some embodiments, the viewing angle of the center of the distortion-free pattern may be 15° to 20°.

[0019] According to another aspect of the present disclosure, a head-mounted display device is also provided, which includes the near-eye display system according to any one of the above paragraphs.

[0020] According to another aspect of the present disclosure, a near-eye display method is also provided, which includes:

[0021] collecting a barrel distortion pattern having a desired field angle through an objective lens having a distortion rate determined according to the desired field angle; and

[0022] The barrel distortion pattern is optically corrected to obtain a distortion-free pattern with an angular resolution that gradually decreases from the center to the periphery for human eye observation.

[0023] According to the above technical solution, by using a large distortion objective lens to obtain a barrel-shaped distorted image in which the geometric shape difference between the center and the edge is magnified, a larger field of view angle can be obtained compared to the distortion-free image captured by a distortion-free objective lens of the same focal length and the same surface size. In addition, by optically correcting the barrel-shaped distortion pattern to obtain a distortion-free pattern whose angular resolution gradually decreases from the center to the surroundings and conforms to the angular resolution characteristics of the human eye, the human eye can observe a high-definition image. As a result, in the case of the current image sensors and display screens with limited pixel levels, a larger field of view angle can be obtained while still enabling the human eye to observe a high-definition image. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The features and advantages of the embodiments of the present disclosure will become more easily understood through the following description with reference to the accompanying drawings. The drawings are not drawn to scale and some features may be exaggerated or reduced to show details of particular components.

[0025] In the attached picture:

[0026] Figure 1 It is a schematic structural diagram of a near-eye display system according to an embodiment of the present disclosure.

[0027] Figure 2 This is a schematic comparison diagram of the distortion-free image collected by the distortion-free objective lens and the barrel-shaped distortion image collected by the large distortion objective lens.

[0028] Figure 3 A schematic optical path diagram for collecting barrel distortion patterns of an objective lens of a near-eye display system according to an embodiment of the present disclosure.

[0029] Figure 4 A schematic optical path diagram of a near-eye optical unit of a near-eye display system according to an embodiment of the present disclosure for correcting barrel distortion patterns.

[0030] Figure 5 Schematic comparison diagram of the barrel distortion image collected by a large distortion objective lens and the distortion-free image after correction by a near-eye optical unit.

[0031] Figure 6 It is a graph showing the variation of the objective lens distortion rate and the near-eye optical unit distortion rate with the field of view angle.

[0032] Figure 7 The field of view angle detected by the objective lens and the field of view angle detected by the near-eye optical unit are schematically shown.

[0033] Figure 8 4 is a schematic structural diagram of a head mounted display device according to an embodiment of the present disclosure.

[0034] Fig. 9 The present invention is a flowchart of a near-eye display method according to an embodiment of the present disclosure.

[0035] In the drawings, the same or corresponding technical features or components are represented by the same or corresponding reference numerals. DETAILED DESCRIPTION

[0036] The present disclosure is described in detail below with reference to the accompanying drawings by means of exemplary embodiments. It should be noted that the following detailed description of the present disclosure is only for illustrative purposes and is by no means a limitation of the present disclosure.

[0037] It should be noted that, for the sake of clarity, not all features of a specific implementation are described and illustrated in the specification and drawings. Furthermore, in order to avoid unnecessary details that obscure the technical solution that the present disclosure focuses on, only the device structure closely related to the technical solution of the present disclosure is described and illustrated in the specification and drawings, while other details that are not closely related to the technical content of the present disclosure and are known to those skilled in the art are omitted.

[0038] For head-mounted display devices that provide near-eye display, such as VR devices and AR devices, during the imaging process, usually, the reflected light of the natural scene is converged to the image sensor through the objective lens to display the captured image on the display screen, and the displayed image is magnified through the eyepiece for human eye observation. Conventionally, the distortion rate of the objective lens is required to be as small as possible, for example, less than 5%, so as to obtain an image with as little distortion as possible, so as not to basically affect the viewer's recognition of the real scene reflected by the image. On the other hand, in the related art, such smaller distortion in the image can also be corrected by optical components and algorithms to obtain an image with very uniform resolution.

[0039] In near-eye display, in order to achieve a better immersive visual experience, a larger field of view and higher image clarity are required.

[0040] Specifically, the field of view refers to the range of vision that the viewer can observe, expressed as the angle formed by the two edges of the maximum field of view. The field of view includes the field of view in the horizontal direction and the field of view in the vertical direction. Usually, the human eye's observation range in the horizontal direction is about 160°, and the observation range in the vertical direction is about 135°. Therefore, if you want to enhance the immersive visual experience of near-eye display, the field of view of the near-eye display of the head-mounted display device must be larger, for example, close to or covering the observation range of the human eye.

[0041] The clarity of the image displayed by the head-mounted display device is usually expressed by angular resolution (Pixels Per Degree, PPD). PPD refers to the average number of pixels filled in every 1° angle in the field of view. In other words, PPD is obtained by dividing the number of pixels filled in the field of view diameter by the field of view. The greater the number of pixels filled in every 1° angle, the higher the PPD value, and the clearer the displayed image.

[0042] However, when the number of pixels filling the field of view diameter is constant, for example, when the head-mounted display device uses an image sensor and display screen with fixed pixels, the larger the field of view angle, the lower the PPD will be, resulting in lower clarity of the displayed image. Therefore, in order to achieve a higher PPD while obtaining a larger field of view angle, it is usually adopted to increase the number of pixels filling the field of view diameter. For example, in the case of obtaining a horizontal field of view angle of 100°, when using a display screen with a resolution of 1080P (corresponding to 1920 horizontal pixels), the PPD is only 19.2; when using a display screen with a resolution of 4K (corresponding to 3840 horizontal pixels), the PPD increases to 38.4.

[0043] It is known that the human eye has a limit to its resolution ability under normal vision, which is measured by PPD, which is about 60 (i.e., retinal level PPD). In other words, the closer the PPD of the image displayed by the head-mounted display device is to 60, the closer the image clarity is to the resolution limit of the human eye, and the viewer will feel that the image is clearer. Once the PPD exceeds 60, the human eye cannot distinguish it. Therefore, in order to achieve a better immersive visual experience, the PPD of the displayed image needs to be close to or even reach the retinal level PPD.

[0044] According to the method mentioned above, when the PPD is required to reach 60, for example, when the horizontal field of view is 100°, a high-resolution image sensor and display screen with 6000 horizontal pixels must be used for image detection and display. When the desired field of view is larger, the resolution requirements for the image sensor and display screen will be higher. However, under the current technical background, it is difficult to obtain higher-resolution image sensors and displays. Even if there are particularly high-resolution image sensors and displays that can still obtain retinal-level PPD at a large field of view, their prices will be very expensive, making it difficult to be widely used in engineering. In addition, higher-resolution image sensors and displays will also result in higher power consumption, affecting the stability of device operation.

[0045] In order to solve the above problems, the embodiments of the present disclosure provide a near-eye display system. The near-eye display system proposes an unconventional solution, in which a large-distortion objective lens is deliberately used to obtain a barrel-shaped distorted image in which the geometric shape difference between the center and the edge is magnified, thereby obtaining a larger field of view angle compared to the distortion-free image captured by a distortion-free objective lens of the same focal length and the same dome size, and the barrel-shaped distortion pattern is optically corrected to obtain a distortion-free pattern with an angular resolution that gradually decreases from the center to the periphery, which is consistent with the angular resolution characteristics of the human eye, so that the human eye can observe a high-definition image.

[0046] Below, refer to Figures 1 to 7 , a near-eye display system 1 according to an embodiment of the present disclosure is described.

[0047] The near-eye display system 1 includes an objective lens 10 , an image sensor 20 , a processing unit 30 , a display unit 40 and a near-eye optical unit 50 .

[0048] The objective lens 10 has a distortion rate determined according to a desired field angle to collect a barrel distortion pattern having the field angle, and the image sensor 20 is configured to sense the barrel distortion pattern and convert it into image data.

[0049] Figure 2 The figure schematically shows the distortion-free figure M1 collected by the distortion-free objective lens and the barrel-shaped distortion figure M2 collected by the large distortion objective lens under the same focal length and the same image size. Barrel distortion is a distortion in which the edge of the image bends outward, causing the image to be in a barrel-shaped expanded state. In the barrel-shaped distortion figure M2, the area M2' located in the center is basically not distorted and is consistent with the area covered by the distortion-free figure M1. It can be clearly observed that, in addition to the area M2', the barrel-shaped distortion figure M2 also includes additional areas located around the area M2', in which the image is curved and more information is collected. Therefore, under the same focal length and the same image size, the barrel-shaped distortion figure M2 can display a larger field of view. In other words, compared with the distortion-free objective lens, the objective lens with a larger distortion rate can perceive information of a larger field of view, thereby obtaining a figure with a larger field of view angle.

[0050] Based on this, in an embodiment of the present disclosure, the required distortion rate and the corresponding objective lens are determined according to the desired field of view, thereby collecting a barrel distortion pattern with the field of view. Figure 3 , the object surface A (the corresponding object shape is A' in Figure 1 and Figure 3The light S reflected by the objective lens 10 passes through the aperture B and is deflected by the objective lens 10 and converges to the image plane C of the image sensor 20. Since the central part and the edge part of the objective lens 10 have different refractive indices for light, radial distortion is formed. In order to obtain the required barrel distortion, the objective lens 10 is configured such that the closer the light is to the main optical axis D along the radial direction of the objective lens 10, the smaller the distortion, and the farther the light is from the main optical axis D, the larger the distortion. As a result, the image sensor 20 can sense the barrel distortion pattern A on the image plane C (see Figure 1 and Figure 3 ) and convert it into image data.

[0051] Re-reference Figure 1 The processing unit 30 is configured to acquire the image data from the image sensor 20 and transmit it to the display unit 40, and the display unit 40 is configured to display the barrel distortion graph A" according to the image data. In this process, the barrel distortion intentionally introduced can be transmitted to the display unit 40 without any correction.

[0052] The near-eye optical unit 50 is configured to perform optical correction on the displayed barrel-shaped distortion pattern A″ to obtain a distortion-free pattern A″′ whose angular resolution for observation by the human eye G gradually decreases from the center to the periphery.

[0053] Reference Figures 4 to 6 , the display unit 40 displays a barrel-shaped distortion pattern A" on its image plane E, and the near-eye optical unit 50 is arranged behind the display unit 40 in the optical path direction (ie, Figure 4 The corrected non-distortion pattern A'' is presented on the side of the display unit 40 opposite to the near-eye optical unit 50 (ie, Figure 4 By making the distortion produced by the objective lens 10 correspond to the distortion correction performed by the near-eye optical unit 50, that is, making the distortion rate curve of the objective lens 10 (objective lens distortion curve) consistent with the distortion rate curve of the near-eye optical unit 50 (near-eye optical distortion curve), as shown in FIG. Figure 6 As shown in , the image obtained by optical correction can be made into a distortion-free image. Figure 6 For the same viewing angle, the distortion rate of the objective lens 10 corresponds to the distortion rate of the near-eye optical unit 50. For example, for a horizontal viewing angle of 30°, the distortion rate of the objective lens 10 is -70%, while the distortion rate of the near-eye optical unit 50 is 70%.

[0054] Figure 5The barrel distortion figure M2 collected by a large distortion objective lens and the distortion-free figure M3 after optical correction are schematically shown. The area M2' located at the center of the barrel distortion figure M2 is basically not distorted, and is consistent with the area M3' located at the center of the distortion-free figure M3 after optical correction, that is, the covered field angles are equal. It can be clearly observed that the distorted area around the area M2' of the barrel distortion figure M2 is optically corrected, and the corresponding image is corrected from a curved state to a state consistent with the real state of the object, so that the distortion-free figure M3 with a larger field angle is obtained while retaining the original information of the barrel distortion figure M2.

[0055] Moreover, through the near-eye optical unit 50, the barrel distortion figure A" is optically corrected into a distortion-free figure A'" whose angular resolution gradually decreases from the center to the surrounding areas. Through optical correction, the distorted curved image of the surrounding areas of the barrel distortion figure M2 becomes an image consistent with the actual state of the object, and in the case of no loss in the number of pixels, since the field of view of the surrounding areas after correction becomes larger, the corresponding PPD becomes lower, and according to the trend of the change in the degree of distortion, the PPD of the corrected distortion-free figure A'" is highest at the center of the figure and gradually becomes lower along the radial direction of the figure outward, that is, the image center is clearest and the clarity gradually decreases along the radial direction of the image outward.

[0056] The PPD characteristics of this distortion-free graphic A"' are consistent with the visual characteristics of the human eye, or more specifically, the PPD characteristics of the human eye, so that high-definition images can be observed. Specifically, the center of the retina of the human eye (i.e., the macula) is the location where the visual cells are most concentrated, has the highest PPD, and is capable of fine observation, while from the center of the retina to the periphery, the distribution of visual cells becomes less and less, the PPD continues to decrease, and the perception of details becomes blurred. The PPD characteristics of the distortion-free graphic A"' just match this. The central area with the highest PPD of the distortion-free graphic A"' corresponds to the center where the PPD of the human eye retina is the highest, and the surrounding areas where the PPD of the distortion-free graphic A"' gradually decreases correspond to the surrounding areas where the PPD of the human eye retina gradually decreases, so that the human eye can clearly see the details of the central area. Since the field of view corresponding to the central distortion-free area is small, when using the current image sensor and display screen (i.e., display unit) with limited pixel levels, for example, using a display screen with a resolution of 1080P, a high PPD value that meets the requirements can be obtained in the central area, so that the human eye can observe high-definition images.

[0057] In this way, it is possible to obtain a larger field of view while still enabling the human eye to observe a high-definition image under the current limited pixel level of image sensors and display screens. Moreover, since the imaging process only uses optical correction and no algorithm correction is performed, the burden of digital processing is not increased, making the imaging process simpler and more stable. In addition, since the solution disclosed in the present invention deliberately increases the degree of distortion and uses simple optics for distortion correction, the axial size of the objective lens can be effectively reduced and thus its weight can be reduced, and the design difficulty and manufacturing cost of the entire system can be reduced.

[0058] In some embodiments, the distortion rate of the objective lens 10 may be -30% to -100%.

[0059] The distortion rate in this range is much greater than the distortion rate of the objective lens used in the conventional method of acquiring a large field of view image. In the conventional method, the distortion rate of the objective lens is controlled to be as small as possible, such as 5%. Even for a wide-angle lens used to acquire a larger field of view, its distortion rate is far from reaching the above range.

[0060] By using an objective lens with such a large distortion rate in the above range, a desired larger field of view angle can be obtained, for example, a horizontal field of view angle of 160° and a vertical field of view angle of 135°, so as to cover the observation range of the human eye and obtain a better immersive visual experience.

[0061] It is conceivable that the objective lens 10 may be a fisheye lens.

[0062] A fisheye lens is a special type of ultra-wide-angle lens that can capture a particularly wide field of view, for example, a 180° field of view, by providing a significant barrel distortion effect. Due to the ability to provide significant distortion effects, fisheye lenses are often used in fields such as creative photography, and are not used in near-eye display systems that ultimately need to display distortion-free graphics. In conventional near-eye display systems, it is usually difficult to correct excessive image distortion through algorithms without losing signal, so the use of such large-distortion fisheye lenses is avoided. In the solution disclosed in the present invention, this fisheye lens that can bring about large distortion is exactly what is needed to obtain a large field of view.

[0063] It is conceivable that the objective lens 10 may also be other types of lenses or lens groups, as long as a barrel distortion pattern with a desired field of view angle can be obtained therethrough.

[0064] In some embodiments, the processing unit 30 is further configured to correct distortion introduced by optical processing tolerances and / or assembly errors of the objective lens 10 and the near-eye optical unit 50 .

[0065] In an optical system without the above tolerances and errors, the processing unit 30 is only used for the transmission of image data. As mentioned earlier, the processing unit 30 can drive the image sensor 20 and obtain image data therefrom, and can drive the display unit 40 to transmit the image data to the display unit 40 for displaying the barrel distortion pattern. By enabling the processing unit 30 to correct the distortion introduced by the above tolerances and / or errors, in the presence of the above tolerances and / or errors, the distortion introduced by them can be corrected, so that the distortion-free pattern A'' can achieve a more accurate correspondence with the barrel distortion pattern A' captured by the objective lens 10, thereby obtaining a better near-eye display effect.

[0066] In some embodiments, the near-eye optical unit 50 may be an aspherical lens.

[0067] By using an aspherical lens, the focusing method of light can be controlled more accurately, and the curvature distribution of the lens can be adjusted so that the central area of ​​the corrected distortion-free image has a higher PPD, while the PPD of the edge area gradually decreases.

[0068] Specifically, the curved surface distribution of the aspheric lens group can satisfy the following radial distortion mathematical model:

[0069] x0=x(1+k1r 2 +k2r 4 +k3r 6 )

[0070] y0=y(1+k1r 2 +k2r 4 +k3r 6 )

[0071] Wherein, x0 and y0 are the coordinate positions of the image points of the barrel distortion pattern displayed by the display unit 40, x and y are the coordinate positions of the corresponding image points of the non-distorted pattern after optical correction, k1, k2, and k3 are adjustment coefficients, and their values ​​can be determined by measuring the data of multiple coordinate points before and after correction, and r 2 =x 2 +y 2 .

[0072] In some embodiments, Figure 7 As shown in , the field angle β of the distortion-free image corrected by the near-eye optical unit 50 can be equal to the field angle α of the barrel-shaped distortion image collected by the objective lens 10. In other words, the field angle of the near-eye display can be equal to the field angle detected by the objective lens.

[0073] In this way, the range of the scene observed by the near-eye display system (i.e., the corrected undistorted image) is exactly the same as the range of the scene captured by the objective lens. This means that the edges of the image observed in these two scene viewing modes are the same, thereby providing a seamless and natural visual experience, further enhancing the viewer's sense of immersion.

[0074] In some embodiments, the PPD at the center of the distortion-free pattern A'" does not change before and after optical correction and reaches the retinal level PPD of the human eye.

[0075] As mentioned before, the closer the PPD of an image is to the PPD at the retinal level of the human eye, the clearer the image the viewer will feel. Based on this, for the center of the distortion-free pattern A"' that does not require distortion correction during the optical correction process, i.e., area M3', its PPD can reach the PPD at the retinal level of the human eye, that is, reach the limit of what the human eye can distinguish. As a result, the human eye can observe an image with the best clarity, thereby further improving the visual experience.

[0076] In some embodiments, the viewing angle of the center of the distortion-free pattern A'' may be 15° to 20°.

[0077] The opening angle of the macular area of ​​the human eye is about 6° to 7°. Since the macular area shakes back and forth, the range of the opening angle is about 15° to 20° during human eye observation. By making the field of view angle of the center of the distortion-free pattern A''' in the range of 15° to 20°, the range of the opening angle of the macular area of ​​the human eye can be matched with the field of view angle of the center of the distortion-free pattern A''', thereby enabling the human eye to observe the best definition image in the largest range, thereby further improving the visual experience.

[0078] According to another aspect of the present disclosure, Figure 8 As shown in the figure, a head-mounted display device 2 is also provided, which includes a near-eye display system 1. The head-mounted display device 2 is, for example, an AR device such as AR glasses, a VR device such as VR glasses, and an MR device such as MR glasses. The near-eye display system 1 can be integrated into the head-mounted display device 2 by being installed in a housing of the head-mounted display device 2.

[0079] According to another aspect of the present disclosure, Fig. 9 As shown in , a near-eye display method is also provided, which includes:

[0080] collecting a barrel distortion pattern having a desired field angle through an objective lens having a distortion rate determined according to the desired field angle; and

[0081] The barrel-shaped distortion pattern is optically corrected to obtain a distortion-free pattern with an angular resolution that gradually decreases from the center to the periphery for human eye observation.

[0082] In the above-mentioned near-eye display method, the distortion rate can also be made from -30% to -100%, or the field of view angle of the near-eye display can be made equal to the field of view angle detected by the objective lens, or the PPD of the center of the distortion-free image can remain unchanged before and after optical correction and reach the PPD of the human eye retina level, or the field of view angle of the above-mentioned center of the distortion-free image can be made from 15° to 20°.

[0083] In the present disclosure, although the present disclosure has been described with reference to exemplary embodiments, it should be understood that the present disclosure is not limited to the specific embodiments described and shown in detail herein. Those skilled in the art may make various changes to the exemplary embodiments without departing from the scope defined by the claims of the present disclosure.

[0084] The features mentioned and / or shown in the above description of the exemplary embodiments of the present disclosure may be combined in the same or similar manner into one or more other embodiments, combined with the features in other embodiments or substituted for the corresponding features in other embodiments. The technical solutions obtained by these combinations or substitutions shall also be deemed to be included in the protection scope of the present disclosure.

Claims

1. A near-eye display system, characterized in that: It includes an objective lens, an image sensor, a processing unit, a display unit and a near-eye optical unit. The objective lens is a fisheye lens and has a distortion rate determined according to a desired field of view angle, so as to collect a barrel-shaped distortion pattern with the field of view angle, wherein the distortion rate curve of the objective lens is consistent with the distortion rate curve of the near-eye optical unit; The image sensor is configured to sense the barrel distortion pattern and convert it into image data; The processing unit is configured to acquire the image data from the image sensor and transmit it to a display unit; The display unit is configured to display the barrel distortion pattern according to the image data; and The near-eye optical unit is configured to optically correct the displayed barrel distortion pattern to obtain an undistorted pattern for observation by the human eye, the angular resolution of the center of the undistorted pattern does not change before and after the optical correction and reaches the angular resolution of the human eye retina, the trend of the angular resolution of the undistorted pattern gradually decreasing from the center to the periphery matches the trend of the angular resolution of the human eye retina changing from the center to the periphery, and the field of view angle of the center of the undistorted pattern is 15° to 20°.

2. The near-eye display system according to claim 1, characterized in that: The distortion rate is -30% to -100%.

3. The near-eye display system according to claim 1, characterized in that: The processing unit is further configured to correct distortion introduced by optical processing tolerances and / or assembly errors of the objective lens and the near-eye optical unit.

4. The near-eye display system according to claim 1, characterized in that: The near-eye optical unit is an aspherical lens.

5. The near-eye display system according to claim 1, characterized in that: The viewing angle of the distortion-free image after correction by the near-eye optical unit is equal to the viewing angle of the barrel-shaped distortion image collected by the objective lens.

6. A head mounted display device, characterized in that: Comprising a near-eye display system according to any one of claims 1 to 5.

7. A near-eye display method, characterized in that: include: Collecting a barrel-shaped distortion pattern with a desired field of view angle through an objective lens of a fisheye lens having a distortion rate determined according to the desired field of view angle, wherein the distortion rate curve of the objective lens is consistent with the distortion rate curve of the near-eye optical unit; as well as The barrel distortion pattern is optically corrected by the near-eye optical unit to obtain a distortion-free pattern for observation by the human eye, the angular resolution of the center of the distortion-free pattern does not change before and after the optical correction and reaches the angular resolution of the human eye retina, the trend of the angular resolution of the distortion-free pattern gradually decreasing from the center to the periphery matches the trend of the angular resolution of the human eye retina changing from the center to the periphery, and the field of view angle of the center of the distortion-free pattern is 15° to 20°.

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