A virtual reality device

Abstract

The embodiment of the present application provides a virtual reality device, comprising: a see-through optical system and a display optical system; the see-through optical system generates negative distortion in an imaging process, the display optical system generates positive distortion in the imaging process, and the absolute value of the difference between the negative distortion and the positive distortion is within a preset threshold; the see-through optical system is used for collecting an external environment image and transmitting the external environment image to the display optical system; and the display optical system is used for displaying the external environment image. The embodiment of the present application solves the problems of serious image distortion and color distortion, and effectively improves the user experience.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of electronic optical equipment, and particularly relate to a virtual reality device. BACKGROUND

[0002] A virtual reality (VR) device provides a user with an interactive virtual three-dimensional space, and through a perception unit, provides simulation of visual, auditory, tactile and other sensory organs, allowing a person to enter a completely immersive virtual world. Therefore, the VR device requires a user to use a specific head-mounted display to form a completely closed virtual space, and video see-through (VST) breaks this limitation, allowing the user to walk out of the VR world.

[0003] At present, the see-through function of the VR device is achieved by the following method: the real-time pictures of the surrounding environment are collected by the front camera of the head-mounted device and transmitted to the chip processor, and the pictures are transmitted to the near-eye optical system after being corrected by the chip processor. The corrected pictures enter the human eye through the near-eye optical system, giving the feeling that the human eye can directly see the real world through the head-mounted display.

[0004] However, in the above method, although the VR device uses a software algorithm to correct the distortion of the optical system of the front camera, the near-eye optical system also produces distortion, which causes the image seen by the human eye to still have serious image distortion, color distortion and other problems, causing the user to feel dizzy and nauseous, thereby affecting the user experience. SUMMARY

[0005] Embodiments of the present application provide a virtual reality device, which solves the problems of serious image distortion and color distortion, and effectively improves the user experience.

[0006] Embodiments of the present application provide a virtual reality device, which includes a see-through optical system and a display optical system.

[0007] The see-through optical system produces negative distortion in the imaging process, and the display optical system produces positive distortion in the imaging process, and the absolute value of the difference between the negative distortion and the positive distortion is within a preset threshold.

[0008] The see-through optical system is configured to collect an external environment image and transmit the external environment image to the display optical system.

[0009] The display optical system is configured to display the external environment image.

[0010] In the embodiment of the present application, the see-through optical system generates negative distortion in the imaging process, the display optical system generates positive distortion in the imaging process, and the absolute value of the difference between the negative distortion and the positive distortion is within a preset threshold, thereby solving the problem of serious image distortion and color distortion and effectively improving the user experience.

[0011] In an optional implementation, the field of view angle of the see-through optical system is greater than the field of view angle of the display optical system.

[0012] In an optional implementation, the display optical system comprises, in sequence, a diaphragm, a first lens, a polarization component, a second lens, and a display component.

[0013] In an optional implementation, the material of the first lens and the material of the second lens are both resin materials.

[0014] In an optional implementation, the film material of the first lens and the second lens is internally attached.

[0015] In an optional implementation, the range of the positive distortion generated by the display optical system in the imaging process is [30%, 40%].

[0016] In an optional implementation, the see-through optical system comprises six lenses arranged in sequence, and the material of the lenses is a resin material.

[0017] In an optional implementation, the range of the negative distortion generated by the see-through optical system in the imaging process is [-40%, -30%].

[0018] In an optional implementation, the half field of view angle of the see-through optical system is defined as θ, the system focal length is defined as f, the focal lengths of the six lenses are defined as f1, f2, f3, f4, f5, and f6, the system half image size is defined as IH, and the system length is defined as L, and the see-through optical system satisfies the following conditions: 110°≤θ≤150°; 0.014≤IH / (f*θ)≤0.015; 3.7≤L / f≤4.1; 3.9≤L / IH≤4.3; 1.38≤f3 / f≤1.52; -1.82≤f4 / f≤-1.64; 1.17≤f5 / f≤1.29; -2.2≤f6 / f≤-1.99.

[0019] In an optional implementation, the see-through optical system comprises a 16-megapixel complementary metal oxide semiconductor (CMOS) chip. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0021] Figure 1A A schematic diagram of an image distortion form provided by the present application;

[0022] Figure 1B A structural schematic diagram of a virtual reality device provided by the present application;

[0023] Figure 2 A structural schematic diagram of a display optical system provided by the present application;

[0024] Figure 3 An MTF image of a display optical system provided by the present application;

[0025] Figure 4 A distortion image of a display optical system provided by the present application;

[0026] Figure 5 A structural schematic diagram of a perspective optical system provided by the present application;

[0027] Figure 6 An MTF image of a perspective optical system provided by the present application;

[0028] Figure 7 A distortion image of a perspective optical system provided by the present application;

[0029] Figure 8 A flowchart of internal system operation of a virtual reality device provided by the present application. DETAILED DESCRIPTION

[0030] In the description of the present application, it should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0031] In addition, the terms "first", "second", etc. are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or an indicated number of technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0032] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0033] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application.

[0034] In order to more clearly explain the embodiments of the present application, the following terms are explained:

[0035] CMOS: Complementary Metal Oxide Semiconductor, Chinese full name is complementary metal oxide semiconductor, a technology for manufacturing large-scale integrated circuit chips or a chip manufactured by this technology, which is a RAM chip on the computer motherboard that can be read and written. This chip is only used to store data.

[0036] FOV: Field of View, Chinese full name is field of view, in different application fields, the meaning of FOV may be different, but generally refers to the horizontal and vertical range that can be seen from a certain point or the viewing angle of a device. In photography, virtual reality and other fields, FOV is used to describe the size of the field of view of the camera or screen.

[0037] Distortion: In optical systems, when shooting a square object, the phenomenon of making the surrounding shoot into a roll or bulging. According to the shape, it is divided into pillow-shaped distortion (also known as positive distortion) and barrel-shaped distortion (also known as negative distortion).

[0038] MTF curve: Modulation transfer function, in the concept of contrast to test the sharpness of the lens, MTF curve is divided into different spatial frequency (such as 10 lp / mm, 30 lp / mm, etc.), the closer to 1, the better the actual resolution of the image.

[0039] First, the related principles of the embodiments of the application are described as follows:

[0040] Referring to Figure 1A In the field of virtual reality, since the perspective optical system can only be a convex lens scheme, and the number of lenses is limited, the perspective optical system produces a large negative distortion in the imaging process while maintaining a large field of view.

[0041] The display optical system is designed reversely, the actual light emitting display surface is the near-eye display screen in the display optical system, and the image received by the human eye is actually a positive distortion image. Therefore, the video or picture source actually received by the display optical system should be in the form of negative distortion to be seen by the human eye as a normal picture or image.

[0042] Therefore, referring to Figure 1B The embodiments of the application provide a virtual reality device, which comprises a perspective optical system 101 and a display optical system 102; the perspective optical system 101 produces a negative distortion in the imaging process, the display optical system 102 produces a positive distortion in the imaging process, and the difference between the negative distortion and the positive distortion is within a preset threshold; the perspective optical system 101 is used for collecting an external environment image and transmitting the external environment image to the display optical system 102; and the display optical system 102 is used for displaying the external environment image.

[0043] In the embodiments of the application, the perspective optical system 101 produces a negative distortion in the imaging process, the display optical system 102 produces a positive distortion in the imaging process, and the difference between the negative distortion and the positive distortion is within a preset threshold, thereby solving the problems of serious image distortion and color distortion and effectively improving the user experience.

[0044] In an optional embodiment, the field of view of the perspective optical system 101 is greater than the field of view of the display optical system 102.

[0045] Specifically, in the imaging process of the see-through optical system and the display optical system, when the object passes through the lens system, an aberration with different magnifications for different parts of the object is generated. According to the difference in magnification for the periphery and the center of the object, the aberration is divided into two categories: positive distortion: the magnification of the periphery of the object is greater than the magnification of the center; and negative distortion: the magnification of the periphery of the object is less than the magnification of the center. The "negative" and "positive" referred to by the negative distortion and the positive distortion do not represent the numerical size, that is, the absolute value of the negative distortion and the absolute value of the positive distortion differ by within ±2%, so that the virtual reality device has no image distortion problem, and the user using the virtual reality device provided by the embodiment of the application will not feel dizzy due to the position inaccuracy caused by the display image distortion, and the field of view angle of the see-through optical system 101 is greater than the field of view angle of the display optical system 102, which ensures that the user has a bright and clear field of view when using the device.

[0046] In an optional embodiment, referring to Figure 2 The display optical system 102 includes, in sequence, a diaphragm 201, a first lens 202, a polarization assembly 203, a second lens 204, and a display assembly 205. The material of the first lens 202 and the material of the second lens 204 are both resin materials, and the film material of the first lens 202 and the second lens 204 is internally attached.

[0047] Specifically, the display optical system 102 can adopt a design scheme of 2P for 2.56inh Display FOV 110deg, and the design indicators and design values are shown in Table 1:

[0048] Table 1

[0049] Design Index Item Design Value Screen Size (inch) 2.56 System Focal Length (mm) 26.17 Field of View (degree) 110 Eye Motion Range (mm) 12 Eye Relief (mm) 13 Max Optical Distortion (percent) 40％ First Lens Focal Length (mm) 349.48 Second Lens Focal Length (mm) 142.35 System Total Length (mm) 22.5

[0050] The material of the first lens 202 and the material of the second lens 204 are both plastic resin, which greatly reduces the process cost. The film material of the first lens 202 and the second lens 204 is internally attached, which effectively protects the film material and prevents the lens from being unclear due to scratches. The surface of the first lens 202 is coated with a hardening oil stain-resistant film, and the film material is attached to the first lens 202 in a flat manner, which greatly reduces the process difficulty. The specific parameters of each surface of the display optical system 102 are shown in Table 2:

[0051] Table 2

[0052]

[0053]

[0054] In Table 2, the virtual image distance is 2m, surface 1 is the stop 201, the aperture size is 12mm, that is, the entrance pupil size, the thickness is set to 13mm, that is, the eye relief is 13mm, and surfaces 3 to 6 are polarized film materials. Surfaces 2, 7 and 8 in the system are aspherical surfaces, and the aspherical surface data is shown in Table 3:

[0055] Table 3

[0056] Face Order Number Conic Constant (K) A4 A6 A8 A10 2 3.033 1.31E-06 1.86E-10 7 1 84.6372 -3.63E-07 7.74E-11 8 4.274335 6.58E-07 6.75E-10 -4.39E-13 3.97E-16 9 -94.6372 -3.63E-07 -7.74E-11 15 -94.6372 -3.63E-07 -7.74E-11 16 4.274335 6.58E-07 6.75E-10 -4.39E-13 3.97E-16

[0057] The aspherical depth is calculated by the following formula (1):

[0058] z = (cr2) / {1 + [1-(k+1)(c2r 3 ] 1 / 2}+A4r 4 +A6r 6 +A8r 8 +A10r 10 +A12r 12 +A14r 14 +A16r 16

[0059] +A18r 18 +A20r 20 …………………(1)

[0060] wherein k is the conic coefficient, A4, A6, A8 and A10 are aspherical coefficients, c is the curvature at the center of the optical surface, r is the vertical distance of a point on the aspherical curve from the optical axis, and z is the aspherical depth (the vertical distance between the point on the aspherical curve with a distance of r from the optical axis and the tangent plane tangent to the vertex of the aspherical surface on the optical axis).

[0061] Referring to Figure 3 , the display optical system 102 in the embodiment has excellent MTF performance, and has a larger field of view to ensure a stronger immersive experience for the user, and has high image clarity to restore the actual clarity of the image to a greater extent.

[0062] Referring to Figure 4 , the abscissa is the distortion, and the ordinate is the half field of view. As the field of view increases, the image distortion increases, and the display optical system 102 generates a positive distortion in the range of [30%, 40%] during imaging.

[0063] In an optional embodiment, referring to Figure 5The perspective optical system 101 comprises six lenses (labeled 501, 502, 503, 504, 505, and 506, respectively) and a diaphragm 507 arranged in sequence, the lenses are made of resin material, the half field angle of the perspective optical system 101 is defined as θ, the system focal length is defined as f, the focal lengths of the six lenses are defined as f1, f2, f3, f4, f5, and f6, respectively, the system half image size is defined as IH, and the system length is defined as L, and the perspective optical system 101 satisfies the following conditions: 110°≤θ≤150°; 0.014≤IH / (f*θ)≤0.015; 3.7≤L / f≤4.1; 3.9≤L / IH≤4.3; 1.38≤f3 / f≤1.52; -1.82≤f4 / f≤-1.64; 1.17≤f5 / f≤1.29; and -2.2≤f6 / f≤-1.99.

[0064] Specifically, the design indexes and design values of the perspective optical system 101 are shown in Table 4.

[0065] Table 4

[0066] Design Index Item Design Value CMOS 16M EFL (mm) 3.19 FOV (degree) 138 F# 2.2 Equivalent Focal Length (mm) 23

[0067] In the embodiment, the perspective optical system 101 adopts a 16-megapixel CMOS chip, which has high pixels and the picture taken by the equivalent focal length of 23 mm is closer to the picture actually seen by the human eye; the specific surface parameters of the perspective optical system 101 are shown in Table 5.

[0068] Table 5

[0069]

[0070] The aspheric surface data in the system are shown in Table 6.

[0071] Table 6

[0072]

[0073] The aspheric surface depth is calculated by the following formula (2):

[0074] z=(cr2) / {1+[1-(k+1)(c2r 3 ] 1 / 2}+A4r 4 +A6r 6 +A8r 8 +A10r 10 +A12r 12 +A14r 14 +A16r 16

[0075] +A18r 18 +A20r20 …………………(2)

[0076] wherein k is a conic coefficient, A4, A6, A8, A10 are aspherical coefficients, c is the curvature at the center of the optical surface, r is the perpendicular distance of a point on the aspherical curve from the optical axis, and z is the aspherical depth (the perpendicular distance between a point on the aspherical curve at a distance r from the optical axis and a tangent plane at the vertex of the aspherical surface).

[0077] Referring to Figure 6 The display optical system 102 in the embodiments of the present application has excellent MTF performance, and has a large field of view, which ensures a stronger immersive experience for the user, and has high image clarity, which restores the actual clarity of the image to a large extent.

[0078] In an optional embodiment, the perspective optical system 101 generates a range of negative distortion of [-40%, -30%] in the imaging process.

[0079] Specifically, referring to Figure 7 The perspective optical system 101 is optimized according to the distortion (VR F-tanDistortion) range of each field of view of the display optical system 102, so that the distortion (VST lens F-tan distortion) of each field of view of the perspective optical system 101 satisfies: |VR F-tan Distortion-VST lens F-tan distortion|≤2%, for example, if the VR F-tan Distortion is 35%, the range of VST lens F-tan distortion is [-37%, -32%]; if the VR F-tan Distortion is 37%, the range of VST lens F-tan distortion is [-39%, -35%]. It should be noted that when the difference between the negative distortion and the positive distortion is not more than a predetermined threshold, the absolute value of the negative distortion and the absolute value of the positive distortion are actually constrained to be not more than the predetermined threshold, that is, the absolute value of the difference between the absolute value of the VR F-tan Distortion and the absolute value of the VST lens F-tan distortion is not more than 2%.

[0080] Finally, referring to Figure 8 The embodiments of the present application show a specific process of internal system operation of a virtual reality device, including the following steps:

[0081] Step 801, the perspective optical system 101 collects an external environment information image.

[0082] Step 802, the see-through optical system 101 transmits the image to the chip and then to the display optical system 102.

[0083] Step 803, the display optical system 102 displays the image.

[0084] Although preferred embodiments of the application have been described herein, additional changes and modifications to these embodiments can occur to those skilled in the art. Therefore, it is intended that the appended claims cover all such changes and modifications as fall within the scope of the application.

[0085] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described herein.

Claims

1. A virtual reality device, characterized in that, include: Perspective optical systems and display optical systems; The perspective optical system generates negative distortion during the imaging process, and the display optical system generates positive distortion during the imaging process. Furthermore, the difference between the negative distortion and the positive distortion is within a preset threshold. The perspective optical system is used to acquire images of the external environment and transmit the images of the external environment to the display optical system; The display optical system is used to display the image of the external environment; The display optical system includes an aperture stop, a first lens, a polarizing component, a second lens, and a display component arranged in sequence; the perspective optical system includes an aperture stop and six lenses arranged in sequence. The half-field angle of the perspective optical system is defined as θ, the system focal length is defined as f, the focal lengths of the six lenses are defined as f1, f2, f3, f4, f5, and f6, the half-image plane size of the system is defined as IH, and the system length is defined as L. Then, the perspective optical system satisfies the following conditions: 110°≤θ≤150°; 0.014≤IH / (f*θ)≤0.015; 3.7≤L / f≤4.1; 3.9≤L / IH≤4.3; 1.38≤f3 / f≤1.52; -1.82≤f4 / f≤-1.64; 1.17≤f5 / f≤1.29; -2.2≤f6 / f≤-1.

99.

2. The device as described in claim 1, characterized in that, The field of view of the perspective optical system is greater than that of the display optical system.

3. The device as described in claim 1, characterized in that, Both the first lens and the second lens are made of resin.

4. The device as described in claim 1, characterized in that, The first and second lenses are coated with films internally.

5. The device as described in claim 1, characterized in that, The range of positive distortion generated by the display optical system during the imaging process is [30%, 40%].

6. The device as described in any one of claims 1 to 5, characterized in that, The lens is made of resin.

7. The device as described in claim 1, characterized in that, The negative distortion generated by the perspective optical system during the imaging process is in the range of [-40%, -30%].

8. The device as described in claim 1, characterized in that, The perspective optical system includes a 16-megapixel complementary metal-oxide-semiconductor CMOS chip.

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