Augmented reality display component and augmented reality display device having the same

Abstract

The present invention provides an augmented reality display component, including an image unit, an eyepiece unit and a refraction unit, the refraction unit including a first optical switch and a first birefringent crystal, the first optical switch being located between the image unit and the first birefringent crystal, the refraction unit also including a second birefringent crystal and a first phase retarder, the first phase retarder having a phase delay of π / 2 and being arranged between the first birefringent crystal and the second birefringent crystal. The present invention also provides a display device using the augmented reality display component. The present invention utilizes the first birefringent crystal, the second birefringent crystal and the first phase retarder arranged between the first birefringent crystal and the second birefringent crystal to realize a spherical imaging image output mode with multiple depths of field, which can ensure that the quality of the image output is maintained in the spherical high-quality output mode, with less image distortion and improved imaging clarity, and has broad application prospects and extremely high economic value.

Description

Technical Field

[0001] The present invention relates to the field of augmented reality technology, and in particular to an augmented reality display component and an augmented reality display device having the component. Background Art

[0002] Augmented reality (AR) technology can integrate the virtual world and the real world on the screen. It achieves a sensory experience that transcends and increases reality through the real-time superposition of multi-sensory simulated information such as vision and hearing with real environmental information. It has extremely broad application prospects in many fields such as entertainment, medical care, and military. The augmented reality display component is the core component of the entire system, which directly displays the superimposed image of simulated information and environmental information to the user. The existing augmented reality display component uses two birefringent crystals to achieve high-quality spherical display of the image on the basis of multi-depth image display, but the existing augmented reality display component is prone to image misalignment when realizing multi-depth display, which easily reduces the clarity of the image display and affects the user experience. Summary of the invention

[0003] In view of this, it is necessary to provide an improved augmented reality display component and an augmented reality display device having the component, which can overcome the image misalignment problem occurring during multi-depth display and has broad application prospects and excellent economic effects.

[0004] The present invention provides an augmented reality display component, comprising an image unit, an eyepiece unit, and a refraction unit disposed between the image unit and the eyepiece unit, wherein the refraction unit comprises a first optical switch, a first birefringent crystal, a first phase retarder, and a second birefringent crystal, wherein the first optical switch is disposed between the image unit and the first birefringent crystal, and the first phase retarder has a phase delay of π / 2 and is disposed between the first birefringent crystal and the second birefringent crystal;

[0005] The refraction unit further comprises a first polarizer, a third birefringent crystal and a fourth birefringent crystal, wherein the first polarizer is arranged between the image unit and the first optical switch, the third birefringent crystal is arranged between the first birefringent crystal and the first phase retarder, and the fourth birefringent crystal is arranged between the second birefringent crystal and the eyepiece unit;

[0006] The polarization direction of the linear polarized light output by the first polarizer is named as a first direction, and the direction perpendicular to the first direction is named as a second direction, the crystal optical axis of the first birefringent crystal and the crystal optical axis of the third birefringent crystal are both perpendicular to the second direction, and the crystal optical axis of the first birefringent crystal forms an angle of θ1 with respect to the first direction, and the crystal optical axis of the third birefringent crystal forms an angle of -θ1 with respect to the first direction;

[0007] The crystal optical axis of the second birefringent crystal and the crystal optical axis of the fourth birefringent crystal are both perpendicular to the first direction, the crystal optical axis of the second birefringent crystal forms an angle θ2 relative to the second direction, and the crystal optical axis of the fourth birefringent crystal forms an angle -θ2 relative to the second direction.

[0008] Further, the θ1 is 45°; and / or,

[0009] The θ2 is 45°.

[0010] Furthermore, the refraction unit also includes a second optical switch, the eyepiece unit includes a polarized reflector, a second phase delay and an optical coupler, the second optical switch is arranged between the fourth birefringent crystal and the polarized reflector, the second phase delay is arranged between the polarized reflector and the optical coupler and delays the phase of the polarized light transmitted between the polarized reflector and the optical coupler.

[0011] Furthermore, the phase delay of the phase delay device is π / 4.

[0012] Furthermore, the refraction unit further includes a second polarizer, and the second polarizer is arranged between the second optical switch and the polarization reflector.

[0013] Furthermore, the first polarizer is a polarizing plate; and / or,

[0014] The second polarizer is a polarizing plate.

[0015] Furthermore, the brightness of the image unit is greater than 5000 nits; and / or,

[0016] The refresh rate of the image unit is above 120 Hz.

[0017] Furthermore, the response time of the optical switch is less than 10 milliseconds; and / or,

[0018] The light transmittance of the optical switch is greater than 90%.

[0019] Furthermore, the resolution of the image unit is above 1080P.

[0020] The present invention also provides an augmented reality display device, comprising an augmented reality display component, wherein the augmented reality display component is any one of the augmented reality display components described above.

[0021] The present invention adjusts the optical axis positions of the first birefringent crystal, the second birefringent crystal, the third birefringent crystal and the fourth birefringent crystal so that the images on different birefringent crystal units are symmetrically distributed, so that the superimposed images can remain consistent, thereby eliminating image misalignment and improving image clarity. The present invention has broad application prospects and extremely high economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of an augmented reality display component in one embodiment of the present invention;

[0023] Figure 2 Schematic diagram of the optical path after adding a compensation surface to the eyepiece unit;

[0024] Figure 3 To show the MTF curve of the image at the first depth of field,

[0025] Figure 4 To display the distortion grid of the image at the first depth of field,

[0026] Figure 5 To show the MTF curve of the image at the second depth of field,

[0027] Figure 6 A distortion grid to show the image at the second depth of field;

[0028] Figure 7 for Figure 1 A schematic diagram of the optical path of the first birefringent crystal is shown;

[0029] Figure 8 for Figure 1 A schematic diagram of the optical path of the second birefringent crystal is shown;

[0030] Fig. 9 for Figure 1 A schematic diagram of the optical path of the first phase retarder shown;

[0031] Fig.10 for Figure 1 A schematic diagram of the optical paths of the first birefringent crystal and the third birefringent crystal is shown;

[0032] Fig.11 for Figure 1 A schematic diagram of the optical paths of the second birefringent crystal and the fourth birefringent crystal is shown;

[0033] Fig.12 FIG. 4 is a schematic diagram of the structure of an augmented reality display component in another embodiment of the present invention.

[0034] Main component symbols

[0035]

[0036]

[0037] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that when a component is referred to as being "mounted on" another component, it may be directly mounted on the other component or there may be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component at the same time. When a component is considered to be "fixed to" another component, it may be directly fixed on the other component or there may be a central component at the same time.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" used herein includes any and all combinations of one or more of the related listed items.

[0041] See also Figure 1 , Figure 1 FIG. 1 is a schematic diagram of the structure of an augmented reality display component 100 in one embodiment of the present invention. The augmented reality display component 100 is provided for observation by a user and is used to display image information projected into the user's eyes.

[0042] In this embodiment, the augmented reality display component 100 is applied to wearable augmented reality glasses (not shown), and the augmented reality display component 100 serves as the lens of the augmented reality glasses. The user observes the virtual environment information and the real environment information by wearing the augmented reality glasses and observing the augmented reality display component 100.

[0043] It can be understood that in other embodiments, the augmented reality display component 100 is also applied to other devices such as wearable helmets, as long as the augmented reality display component 100 can be perceived and observed by the user.

[0044] The augmented reality display component 100 includes an image unit 10, an eyepiece unit 20 and a refraction unit 30, wherein the refraction unit 30 is located between the image unit 10 and the eyepiece unit 20; the image unit 10 is used to display image information for observation by a user, the eyepiece unit 20 is used to converge the image light refracted by the refraction unit 30 and transmit it to the human eye for imaging, and the refraction unit 30 is used to selectively refract the image light provided by the image unit 10.

[0045] The image light provided by the image unit 10 changes its polarization direction after the selective refraction of the refraction unit 30, and then converges at different positions after being converged by the eyepiece unit 20, thereby forming different depths of field.

[0046] Specifically, the image unit 10 is a display, which may be a CRT display, an LCD display, a PDP display or an OLED display.

[0047] In this embodiment, considering the comprehensive performance and cost advantages, the image unit 10 in this embodiment uses Sony OLED screen ECX337A display, which is a micro display with a diagonal length of only 0.5 inches and a resolution of 1280×960. It has better product competitiveness and relatively better user experience.

[0048] It can be understood that in other embodiments, the image unit 10 can also use other displays besides the Sony OLED screen ECX337A display. The present invention does not limit the specific type of display used by the image unit 10, nor does it limit the specific model of the display selected by the image unit 10, as long as the display used by the image unit 10 can normally output environmental image information and virtual image information.

[0049] The eyepiece unit 20 is located between the user's eyes and the image unit 10. The eyepiece unit 20 can be tilted relative to the image unit 10 as needed, so as to smoothly guide the image information to the user's eyes.

[0050] It can be understood that the eyepiece unit 20 can use either a positive eyepiece or other types of eyepieces other than the positive eyepiece, such as a negative eyepiece; the number of eyepieces included in the eyepiece unit 20 can be one or more.

[0051] The refraction unit 30 includes a first polarizer 31 , a first optical switch 32 and a first birefringent crystal 33 . The first polarizer 31 is disposed between the image unit 10 and the first optical switch 32 , and the first birefringent crystal 33 is located between the first optical switch 32 and the eyepiece unit 20 .

[0052] The first polarizer 31 is used to convert the image light displayed by the image unit 10 from natural light into linearly polarized light. The first optical switch 32 is used to adjust the polarization direction of the linearly polarized light, so that the natural light emitted by the image unit 10 has different polarization directions. The first birefringent crystal 33 is used to refract the linearly polarized light transmitted through the first optical switch 32, so that the linearly polarized light with different polarization directions has different refraction directions.

[0053] The natural light containing image information emitted from the image unit 10 is converted into linearly polarized light under the polarization effect of the first polarizer 31, and then forms different polarization directions under the adjustment effect of the first optical switch 32, and finally forms an image display with dual depth of field under the different refraction effects of the first birefringent crystal 33 on polarized light with different polarization directions.

[0054] Specifically, the first polarizer 31 can convert light into polarized light under natural light conditions, and it uses the anisotropy of optical properties of specific materials to polarize natural light.

[0055] In this embodiment, the first polarizer 31 uses a polarizer to polarize the natural light containing image information emitted by the image unit 10. The first polarizer 31 can be a microcrystalline polarizer such as a tourmaline wafer or a molecular polarizer such as a wire grid polarizer.

[0056] It can be understood that in other embodiments, the first polarizer 31 can also be a polarizing beam splitter prism or other types of polarizers other than a polarizing plate, as long as the polarizer of this type can realize polarization of image information.

[0057] The first optical switch 32 is connected to the first polarizer 31, and is used to adjust the polarization direction of the optical signal output by the first polarizer 31. When the first optical switch 32 is turned on, the first optical switch 32 acts on the first polarizer 31; when the first optical switch 32 is turned off, the first optical switch 32 has no regulating effect on the optical signal output by the first polarizer 31.

[0058] As for the structure of the first optical switch 32 itself, it can adopt a conventional structure. In this embodiment, the first optical switch 32 adopts a liquid crystal light valve; preferably, the response time of the first optical switch 32 is set to be less than 10 milliseconds, and the transmittance of the first optical switch 32 is set to be greater than 90%.

[0059] It can be understood that in other embodiments, the first optical switch 32 can also adopt other types of optical switch elements such as electro-optical switches, thermo-optical switches, acousto-optic switches, micromechanical optical switches and traditional mechanical optical switches, as long as the first optical switch 32 of this type can achieve the direction adjustment of the first polarizer 31; the response time and transmittance of the first optical switch 32 can be selected according to the actual working conditions, for example, the response time of the first optical switch 32 is set to more than 10 milliseconds, and the transmittance of the first optical switch 32 is set to a range of less than 90%.

[0060] The first birefringent crystal 33 is located on the optical path between the first optical switch 32 and the eyepiece unit 20, and is used to refract polarized light; the first birefringent crystal 33 has different refractive indices for linear polarized light with different polarization directions, and the first birefringent crystal 33 cooperates with the first optical switch 32 so that the image light after the action has different transmission directions.

[0061] In this embodiment, the first birefringent crystal 33 is a birefringent crystal prism; the first birefringent crystal 33 uses a birefringent crystal prism, which can make the light incident on the birefringent crystal prism The surface and the optical axis and the exit surface of the birefringent crystal prism are parallel to each other, and linear polarized light with different polarization directions only has different refractive indices when passing through the first birefringent crystal 33, and the main light is still in a state of overlap and misalignment, and no additional aberrations will be generated.

[0062] Furthermore, the refractive index of the first birefringent crystal 33 for O light is 1.6585, and the refractive index for E light is 1.4865.

[0063] It can be understood that in other embodiments, the first birefringent crystal 33 can also have other shapes besides the birefringent crystal prism, as long as the first birefringent crystal 33 of this shape and type can refract the linear polarized light adjusted by the first optical switch 32; the first birefringent crystal 33 can also use other refractive indices besides the above-mentioned refractive indices for different polarized light (such as O light or E light), as long as the first birefringent crystal 33 has different refractive indices for polarized light in different polarization directions.

[0064] In actual use, considering that the first optical switch 32 needs to continuously switch its on / off state, the first optical switch 32 preferably has a higher response frequency, so that the first optical switch 32 has a sufficient response speed to switch its on / off state and adapt to different display requirements of the image unit 10.

[0065] The following briefly explains the display principle of the augmented reality display component 100 with multiple depths of field:

[0066] After the image light generated by the image unit 10 passes through the first polarizer 31 in the refraction unit 30, only linear polarized light of a certain characteristic direction (such as ordinary light, referred to as O light) will remain; when the first optical switch 32 is turned on, the linear polarized light (O light) will be converted into linear polarized light of another polarization direction (such as extraordinary light, referred to as E light) after the adjustment of the first optical switch 32. When the first optical switch 32 is turned off, the first optical switch 32 does not change the polarization direction of the linear polarized light, and the linear polarized light (O light) is directly incident on the first birefringent crystal 33;

[0067] The first birefringent crystal 33 has different refractive indices for linear polarized light in different directions; when the first optical switch 32 is turned on, the first birefringent crystal 33 refracts the O light at a first refraction angle, and the image light in the form of O light is converged to the human eye after passing through the converging effect of the eyepiece unit 20, thereby obtaining an image that can be observed by the user and has a first depth of field; when the first optical switch 32 is turned off, the first birefringent crystal 33 refracts the E light at a second refraction angle, and the image light in the form of E light is converged to the human eye after passing through the converging effect of the eyepiece unit 20, thereby obtaining an image that can be observed by the user and has a second depth of field, thereby completing the display process of the dual depth of field of the augmented reality display component 100.

[0068] Furthermore, when the first optical switch 32 is continuously refreshed at an appropriate frequency, the depth of field perceived by human eyes may be between the first depth of field and the second depth of field, thereby forming a controllable adjustment of the optical parameter of the depth of field between the first depth of field and the second depth of field.

[0069] It should be noted that the present invention does not limit the first optical switch 32 to only be able to adjust the direction of the O light to the E light. It is understandable that in other embodiments, the first optical switch 32 can also adjust the direction of the E light to the O light.

[0070] The augmented reality display component 100 provided by the present invention is provided with a first polarizer 31, a first optical switch 32 and a first birefringent crystal 33 between the image unit 10 and the eyepiece unit 20, and uses the different refraction effects of the first birefringent crystal 33 on polarized light in different polarization directions to form images with different depths of field, so that virtual information of any depth can be presented, and the adjustment convergence conflict is solved, which not only improves the user experience, but also can be more in line with the observation habits of the human eye, and can avoid the user from experiencing adverse reactions such as fatigue, nausea, vomiting, etc. after long-term observation, and has broad application prospects.

[0071] In one embodiment of the present invention, the refraction unit 30 also includes a projection unit 34, which is located between the first birefringent crystal 33 and the eyepiece unit 20. The projection unit 34 is used to transmit the linearly polarized light transmitted by the first birefringent crystal 33 into an enlarged relay real image. The projection unit 34 uses its own relay amplification effect to make the image signal output by the refraction unit 30 be transmitted to the eyepiece unit 20 more clearly, thereby reducing the transmission loss between the refraction unit 30 and the eyepiece unit 20, and realizing image transmission over a longer distance.

[0072] Furthermore, the projection ratio of the projection unit 34 is preferably less than 1.6 to reduce the structural compactness of the projection unit, effectively reduce the spatial scale of the entire assembly and reduce the optical path space, leaving more room for industrial design and making it more ergonomic.

[0073] In this embodiment, the projection unit 34 includes four lenses, and the eyepiece unit 20 includes two semi-transparent and semi-reflective lenses. The data of the equivalent optical path is shown in Table 1:

[0074] Table 1 Equivalent optical path data table

[0075]

[0076]

[0077] Please also read Figure 2 , Figure 2 The diagram is a light path diagram after a compensation surface is added to the eyepiece unit 20. The function of adding the compensation surface to the eyepiece unit 20 is to ensure that when the human eye views the real world through the eyepiece unit, the image of the real world is not distorted.

[0078] Please also read Figures 3 to 6 , Figure 3 To show the MTF curve of the image at the first depth of field, Figure 4 To display the distortion grid of the image at the first depth of field, Figure 5 To show the MTF curve of the image at the second depth of field, Figure 6 A distortion grid showing the image at the second depth of field.

[0079] In this embodiment, the pupil diameter is 10 mm, the pupil distance is 18 mm, and the full field angle is 50 degrees. Excellent imaging quality is obtained at the first depth and the second depth, the maximum field distortion is less than 0.2%, and the maximum field of view has an MTF (Modulation Transfer Function) greater than 0.4 at a cutoff frequency of 30 lp / mm. The MTF value of the maximum field of view at the second depth at a cutoff frequency of 30 lp / mm reaches more than 0.6, and an excellent light field display effect can be obtained.

[0080] In one embodiment of the present invention, the augmented reality display component 100 is further provided with a control unit (not shown), which is connected to the first optical switch 32 and the image unit 10 through a medium such as a wire, and is used to synchronously control the operating states of the first optical switch 32 and the image unit 10, and control the opening and closing of the first optical switch 32 according to the depth of field required to be displayed by the image unit 10. Integrating the control unit inside the augmented reality display component 100 can improve the integration of the entire system and help realize the control function of the entire system.

[0081] It can be understood that in other embodiments, the control unit can also be arranged outside the augmented reality display component 100, that is, the control unit is arranged outside the augmented reality display component 100 as an environmental element, as long as the control unit can communicate with the first light switch 32 and the image unit 10 and coordinate and control the operating status of the first light switch 32 and the image unit 10.

[0082] In one embodiment of the present invention, in order to improve the quality of image display, the resolution of the image unit 10 is preferably 1080P or above, and the brightness of the image unit 10 is preferably above 5000 nits. Setting the resolution and brightness of the image unit 10 to be higher helps to improve the realism of the image information display and the user experience, so that the virtual image information superimposed on the real image information is more realistic.

[0083] In one embodiment of the present invention, in order to ensure the user experience and take into account the dual-depth image display, the refresh rate of the image unit 10 is 120 Hz or more (twice or more than the single-depth 60 Hz), so that the user does not feel flickering when observing; and / or,

[0084] The extinction ratio of the first polarizer 31 is above 10000:1, so that the polarized light after polarization by the first polarizer 31 will not contain o-light and e-light at the same time, thereby ensuring that the image observed by the user through the eyepiece unit 20 will not exist at two depths at the same time, avoiding image crosstalk and improving the quality of imaging.

[0085] In one embodiment of the present invention, in order to reduce the thickness of the first birefringent crystal 33, the refractive index difference of the first birefringent crystal 33 for o-light or e-light is preferably greater than 0.2, thereby reducing the requirement for the thickness of the first birefringent crystal 33 during refraction and further reducing the system load.

[0086] In one embodiment of the present invention, in order to improve the user's field of view, the eyepiece unit 30 of the present invention includes an optical coupler 23, and the optical coupler 23 is an aspherical mirror, and its surface equation is:

[0087]

[0088] Where c is the curvature at the vertex of the surface; k is the quadratic constant of the surface, A i is the i-th order aspheric coefficient of the surface.

[0089] The optical coupler 23 used in the present invention has the advantages of a large exit pupil diameter, a long exit pupil distance, and a wide field of view. The large exit pupil diameter can meet the needs of users who squint when wearing the device, and the long exit pupil distance can meet the needs of users who wear myopia glasses and hyperopia glasses. The wide field of view can present virtual information more realistically, allowing virtual information to be better integrated with the real world. According to experimental measurements, the field of view of the optical coupler 23 used in the present invention can reach 50°, which has a wider field of view and a better user experience.

[0090] Of course, the augmented reality display component 100 may also be equipped with a variety of functional elements to improve the user experience. For example, an inertial measurement unit (IMU) may be integrated on the augmented reality display component 100. The control unit controls the inertial measurement unit to detect the posture of the entire device, thereby further improving the user experience.

[0091] When a conventional augmented reality display component uses the first birefringent crystal 33 to realize multi-depth image display, it is difficult to simultaneously guarantee the imaging quality of the image when displaying the image because the birefringent crystal itself has different regulation rules for different linear polarized lights.

[0092] For example, the refractive index of a birefringent crystal for O light does not change with the incident angle of O light. The refractive index of a birefringent crystal for O light is constant, and a "spherical mirror" imaging effect is presented when displaying images; while the refractive index of a birefringent crystal for E light changes with the incident angle of E light, and its refractive index at its own sagittal and meridian planes is different, and a "cylindrical mirror" imaging effect is presented when displaying images. This results in different imaging effects at different depths of field, and users will switch back and forth between different images with different imaging effects when observing, affecting normal observation of the image.

[0093] The augmented reality display component 100 provided by the present invention maintains consistent imaging effects at different depths of field by disposing two birefringent crystals and a phase retarder, thereby overcoming the problem of image quality degradation caused by using a single birefringent crystal.

[0094] Specifically, the refraction unit 30 further includes a second birefringent crystal 35 and a first phase retarder 36, wherein the first phase retarder 36 is located between the first birefringent crystal 33 and the second birefringent crystal 35, and the second birefringent crystal 35 is located between the first phase retarder 36 and the eyepiece unit 20. The first phase retarder 36 has a phase delay of π / 2, and is used to convert linearly polarized light into linearly polarized light perpendicular to the original vibration direction.

[0095] When the first optical switch 32 is turned off, the linear polarized light formed after the polarizer 31 is polarized is not converted by the first optical switch 32. At this time, the linear polarized light in the initial state is output in a "spherical imaging" mode through the first birefringent crystal 33; the polarization direction of the linear polarized light after passing through the first phase retarder 36 is perpendicular to the initial state, and at this time, the linear polarized light is still output in a "spherical imaging" mode through the second birefringent crystal 35; in general, the refraction unit 30 forms an output in a "spherical imaging" mode after the first optical switch 32 is turned off;

[0096] When the first optical switch 32 is turned on, the linearly polarized light formed after the polarization of the polarizer 31 is converted by the first optical switch 32, and the converted linearly polarized light is then subjected to the first birefringent crystal 33 to form an output mode of "cylindrical imaging". The linearly polarized light is converted into linearly polarized light with the same vibration direction as that in the initial state by the first phase retarder 36, and then is subjected to the second birefringent crystal 35 to still form an output mode of "cylindrical imaging", but the cylinders formed by the first birefringent crystal 33 and the second birefringent crystal 35 are perpendicular to each other. In general, the refraction unit 30 forms an output mode of "spherical imaging" after the first optical switch 32 is turned on.

[0097] Please also read Figures 7 to 9 , Figure 7 for Figure 1 The optical path schematic diagram of the first birefringent crystal 33 is shown in FIG. Figure 8 for Figure 1 The optical path schematic diagram of the second birefringent crystal 35 is shown in FIG. Fig. 9 for Figure 1 Schematic diagram of the optical path of the first phase retarder 36 is shown.

[0098] The light entering the first birefringent crystal 33 passes through the first birefringent crystal 33 along the propagation direction 301; wherein, the polarization direction of the linearly polarized light after polarization by the first polarizer 31 is named as the first direction 302, and the direction perpendicular to the first direction 302 is named as the second direction 303, and the crystal optical axis 331 of the first birefringent crystal 33 is set to be located in the plane formed by the propagation direction 301 and the first direction 302, that is, the crystal optical axis 333 of the first birefringent crystal 33 is preferably perpendicular to the second direction 303.

[0099] The light entering the second birefringent crystal 35 passes through the second birefringent crystal 35 along the propagation direction 301; wherein the polarization direction of the linearly polarized light after polarization by the first polarizer 31 is named as the first direction 302, and the direction perpendicular to the first direction 302 is named as the second direction 303, and the crystal optical axis 351 of the second birefringent crystal 35 is set to be located in the plane formed by the propagation direction 301 and the second direction 303, that is, the crystal optical axis 351 of the second birefringent crystal 35 is preferably perpendicular to the first direction 302. In this way, the image quality is better.

[0100] Furthermore, the crystal optical axis 331 of the first birefringent crystal 33 is perpendicular to the second direction 303 and forms an angle of 45° with the first direction 301, and the crystal optical axis 351 of the second birefringent crystal 35 is preferably perpendicular to the first direction 302 and forms an angle of 45° with the second direction 303. In this way, the best image quality is achieved.

[0101] Furthermore, the optical axis 361 of the first phase retarder 36 is perpendicular to the propagation direction 301 of the light, and is at an angle of 45 degrees to both the first direction 302 and the second direction 303, thereby completing the position-limiting delay function.

[0102] The present invention utilizes the first birefringent crystal 33, the second birefringent crystal 35 and the first phase retarder 36 disposed between the first birefringent crystal 33 and the second birefringent crystal 35 to realize a spherical imaging image output method with multiple depths of field, which can ensure that the quality of the image output is maintained in the spherical high-quality output mode, with less image distortion and improved imaging clarity.

[0103] Considering that the crystal optical axis 331 of the first birefringent crystal 33 can be perpendicular to the second direction 303, and the crystal optical axis 351 of the second birefringent crystal 35 can be perpendicular to the first direction, since the crystal optical axis 331 of the first birefringent crystal 33 is not parallel to the first direction 302, and the crystal optical axis 351 of the second birefringent crystal 35 is not parallel to the second direction 303, this results in that the image positions cannot be kept consistent when imaging using the first birefringent crystal 33 and the second birefringent crystal 35 and observing at a fixed point, and the images at the two depths of field are misaligned.

[0104] Please also read Figure 10 to Figure 11 , Fig.10 for Figure 1 The optical path diagram of the first birefringent crystal 33 and the third birefringent crystal 37 is shown in FIG. Fig.11 for Figure 1 Schematic diagram of the optical paths of the second birefringent crystal 35 and the fourth birefringent crystal 38 is shown.

[0105] In one embodiment of the present invention, in order to overcome the misalignment problem of the images at the two depths of field, the refraction unit 30 in one embodiment of the present invention is further provided with a third birefringent crystal 37 and a fourth birefringent crystal 38. The third birefringent crystal 37 is located between the first birefringent crystal 33 and the first phase retarder 36, and the fourth birefringent crystal 38 is disposed between the second birefringent crystal 35 and the projection unit 34.

[0106] In order to eliminate image misalignment, the crystal optical axis 331 of the first birefringent crystal 33 and the crystal optical axis 371 of the third birefringent crystal 37 are set to be perpendicular to the second direction 303, and the crystal optical axis 331 of the first birefringent crystal 33 forms an angle θ1 with the first direction 302, and the crystal optical axis 371 of the third birefringent crystal 37 forms an angle -θ1 with the first direction 302;

[0107] The crystal optical axis 351 of the second birefringent crystal 35 and the crystal optical axis 381 of the fourth birefringent crystal 38 are set to be perpendicular to the first direction 302, and the crystal optical axis 351 of the second birefringent crystal 35 forms an angle θ2 with the second direction 303, and the fourth birefringent crystal 38 forms an angle -θ2 with the second direction 303. At this time, the images at the two depths of field can be consistent after superposition due to the symmetrically distributed positional relationship, thereby eliminating image misalignment and improving image clarity.

[0108] Further, θ1 is set to 45°, at which time the image symmetry of the first birefringent crystal 33 and the third birefringent crystal 37 during refraction is optimal, and the image misalignment elimination effect is optimal; and / or,

[0109] When θ2 is set to 45°, the image symmetry between the second birefringent crystal 35 and the fourth birefringent crystal 38 during refraction is optimal, and the image misalignment elimination effect is in an optimal state.

[0110] The present invention adjusts the optical axis positions of the first birefringent crystal 33, the second birefringent crystal 35, the third birefringent crystal 37 and the fourth birefringent crystal 38 so that the images on different birefringent crystal units are symmetrically distributed, so that the superimposed images can remain consistent, thereby eliminating image misalignment and improving image clarity.

[0111] Please also read Fig.12 , Fig.12 FIG. 1 is a schematic structural diagram of an augmented reality display component 100 in another embodiment of the present invention.

[0112] In one embodiment of the present invention, taking into account the insufficient light intensity when linearly polarized light is used for imaging, in order to compensate for the loss of light intensity and display brightness, the augmented reality display component 100 in this embodiment is additionally provided with an optical switch on the basis of the first optical switch 32, and utilizes two optical switches with the same switching state and a polarization reflector to reduce the light intensity loss.

[0113] Specifically, the augmented reality display component 100 also includes a second optical switch 39, which is located between the projection unit 34 and the fourth birefringent crystal 38; the second optical switch 39 has the same working state as the first optical switch 32, that is, the second optical switch 39 and the first optical switch 32 are in an open or closed state at the same time, and the working states of the two are controlled by the control unit and are in the same coupled state.

[0114] As for the structure of the second optical switch 39 itself, it can adopt a conventional structure, and can use the same switch device as the first optical switch 32, or can use a different switch device from the first optical switch 32. In this embodiment, considering the interchangeability of the entire component, the second optical switch 39 and the first optical switch 32 both use liquid crystal light valves; preferably, the response time of the second optical switch 39 is set to be less than 10 milliseconds, and the transmittance of the second optical switch 39 is set to be greater than 90%.

[0115] It can be understood that in other embodiments, the second optical switch 39 can also adopt other types of optical switch elements such as electro-optical switches, thermo-optical switches, acousto-optic switches, micromechanical optical switches and traditional mechanical optical switches, as long as the optical switch elements of this type can achieve polarization direction adjustment; the response time and transmittance of the second optical switch 39 can be selected according to actual working conditions, for example, the response time of the second optical switch 39 is set to more than 10 milliseconds, and the transmittance of the second optical switch 39 is set to a range of less than 90%.

[0116] The eyepiece unit 20 in the augmented reality display component 100 further includes a second phase retarder 22 and a lens 21. The lens 21 in the eyepiece unit 20 is a polarized reflector, and the second phase retarder 22 is located between the polarized reflector and the optical coupler 23. The phase delay of the second phase retarder 22 is π / 4, and it is used to delay the phase of linearly polarized light; the optical coupler 23 is used to reflect linearly polarized light, and the polarized reflector is used to selectively reflect or transmit polarized light, which can allow polarized light perpendicular to the original polarization direction to pass through, and reflect polarized light in other polarization directions.

[0117] The display principle of the augmented reality display component 100 with high brightness is explained below:

[0118] The first optical switch 32 and the second optical switch 39 have the same working state. When the first optical switch 32 and the second optical switch 39 are both in the closed state, the linearly polarized light polarized by the first polarizer 31 will not have its polarization direction changed by the first optical switch 32 and the second optical switch 39, and will be reflected when projected onto the polarization reflector, thereby passing through the second phase retarder 22 and achieving a phase delay of π / 4; the linearly polarized light is reflected by the optical coupler 23 after achieving a phase delay of π / 4, passes through the second phase retarder 22 again and achieves a phase delay of π / 4 again; the linearly polarized light achieves a phase delay of π / 2 after two superpositions of phase delays of π / 4, and at this time the linearly polarized light is converted into linearly polarized light perpendicular to the original vibration direction, thereby passing through the polarization reflector and forming an image in the human eye;

[0119] When the first optical switch 32 and the second optical switch 39 are both in the on state, the linearly polarized light polarized by the first polarizer 31 will return to its own polarization direction after two polarization conversions by the first optical switch 32 and the second optical switch 39, and will be reflected when projected onto the polarization reflector, thereby passing through the second phase retarder 22 and achieving a phase delay of π / 4; the linearly polarized light will be reflected by the optical coupler 23 after achieving a phase delay of π / 4, pass through the second phase retarder 22 again and achieve a phase delay of π / 4 again; the linearly polarized light will achieve a total phase delay of π / 2 after two superpositions of π / 4 phase delays, and at this time the linearly polarized light will be converted into linearly polarized light perpendicular to the original vibration direction, thereby passing through the polarization reflector and forming an image in the human eye.

[0120] The augmented reality display assembly 100 provided by the present invention utilizes the first polarizer 31, the first optical switch 32 and

[0121] The second optical switch 39, the second phase retarder 22 and the optical coupler 23 transform the type of polarized light used for imaging, thereby improving the brightness of the image display, which can theoretically be increased to four times the brightness of the traditional display image, and has high application value and broad application prospects.

[0122] Furthermore, considering that the optical rotation capabilities of the first optical switch 32 and the second optical switch 39 are limited, the first optical switch 32 and the second optical switch 39 do not have sufficient capabilities to completely convert the linearly polarized light into the initial state after two transformations, resulting in the optical signal output by the second optical switch 39 having two linear polarized lights with different polarization directions at the same time, which will cause the contrast of the image display to decrease; for this reason, the augmented reality display component 100 in this embodiment is also provided with a second polarizer 391 in the refraction unit 30, and the second polarizer 391 is located between the second optical switch 39 and the projection unit 34.

[0123] The second polarizer 391 plays a role of re-polarization, thereby filtering out the linear polarized light with redundant polarization directions that can be completely converted by the second optical switch 39, leaving only the linear polarized light with the same polarization direction as the initial polarization direction, thereby ensuring the contrast of the image display.

[0124] Further, the first polarizer 31 is a polarizing plate; and / or,

[0125] The second polarizer 391 also uses a polarizing plate.

[0126] Since the polarization ability of the polarizer is stable, it is conducive to the realization of the polarization function of the entire component and also has a great advantage in cost performance.

[0127] It can be understood that in other embodiments, the phase delay of the second phase retarder 22 can also adopt other angles besides π / 4, as long as the total accumulated phase delay of the front and back sides of the second phase retarder 22 is π / 2.

[0128] The present invention also provides an augmented reality display device (not shown), which includes a wearable device body (not shown) and an augmented reality display component 100 disposed on the device body. The augmented reality display device provided by the present invention uses the augmented reality display component 100 to achieve a consistent imaging mode when displaying images in multiple depths of field, and can maintain a high-quality spherical mirror imaging mode.

[0129] The present invention adjusts the optical axis positions of the first birefringent crystal 33, the second birefringent crystal 35, the third birefringent crystal 37 and the fourth birefringent crystal 38 so that the images on different birefringent crystal units are symmetrically distributed, so that the superimposed images can remain consistent, thereby eliminating image misalignment and improving image clarity. The present invention has broad application prospects and extremely high economic value.

[0130] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0131] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, appropriate changes and modifications to the above embodiments are within the scope of protection claimed by the present invention.

Claims

1. An augmented reality display component, comprising an image unit, an eyepiece unit, and a refraction unit disposed between the image unit and the eyepiece unit, the refraction unit comprising a first optical switch, a first birefringent crystal, a first phase retarder, and a second birefringent crystal, the first optical switch being disposed between the image unit and the first birefringent crystal, the first phase retarder having a phase delay of π / 2 and being disposed between the first birefringent crystal and the second birefringent crystal; It is characterized in that The refraction unit further comprises a first polarizer, a third birefringent crystal and a fourth birefringent crystal, wherein the first polarizer is arranged between the image unit and the first optical switch, the third birefringent crystal is arranged between the first birefringent crystal and the first phase retarder, and the fourth birefringent crystal is arranged between the second birefringent crystal and the eyepiece unit; The polarization direction of the linear polarized light output by the first polarizer is named as a first direction, and the direction perpendicular to the first direction is named as a second direction, the crystal optical axis of the first birefringent crystal and the crystal optical axis of the third birefringent crystal are both perpendicular to the second direction, and the crystal optical axis of the first birefringent crystal forms an angle of θ1 with respect to the first direction, and the crystal optical axis of the third birefringent crystal forms an angle of -θ1 with respect to the first direction; The crystal optical axis of the second birefringent crystal and the crystal optical axis of the fourth birefringent crystal are both perpendicular to the first direction, the crystal optical axis of the second birefringent crystal forms an angle θ2 with respect to the second direction, and the crystal optical axis of the fourth birefringent crystal forms an angle -θ2 with respect to the second direction; The optical axis of the first phase retarder forms an angle of 45 degrees with both the first direction and the second direction.

2. The augmented reality display assembly according to claim 1, wherein: The θ1 is 45°; and / or, The θ2 is 45°.

3. The augmented reality display assembly according to claim 2, wherein: The refraction unit also includes a second optical switch, and the eyepiece unit includes a polarization reflector, a second phase delay and an optical coupler, the second optical switch is arranged between the fourth birefringent crystal and the polarization reflector, the second phase delay is arranged between the polarization reflector and the optical coupler and delays the phase of the polarized light transmitted between the polarization reflector and the optical coupler.

4. The augmented reality display assembly according to claim 3, wherein: The phase delay of the phase delay device is π / 4.

5. The augmented reality display assembly according to claim 4, wherein: The refraction unit further includes a second polarizer, and the second polarizer is arranged between the second optical switch and the polarization reflector.

6. The augmented reality display assembly according to claim 5, wherein: The first polarizer is a polarizing plate; and / or, The second polarizer is a polarizing plate.

7. The augmented reality display assembly according to claim 1, wherein: The brightness of the image unit is greater than 5000 nits; and / or, The refresh rate of the image unit is above 120 Hz.

8. The augmented reality display assembly according to claim 1, wherein: The response time of the first optical switch is less than 10 milliseconds; and / or, The light transmittance of the first optical switch is greater than 90%.

9. The augmented reality display assembly according to claim 1, wherein: The resolution of the image unit is above 1080P.

10. An augmented reality display device, comprising an augmented reality display component, characterized in that: The augmented reality display component is the augmented reality display component described in any one of claims 1 to 9.

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