Wearable display device and optical system

Abstract

A wearable display device and an optical system. The optical system comprises a first control assembly (101), a semi-transparent and semi-reflective layer (102), a first lens assembly (103) and a second control assembly (104) which are located on a display surface of a display panel (20) and are sequentially arranged in the direction away from the display panel (20). The refractive index of the first lens assembly (103) is greater than or equal to 1.6, and the light emitted by the display panel (20) enters the human eye after being converged for three times from the first lens assembly (103), so that the overall length of the optical system is shortened, and light thinning is facilitated.

Description

Wearable display devices and optical systems Technical Field

[0001] The present application relates to the field of display technology, and in particular to a wearable display device and an optical system. Background Art

[0002] Wearable display devices refer to devices that can create a virtual environment through displayed images and immerse users in the virtual environment.

[0003] Summary of the Invention

[0004] The present application provides a wearable display device and an optical system, and the technical solutions are as follows:

[0005] In one aspect, an optical system is provided, comprising:

[0006] a first control assembly, a transflective layer, a first lens assembly, and a second control assembly, wherein the first control assembly, the transflective layer, the first lens assembly, and the second control assembly are all located on a display surface of the display panel and are sequentially arranged in a direction away from the display panel;

[0007] The light emitted by the display panel is modulated into a first polarized light after passing through the first control component; the semi-transmissive and semi-reflective layer is used to transmit a first light in the first polarized light; the second control component is used to reflect the first light after passing through the first lens component, and the first light can be reflected to the semi-transmissive and semi-reflective layer after passing through the first lens component and can be changed into a second polarized light; the semi-transmissive and semi-reflective layer is used to reflect a second light in the second polarized light; and the second control component is used to transmit the second light after passing through the first lens component.

[0008] The refractive index of the first lens component is greater than or equal to 1.6, and the second phase of the second polarized light is different from the first phase of the first polarized light.

[0009] Optionally, the first lens assembly includes: a first lens and a second lens sequentially arranged in a direction away from the display panel;

[0010] The refractive index of the first lens is in a range of 1.6 to 1.9, and the refractive index of the second lens is in a range of 1.7 to 2.0.

[0011] Optionally, the first lens has a first surface close to the display panel and a second surface away from the display panel; the second lens has a third surface close to the display panel and a fourth surface away from the display panel;

[0012] Each of the first surface, the second surface, the third surface and the fourth surface can be one of a spherical surface, an aspherical surface, a Fresnel surface, a free-form surface, a refractive-diffractive hybrid surface, a diffractive surface and a micro-nanostructured surface.

[0013] Optionally, the curvature radius of the first surface and the second surface ranges from 45 mm to 100 mm, the ratio of the center thickness to the edge thickness of the first lens is less than 3:1, the ratio of the diameter of the first lens to the center thickness of the first lens is greater than 5:1, and the distance between the center position of the first surface of the first lens and the display panel is greater than or equal to 1 mm;

[0014] The radius of curvature of the third surface ranges from 100 mm to 200 mm, the fourth surface is a plane, or the radius of curvature of the fourth surface is greater than 300 mm, and the ratio of the center thickness to the edge thickness of the second lens is greater than 0.5:1 and less than 3:1.

[0015] Optionally, the second surface and the third surface are Fresnel surfaces;

[0016] The Fresnel surface includes a plurality of sawtooth structures, the sawtooth structure includes an effective surface and an ineffective surface, the effective surface and the ineffective surface are connected and both are side surfaces of the sawtooth structure;

[0017] The ineffective surface is blackened, or mirror-coated, or frosted.

[0018] Optionally, the second surface and the third surface are Fresnel surfaces;

[0019] The Fresnel surface includes a plurality of sawtooth structures, the sawtooth structure includes an effective surface and an ineffective surface, the effective surface and the ineffective surface are connected and both are side surfaces of the sawtooth structure;

[0020] The Fresnel surface further includes a plurality of tooth-like structures, and the tooth-like structures are located at the junction of the effective surface and the ineffective surface.

[0021] Optionally, the distance between the second surface and the third surface is greater than or equal to 1 mm.

[0022] Optionally, the first lens assembly includes a third lens, and the third lens is a liquid crystal lens; the liquid crystal lens includes:

[0023] a first substrate and a second substrate arranged opposite to each other;

[0024] and, a first electrode, a liquid crystal layer, and a second electrode, which are located between the first substrate and the second substrate and stacked in sequence;

[0025] The liquid crystal molecules in the liquid crystal layer are used to be deflected under the control of the first electrode and the second electrode, and the deflected liquid crystal molecules are used to converge light.

[0026] Optionally, the first lens assembly further includes: a fourth lens located on a side of the third lens away from the display panel, and the fourth lens is also a liquid crystal lens.

[0027] Optionally, the first control component includes: a first polarizer and a first phase control element sequentially arranged in a direction away from the display panel; the second control component includes: a second phase control element, a second polarizer, and a third polarizer sequentially arranged in a direction away from the display panel;

[0028] The first polarizer is an absorbing polarizer, the light transmission direction of the first polarizer is a first direction, the absorption direction of the first polarizer is a second direction, the first polarizer is used to transmit a first linearly polarized light, the polarization direction of the first linearly polarized light is the first direction, and the first polarizer is also used to absorb light in the second direction, which is perpendicular to the first direction;

[0029] The first phase control element is used to modulate the first linear polarization light into a first circular polarization light;

[0030] The second phase control element is used to modulate the first circularly polarized light after passing through the first lens assembly into a second linearly polarized light;

[0031] The second polarizer is a reflective polarizer. The second polarizer transmits light in the first direction and reflects light in the second direction. The second polarizer is configured to reflect a second linearly polarized light in the second direction and transmit a third linearly polarized light in the first direction. The third linearly polarized light is light obtained by sequentially passing through the first lens assembly, the semi-transmissive layer, the first lens assembly, and the second phase control element.

[0032] The third polarizer is an absorbing polarizer. The light transmission direction of the third polarizer is the first direction, and the absorption direction of the third polarizer is the second direction. The third polarizer is used to transmit the third linear polarized light in the first direction and absorb the light in the second direction.

[0033] Optionally, both the first control component and the second control component are liquid crystal control components;

[0034] The first control component is used to modulate the light emitted by the display panel;

[0035] The second control component is used to reflect the first target light and to transmit the second target light. The first target light is the light emitted by the display panel after passing through the first control component and the first lens component. The second target light is the light after the first target light passes through the first lens component, is reflected by the semi-transmissive and semi-reflective layer, and passes through the first lens component again.

[0036] Optionally, the wearable display device further includes: a second lens assembly located on a side of the second control assembly away from the display panel; the second lens assembly at least includes: a fifth lens;

[0037] The refractive index of the fifth lens element is in a range of 1.5 to 1.75.

[0038] Optionally, the third lens has a fifth surface close to the display panel and a sixth surface away from the display panel;

[0039] Each of the fifth surface and the sixth surface can be one of a spherical surface, an aspherical surface, a Fresnel surface, a free-form surface, a refractive-diffractive hybrid surface, a diffractive surface, and a micro-nanostructured surface.

[0040] Optionally, the curvature radius of the fifth surface and the sixth surface ranges from 50 mm to 100 mm, and the ratio of the center thickness to the edge thickness of the fifth lens is greater than 0.5:1 and less than 3:1.

[0041] Optionally, the second lens assembly further includes: at least one sixth lens located on a side of the fifth lens away from the display panel; each of the sixth lenses has a seventh surface close to the display panel and an eighth surface away from the display panel;

[0042] Each of the seventh surface and the eighth surface can be one of a spherical surface, an aspherical surface, a Fresnel surface, a free-form surface, a refractive-diffractive hybrid surface, a diffractive surface, and a micro-nanostructured surface.

[0043] Optionally, the optical path transmission process of the optical system includes:

[0044] The display panel emits light;

[0045] The first control component modulates the light emitted by the display panel into a first polarized light;

[0046] The semi-transmissive and semi-reflective layer transmits the first light in the first polarized light;

[0047] The first light is reflected by the second control assembly after passing through the first lens assembly;

[0048] The light reflected by the second control component passes through the first lens component and then irradiates the semi-transmissive and semi-reflective layer, and is modulated into a second polarized light by the semi-transmissive and semi-reflective layer;

[0049] The semi-transmissive and semi-reflective layer reflects the second light in the second polarized light;

[0050] The second light is transmitted by the second control component after passing through the second lens component.

[0051] On the other hand, a wearable display device is provided, comprising: a display panel, and the optical system as described in the above aspect;

[0052] The light emitted by the display panel is used to be emitted after passing through the optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0054] FIG1 is a schematic structural diagram of a wearable display device provided in an embodiment of the present application;

[0055] FIG2 is a graph showing the relationship between frequency and contrast provided in an embodiment of the present application;

[0056] FIG3 is a schematic structural diagram of another wearable display device provided in an embodiment of the present application;

[0057] FIG4 is a schematic diagram of a first lens provided in an embodiment of the present application;

[0058] FIG5 is a partial schematic diagram of a second surface of a first lens provided in an embodiment of the present application;

[0059] FIG6 is a partial schematic diagram of the second surface of another first lens provided in an embodiment of the present application;

[0060] FIG7 is a partial schematic diagram of the second surface of another first lens provided in an embodiment of the present application;

[0061] FIG8 is a partial schematic diagram of the second surface of another first lens provided in an embodiment of the present application;

[0062] FIG9 is a schematic diagram of a tooth structure provided in an embodiment of the present application;

[0063] FIG10 is a schematic diagram of a first lens and a second lens provided in an embodiment of the present application;

[0064] FIG11 is another graph showing the relationship between frequency and contrast provided in an embodiment of the present application;

[0065] FIG12 is a schematic structural diagram of another wearable display device provided in an embodiment of the present application;

[0066] FIG13 is a schematic diagram of a liquid crystal lens provided in an embodiment of the present application;

[0067] FIG14 is a schematic structural diagram of another wearable display device provided in an embodiment of the present application;

[0068] FIG15 is a schematic structural diagram of another wearable display device provided in an embodiment of the present application;

[0069] FIG16 is another frequency-contrast relationship curve diagram provided in an embodiment of the present application;

[0070] FIG17 is a schematic structural diagram of another wearable display device provided in an embodiment of the present application;

[0071] FIG18 is a schematic structural diagram of another wearable display device provided in an embodiment of the present application;

[0072] FIG19 is a schematic structural diagram of another wearable display device provided in an embodiment of the present application;

[0073] FIG20 is a schematic diagram of an optical path transmission provided in an embodiment of the present application;

[0074] FIG21 is a schematic diagram of another optical transmission path provided in an embodiment of the present application;

[0075] FIG22 is a schematic diagram of another optical transmission path provided in an embodiment of the present application;

[0076] FIG23 is a schematic diagram of a display panel, a first polarizer, and a first phase control element provided in an embodiment of the present application;

[0077] FIG24 is a schematic diagram of another display panel, a first polarizer, and a first phase control element provided in an embodiment of the present application;

[0078] FIG25 is a schematic diagram of another display panel, a first polarizer, and a first phase control element provided in an embodiment of the present application;

[0079] FIG26 is a schematic diagram of another display panel, a first polarizer, and a first phase control element provided in an embodiment of the present application;

[0080] FIG27 is a schematic diagram of a liquid crystal control assembly provided in an embodiment of the present application;

[0081] FIG28 is a schematic diagram of another optical transmission path provided in an embodiment of the present application;

[0082] FIG29 is a schematic diagram of the optical path transmission process of an optical system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0083] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0084] In the related art, a wearable display device includes a display panel and an optical path component. The image displayed on the display panel can be irradiated to the user's eyes after being converged by the optical path component, thereby allowing the user to view the relevant image.

[0085] However, since the optical path components in the wearable display device occupy a large space, the wearable display device is large in size and difficult to meet the requirements of lightness and thinness.

[0086] The wearable display device may be a virtual reality (VR) device or an augmented reality (AR) device.

[0087] VR and AR devices have attracted widespread attention due to their enormous potential applications in entertainment, education, and social interaction. As VR and AR devices become more popular, users are placing higher demands on their thinness and wearing experience, making thinness a significant trend.

[0088] The optical principle of VR and AR devices is to place the display panel within the clear distance of the human eye, and use the lens assembly to magnify and extend the image. The magnified virtual image can be received by the human eye, thereby expanding the viewing angle.

[0089] Typically, a lens assembly may include one or more aspheric lenses. Although this can ensure a higher imaging effect, multiple aspheric lenses will bring the disadvantages of large thickness and volume, making it impossible for wearable display devices to be lightweight and unable to meet consumers' demand for thinness and lightness.

[0090] Figure 1 is a schematic diagram of the structure of a wearable display device provided by an embodiment of the present application. Referring to Figure 1 , the optical system includes: a first control assembly 101, a transflective layer 102, a first lens assembly 103, and a second control assembly 104, positioned on the display surface of a display panel 20 and arranged in sequence away from the display panel 20.

[0091] The display panel 20 is configured to emit light. The light emitted by the display panel 20 may first pass through the first control assembly 101, the transflective layer 102, and the first lens assembly 103 in sequence before being reflected by the second control assembly 104. The reflected light then passes through the first lens assembly 103 and is reflected by the transflective layer 102. The light reflected by the transflective layer 102 passes through the first lens assembly 103 again before being transmitted to the human eye by the second control assembly 104.

[0092] Because light is reflected when it first reaches the second control assembly 104 and transmitted when it reaches the second control assembly 104, the light passes through the first lens assembly 103 three times, achieving three-fold convergence of the light. This ensures that the quality of light transmitted to the human eye is guaranteed while shortening the overall length of the optical system.

[0093] In the embodiment of the present application, the transflective layer 102 serves to partially reflect and partially transmit light incident on the transflective layer 102. In the embodiment of the present application, the light transmitted by the transflective layer 102 is referred to as the first light, and the light reflected by the transflective layer 102 is referred to as the second light.

[0094] The light emitted by the display panel 20 is modulated into a first polarized light after passing through the first control component 101. The semi-transparent and semi-reflective layer 102 is used to transmit the first light in the first polarized light (the first light is the part of the first polarized light that is transmitted by the semi-transparent and semi-reflective layer 102). The first light passes through the first lens component 103 and is reflected by the second control component 104. The light reflected by the second control component 104 passes through the first lens component 103 again and is irradiated to the semi-transparent and semi-reflective layer 102, and can be changed into a second polarized light (the phase of the second polarized light is different from the phase of the first polarized light). The semi-transparent and semi-reflective layer 102 can reflect the second light in the second polarized light (the second light is the part of the second polarized light that is reflected by the semi-transparent and semi-reflective layer 102). The second light passes through the first lens component 103 and is transmitted by the second control component 104. As a result, the light transmitted by the second control component 104 can enter the human eye, allowing the user to view the content displayed on the display panel 20.

[0095] Among them, since the phase of the second polarized light is different from the phase of the first polarized light, the performance of the second control component 104 can be adjusted to control the phase of the light that can be transmitted by the second control component 104 and the phase of the light that can be reflected, so that the second control component 104 can reflect the light of the first phase and transmit the light of the second phase.

[0096] In the embodiment of the present application, the light emitted by the display panel 20 passes through the first lens assembly 103 three times, thereby achieving three-fold convergence of the light. In this way, the light path of the wearable display device 10 can be shortened while ensuring the effect of light transmission to the human eye.

[0097] The refractive index of the first lens assembly 103 is greater than or equal to 1.6, that is, the refractive index of the first lens assembly 103 can be relatively large. As a result, the first lens assembly 103 has a stronger ability to deflect light, which in turn allows the first lens assembly 103 to achieve a shorter focal length, thereby further shortening the overall length of the optical system and facilitating the thinning and lightening of the wearable display device.

[0098] In summary, embodiments of the present application provide an optical system comprising a first control assembly, a transflective layer, a first lens assembly, and a second control assembly, positioned on the display surface of a display panel and arranged in sequence away from the display panel. The first lens assembly has a refractive index greater than or equal to 1.6, and light emitted from the display panel is converged three times by the first lens assembly before entering the human eye. This allows the overall length of the optical system to be shortened while ensuring effective light transmission to the human eye, facilitating a thinner and lighter design.

[0099] In the embodiment of the present application, the display panel 20 can be a liquid crystal display (LCD) display panel, a digital light processing (DLP) display panel, an organic light-emitting diode (OLED) display panel, a sub-millimeter organic light-emitting diode (mini OLED) display panel, and a micro organic light-emitting diode (micro OLED) display panel. Optionally, the size of the display panel can range from 0.3 inches to 3.5 inches.

[0100] Referring to FIG. 1 , it can be seen that the first lens assembly 103 includes a first lens 1031 and a second lens 1032, which are sequentially arranged in a direction away from the display panel 20. The refractive index of the first lens 1031 ranges from 1.6 to 1.9, and the refractive index of the second lens 1032 ranges from 1.7 to 2.0. In other words, the refractive indices of the first lens 1031 and the second lens 1032 included in the first lens assembly 103 are both relatively high, and the first lens 1031 and the second lens 1032 have relatively strong light deflection capabilities, providing a better opportunity to shorten the overall length of the optical system.

[0101] Furthermore, the first lens assembly 103 may also include only one lens, or include three or more lenses. The embodiment of the present application does not limit the number of lenses included in the first lens assembly 103, and it is only necessary to ensure that the first lens assembly 103 can achieve the effect of light convergence.

[0102] 1 , the first lens 1031 has a first surface n1 close to the display panel 20 and a second surface n2 away from the display panel 20 . The second lens 1032 has a third surface n3 close to the display panel 20 and a fourth surface n4 away from the display panel 20 .

[0103] Each of the first surface n1, the second surface n2, the third surface n3 and the fourth surface n4 can be one of a spherical surface, an aspherical surface, a Fresnel surface, a free-form surface, a refractive-diffractive hybrid surface, a diffractive surface and a micro-nanostructured surface.

[0104] For example, referring to FIG. 1 , the first surface n1 and the second surface n2 can both be convex. The radius of curvature of the first surface n1 and the second surface n2 ranges from 45 mm (millimeter) to 100 mm. The ratio of the center thickness a1 of the first lens 1031 to its edge thickness a2 is less than 3:1, and the ratio of the diameter a3 of the first lens 1031 to the center thickness a1 of the first lens 1031 is greater than 5:1. Furthermore, a distance a4 between the center position of the first surface n1 of the first lens 1031 and the display panel 20 is ≥ 1 mm.

[0105] By setting the radius of curvature of the first lens 1031, effective light deflection by the first lens 1031 can be achieved. By setting the ratio of the center thickness a1 to the edge thickness a2 of the first lens 1031, as well as the ratio of the diameter of the first lens 1031 to the center thickness a of the first lens 1031, the first lens 1031 can be made easier to manufacture, the manufacturing stability can be improved, and the first lens 1031 can be prevented from breaking. By setting the distance between the center position of the first surface of the first lens 1031 and the display panel 20, errors caused by manufacturing and assembly can be reduced.

[0106] Referring to Figure 1 , the third surface n3 of the second lens 1032 can be convex, with a radius of curvature ranging from 100 mm to 200 mm. The fourth surface n4 of the second lens 1032 can be flat. Alternatively, the fourth surface n4 of the second lens 1032 can be convex or concave. If so, the radius of curvature of the fourth surface n4 is greater than 300 mm. The ratio of the center thickness b1 to the edge thickness b2 of the second lens 1032 is greater than 0.5:1 and less than 3:1.

[0107] By adjusting the radius of curvature of the second lens 1032, effective light deflection by the second lens 1032 can be achieved. By adjusting the ratio of the center thickness b1 to the edge thickness b2 of the second lens 1032, the second lens 1032 can be more easily processed, with improved processing stability and the prevention of breakage of the second lens 1032.

[0108] For the second lens 1032, the relationship between the diameter b3 of the second lens 1032, the exit pupil distance E, the field of view angle θ, and the eye movement range B is as follows:

[0109] The wearable display device requires a field of view angle θ of 90° (degrees), an eye movement range of 8mm*8mm, and an exit pupil distance greater than 11mm. Based on these design requirements and using the above formula (1), the range of the diameter b3 of the second lens 1032 can be calculated.

[0110] In the embodiment of the present application, the above design can make the distance between the second control component 104 and the display panel 20 ≤14mm, and the focal length ≤20mm. In addition, the performance of the wearable display device is tested using the modulation transfer function (MTF). Referring to Figure 2, by plotting the relationship between contrast (ordinate) and frequency (abscissa), the relationship between contrast and attenuation as frequency increases is represented. Among them, the slower the contrast decays with increasing frequency, the better the image quality of the wearable display device. Referring to Figure 2, when the frequency increases to 30, the contrast is still greater than 0.3 (denoted as MTF>0.3), that is, the image quality of the wearable display device 10 provided in the embodiment of the present application is good. Among them, each curve in Figure 2 represents the MTF curve in the meridian and sagittal directions of different half fields of view. The half field of view ranges from 0° to 45°, and the slowness of the downward trend of the MTF curve is positively correlated with the half field of view. That is, the larger the half field of view, the steeper the downward trend of the MTF curve; the smaller the half field of view, the slower the downward trend of the MTF curve. For example, the MTF curve with a half field of view of 0° has the slowest downward trend; the MTF curve with a half field of view of 45° has the steepest downward trend.

[0111] In the embodiment of the present application, in conjunction with Figures 3 and 4, the second surface n2 of the first lens 1031 can be a Fresnel surface. The Fresnel surface includes a plurality of sawtooth structures m, and the sawtooth structure m includes an effective surface m1 and an invalid surface m2. Among them, the effective surface m1 and the invalid surface m2 are connected, and both are side surfaces of the sawtooth structure m. The effective surface m1 can refer to a surface that can effectively refract light, and the refracted light can eventually form an image on the human eye. The invalid surface m2 can refer to a surface that can reflect or refract light and cause the light to deviate from the normal path. These light rays will form stray light (i.e., non-sequential light).

[0112] Referring to Figure 5 , the inactive surface m2 can be painted black. Alternatively, referring to Figure 6 , the inactive surface m2 can be mirror-coated. Alternatively, referring to Figure 7 , the inactive surface m2 can be frosted. The purpose of treating the inactive surface m2 is to prevent stray light from passing through it, which can affect viewing quality.

[0113] In conjunction with Figures 8 and 9, the Fresnel surface can also include multiple tooth-like structures k, located at the junction of the effective surface m1 and the ineffective surface m2. Typically, due to the limitations of the drafting process, the top angle of the Fresnel surface will produce a rounded corner at the junction of the effective surface m1 and the ineffective surface m2, which will cause stray light. Therefore, providing a tooth-like structure k at the junction of the effective surface m1 and the ineffective surface m2 can cause stray light to diffract, changing the propagation direction of the light, thereby reducing the stray light entering the human eye and improving the viewing effect. Optionally, the tooth-like structure k can be produced using embossing or interference exposure.

[0114] Optionally, each sawtooth structure in the Fresnel surface may be ring-shaped, and the corresponding tooth-shaped structure may also be ring-shaped.

[0115] Furthermore, the third surface n3 of the second lens 1032 can also be a Fresnel surface. The inactive surface m2 of the sawtooth structure m in the Fresnel surface can also be blackened, mirror-coated, or frosted. The structures of the second surface n2 and the third surface n3 can be arranged as shown in FIG10 . The distance between the second surface n2 and the third surface n3 is greater than or equal to 1 mm.

[0116] Specifically, by setting the distance between the second surface n2 of the first lens 1031 and the third surface n3 of the second lens 1032 , errors caused by processing and assembly can be reduced.

[0117] In the embodiment of the present application, when the second surface n2 and the third surface n3 are set as Fresnel surfaces, the distance between the second control component 104 and the display panel 20 can be ≤14mm, and the focal length can be ≤20mm. Furthermore, the performance of the wearable display device is tested using MTF. Referring to FIG11 , a graph showing the relationship between contrast (vertical axis) and frequency (horizontal axis) is plotted to illustrate the relationship between contrast attenuation as frequency increases. The slower the contrast attenuation rate as the MTF increases with frequency, the better the image quality of the wearable display device. Referring to FIG11 , when the frequency increases to 30, the contrast is still greater than 0.3 (denoted as MTF>0.3), indicating that the image quality of the wearable display device provided in the embodiment of the present application is good. Furthermore, the field of view angle θ of the wearable display device can be 90°, and the eye movement range is 8mm*8mm. The curves in FIG11 represent the MTF curves in the meridian and sagittal directions for different half-fields of view. The half field of view ranges from 0° to 45°, and the degree of the MTF curve's downward trend is positively correlated with the half field of view. That is, the larger the half field of view, the steeper the MTF curve's downward trend; the smaller the half field of view, the slower the MTF curve's downward trend. For example, the MTF curve with a half field of view of 0° has the slowest downward trend; the MTF curve with a half field of view of 45° has the steepest downward trend.

[0118] Figure 12 is a schematic diagram of the structure of another wearable display device provided in an embodiment of the present application. Referring to Figure 12, the first lens assembly 103 includes a third lens 1033, which can be a liquid crystal lens, which can be a flat lens. Referring to Figure 13, the liquid crystal lens includes: a first substrate and a second substrate arranged opposite each other, and a first electrode, a liquid crystal layer, and a second electrode located between the first and second substrates and stacked in sequence.

[0119] The liquid crystal molecules in the liquid crystal layer can be deflected under the control of the first electrode and the second electrode, and the light can be focused after passing through the deflected liquid crystal molecules. In addition, the light can be directly converted into circularly polarized light after passing through the third lens 1033.

[0120] For liquid crystal lenses, they use the changes in the arrangement of liquid crystal molecules to achieve the effects of changing the propagation direction and focusing of light.

[0121] Among them, liquid crystal molecules have anisotropy, that is, the refractive index is different in different directions. For example, the liquid crystal molecules have a single axis, and the refractive index of light along the direction of the single axis and the direction perpendicular to the single axis are different. When an electric field is applied, different electric fields cause the liquid crystal molecules to have different rotations, and different rotations will cause the liquid crystal molecules to be arranged differently. Because the liquid crystal molecules are anisotropic, light is affected by different refractive indices after passing through different liquid crystal molecules. Therefore, if a beam of parallel light passes through liquid crystal molecules without an electric field, its light path will not change (it will still be parallel light). However, after passing through liquid crystal molecules with different electric fields, the light path will change differently, achieving the light convergence effect as shown in Figure 13, realizing image magnification.

[0122] Furthermore, since the first lens assembly 103 in FIG12 includes only one third lens 1033, it is necessary to ensure that the third lens 1033 has a good light-gathering and refractive power. Therefore, the light-gathering and refractive power of the third lens 1033 can be increased by increasing the thickness of the liquid crystal layer in the third lens 1033 or by increasing the external voltage of the liquid crystal lens.

[0123] FIG14 is a schematic diagram of the structure of another wearable display device provided by an embodiment of the present application. Referring to FIG14 , the first lens assembly 103 further includes: a fourth lens 1034 located on a side of the third lens 1033 away from the display panel 20. The fourth lens 1034 may also be a liquid crystal lens.

[0124] That is, compared to the solution in FIG12 , the solution in FIG14 includes an additional liquid crystal lens in the first lens assembly 103. Therefore, the two liquid crystal lenses in FIG14 can perform the function of the single liquid crystal lens in FIG12 . Therefore, when the first lens assembly 103 includes the third lens 1033 and the fourth lens 1034, the thickness of the liquid crystal layer can be appropriately reduced, or the external voltage applied to the liquid crystal lens can be lowered. The overall effect of the third lens 1033 and the fourth lens 1034 need only achieve a certain focusing and refractive effect. For example, the sum of the focal lengths of the third lens 1033 and the fourth lens 1034 needs to be less than or equal to 20 mm.

[0125] FIG15 is a schematic diagram of the structure of another wearable display device provided in an embodiment of the present application. Referring to FIG15 , the optical system 10 further includes a second lens assembly 105 located on a side of the second control assembly 104 away from the display panel 20. The second lens assembly 105 includes a fifth lens 1051. The refractive index of the fifth lens 1051 ranges from 1.5 to 1.75.

[0126] By providing the second lens assembly 105, the light transmitted from the second control assembly 104 can be further converged by the second lens assembly 105 and then incident on the human eye after being converged by the second lens assembly 105. This can improve the convergence effect of the light incident on the human eye and enhance the user's viewing experience.

[0127] 15 , the third lens 1033 has a fifth surface n5 close to the display panel 20 and a sixth surface n6 away from the display panel 20. Each of the fifth surface n5 and the sixth surface n6 can be one of a spherical surface, an aspherical surface, a Fresnel surface, a free-form surface, a diffractive-refractive hybrid surface, a diffractive surface, and a micro-nanostructured surface.

[0128] For example, the fifth surface n5 and the sixth surface n6 can both be curved surfaces. The radius of curvature of the fifth surface n5 and the sixth surface n6 ranges from 50 mm to 100 mm. The ratio of the center thickness f1 to the edge thickness f2 of the fifth lens 1051 is greater than 0.5:1 and less than 3:1.

[0129] Specifically, by setting the curvature radii of the fifth surface n5 and the sixth surface n6 of the third lens 1033 , the third lens 1033 can effectively deflect light.

[0130] In addition, when the second lens assembly 105 includes only one fifth lens 1051, the relationship between the diameter f3 of the fifth lens 1051 and the exit pupil distance E, the field of view angle θ and the eye movement range B is as follows:

[0131] The wearable display device requires a field of view angle θ of 90° (degrees), an eye movement range of 8mm*8mm, and an exit pupil distance greater than 11mm. Based on these design requirements and using the above formula (2), the range of the diameter f3 of the fifth lens 1051 can be calculated.

[0132] In the embodiment of the present application, the above design can make the distance between the second lens assembly 105 and the display panel 20 ≤16mm, and the focal length ≤20mm. In addition, the performance of the wearable display device is tested using MTF. Referring to Figure 16, by plotting the relationship between contrast (ordinate) and frequency (abscissa), the relationship between contrast and attenuation as frequency increases is represented. Among them, the slower the rate of contrast decay as the MTF increases with frequency, the better the image quality of the wearable display device. Referring to Figure 16, when the frequency increases to 30, the contrast is still greater than 0.4 (denoted as MTF>0.4), that is, the image quality of the wearable display device provided by the embodiment of the present application is good. Among them, each curve in Figure 16 represents the MTF curve in the meridian and sagittal directions of different half fields of view. The range of the half field of view is 0° to 45°, and the slowness of the downward trend of the MTF curve is positively correlated with the half field of view. That is, the larger the half field of view, the steeper the downward trend of the MTF curve; the smaller the half field of view, the slower the downward trend of the MTF curve. For example, the MTF curve with a half field of view of 0° has the slowest downward trend; the MTF curve with a half field of view of 45° has the steepest downward trend.

[0133] Furthermore, referring to FIG17 , the second lens assembly 105 further includes at least one sixth lens 1052 located on a side of the fifth lens 1051 away from the display panel 20. Each sixth lens 1052 has a seventh surface n7 proximal to the display panel 20 and an eighth surface n8 distal to the display panel 20. Each of the seventh surface n7 and the eighth surface n8 can be one of a spherical surface, an aspherical surface, a Fresnel surface, a free-form surface, a diffractive-refractive hybrid surface, a diffractive surface, and a micro-nanostructured surface.

[0134] For example, referring to FIG17 , the second lens assembly 105 includes a sixth lens 1052, and the seventh surface n7 and the eighth surface n8 of the sixth lens 1052 are both convex. Alternatively, referring to FIG18 , the second lens assembly 105 includes two sixth lenses 1052, wherein the seventh surface n7 and the eighth surface n8 of the sixth lens 1052 closer to the fifth lens 1051 are both convex, and the seventh surface n7 of the other sixth lens 1052 farther from the fifth lens 1051 is a flat surface, and the eighth surface n8 is a concave surface. Alternatively, referring to FIG19 , the second lens assembly 105 includes three sixth lenses 1052, wherein the seventh surface n7 and the eighth surface n8 of the sixth lens 1052 closest to the fifth lens 1051 and the sixth lens 1052 farther from the fifth lens 1051 are both convex, and the seventh surface n7 of the middle sixth lens 1052 is a flat surface, and the eighth surface n8 is a concave surface.

[0135] It should be noted that the number of sixth lenses 1052 included in the second lens assembly 105 cannot be too many, because if the number of sixth lenses 1052 is too many, the overall length of the wearable display device will be too long, which is not conducive to a lightweight design.

[0136] In the embodiment of the present application, each time light passes through the translucent and reflective layer 102, a portion of the light is transmitted and another portion is reflected. Optionally, the transmittance and reflectance of the translucent and reflective layer 102 are each 50%. Alternatively, the transmittance and reflectance of the translucent and reflective layer 102 are 35% and 65%. Alternatively, the transmittance and reflectance of the translucent and reflective layer 102 can be distributed in any other ratio, which is not limited in the embodiment of the present application.

[0137] Optionally, the transflective layer 102 may be a single-layer coating or a multi-layer coating. The transflective layer 102 may be a planar film or a curved film with a curvature. When the transflective layer 102 and the first surface n1 of the first lens 1031 are in contact, the transflective layer 102 may be a curved film, and the radius of curvature may be consistent with the radius of curvature of the first surface n1 of the first lens 1031, and the diameter of the transflective layer 102 may be the same as the diameter of the first lens 1031. When there is a gap between the transflective layer 102 and the first surface n1 of the first lens 1031, the transflective layer 102 may be a planar film, and the gap between the two may be less than or equal to 2 mm.

[0138] As an optional implementation, referring to Figures 1, 3, 16, and 17 to 19, the first control assembly 101 includes: a first polarizer 1011 and a first phase control element 1012, which are sequentially arranged in a direction away from the display panel 20. The second control assembly 104 includes: a second phase control element 1041, a second polarizer 1042, and a third polarizer 1043, which are sequentially arranged in a direction away from the display panel 20.

[0139] The first polarizer 1011 is an absorbing polarizer. It transmits light in a first direction and absorbs light in a second direction. The first polarizer 1011 converts natural light into linearly polarized light. It transmits first linearly polarized light in the first direction. Furthermore, it absorbs light in a second direction, which is perpendicular to the first direction.

[0140] The function of the first phase control element 1012 is to increase the phase delay and modulate the first linear polarization light into the first circular polarization light.

[0141] The first circularly polarized light can still be circularly polarized light after passing through the first lens assembly 103, which is recorded as second circularly polarized light. The phase of the second circularly polarized light is the same as the phase of the first circularly polarized light.

[0142] The function of the second phase control element 1041 is to increase the phase delay and modulate the second circularly polarized light into the second linearly polarized light.

[0143] The second polarizer 1042 is a reflective polarizer. The second polarizer 1042 transmits light in a first direction and reflects light in a second direction. Light with the same polarization direction as the transmission direction is transmitted, while light with a polarization direction perpendicular to the transmission direction is reflected. The second polarizer 1042 is configured to reflect the second linearly polarized light in the second direction.

[0144] The second linear polarization light is modulated into a third circular polarization light after passing through the second phase control element 1041. The phase of the third circular polarization light is the same as that of the second circular polarization light.

[0145] The third circularly polarized light can still be circularly polarized light after passing through the first lens assembly 103, which is recorded as fourth circularly polarized light. The phase of the fourth circularly polarized light is the same as the phase of the third circularly polarized light.

[0146] The fourth circularly polarized light may be reflected by the semi-transmissive and semi-reflective layer 102 to become the fifth circularly polarized light. The reflection principle determines that surface reflection may cause a phase shift of π / 2. That is, the phase of the fifth circularly polarized light is different from that of the fourth circularly polarized light.

[0147] The fifth circularly polarized light can still be circularly polarized light after passing through the first lens assembly 103, which is recorded as the sixth circularly polarized light. The phase of the sixth circularly polarized light is the same as the phase of the fifth circularly polarized light.

[0148] The sixth circularly polarized light is modulated into a third linearly polarized light after passing through the second phase control element 1041 , and the polarization direction of the third linearly polarized light is the first direction.

[0149] The light transmission direction of the second polarizer 1042 is the first direction, so the third linear polarized light can pass through the second polarizer 1042 .

[0150] The third polarizer 1043 is an absorbing polarizer. Its transmission direction is the first direction, and its absorption direction is the second direction. Light with the same polarization direction as the transmission direction is allowed to pass through, while light with a polarization direction perpendicular to the transmission direction is absorbed. The third polarizer 1043 is configured to transmit the third polarized light and absorb light with the second direction.

[0151] Through the above process, it can be seen that in Figures 20 and 21, the optical path of the light emitted by the display panel 20 can be: first passing through the first polarizer 1011, the first phase control element 1012, the semi-transparent and semi-reflective layer 102, the first lens assembly 103, and the second phase control element 1041 in sequence, and then being reflected by the second polarizer 1042; the light reflected by the second polarizer 1042 passes through the second phase control element 1041 and the first lens assembly 103 in sequence, and then is reflected by the semi-transparent and semi-reflective layer 102; the light reflected by the semi-transparent and semi-reflective layer 102 passes through the first lens assembly 103, the second phase control element 1041, the second polarizer 1042 and the third polarizer 1043 in sequence, and then is incident on the human eye.

[0152] In Figure 22, the optical path of the light emitted by the display panel 20 can be: first passing through the first polarizer 1011, the first phase control element 1012, the semi-transparent and semi-reflective layer 102, the first lens assembly 103, and the second phase control element 1041 in sequence, and then being reflected by the second polarizer 1042; the light reflected by the second polarizer 1042 passes through the second phase control element 1041 and the first lens assembly 103 in sequence, and then is reflected by the semi-transparent and semi-reflective layer 102; the light reflected by the semi-transparent and semi-reflective layer 102 passes through the first lens assembly 103, the second phase control element 1041, the second polarizer 1042, the third polarizer 1043 and the second lens assembly 105 in sequence, and then is incident on the human eye.

[0153] Thus, the light emitted from the display panel 20 can pass through the first lens assembly 103 three times and be converged three times by the first lens assembly 103. That is, the overall length of the optical system can be shortened by folding the light path while ensuring the effect of the light incident on the human eye.

[0154] It should be noted that when light emitted from the display panel 20 first reaches the second polarizer 1042, its polarization direction is perpendicular to the transmission direction of the second polarizer 1042, and the light is reflected. Furthermore, after being reflected, the light passes through the second phase control element 1041 and the transflective layer 102. When the light reaches the second polarizer 1042 a second time, its polarization direction is the same as the transmission direction of the second polarizer 1042. Therefore, the light reaching the second polarizer 1042 a second time can pass through.

[0155] In the embodiment of the present application, the first polarizer 1011 and the first phase control element 1012 included in the first control assembly 101 can be in contact, glued together, or have a certain distance between them (distance ≤ 2 mm). Alternatively, the first polarizer 1011 and the first phase control element 1012 can be attached to the display surface of the display panel 20, or can be integrated into the display panel 20, or can have a certain distance between them and the display panel 20 (distance ≤ 5 mm).

[0156] For example, in FIG23 , a gap is provided between adjacent polarizers 1011, 1012, and 1011 on the display panel 20. In FIG24 , the first polarizer 1011 is attached to the display surface of the display panel 20, and a gap is provided between the first phase control element 1012 and the first polarizer 1011. In FIG25 , a gap is provided between the first polarizer 1011 and the display panel 20, and the first polarizer 1011 and the first phase control element 1012 are glued together. In FIG26 , the first polarizer 1011 is attached to the display surface of the display panel 20, and the first polarizer 1011 and the second phase control element 1041 are glued together.

[0157] In the embodiment of the present application, the second phase control element 1041, the second polarizer 1042, and the third polarizer 1043 included in the second control assembly 104 can be in contact, glued together, or have a certain distance between them (distance ≤ 2 mm). Alternatively, the second phase control element 1041, the second polarizer 1042, and the third polarizer 1043 can be attached to the fourth surface n4 of the second lens 1032, or can have a certain distance from the fourth surface n4 of the second lens 1032 (distance ≤ 5 mm).

[0158] As another optional implementation, both the first control assembly 101 and the second control assembly 104 are liquid crystal control assemblies. The first control assembly 101 is used to modulate the light emitted by the display panel 20. The second control assembly 104 is used to reflect a first target light and transmit a second target light. The first target light is the light emitted by the display panel 20 after passing through the first control assembly 101 and the first lens assembly 103. The second target light is the light emitted by the first target light after passing through the first lens assembly 103, being reflected by the semi-transmissive and semi-reflective layer 102, and passing through the first lens assembly 103 again.

[0159] The first control component 101 can be provided separately from the display panel 20 or integrated into the display panel 20. The first control component 101 and the second control component 104 can have the same structure, and by providing different signals, the first control component 101 and the second control component 104 can achieve different functions.

[0160] 27 , the liquid crystal control assembly may include a third substrate and a fourth substrate arranged opposite to each other, and a first conductive film, a third electrode, a first orientation film, a liquid crystal layer, a second orientation film, a fourth electrode and a second conductive film located between the third substrate and the fourth substrate.

[0161] The first conductive film and the second conductive film may be thin films having a conductive function, and materials of the first conductive film and the second conductive film may be indium tin oxide (ITO).

[0162] The first alignment film and the second alignment film are used to control the twist state of the liquid crystal molecules in the liquid crystal layer. The liquid crystal molecules in the liquid crystal layer can only be arranged regularly in a certain direction on the surface of the alignment film.

[0163] The third electrode and the fourth electrode can be used to provide different electrical signals. The liquid crystal molecules in the liquid crystal layer can be deflected under the control of the third electrode and the fourth electrode, thereby achieving phase control of the light.

[0164] Optionally, the structures of the liquid crystal control assembly and the liquid crystal lens can be the same or different. The liquid crystal control assembly and the liquid crystal lens implement different functions by providing different electrical signals. For example, it may be necessary to enable the liquid crystal control assembly to implement phase modulation, while the liquid crystal lens may implement light convergence.

[0165] For a liquid crystal control assembly, the liquid crystal molecules in the liquid crystal layer of the liquid crystal control assembly have anisotropy, that is, the refractive index varies in different directions. For example, the liquid crystal molecules have a single axis, and the refractive index of light along the axis and perpendicular to the axis is different.

[0166] Light can actually be decomposed into two polarization directions perpendicular to each other, called O and E. Since liquid crystal molecules have different refractive indices in the two directions, the propagation speeds of O and E light are different, leading to different phases.

[0167] When different electric fields are applied, the liquid crystal molecules rotate to different degrees, and the refractive index changes for light in two directions are different, resulting in different changes in the phase difference between O light and E light, thereby controlling the phase of the light.

[0168] It should be noted that the liquid crystal control assembly is only used to achieve phase control of light and has nothing to do with the convergence or divergence of light. Therefore, assuming that the light emitted by the display panel 20 is a beam of parallel light, this parallel light can still be a beam of parallel light after passing through the liquid crystal control assembly. This parallel light then passes through the liquid crystal lens, where it is converged and amplified.

[0169] In Figure 28, the optical path of the light emitted by the display panel 20 can be: first passing through the first control component 101, the semi-transparent and semi-reflective layer 102, and the first lens component 103 in sequence, and then reflected by the second phase control component; the light reflected by the second phase control component passes through the first lens component 103 in sequence, and then reflected by the semi-transparent and semi-reflective layer 102; the light reflected by the semi-transparent and semi-reflective layer 102 passes through the first lens component 103 and the second phase control component in sequence, and then enters the human eye.

[0170] In the embodiment of the present application, referring to FIG29 , the optical path transmission process of the optical system includes:

[0171] S101: The display panel emits light.

[0172] S102: The first control component modulates the light emitted by the display panel into a first polarized light.

[0173] S103 , the semi-transmissive and semi-reflective layer transmits the first light in the first polarized light.

[0174] S104: The first light passes through the first lens assembly and is reflected by the second control assembly.

[0175] S105 , the light reflected by the second control component passes through the first lens component and then irradiates the semi-transparent plate reflective layer, and the light irradiating the semi-transparent and semi-reflective layer is the second polarized light.

[0176] S106 , the semi-transmissive and semi-reflective layer reflects the second light in the second polarized light.

[0177] S107 , the second light passes through the second lens assembly and is transmitted by the second control assembly.

[0178] During the above optical transmission process, the light emitted by the display panel 20 can pass through the first lens assembly 103 three times and be converged three times by the first lens assembly 103. In other words, the overall length of the optical system can be shortened by folding the optical path while ensuring the quality of the light incident on the human eye.

[0179] In summary, embodiments of the present application provide an optical system comprising a first control assembly, a transflective layer, a first lens assembly, and a second control assembly, positioned on the display surface of a display panel and arranged in sequence away from the display panel. The first lens assembly has a refractive index greater than or equal to 1.6, and light emitted from the display panel is converged three times by the first lens assembly before entering the human eye. This allows the overall length of the optical system to be shortened while ensuring effective light transmission to the human eye, facilitating a thinner and lighter design.

[0180] The present application also provides a wearable display device, as shown in Figures 1, 3, 12, 14, 15, and 17 to 19. The wearable display device includes a display panel and an optical system as provided in the above embodiments. Light emitted by the display panel is configured to pass through the optical system and then be emitted.

[0181] Since the wearable display device can have basically the same technical effects as the optical system described in the previous embodiment, for the purpose of brevity, the technical effects of the wearable display device will not be repeated here.

[0182] The terms used in the embodiments of this application are only used to explain the embodiments of this application and are not intended to limit this application. Unless otherwise defined, the technical terms or scientific terms used in the embodiments of this application should have the common meaning understood by people with ordinary skills in the field to which this application belongs.

[0183] The terms used in the embodiments of this application are intended solely to illustrate the embodiments of this application and are not intended to limit this application. Unless otherwise defined, technical or scientific terms used in the embodiments of this application should have the same ordinary meaning as those understood by persons of ordinary skill in the art to which this application belongs. The terms "first," "second," "third," and similar terms used in this patent specification and claims do not denote any order, quantity, or importance, but are simply used to distinguish between different components. Similarly, terms such as "a" or "an" do not denote a limitation of quantity, but rather denote the presence of at least one. Terms such as "include" or "comprising" and similar terms mean that the elements or objects listed before "include" or "comprising" include the elements or objects listed after "include" or "comprising," and their equivalents, and do not exclude other elements or objects. Terms such as "connected" or "connected" are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used solely to indicate relative positions. When the absolute position of the described objects changes, the relative positions may also change accordingly.

[0184] The above description is merely an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. An optical system, characterized in that: The optical system comprises: A first control assembly, a semi-transmissive and semi-reflective layer, a first lens assembly and a second control assembly, wherein the first control assembly, the semi-transmissive and semi-reflective layer, the first lens assembly and the second control assembly are all located on a display surface of the display panel and are sequentially arranged in a direction away from the display panel; Wherein, the light emitted by the display panel is modulated into a first polarized light after passing through the first control component; the semi-transmissive and semi-reflective layer is used to transmit the first light in the first polarized light; the second control component is used to reflect the first light after passing through the first lens component, and the first light can be irradiated to the semi-transmissive and semi-reflective layer after passing through the first lens component and can be changed into a second polarized light; the semi-transmissive and semi-reflective layer is used to reflect the second light in the second polarized light; the second control component is used to transmit the second light after passing through the first lens component; The refractive index of the first lens component is greater than or equal to 1.6, and the second phase of the second polarized light is different from the first phase of the first polarized light.

2. The optical system according to claim 1, characterized in that The first lens assembly comprises: a first lens and a second lens arranged in sequence in a direction away from the display panel; The refractive index of the first lens is in a range of 1.6 to 1.9, and the refractive index of the second lens is in a range of 1.7 to 2.

0.

3. The optical system according to claim 2, characterized in that The first lens has a first surface close to the display panel and a second surface far from the display panel; the second lens has a third surface close to the display panel and a fourth surface far from the display panel; Each of the first surface, the second surface, the third surface and the fourth surface can be one of a spherical surface, an aspherical surface, a Fresnel surface, a free-form surface, a refractive-diffractive mixed surface, a diffractive surface and a micro-nanostructured surface.

4. The optical system according to claim 3, characterized in that The curvature radii of the first surface and the second surface range from 45 mm to 100 mm, the ratio of the center thickness to the edge thickness of the first lens is less than 3:1, the ratio of the diameter of the first lens to the center thickness of the first lens is greater than 5:1, and the distance between the center position of the first surface of the first lens and the display panel is greater than or equal to 1 mm; The radius of curvature of the third surface ranges from 100 mm to 200 mm, the fourth surface is a plane, or the radius of curvature of the fourth surface is greater than 300 mm, and the ratio of the center thickness to the edge thickness of the second lens is greater than 0.5:1 and less than 3:

1.

5. The optical system according to claim 3, characterized in that The second surface and the third surface are Fresnel surfaces; The Fresnel surface includes a plurality of sawtooth structures, the sawtooth structure includes an effective surface and an ineffective surface, the effective surface and the ineffective surface are connected and both are side surfaces of the sawtooth structure; The ineffective surface is blackened, or mirror-coated, or frosted.

6. The optical system according to claim 5, characterized in that The second surface and the third surface are Fresnel surfaces; The Fresnel surface includes a plurality of sawtooth structures, the sawtooth structure includes an effective surface and an ineffective surface, the effective surface and the ineffective surface are connected and both are side surfaces of the sawtooth structure; The Fresnel surface further includes a plurality of tooth-shaped structures, and the tooth-shaped structures are located at the junction of the effective surface and the ineffective surface.

7. The optical system according to claim 5 or 6, characterized in that: A distance between the second surface and the third surface is greater than or equal to 1 mm.

8. The optical system according to claim 1, characterized in that The first lens assembly includes a third lens, and the third lens is a liquid crystal lens; the liquid crystal lens includes: A first substrate and a second substrate arranged opposite to each other; and, a first electrode, a liquid crystal layer and a second electrode which are located between the first substrate and the second substrate and are stacked in sequence; The liquid crystal molecules in the liquid crystal layer are used to be deflected under the control of the first electrode and the second electrode, and the deflected liquid crystal molecules are used to converge light.

9. The optical system according to claim 8, characterized in that The first lens assembly further includes: a fourth lens located at a side of the third lens away from the display panel, and the fourth lens is also a liquid crystal lens.

10. The optical system according to any one of claims 1 to 9, characterized in that: The first control component comprises: a first polarizer and a first phase control element arranged in sequence in a direction away from the display panel; the second control component comprises: a second phase control element, a second polarizer and a third polarizer arranged in sequence in a direction away from the display panel; The first polarizer is an absorption polarizer, the light transmission direction of the first polarizer is a first direction, the absorption direction of the first polarizer is a second direction, the first polarizer is used to transmit a first linear polarized light, the polarization direction of the first linear polarized light is the first direction, and the first polarizer is also used to absorb light in the second direction, and the second direction is perpendicular to the first direction; The first phase control element is used to modulate the first linear polarization light into a first circular polarization light; The second phase control element is used to modulate the first circularly polarized light after passing through the first lens assembly into a second linearly polarized light; The second polarizer is a reflective polarizer, the light transmission direction of the second polarizer is the first direction, the reflection direction of the second polarizer is the second direction, the second polarizer is used to reflect the second linear polarization light in the second direction, and transmit the third linear polarization light in the first direction, the third linear polarization light is the light of the second linear polarization light after passing through the first lens assembly, the semi-transmissive and semi-reflective layer, the first lens assembly and the second phase control element in sequence; The third polarizer is an absorbing polarizer, the light transmission direction of the third polarizer is the first direction, the absorption direction of the third polarizer is the second direction, and the third polarizer is used to transmit the third linear polarized light in the first direction and absorb the light in the second direction.

11. The optical system according to any one of claims 1 to 9, characterized in that: The first control component and the second control component are both liquid crystal control components; The first control component is used to perform phase modulation on the light emitted by the display panel; The second control component is used to reflect the first target light and to transmit the second target light, the first target light being the light emitted by the display panel passing through the first control component and the first transmission component. The second target light is the light after the first lens assembly, and the second target light is the light after the first target light passes through the first lens assembly, is reflected by the semi-transmissive and semi-reflective layer, and passes through the first lens assembly again.

12. The optical system according to any one of claims 1 to 9, characterized in that: The wearable display device further includes: a second lens assembly located on a side of the second control assembly away from the display panel; the second lens assembly at least includes: a fifth lens; The refractive index of the fifth lens element is in a range of 1.5 to 1.

75.

13. The optical system according to claim 12, characterized in that The third lens has a fifth surface close to the display panel and a sixth surface far from the display panel; Each of the fifth surface and the sixth surface can be one of a spherical surface, an aspherical surface, a Fresnel surface, a free-form surface, a refractive-diffractive mixed surface, a diffractive surface and a micro-nano structure surface.

14. The optical system according to claim 13, characterized in that The curvature radii of the fifth surface and the sixth surface range from 50 mm to 100 mm, and the ratio of the center thickness to the edge thickness of the fifth lens is greater than 0.5:1 and less than 3:

1.

15. The optical system according to claim 12, characterized in that The second lens assembly further includes: at least one sixth lens located on a side of the fifth lens away from the display panel; each of the sixth lenses has a seventh surface close to the display panel and an eighth surface away from the display panel; Each of the seventh surface and the eighth surface can be one of a spherical surface, an aspherical surface, a Fresnel surface, a free-form surface, a refractive-diffractive mixed surface, a diffractive surface and a micro-nano structure surface.

16. The optical system according to any one of claims 1 to 9, characterized in that: The optical path transmission process of the optical system includes: The display panel emits light; The first control component modulates the light emitted by the display panel into a first polarized light; The semi-transmissive and semi-reflective layer transmits the first light in the first polarized light; The first light is reflected by the second control component after passing through the first lens component; The light reflected by the second control component passes through the first lens component and irradiates the semi-circular The light is transmitted through the semi-transmissive and semi-reflective layer and modulated into a second polarized light by the semi-transmissive and semi-reflective layer; The semi-transmissive and semi-reflective layer reflects the second light in the second polarized light; The second light is transmitted by the second control component after passing through the second lens component.

17. A wearable display device, characterized in that: The wearable display device comprises: a display panel, and an optical system according to any one of claims 1 to 16; The light emitted by the display panel is used to be emitted after passing through the optical system.

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