Optical structure, method of manufacturing the same and display device

Abstract

An optical structure, a manufacturing method thereof and a display device. The optical structure has an incident light side and an emergent light side, and comprises a first lens, a transflective film, a phase delay layer and a polarized reflective film. The first lens comprises oppositely arranged first and second surfaces, the first surface being the surface of the incident light side of the first lens, the transflective film being located on the side of the first surface away from the second surface, the phase delay layer being located on the side of the second surface away from the first surface, and the polarized reflective film being located on the side of the phase delay layer away from the first surface. The phase delay layer comprises an alignment layer and a liquid crystal layer. The manufacturing method comprises: coating the alignment layer on the second surface of the first lens; using an alignment light source to perform light alignment on the alignment layer from the incident light side; and coating the liquid crystal layer on the side of the alignment layer away from the second surface. Thus, the phase delay layer can be directly formed on the first lens, and the conversion efficiency of the complete linearly polarized light and the complete circularly polarized light of the phase delay layer can be improved.

Description

Optical structures, their fabrication methods, and display devices Technical Field

[0001] Embodiments of this disclosure relate to an optical structure, a method for manufacturing the same, and a display device. Background Technology

[0002] In Virtual Reality (VR) and Mixed Reality (MR) devices, near-eye displays magnify the image on the screen using lenses, creating an immersive experience. Currently, the main lens technologies are Fresnel lenses and Pancake (ultra-short focal length folded optical path) lenses. Pancake lenses significantly reduce the distance between the near-eye display and the viewer's eye by folding the optical path, making VR and MR devices thinner and lighter. Summary of the Invention

[0003] To address the problems encountered when forming a phase retardation layer on a lens, especially a curved lens, this disclosure provides an optical structure, a method for manufacturing the same, and a display device. By coating the phase retardation layer onto the lens, the bonding process and its defects can be avoided.

[0004] At least one embodiment of this disclosure provides a method for fabricating an optical structure having an incident light side and an exit light side. The optical structure includes a first lens, a transflective coating, a phase retardation layer, and a polarizing reflective coating. The first lens includes a first surface and a second surface disposed opposite to each other. The first surface is the incident light side surface of the first lens and is curved. The transflective coating is located on the side of the first surface away from the second surface. The phase retardation layer is located on the side of the second surface away from the first surface. The polarizing reflective coating is located on the side of the phase retardation layer away from the first surface. The phase retardation layer includes an alignment layer and a liquid crystal layer. The fabrication method includes: coating the alignment layer on the second surface of the first lens; performing photoalignment of the alignment layer from the incident light side using an alignment light source; and coating the liquid crystal layer on the side of the alignment layer away from the second surface.

[0005] For example, in a method for manufacturing an optical structure provided in an embodiment of this disclosure, when the optical structure is applied to a display device, a display screen is provided on the light-incident side of the optical structure, the optical structure includes a focal point located at the position of the display screen, and the alignment layer is optically aligned from the light-incident side using the alignment light source includes: emitting light from the plane where the focal point is located using the alignment light source to optically align the alignment layer, the plane being perpendicular to the optical axis of the first lens.

[0006] For example, in a method for manufacturing an optical structure provided in an embodiment of this disclosure, the light-emitting surface of the alignment light source is located in the plane where the focal point is located, and the size and shape of the light-emitting surface of the alignment light source are the same as the size and shape of the light-emitting surface of the display screen.

[0007] For example, in a method for fabricating an optical structure provided in one embodiment of this disclosure, the area of ​​the light-emitting surface of the aligned light source is smaller than the area of ​​the orthogonal projection of the phase retardation layer onto the plane.

[0008] For example, in a method for fabricating an optical structure provided in an embodiment of this disclosure, the method of using the alignment light source to perform optical alignment of the alignment layer from the light incident side includes: linearly polarized light emitted by the alignment light source performs optical alignment of the alignment layer from the light incident side, wherein the portion of the linearly polarized light whose propagation direction coincides with the optical axis of the first lens has a first polarization direction, the first polarization direction is perpendicular to the optical axis, and in the plane formed by the first polarization direction and the direction of the optical axis, from the center region to the edge region of the first lens, the angle between the polarization direction of the linearly polarized light incident on the alignment layer and the optical axis becomes smaller and smaller.

[0009] For example, in a method for fabricating an optical structure provided in an embodiment of this disclosure, the angle between the long axis direction of the liquid crystal molecules in the liquid crystal layer and the tangent at the position of the liquid crystal molecules on the second surface ranges from 0 to 40 degrees.

[0010] For example, in a method for fabricating an optical structure provided in an embodiment of this disclosure, the average thickness of the alignment layer is 30-200 nanometers, and the average thickness of the liquid crystal layer is 1-5 micrometers.

[0011] For example, in a method for manufacturing an optical structure provided in an embodiment of this disclosure, the second surface of the first lens includes a curved surface or a flat surface.

[0012] For example, a method for fabricating an optical structure provided in one embodiment of this disclosure further includes: forming the transflective film on the first surface of the first lens; forming the polarizing reflective film on the side of the liquid crystal layer away from the first surface; forming a polarizing absorption layer on the side of the polarizing reflective film away from the first surface; and forming a first antireflective layer on the side of the polarizing absorption layer away from the first surface.

[0013] For example, a method for fabricating an optical structure provided in one embodiment of this disclosure further includes: providing a second lens and a third lens; forming a second antireflection layer on one side of the second lens; forming the transmission-reflection film on a first surface of the first lens; attaching the side of the first lens where the transmission-reflection film is formed to the side of the second lens where the second antireflection layer is not formed; forming a polarization absorption layer on a third surface of the third lens; forming a polarization reflection film on the side of the polarization absorption layer away from the third surface; forming a third antireflection layer on the side of the third lens away from the third surface; and attaching the surface of the first lens where the liquid crystal layer is formed to the side of the third lens where the third antireflection layer is not formed.

[0014] At least one embodiment of this disclosure provides a method for fabricating an optical structure having an incident light side and an exit light side. The optical structure includes a first lens, a transmissive coating, a phase retardation layer, and a polarizing reflective coating. The first lens includes a first surface and a second surface disposed opposite to each other. The first surface is the incident light side surface of the first lens and is curved. The transmissive coating is located on the side of the first surface away from the second surface. The phase retardation layer is located on the side of the second surface away from the first surface. The polarizing reflective coating is located on the side of the phase retardation layer away from the first surface. The phase retardation layer includes a liquid crystal layer. The fabrication method includes: coating the liquid crystal layer on the second surface of the first lens; and performing photo-alignment of the liquid crystal layer from the incident light side using an alignment light source.

[0015] For example, in a method for manufacturing an optical structure provided in an embodiment of this disclosure, when the optical structure is applied to a near-eye display device, a display screen is provided on the light-incident side of the optical structure, and the optical structure includes a focal point located at the position of the display screen. The method of using the alignment light source to perform photo-alignment of the liquid crystal layer from the light-incident side includes: using the alignment light source to emit light from the plane where the focal point is located to perform photo-alignment of the liquid crystal layer, the plane being perpendicular to the optical axis of the first lens, the light-emitting surface of the alignment light source being located in the plane where the focal point is located, and the size and shape of the light-emitting surface of the alignment light source being the same as the size and shape of the light-emitting surface of the display screen.

[0016] At least one embodiment of this disclosure provides an optical structure having an incident light side and an exit light side, comprising: a first lens including a first surface and a second surface disposed opposite to each other, the first surface being the incident light side surface of the first lens and the first surface being curved; a transmissive reflective film located on the side of the first surface away from the second surface; a phase retardation layer located on the side of the second surface away from the first surface; and a polarizing reflective film located on the side of the phase retardation layer away from the first surface, the phase retardation layer being configured to be coated on the second surface of the first lens, the phase retardation layer including a liquid crystal layer, wherein the long axis directions of the liquid crystal molecules of the liquid crystal layer are parallel to each other in orthographic projections onto a plane perpendicular to the optical axis of the first lens, the long axis directions of the liquid crystal molecules intersecting the optical axis are perpendicular to the optical axis, and in the plane formed by the long axis directions of the liquid crystal molecules and the direction of the optical axis, from the center region to the edge region of the first lens, the angle between the long axis directions of the liquid crystal molecules and the optical axis gradually decreases.

[0017] For example, in an optical structure provided in one embodiment of this disclosure, the phase retardation layer further includes an alignment layer located between the liquid crystal layer and the second surface, the alignment layer being configured to be coated on the second surface of the first lens, and the liquid crystal layer being configured to be coated on the alignment layer.

[0018] For example, in an optical structure provided in one embodiment of this disclosure, the angle between the long axis direction of the liquid crystal molecule in the liquid crystal layer and the tangent at the position of the liquid crystal molecule on the second surface ranges from 0 to 40 degrees.

[0019] For example, in an optical structure provided in one embodiment of this disclosure, in the plane formed by the long axis direction of the liquid crystal molecules and the direction of the optical axis, from the center region to the edge region of the first lens, the long axis direction of the liquid crystal molecules of the liquid crystal layer has the same deflection tendency.

[0020] For example, in an optical structure provided in one embodiment of this disclosure, the average thickness of the alignment layer is 30-200 nanometers, and the average thickness of the liquid crystal layer is 1-5 micrometers.

[0021] For example, in an optical structure provided in one embodiment of this disclosure, the second surface of the first lens includes a curved surface.

[0022] For example, in an optical structure provided in one embodiment of this disclosure, the second surface of the first lens includes a plane. In the plane formed by the long axis direction of the liquid crystal molecules and the direction of the optical axis, the line connecting the centers of the liquid crystal molecules of the liquid crystal layer is not parallel to the second surface, and the center of the line is farther away from the second surface than the edge of the line.

[0023] For example, an optical structure provided in one embodiment of this disclosure further includes: a second lens located on the side of the first surface away from the second surface; a second antireflection layer located on the side of the second lens away from the first lens; a third lens located on the side of the first lens away from the second lens, including a third surface; a polarization absorption layer located on the third surface of the third lens; and a third antireflection layer located on the side of the third lens away from the first lens, wherein the polarization reflection film is located on the third lens and on the side of the polarization absorption layer away from the third surface, the side of the first lens with the reflective film is bonded to the side of the second lens without the second antireflection layer, and the side of the first lens with the liquid crystal layer is bonded to the side of the third lens without the third antireflection layer.

[0024] At least one embodiment of this disclosure provides a display device, including a display screen and the optical structure described above, wherein the display screen is located on the light-incident side of the optical structure. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this disclosure and are not intended to limit this disclosure.

[0026] Figure 1 is a schematic diagram of the structure of a Pancake lens;

[0027] Figure 2 is a flowchart of a method for fabricating an optical structure according to an embodiment of this disclosure;

[0028] Figure 3 is a schematic diagram of the optical alignment of the phase retardation layer of the optical structure shown in Figure 2;

[0029] Figure 4 is a schematic diagram of the optical path used for display by the optical structure shown in Figure 2;

[0030] Figure 5 is a cross-sectional schematic diagram of the liquid crystal layer shown in Figure 2;

[0031] Figure 6 is a schematic diagram of the projection of the liquid crystal molecules of the liquid crystal layer shown in Figure 2 onto a plane perpendicular to the optical axis.

[0032] Figure 7 is a flowchart of another method for fabricating an optical structure according to an embodiment of this disclosure;

[0033] Figure 8 is a schematic diagram of the optical structure formed according to the fabrication method in Figure 7;

[0034] Figure 9 is a flowchart of another method for fabricating an optical structure according to an embodiment of this disclosure;

[0035] Figure 10 is a schematic diagram of the optical alignment of the phase retardation layer of the optical structure shown in Figure 9;

[0036] Figure 11 is a partial optical path diagram of the optical structure shown in Figure 10 at the position of the dashed box when it is used for display.

[0037] Figure 12 is a cross-sectional schematic diagram of the liquid crystal layer shown in Figure 9;

[0038] Figure 13 is a flowchart of another method for fabricating an optical structure according to an embodiment of this disclosure;

[0039] Figure 14 is a schematic diagram of the optical alignment of the phase retardation layer of the optical structure shown in Figure 13;

[0040] Figure 15 is a flowchart of another method for fabricating an optical structure according to an embodiment of this disclosure;

[0041] Figure 16 is a schematic diagram of the optical alignment of the phase retardation layer of the optical structure shown in Figure 15;

[0042] Figure 17 is a cross-sectional schematic diagram of an optical structure provided in an embodiment of this disclosure;

[0043] Figure 18 is a cross-sectional schematic diagram of another optical structure provided in an embodiment of this disclosure;

[0044] Figure 19 is a cross-sectional schematic diagram of another optical structure provided in an embodiment of the present disclosure;

[0045] Figure 20 is a cross-sectional schematic diagram of another optical structure provided in an embodiment of this disclosure;

[0046] Figure 21 is a cross-sectional schematic diagram of the liquid crystal layer of the optical structure shown in Figure 20;

[0047] Figure 22 is a cross-sectional schematic diagram of another optical structure provided in an embodiment of this disclosure;

[0048] Figure 23 is a cross-sectional schematic diagram of the liquid crystal layer of the optical structure shown in Figure 22; and

[0049] Figure 24 is a schematic diagram of a display device provided in an embodiment of this disclosure. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0051] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that an element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0052] Unless otherwise defined, the characteristics such as "parallel," "perpendicular," and "identical" used in the embodiments of this disclosure include strictly defined cases of "parallel," "perpendicular," and "identical," as well as cases involving a certain margin of error, such as "approximately parallel," "approximately perpendicular," and "approximately identical." For example, the aforementioned "approximately" may indicate that the difference between the compared objects is within 10% or 5% of the average value of the compared objects. Unless otherwise specified in the following embodiments of this disclosure, the quantity of a component or element is implied to mean that the component or element may be one or more, or can be understood as at least one. "At least one" refers to one or more, and "more" refers to at least two.

[0053] Pancake lenses have become the mainstream lens technology for near-eye display systems in virtual reality and mixed reality, adopted by various virtual reality and mixed reality near-eye display manufacturers. A pancake lens typically includes a lens and a transmissive coating, a phase retardation coating, a polarizing reflective coating, and a polarizing absorption coating formed on the lens. The transmissive coating can simultaneously reflect and transmit light; for example, it can be a semi-transmissive, semi-reflective coating. The phase retardation coating has a fast axis and a slow axis, capable of converting circularly polarized light into linearly polarized light, or vice versa. The polarizing reflective coating has a reflection axis and a transmission axis. It reflects linearly polarized light parallel to the reflection axis while maintaining the polarization state of that light, and transmits linearly polarized light parallel to the transmission axis while maintaining its polarization state. The polarizing absorption coating has a transmission axis, parallel to the transmission axis of the polarizing reflective coating. The fast axis of the phase retardation coating forms a 45-degree or 135-degree angle with the transmission axis of the polarizing reflective coating.

[0054] Figure 1 is a schematic diagram of a Pancake lens. As shown in Figure 1, the Pancake lens includes a lens group consisting of lens 01 and lens 02. Lens 01 has a transmissive reflective film 03 and a phase retardation film 04 formed on it, and lens 02 has a polarizing reflective film 05 formed on it. The light emitted from the display screen 06 completes the optical path folding after passing through the Pancake lens, which shortens the space required by the lens group.

[0055] Table 1 shows the development trend of pancake lenses, the corresponding problems, and general pancake lenses for addressing these problems.

[0056] Table 1:

[0057]

[0058] As can be seen from the table above, to address the problems encountered in the development trend of pancake lenses, the solutions generally offered by pancake lenses are more of a compromise. One important reason for this compromise is the physical characteristics of the phase retardation film, a crucial optical element within pancake lenses. Pancake lenses require the phase retardation film to maintain its original birefringence properties when formed on the lens surface. However, with existing technologies, the birefringence properties of phase retardation films inevitably change after being formed on curved lens surfaces.

[0059] As a key optical component for converting between linearly polarized and circularly polarized light, the phase retardation film is crucial in determining the quality of a pancake lens. An ideal phase retardation film enables light to convert between completely linearly polarized light (ellipticity = 0) and completely circularly polarized light (ellipticity = 1), ensuring that all light rays in the display screen follow the preset folded light path to reach the human eye. If the phase retardation film deviates from the ideal state, linearly polarized light will become elliptically polarized light (0 < ellipticity < 1) after passing through the phase retardation film. Consequently, some light will not follow the preset folded light path and will reach the human eye, forming ghosting and stray light.

[0060] Currently, phase retardation films suitable for pancake lenses are manufactured using the following two methods: 1) By stretching a polymer film, the molecules are stretched and arranged regularly, thus forming a polymer phase retardation film with birefringence and a thickness of approximately 40-60 micrometers. 2) By uniformly coating a solution of liquid crystal molecules onto a polymer film, and then aligning the liquid crystal molecules to arrange them regularly, a phase retardation coating with birefringence and a thickness of approximately 1-5 micrometers is formed.

[0061] In their research, the inventors of this application discovered that both phase retardation films manufactured using the above method are applied to pancake lenses via bonding, i.e., the thin-film phase retardation film is adhered to the lens surface using an adhesive. This bonding method has the following drawbacks: 1) Applying the optical film to the lens with an adhesive makes precise control of flatness difficult. Because the adhesive is relatively soft, uneven stress during bonding is easily reflected at the interface between the film and the adhesive, affecting image formation and causing distortion. 2) Bonding a soft film material to a hard lens with an adhesive carries reliability risks, especially when the bonding interface is curved, making it prone to common adhesive failure problems such as film wrinkling, delamination, bubbling, and fogging. 3) If the surface of the lens used to attach the phase retardation film is planar, the further away from the optical axis of the lens, the larger the incident angle of the light rays incident on the phase retardation film in the designed optical path. Due to the material properties of the phase retardation film, when the light is incident at an angle, its phase retardation characteristics will change compared to when the light is incident perpendicularly, because of the phase retardation Rth in the thickness direction. This results in a lower ellipticity of the polarized light incident at an angle. Adding a compensation film (e.g., a positive C film) can compensate for the aforementioned large-angle phase retardation change, but the degree of compensation is anisotropic, providing complete compensation only in a specific direction, and it increases cost and manufacturing complexity. 4) If the surface of the lens used to bond the phase retardation film is curved, the phase retardation film, which was originally a planar thin film, must be stretched in order to be perfectly bonded to the curved surface. For the phase retardation film manufactured by the first method, its phase retardation is obtained by stretching. The additional stretching during the bonding process will cause changes in the retardation, and these changes are likely to be uneven and uncontrollable. This makes the ghosting and stray light conditions of the final pancake uneven and uncontrollable. For the phase retardation film manufactured by the second method, although the change in retardation caused by stretching during the transfer process is theoretically weaker than that of the first method, the process of transferring a coating with a thickness of only 1-5 micrometers to a curved surface is extremely challenging.

[0062] This disclosure provides a method for fabricating an optical structure. The optical structure has an incident light side and an exit light side, and includes a first lens, a transmissive coating, a phase retardation layer, and a polarizing reflective coating. The first lens includes a first surface and a second surface disposed opposite to each other. The first surface is the incident light side surface of the first lens and is curved. The transmissive coating is located on the side of the first surface away from the second surface. The phase retardation layer is located on the side of the second surface away from the first surface. The polarizing reflective coating is located on the side of the phase retardation layer away from the first surface. The phase retardation layer includes an alignment layer and a liquid crystal layer. The method for fabricating this optical structure includes: coating the alignment layer on the second surface of the first lens; performing photo-alignment of the alignment layer from the incident light side using an alignment light source; and coating the alignment layer on the side of the alignment layer away from the second surface.

[0063] In the method for fabricating the optical structure provided in this embodiment, an alignment layer is coated on a first lens and a liquid crystal layer is coated on the alignment layer, so that the phase retardation layer can be directly formed on the first lens without the need to use an adhesive to bond the phase retardation layer to the first lens. This avoids the process of transferring the phase retardation layer to the first lens and also avoids the defects caused by the bonding process.

[0064] In this embodiment, the molecular structure of the alignment layer is aligned according to the light emitted by the alignment light source. A liquid crystal layer is coated on the alignment layer after alignment. The liquid crystal molecules of the liquid crystal layer are arranged according to the alignment direction of the alignment layer. The liquid crystal molecules have a long axis direction and a short axis direction. For example, the long axis direction of the liquid crystal molecules can be arranged according to the alignment direction of the alignment layer. The long axis direction and the short axis direction have different refractive indices. The incident light used for display undergoes phase delay after passing through the phase retardation layer, thereby realizing the conversion between linearly polarized light and circularly polarized light.

[0065] This optical structure can be used in conjunction with a display screen. Light emitted from the display screen passes through the first surface of the first lens from the incident light side to the phase retardation layer. Light emitted from the alignment light source passes through the first surface of the first lens from the incident light side to the alignment layer. Therefore, the incident angles of the light emitted from the alignment light source and the light emitted from the display screen at the same location on the second surface of the first lens are close. Consequently, at every location on the alignment layer coated on the second surface of the first lens, the incident angle of the light emitted from the alignment light source is close to the incident angle of the light used for display. A liquid crystal layer is coated on the alignment layer after alignment by the alignment light source. The liquid crystal molecules are arranged according to the alignment direction of the alignment layer. Therefore, the arrangement direction of the liquid crystal molecules can better match the incident angle of the light used for display. The phase retardation layer can achieve the conversion between fully linearly polarized light and fully circularly polarized light as much as possible, improving the conversion efficiency of the phase retardation layer between fully linearly polarized light and fully circularly polarized light.

[0066] This disclosure provides another method for fabricating an optical structure. The difference between this optical structure and the one described above is that the phase retardation layer consists only of a liquid crystal layer. The method for fabricating this optical structure includes: coating a liquid crystal layer on the second surface of a first lens; and using an alignment light source to perform photoalignment of the liquid crystal layer from the incident light side.

[0067] In the method for manufacturing the optical structure provided in this embodiment, the phase retardation layer is coated on the first lens. It is not necessary to use an adhesive to bond the phase retardation layer to the first lens. This avoids both the process of transferring the phase retardation layer to the first lens and the defects caused by the bonding process.

[0068] In this example, the light emitted from the alignment light source passes through the first surface of the first lens from the incident light side to the liquid crystal layer. Therefore, the incident angles of the light emitted from the alignment light source and the light emitted from the display screen at the same location on the second surface of the first lens are close. Consequently, at every location on the liquid crystal layer coated on the second surface of the first lens, the incident angle of the light emitted from the alignment light source is close to the incident angle of the light used for display. After the liquid crystal layer is aligned by this alignment light source, the arrangement direction of the liquid crystal molecules can be better matched with the incident angle of the light used for display. The phase retardation layer can achieve the conversion between fully linearly polarized light and fully circularly polarized light as much as possible, improving the conversion efficiency of the phase retardation layer between fully linearly polarized light and fully circularly polarized light.

[0069] This disclosure provides an optical structure. The optical structure has an incident light side and an exit light side, and includes a first lens, a transmissive coating, a phase retardation layer, and a polarizing reflective coating. The first lens includes a first surface and a second surface disposed opposite to each other. The first surface is the incident light side surface of the first lens and is curved. The transmissive coating is located on the side of the first surface away from the second surface. The phase retardation layer is located on the side of the second surface away from the first surface, and the polarizing reflective coating is located on the side of the phase retardation layer away from the first surface. The phase retardation layer is configured to be coated on the second surface of the first lens. The phase retardation layer includes a liquid crystal layer. The long axis directions of the liquid crystal molecules in the liquid crystal layer are parallel to each other when projected onto a plane perpendicular to the optical axis of the first lens. The long axis directions of the liquid crystal molecules intersecting the optical axis are perpendicular to the optical axis. In the plane formed by the long axis directions of the liquid crystal molecules and the optical axis, the angle between the long axis directions of the liquid crystal molecules and the optical axis decreases from the center region to the edge region of the first lens.

[0070] In the optical structure provided in this embodiment, the phase retardation layer is configured to be coated on the second surface of the first lens, so that the phase retardation layer can be directly formed on the first lens without the need for adhesive to bond the phase retardation layer to the first lens. This avoids both the process of transferring the phase retardation layer to the first lens and the defects caused by the bonding process. In this example, the second surface is curved; however, this embodiment does not limit this.

[0071] In this embodiment, the propagation direction of the light emitted from the incident light side for display is parallel to the optical axis of the first lens. Since the first surface of the first lens is curved, the angle between the propagation direction of the light for display incident on the second surface and the optical axis increases from the center region to the edge region of the first lens within the plane. Based on the changing trend of the propagation direction of the incident light for display, by setting the angle between the long axis of the liquid crystal molecules and the optical axis to become smaller and smaller, the long axis of the liquid crystal molecules can always be perpendicular or nearly perpendicular to the propagation direction of the incident light. Therefore, the phase retardation layer can achieve the conversion between fully linearly polarized light and fully circularly polarized light as much as possible, improving the conversion efficiency of the phase retardation layer between fully linearly polarized light and fully circularly polarized light.

[0072] The optical structure, its manufacturing method, and the display device provided in the embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0073] This disclosure provides a method for fabricating an optical structure. Figure 2 is a flowchart of a method for fabricating an optical structure according to an embodiment of this disclosure; Figure 3 is a schematic diagram of the light alignment of the phase retardation layer of the optical structure shown in Figure 2. As shown in Figures 2 and 3, the optical structure 100 has an incident light side S1 and an exit light side S2, and the optical structure 100 includes a first lens 110, a transmissive-reflective film 120, a phase retardation layer 130, and a polarizing-reflective film 140. The first lens 110 includes a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 is the surface of the light-incident side S1 of the first lens 110 and the first surface 111 is curved. The transmissive film 120 is located on the side of the first surface 111 away from the second surface 112. The phase retardation layer 130 is located on the side of the second surface 112 away from the first surface 111. The polarizing reflective film 140 is located on the side of the phase retardation layer 130 away from the first surface 111. The phase retardation layer 130 includes an alignment layer 131 and a liquid crystal layer 132. The method for fabricating the optical structure 100 includes: 1) coating the alignment layer 131 on the second surface 112 of the first lens 110; 2) performing photo-alignment of the alignment layer 131 from the light-incident side S1 using an alignment light source L; 3) coating the liquid crystal layer 132 on the side of the alignment layer 131 away from the second surface 112.

[0074] In the fabrication method of the optical structure 100 provided in this embodiment, an alignment layer 131 is coated on the first lens 110, and a liquid crystal layer 132 is coated on the alignment layer 131. Therefore, the phase retardation layer 130 can be directly formed on the first lens 110 without the need for adhesive bonding. This avoids the process of transferring the phase retardation layer 130 to the first lens 110 and also avoids defects associated with bonding processes. In this example, the second surface 112 is curved; however, this embodiment is not limited to this. For example, the second surface 112 can also be planar.

[0075] In this embodiment, the molecular structure of the alignment layer 131 is aligned according to the light emitted by the alignment light source L. A liquid crystal layer 132 is coated on the aligned alignment layer 131. The liquid crystal molecules of the liquid crystal layer 132 are arranged according to the alignment direction of the alignment layer 131. The liquid crystal molecules have a long axis direction and a short axis direction. For example, the long axis direction of the liquid crystal molecules can be arranged according to the alignment direction of the alignment layer 131. The long axis direction and the short axis direction have different refractive indices. The incident light used for display undergoes phase delay after passing through the phase retardation layer 130, thereby realizing the conversion between linearly polarized light and circularly polarized light.

[0076] Figure 4 is a schematic diagram of the optical path of the optical structure shown in Figure 2 for display. As shown in Figures 2 and 4, the optical structure 100 can be used in conjunction with the display screen 210 for display. The light emitted from the display screen 210 passes through the first surface 111 of the first lens 110 from the light incident side S1 to the phase retardation layer 130. The light emitted from the alignment light source L passes through the first surface 111 of the first lens 110 from the light incident side S1 to the alignment layer 131. Thus, the incident angle of the light emitted from the alignment light source L and the light emitted from the display screen 210 at the same position on the second surface 112 of the first lens 110 is close. Therefore, at each position of the alignment layer 131 coated on the second surface 112 of the first lens 110, the incident angle of the light emitted from the alignment light source L is close to the incident angle of the light used for display. A liquid crystal layer 132 is coated on an alignment layer 131 after alignment by an alignment light source L. The liquid crystal molecules are arranged according to the alignment direction of the alignment layer 131. Therefore, the arrangement direction of the liquid crystal molecules can better match the incident angle of the light used for display. The phase retardation layer 130 can achieve the conversion between fully linearly polarized light and fully circularly polarized light as much as possible, improving the conversion efficiency of the phase retardation layer 130 between fully linearly polarized light and fully circularly polarized light. This disclosure does not limit the type of liquid crystal molecules or their arrangement direction. For example, the liquid crystal molecules can be nematic liquid crystals or smectic liquid crystals. For example, the arrangement direction of the liquid crystal molecules can be the long axis direction of the liquid crystal molecules.

[0077] For example, as shown in Figure 3, the light emitted by the alignment light source L can be linearly polarized light. For example, the wavelength of the light emitted by the alignment light source L can be the wavelength that causes photoalignment of the alignment layer 131. The alignment direction of the alignment layer 131 is the polarization direction of the linearly polarized light. After the liquid crystal layer 132 is coated on the alignment layer 131, the long axis of the liquid crystal molecules is arranged according to the alignment direction of the alignment layer 131, that is, the long axis is perpendicular to the propagation direction of the light incident from the alignment light source L onto the phase retardation layer 130. Therefore, the propagation direction of the incident light after it is incident on the phase retardation layer 130 is perpendicular or nearly perpendicular to the long axis of the liquid crystal molecules. The phase retardation layer 130 can achieve the conversion of light between completely linearly polarized light and completely circularly polarized light as much as possible.

[0078] For example, the alignment light source L can be one or more point light sources, or it can be a surface light source.

[0079] In some examples, as shown in Figures 2 to 4, when the optical structure 100 is applied to a display device, a display screen 210 is provided on the light-incident side S1 of the optical structure 100. The optical structure 100 includes a focal point F located at the position of the display screen 210. Optical alignment of the alignment layer 131 using an alignment light source L from the light-incident side S1 includes emitting light from the plane P1 where the focal point F is located to optically align the alignment layer 131. The plane P1 is perpendicular to the optical axis OA of the first lens 110. By emitting light from the plane P1 where the focal point F is located using the alignment light source L, the incident angles of the light emitted by the alignment light source L and the light emitted by the display screen 210 at the same position on the second surface 112 of the first lens 110 are closer. This allows the arrangement direction of the liquid crystal molecules to be more closely matched with the light used for display, enabling the phase retardation film to achieve the transition between completely linearly polarized light and completely circularly polarized light as much as possible. The focal point F in this disclosure can also be the object-side focal point of the optical structure.

[0080] In some examples, as shown in Figures 2 to 4, the light-emitting surface of the alignment light source L is located within the plane P1 where the focal point F is located, and the size and shape of the light-emitting surface of the alignment light source L are the same as the size and shape of the light-emitting surface of the display screen 210. Therefore, the light emitted from the alignment light source L and the light emitted from the display screen 210 reach the same position on the second surface 112 of the first lens 110 at the same angle of incidence. The alignment layer 131, aligned by the alignment light source L, allows the liquid crystal molecules to be perfectly matched with the light used for display.

[0081] For example, the long axis of the liquid crystal molecules is arranged according to the alignment direction of the alignment layer 131. At any position on the second surface 112 of the first lens 110, the propagation direction of the light emitted from the display screen 210 for display is perpendicular to the long axis of the liquid crystal molecules. Thus, at any position on the second surface 112 of the first lens 110, the phase retardation layer 130 can realize the conversion between fully linearly polarized light and fully circularly polarized light. This embodiment does not limit the size and shape of the light-emitting surface of the light source; it can be designed according to the size and shape of the display screen 210 that is matched with the optical structure 100.

[0082] For example, the diagonal dimension or diameter of the light-emitting surface of the alignment light source L can be 1.3 inches, 1.35 inches, or 1.4 inches. Of course, the embodiments of this disclosure do not limit the shape, aspect ratio, or diameter of the alignment light source L, but match it according to the shape of the actual display screen 210.

[0083] In some examples, the area of ​​the emitting surface of the aligned light source L is smaller than the area of ​​the orthogonal projection of the phase retardation layer 130 onto the plane P1.

[0084] In some examples, as shown in Figures 2 and 3, the optical alignment of the alignment layer 131 from the incident light side S1 using an alignment light source L includes: linearly polarized light emitted from the alignment light source L optically aligning the alignment layer 131 from the incident light side S1. Among the linearly polarized light emitted from the alignment light source L, the linearly polarized light whose propagation direction coincides with the optical axis OA of the first lens 110 has a first polarization direction Y, which is perpendicular to the optical axis OA. Within the plane P2 formed by the first polarization direction Y and the direction X where the optical axis OA is located, from the central region 110a to the edge region 110b of the first lens 110, the angle θ1 between the polarization direction of the linearly polarized light incident on the alignment layer 131 and the optical axis OA gradually decreases.

[0085] In this disclosure, within plane P2, the geometric center 110a and the edge region 110b of the first lens 110 are located on the same side of the geometric center of the first lens 110. The central region 110a of the first lens 110 may refer to the location of the geometric center of the first lens 110. For example, the geometric center of the central region 110a coincides with the geometric center of the first lens 110, the shape of the central region 110a is approximately the same as the shape of the first lens 110, and the area of ​​the central region 110a is less than or equal to 10% of the area of ​​the first lens 110. The edge region 110b of the first lens 110 is approximately located at the outer contour of the first lens 110. For example, the shape of the edge region 110b is approximately the same as the outer contour of the first lens 110 and forms a closed ring along the outer contour of the first lens 110.

[0086] Figure 5 is a cross-sectional schematic diagram of the liquid crystal layer shown in Figure 2. As shown in Figures 2 to 5, after the alignment layer 131 is aligned using the alignment light source L, the liquid crystal layer 132 is coated on the alignment layer 131. The liquid crystal molecules in the liquid crystal layer 132 are arranged according to the alignment direction of the alignment layer 131. The arrangement direction of each liquid crystal molecule is the direction of the dashed line at the position of the liquid crystal molecule in Figure 5. For example, the arrangement direction of the liquid crystal molecules can be the direction of the long axis of the liquid crystal molecules. Thus, on the optical axis OA of the first lens 110, the arrangement direction of the liquid crystal molecules is perpendicular to the optical axis OA. In plane P2, from the central region 110a to the edge region 110b of the first lens 110, the angle θ2 between the arrangement direction of the liquid crystal molecules and the optical axis OA becomes smaller and smaller. That is, on the second surface 112 of the first lens 110, the arrangement of the liquid crystal molecules is not always perpendicular to the optical axis OA; the arrangement direction of the liquid crystal molecules changes. The propagation direction of the incident light emitted from the light-incident side S1 of the display screen 210 for display is parallel to the optical axis OA of the first lens 110, and the angle between them is zero. Within plane P2, since the first surface 111 of the first lens 110 is curved, the angle between the propagation direction of the incident light for display incident on the second surface 112 and the optical axis OA increases from the central region 110a to the edge region 110b of the first lens 110. Therefore, the change trend of the liquid crystal molecule arrangement direction can be matched with the change trend of the incident light propagation direction, ensuring that the liquid crystal molecule arrangement direction is always perpendicular or nearly perpendicular to the propagation direction of the incident light. This allows the phase retardation layer 130 to achieve the conversion between fully linearly polarized light and fully circularly polarized light as much as possible, improving the conversion efficiency of the phase retardation layer 130 between fully linearly polarized light and fully circularly polarized light. Figure 5 schematically shows only one sublayer of the liquid crystal layer 132 and the second surface 112. The liquid crystal layer 132 may include multiple sublayers.

[0087] It should be noted that the first polarization direction Y is at 45 degrees or 135 degrees to the transmission axis of the polarization reflective film 140, and the long axis of the liquid crystal molecules on the optical axis OA is at 45 degrees or 135 degrees to the transmission axis of the polarization reflective film 140.

[0088] For example, the long axis of the liquid crystal molecules is arranged according to the alignment direction of the alignment layer 131. At the optical axis OA, the long axis of the liquid crystal molecules is perpendicular to the incident light used for display. Within plane P2, from the central region 110a to the edge region 110b of the first lens 110, the angle θ2 between the long axis of the liquid crystal molecules and the optical axis OA gradually decreases, while the angle between the propagation direction of the incident light used for display and the optical axis OA gradually increases. Therefore, based on the changing trend of the incident light used for display, the long axis of the liquid crystal molecules at any position can be made perpendicular or nearly perpendicular to the propagation direction of the incident light used for display.

[0089] In some examples, as shown in Figures 3 and 5, within plane P2, the angle θ3 between the long axis of the liquid crystal molecules in liquid crystal layer 132 and the tangent plane P3 at the position of the liquid crystal molecules on the second surface 112 ranges from 0 to 40 degrees. Therefore, the long axis of the liquid crystal molecules can be approximately arranged along the second surface 112, and the propagation direction of incident light from the display screen 210 through the first surface 111 to the alignment layer is approximately perpendicular to the second surface 112, thus the propagation direction of the incident light is approximately perpendicular to the long axis of the liquid crystal molecules. Of course, this embodiment does not limit the range of the angle θ3; it can be matched and designed according to the shape of the first lens 110, the position of the focal point F, and the size of the display screen 210.

[0090] In some examples, as shown in Figure 5, within plane P2, from the central region 110a to the edge region 110b of the first lens 110, the long axis direction of the liquid crystal molecules exhibits the same deflection trend. For example, as shown in Figure 5, the long axis direction of the liquid crystal molecules is deflected away from the second surface 112. For example, from the central region 110a to the edge region 110b, the deflection angle of the long axis direction of the liquid crystal molecules increases.

[0091] In some examples, as shown in Figure 5, the angle θ3 between the long axis of the liquid crystal molecule traversed by the optical axis OA and the corresponding sectional plane P3 is approximately 0 degrees. Within plane P2, from the central region 110a to the edge region 110b of the first lens 110, the angle θ3 between the long axis of the liquid crystal molecule and the corresponding sectional plane P3 gradually increases. In the edge region 110b, the angle θ3 between the long axis of the liquid crystal molecule and the corresponding sectional plane P3 is less than or equal to 40 degrees. Of course, the numerical value of the angle θ3 is not limited in this embodiment.

[0092] Figure 6 is a schematic diagram of the projection of the liquid crystal molecules of the liquid crystal layer shown in Figure 2 onto a plane perpendicular to the optical axis. As shown in Figures 2 and 6, the orthographic projections of the long axis directions of the liquid crystal molecules in the liquid crystal layer 132 onto the plane P1 perpendicular to the optical axis OA are parallel to each other. Along the direction after the long axis projection, from the central region 110a of the first lens 110 to the edge region 110b, the projected length of the long axis of the liquid crystal molecules becomes smaller and smaller.

[0093] In some examples, as shown in Figure 6, the long axis of the liquid crystal molecules in the liquid crystal layer 132 is projected onto the plane P1 at an angle of 45 degrees or 135 degrees to the transmission axis of the polarizing reflective film 140.

[0094] In some examples, as shown in Figure 2, the method of fabricating the optical structure 100 further includes: 4) sequentially attaching a polarizing reflective film 140, a polarizing absorption layer 150 and a first antireflective layer 160 to the side of the liquid crystal layer 132 away from the first surface 111.

[0095] In some examples, as shown in Figure 2, the method of fabricating the optical structure 100 further includes forming a transflective coating 120 on the first surface 111 of the first lens 110.

[0096] In some examples, as shown in Figure 2, a transparent resin lens is formed by injection molding to serve as the first lens 110. For example, the first surface 111 of the first lens 110 is convex, and the second surface 112 is concave.

[0097] In some examples, as shown in FIG2, a transflective coating 120 is formed on the first surface 111 of the first lens 110 by means of a coating. For example, the transflective coating 120 can be a semi-transparent and semi-reflective coating with both reflectivity and transmittance of 50%. Of course, the embodiments of this disclosure do not limit the transflective coating 120, and the reflectivity can be between 30% and 70%, and the corresponding transmittance can be between 70% and 30%, depending on the actual situation.

[0098] In some examples, as shown in Figure 2, an alignment layer 131 is formed by coating and drying on the second surface 112 of the first lens 110 using a liquid phase coating method. For example, liquid phase coating methods such as spin coating, dip coating, ultrasonic atomization deposition, inkjet printing, and electrohydraulic printing can be used. Under polarized light irradiation, the alignment layer 131 can undergo anisotropic photoresponse, such as photocrosslinking alignment, forming its own orientation. A liquid crystal layer 132 is coated on the aligned alignment layer 131, and the liquid crystal molecules will arrange themselves according to the orientation of the alignment layer 131.

[0099] In some examples, the main chemical composition of alignment layer 131 can be small molecules or polymers with photosensitive properties. For example, small molecules can be molecules with long conjugated structures that respond to polarized light, such as biphenyls, polybiphenyls, and azo compounds. For example, polymers can be materials that can undergo photopolymerization, photodegradation, or photoisomerization under polarized light, such as polyvinyl cinnamic acid, polymethyl methacrylate, polybiphenyls, polypolybiphenyls, polyamic acids, polyimides, coumarins, and azo compounds.

[0100] In some examples, the average thickness of the alignment layer 131 after alignment is 30-200 nanometers. For example, the average thickness of the alignment layer is 50-100 nanometers. For example, the average thickness of the alignment layer is 70-150 nanometers.

[0101] In some examples, as shown in Figure 2, a liquid crystal layer 132 is coated onto the aligned layer 131 using a wet coating method. For example, wet coating methods such as spin coating, flow coating, ultrasonic atomization deposition, inkjet printing, and electrohydraulic printing can be used. For instance, the average thickness of the wet liquid crystal film coated using this method is 5-100 micrometers.

[0102] In some examples, the main chemical composition of the liquid crystal layer 132 may be rod-shaped liquid crystal molecules with polymerizable groups, photopolymerization initiators, solvents, crosslinking resins, etc., with a solid content of 1-30% wt. The solvent can dissolve the liquid crystal molecules, initiators, and other components, and may be, but is not limited to, ketones, haloalkanes, heterocyclic compounds, hydrocarbons, esters, ethers, amides, etc. The initiator may be a photoinitiator, which may be one or a mixture of several, with a content of 0.1-10% wt. This disclosure does not limit the main component of the rod-shaped liquid crystal molecules; one or more rod-shaped liquid crystal molecules may be used, with liquid crystal molecules having reverse wavelength dispersion characteristics preferred. Examples of polymerizable groups include vinyl, acryloyl, methacryloyl, epoxy, etc., and the crosslinking agent may be, but is not limited to, isocyanates, acrylates, methacrylates, epoxy resins, carbodiimides, amino resins, etc. This disclosure does not limit the liquid crystal wet film solution. It should be noted that the process of drying and crosslinking the liquid crystal wet film to obtain the liquid crystal coating does not require a surface light source of a specific position and size.

[0103] For example, the average thickness of the cross-linked liquid crystal layer 132 or liquid crystal dry film is 1-5 micrometers. For example, this average thickness can be any value within the range of 1-5 micrometers.

[0104] In some examples, the polarizing reflective film 140, the polarizing absorption layer 150, and the first antireflective layer 160 are sequentially bonded to the side of the liquid crystal layer 132 away from the first surface 111 using stretch bonding or thermoforming bonding. This disclosure does not limit the polarizing reflective film 140, the polarizing absorption layer 150, and the first antireflective layer 160.

[0105] Figure 7 is a flowchart of another method for fabricating an optical structure according to an embodiment of this disclosure; Figure 8 is a schematic diagram of an optical structure formed according to the fabrication method of Figure 7. As shown in Figures 7 and 8, the method for fabricating the optical structure 100 includes:

[0106] S110: Provides a first lens 110, a second lens 170, and a third lens 180;

[0107] S120: A second antireflection layer 161 is formed on one side of the second lens 170, a transmissive film 120 is formed on the first surface 111 of the first lens 110, and the side of the first lens 110 with the transmissive film 120 is attached to the side of the second lens 170 without the second antireflection layer 161.

[0108] S130: An alignment layer 131 is coated on the second surface 112 of the first lens 110, and an alignment light source is used to perform optical alignment on the alignment layer 131 from the light incident side S1.

[0109] S140: A liquid crystal layer 132 is coated on the side of the alignment layer 131 away from the second surface 112 to form a phase retardation layer 130;

[0110] S150: A polarization absorption layer 150 is formed on the third surface 181 of the third lens 180, a polarization reflection film 140 is formed on the side of the polarization absorption layer 150 away from the third surface 181, and a third antireflection layer 162 is formed on the side of the third lens 180 away from the third surface 181.

[0111] S160: The surface of the first lens 110 where the liquid crystal layer 132 is formed is bonded to the side of the third lens 180 where the third antireflection layer 162 is not formed, to form an optical structure 100.

[0112] The embodiments disclosed herein do not impose any restrictions on the order of the steps, and adjustments can be made according to the actual situation.

[0113] In some examples, as shown in Figures 7 and 8, transparent resin lenses are formed by injection molding to serve as the first lens 110, the second lens 170, and the third lens 180. For example, the first surface 111 of the first lens 110 is convex, and the second surface 112 is concave.

[0114] In some examples, as shown in Figures 7 and 8, the light-emitting surface of the aligned light source is located at the position of the display screen matched with the optical structure 100 formed by the first lens 110, the second lens 170, and the third lens 180. For example, the size and shape of the light-emitting surface of the aligned light source are the same as the size and shape of the light-emitting surface of the display screen.

[0115] In some examples, the side of the third lens 180 away from the third surface 181 can be hardened before the third antireflection layer 162 is formed on the side of the third lens 180 away from the third surface 181, thereby improving the product performance of the optical structure 100.

[0116] In some examples, the optical structure 100 may also consist of two or more lenses, the manufacturing process of which is described above and will not be repeated here.

[0117] Figure 9 is a flowchart of another method for fabricating an optical structure according to an embodiment of this disclosure; Figure 10 is a schematic diagram of the light alignment of the phase retardation layer of the optical structure shown in Figure 9. As shown in Figures 9 and 10, the optical structure 100 has an incident light side S1 and an exit light side S2, and the optical structure 100 includes a first lens 110, a transmissive-reflective film 120, a phase retardation layer 130, and a polarizing-reflective film 140. The first lens 110 includes a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 is the surface of the light-incident side S1 of the first lens 110 and the first surface 111 is curved. The transmissive film 120 is located on the side of the first surface 111 away from the second surface 112. The phase retardation layer 130 is located on the side of the second surface 112 away from the first surface 111. The polarizing reflective film 140 is located on the side of the phase retardation layer 130 away from the first surface 111. The phase retardation layer 130 includes an alignment layer 131 and a liquid crystal layer 132. The method for fabricating the optical structure 100 includes: 1) coating the alignment layer 131 on the second surface 112 of the first lens 110; 2) performing photo-alignment of the alignment layer 131 from the light-incident side S1 using an alignment light source L; 3) coating the liquid crystal layer 132 on the side of the alignment layer 131 away from the second surface 112.

[0118] In the fabrication method of the optical structure 100 provided in this embodiment, the alignment layer 131 is coated on the first lens 110, and the liquid crystal layer 132 is coated on the alignment layer 131. Thus, the phase retardation layer 130 can be directly formed on the first lens 110 without the need to bond the phase retardation layer 130 to the first lens 110 with an adhesive. This avoids the process of transferring the phase retardation layer 130 to the first lens 110 and also avoids the defects caused by the bonding process.

[0119] Figure 11 is a partial optical path diagram of the optical structure shown in Figure 10 at the position indicated by the dashed box when used for display. As shown in Figures 10 and 11, the second surface 112 of the first lens 110 of the optical structure 100 is planar. When light emitted from the light-incident side S1 passes through the first surface 111 of the first lens 110 and reaches the second surface 112, the propagation direction of the incident light is not always perpendicular to the second surface 112. On the optical axis OA of the first lens 110, the propagation direction of the incident light is perpendicular to the second surface 112. Within the plane P2, from the central region 110a to the edge region 110b of the first lens 110, the angle between the propagation direction of the incident light and the second surface 112 gradually decreases. The light emitted from the alignment light source L passes through the first surface 111 of the first lens 110 from the incident light side S1 to the alignment layer 131. Therefore, the incident angles of the light emitted from the alignment light source L and the light emitted from the display screen at the same position on the second surface 112 of the first lens 110 are close. Consequently, at every position on the alignment layer coated on the second surface 112 of the first lens 110, the incident angle of the light emitted from the alignment light source L is close to the incident angle of the light used for display. The liquid crystal layer 132 is coated on the alignment layer 131 after alignment by the alignment light source L. The liquid crystal molecules are arranged according to the alignment direction of the alignment layer 131. Therefore, the arrangement direction of the liquid crystal molecules can better match the incident angle of the light used for display. The phase retardation layer 130 can achieve the conversion between fully linearly polarized light and fully circularly polarized light as much as possible, improving the conversion efficiency of the phase retardation layer 130 between fully linearly polarized light and fully circularly polarized light. For example, the arrangement direction of the liquid crystal molecules can be the long axis direction of the liquid crystal molecules.

[0120] In some examples, as shown in Figures 9 to 11, when the optical structure 100 is applied to a display device, a display screen is provided on the light-incident side S1 of the optical structure 100. The optical structure 100 includes a focal point F located at the position of the display screen. Optical alignment of the alignment layer 131 using an alignment light source L from the light-incident side S1 includes emitting light from a plane P1 where the focal point F is located to optically align the alignment layer 131. The plane P1 is perpendicular to the optical axis OA of the first lens 110. By emitting light from the plane P1 where the focal point F is located using the alignment light source L, the incident angles of the light emitted by the alignment light source L and the light emitted by the display screen 210 reaching the same position on the second surface 112 of the first lens 110 are closer. This allows the arrangement direction of the liquid crystal molecules to better match the light used for display, enabling the phase retardation film to achieve the transition between completely linearly polarized light and completely circularly polarized light as much as possible. For example, the arrangement direction of the liquid crystal molecules can be the long axis direction of the liquid crystal molecules, and the propagation direction of the light used for display emitted from the display screen is perpendicular to the long axis direction of the liquid crystal molecules.

[0121] In some examples, as shown in Figures 9 to 11, the light-emitting surface of the alignment light source L is located within the plane P1 where the focal point F is located, and the size and shape of the light-emitting surface of the alignment light source L are the same as the size and shape of the light-emitting surface of the display screen. Therefore, the light emitted from the alignment light source L and the light emitted from the display screen 210 reach the same position on the second surface 112 of the first lens 110 at the same angle of incidence. The alignment layer 131, aligned by the alignment light source L, allows the liquid crystal molecules to be perfectly matched with the light used for display.

[0122] In some examples, as shown in Figures 9 to 11, the optical alignment of the alignment layer 131 from the incident light side S1 using an alignment light source L includes: linearly polarized light emitted from the alignment light source L is optically aligned with the alignment layer 131 from the incident light side S1. Among the linearly polarized light emitted from the alignment light source L, the linearly polarized light whose propagation direction coincides with the optical axis OA of the first lens 110 has a first polarization direction Y, which is perpendicular to the optical axis OA. Within the plane P2 formed by the first polarization direction Y and the direction X where the optical axis OA is located, from the central region 110a to the edge region 110b of the first lens 110, the angle θ1 between the polarization direction of the linearly polarized light incident on the alignment layer 131 and the optical axis OA gradually decreases. Therefore, the liquid crystal layer aligned using the alignment light source L can better match the light used for display, allowing the phase retardation layer 130 to achieve the conversion between completely linearly polarized light and completely circularly polarized light as much as possible.

[0123] Figure 12 is a cross-sectional schematic diagram of the liquid crystal layer shown in Figure 9. As shown in Figures 9 and 12, within plane P2, from the central region 110a to the edge region 110b of the first lens 110, the angle θ2 between the long axis direction of the liquid crystal molecules and the optical axis OA gradually decreases. Referring to Figure 11, the angle between the propagation direction of the incident light used for display and the optical axis OA gradually increases. Therefore, based on the changing trend of the incident light used for display, the long axis direction of the liquid crystal molecules at any position can be made perpendicular or nearly perpendicular to the propagation direction of the incident light used for display. Figure 12 only schematically shows one sublayer and the second surface 112 of the liquid crystal layer 132; the liquid crystal layer 132 may include multiple sublayers.

[0124] In some examples, as shown in Figures 9 and 12, within plane P2, the angle θ4 between the long axis of the liquid crystal molecules in liquid crystal layer 132 and the second surface 112 ranges from 0 to 40 degrees. The angle θ4 between the liquid crystal molecules traversed by the optical axis OA and the second surface 112 is 0 degrees. Within plane P2, from the central region 110a of the first lens 110 to the edge region 110b, the angle θ4 between the long axis of the liquid crystal molecules and the second surface 112 gradually increases. At the edge, the angle θ4 between the long axis of the liquid crystal molecules and the sectional plane P3 is less than or equal to 40 degrees. Of course, the embodiments of this disclosure do not limit the range of the angle θ4, and can be matched and designed according to the shape of the first lens 110, the position of the focal point F, and the size of the display screen 210.

[0125] In some examples, as shown in Figure 12, within plane P2, from the central region 110a to the edge region 110b of the first lens 110, the long axis direction of the liquid crystal molecules exhibits the same deflection trend. For instance, as shown in Figure 12, the long axis direction of the liquid crystal molecules is deflected towards the second surface 112, and from the central region 110a to the edge region 110b, the deflection angle of the long axis direction of the liquid crystal molecules towards the second surface 112 increases.

[0126] Figure 13 is a flowchart of another method for fabricating an optical structure according to an embodiment of this disclosure; Figure 14 is a schematic diagram of the photo-alignment of the phase retardation layer of the optical structure shown in Figure 13. As shown in Figures 13 and 14, the optical structure 100 has an incident light side S1 and an exit light side S2. The optical structure 100 includes a first lens 110, a transflective coating 120, a phase retardation layer 130, and a polarizing reflective coating 140. The first lens 110 includes a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 is the surface of the incident light side S1 of the first lens 110 and the first surface 111 is curved. The transflective coating 120 is located on the side of the first surface 111 away from the second surface 112. The phase retardation layer 130 is located on the side of the second surface 112 away from the first surface 111. The polarizing reflective coating 140 is located on the side of the phase retardation layer 130 away from the first surface 111. The phase retardation layer 130 includes a liquid crystal layer 132. The fabrication method of the optical structure 100 includes: 1) coating the liquid crystal layer 132 on the second surface 112 of the first lens 110; 2) using an alignment light source L to perform photo-alignment on the liquid crystal layer 132 from the incident light side S1.

[0127] In the fabrication method of the optical structure 100 provided in this embodiment, a liquid crystal layer 132 is coated on the second surface 112 of the first lens 110, so that the phase retardation layer 130 can be directly formed on the first lens 110 without the need to bond the phase retardation layer 130 to the first lens 110 with an adhesive. This avoids the process of transferring the phase retardation layer 130 to the first lens 110 and also avoids the defects caused by the bonding process. In this example, the second surface 112 is curved; however, this embodiment is not limited to this. For example, the second surface 112 can also be planar.

[0128] In this example, the liquid crystal layer 132 can be composed of liquid crystal molecules capable of alignment under external excitation. For example, the liquid crystal layer 132 can employ photoalignment. Referring to FIG4, this optical structure 100 can be used in conjunction with a display screen 210 for display. Light emitted from the display screen 210 passes from the light-incident side S1 through the first surface 111 of the first lens 110 to the phase retardation layer 130. Light emitted from the alignment light source L passes from the light-incident side S1 through the first surface 111 of the first lens 110 to the liquid crystal layer 132. Thus, the incident angles of the light emitted from the alignment light source L and the light emitted from the display screen 210 at the same position on the second surface 112 of the first lens 110 are close. Consequently, at each position of the liquid crystal layer 132 coated on the second surface 112 of the first lens 110, the incident angle of the light emitted from the alignment light source L is close to the incident angle of the light used for display. After the liquid crystal layer 132 is aligned with the alignment light source L, the arrangement direction of the liquid crystal molecules can be better matched with the incident angle of the light used for display. The phase retardation layer 130 can realize the conversion between fully linearly polarized light and fully circularly polarized light as much as possible, thereby improving the conversion efficiency of the phase retardation layer 130 between fully linearly polarized light and fully circularly polarized light. For example, the arrangement direction of the liquid crystal molecules can be the direction of the long axis of the liquid crystal molecules.

[0129] In some examples, as shown in Figures 4, 13, and 14, when the optical structure 100 is applied to a display device, a display screen is provided on the light-incident side S1 of the optical structure 100. The optical structure 100 includes a focal point F located at the position of the display screen 210. Photo-aligning the liquid crystal layer 132 from the light-incident side S1 using an alignment light source L involves emitting light from the plane P1 where the focal point F is located to photo-align the liquid crystal layer 132. The plane P1 is perpendicular to the optical axis OA of the first lens 110. By emitting light from the plane P1 where the focal point F is located using the alignment light source L, the incident angles of the light emitted by the alignment light source L and the light emitted by the display screen 210 at the same position on the second surface 112 of the first lens 110 are closer. This allows the arrangement direction of the liquid crystal molecules to be more closely matched with the light used for display, enabling the phase retardation film to achieve the transition between completely linearly polarized light and completely circularly polarized light as much as possible.

[0130] In some examples, as shown in Figures 13 and 14, the light-emitting surface of the alignment light source L is located within the plane P1 where the focal point F is located, and the size and shape of the light-emitting surface of the alignment light source L are the same as those of the light-emitting surface of the display screen. Therefore, the light emitted from the alignment light source L and the light emitted from the display screen 210 reach the same position on the second surface 112 of the first lens 110 at the same angle of incidence. The liquid crystal layer 132 aligned by this alignment light source L can achieve perfect matching between the liquid crystal molecules and the light used for display.

[0131] In some examples, as shown in Figures 13 and 14, the photo-alignment of the liquid crystal layer 132 from the incident light side S1 using an alignment light source L includes: linearly polarized light emitted from the alignment light source L photo-aligns with the liquid crystal layer 132 from the incident light side S1. Among the linearly polarized light emitted from the alignment light source L, the linearly polarized light whose propagation direction coincides with the optical axis OA of the first lens 110 has a first polarization direction Y. Within the plane P2 formed by the first polarization direction Y and the direction X where the optical axis OA is located, from the central region 110a to the edge region 110b of the first lens 110, the angle θ1 between the polarization direction of the linearly polarized light incident on the liquid crystal layer 132 and the optical axis OA gradually decreases.

[0132] In some examples, the arrangement of liquid crystal molecules in the liquid crystal layer is as shown in Figures 5 and 6, and will not be repeated here.

[0133] In some examples, as shown in FIG13, the fabrication method of the optical structure 100 further includes: 3) sequentially attaching a polarizing reflective film 140, a polarizing absorption layer 150, and a first antireflective layer 160 to the side of the liquid crystal layer 132 away from the first surface 111. For example, the fabrication method of the optical structure 100 further includes: forming a transmissive reflective film 120 on the first surface 111 of the first lens 110.

[0134] Figure 15 is a flowchart of another method for fabricating an optical structure according to an embodiment of this disclosure; Figure 16 is a schematic diagram of the light alignment of the phase retardation layer of the optical structure shown in Figure 15. As shown in Figures 15 and 16, the optical structure 100 has an incident light side S1 and an exit light side S2. The optical structure 100 includes a first lens 110, a transmissive reflective film 120, a phase retardation layer 130, and a polarizing reflective film 140. The first lens 110 includes a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 is the surface of the incident light side S1 of the first lens 110 and the first surface 111 is curved. The transmissive reflective film 120 is located on the side of the first surface 111 away from the second surface 112. The phase retardation layer 130... The polarizing reflective film 140 is located on the side of the second surface 112 away from the first surface 111, and the phase retardation layer 130 is located on the side of the phase retardation layer 130 away from the first surface 111. The phase retardation layer 130 includes an alignment layer 131 and a liquid crystal layer 132. The fabrication method of the optical structure 100 includes: 1) coating the alignment layer 131 on the second surface 112 of the first lens 110; 2) performing photo-alignment of the alignment layer 131 from the light-emitting side S2 using an alignment light source L; 3) coating the liquid crystal layer 132 on the side of the alignment layer 131 away from the second surface 112.

[0135] In the fabrication method of the optical structure 100 provided in this embodiment, an alignment layer 131 is coated on the first lens 110, and a liquid crystal layer 132 is coated on the alignment layer 131. Therefore, the phase retardation layer 130 can be directly formed on the first lens 110 without the need for adhesive bonding. This avoids the process of transferring the phase retardation layer 130 to the first lens 110 and also avoids defects caused by the bonding process. In this example, the second surface 112 is curved; however, this embodiment is not limited to this. For example, the second surface 112 can also be planar. Figure 16 only schematically shows one sublayer of the liquid crystal layer 132 and the second surface 112; the liquid crystal layer 132 may include multiple sublayers.

[0136] In some examples, as shown in Figures 15 and 16, the light emitted by the alignment light source L can be linearly polarized light, with the polarization direction of the linearly polarized light at 45 degrees or 135 degrees to the transmission axis of the polarization reflective film 140.

[0137] For example, the alignment direction of alignment layer 131 is parallel to the polarization direction of linearly polarized light. For example, the long axis direction of liquid crystal molecules is arranged according to the alignment direction of alignment layer 131.

[0138] In some examples, as shown in FIG15, the fabrication method of the optical structure 100 further includes: 4) sequentially attaching a polarizing reflective film 140, a polarizing absorption layer 150, and a first antireflective layer 160 to the side of the liquid crystal layer 132 away from the first surface 111. For example, the fabrication method of the optical structure 100 further includes: forming a transmissive reflective film 120 on the first surface 111 of the first lens 110.

[0139] In some examples, the phase retardation layer 130 of the optical structure 100 shown in FIG15 may also include only the liquid crystal layer 132. The fabrication method of the optical structure 100 includes: 1) coating the liquid crystal layer 132 on the second surface 112 of the first lens 110; 2) performing photo-alignment of the liquid crystal layer 132 from the light-emitting side S2 using an alignment light source L; 3) sequentially attaching a polarizing reflective film 140, a polarizing absorption layer 150 and a first antireflective layer 160 on the side of the liquid crystal layer 132 away from the first surface 111.

[0140] This disclosure provides an optical structure. Figure 17 is a cross-sectional schematic diagram of an optical structure provided in this disclosure. As shown in Figures 5, 6 and 17, the optical structure 100 has an incident light side S1 and an exit light side S2. The optical structure 100 includes a first lens 110, a transmissive reflective film 120, a phase retardation layer 130 and a polarizing reflective film 140. The first lens 110 includes a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 is the surface of the incident light side S1 of the first lens 110 and the first surface 111 is curved. The transmissive reflective film 120 is located on the side of the first surface 111 away from the second surface 112. The phase retardation layer 130 is located on the side of the second surface 112 away from the first surface 111. The polarizing reflective film 140 is located on the side of the phase retardation layer 130 away from the first surface 111. A phase retardation layer 130 is configured to be coated on the second surface 112 of the first lens 110. The phase retardation layer 130 includes a liquid crystal layer 132. The long axis directions of the liquid crystal molecules in the liquid crystal layer 132 are parallel to each other when projected onto a plane P1 perpendicular to the optical axis OA of the first lens 110. The long axis directions of the liquid crystal molecules intersecting the optical axis OA are perpendicular to the optical axis OA. In the plane P2 formed by the long axis directions of the liquid crystal molecules and the direction X where the optical axis OA is located, the angle θ2 between the long axis directions of the liquid crystal molecules and the optical axis OA gradually decreases from the central region 110a to the edge region 110b of the first lens 110. The liquid crystal molecules intersecting the optical axis OA are those through which the optical axis OA passes.

[0141] In the optical structure 100 provided in this embodiment, the phase retardation layer 130 is configured to be coated on the second surface 112 of the first lens 110. Therefore, the phase retardation layer 130 can be directly formed on the first lens 110 without the need for adhesive bonding. This avoids the process of transferring the phase retardation layer 130 to the first lens 110 and also avoids defects associated with bonding processes. In this example, the second surface 112 is curved; however, this embodiment is not limited to this. For example, the second surface 112 can also be planar.

[0142] In this embodiment, referring to FIG4, the propagation direction of the light for display emitted from the incident light side S1 is parallel to the optical axis OA of the first lens 110. Since the first surface 111 of the first lens 110 is curved, within plane P2, from the central region 110a to the edge region 110b of the first lens 110, the angle between the propagation direction of the light for display incident on the second surface 112 and the optical axis OA increases. Based on the changing trend of the propagation direction of the incident light for display, by setting the angle θ2 between the long axis direction of the liquid crystal molecules and the optical axis OA to decrease, the long axis direction of the liquid crystal molecules can always be perpendicular or nearly perpendicular to the propagation direction of the incident light. Thus, the phase retardation layer 130 can realize the conversion between fully linearly polarized light and fully circularly polarized light as much as possible, improving the conversion efficiency of the phase retardation layer 130 between fully linearly polarized light and fully circularly polarized light.

[0143] In some examples, the liquid crystal layer 132 may be composed of liquid crystal molecules capable of alignment under external stimuli (e.g., light, electric field, surface energy, shear force, etc.). For example, the liquid crystal layer 132 may employ photo-alignment. For example, the liquid crystal layer 132 may be aligned using the fabrication method of the optical structure 100 described above. Of course, the alignment method of the liquid crystal layer 132 is not limited in the embodiments of this disclosure.

[0144] In some examples, as shown in Figures 5 and 17, within plane P2, the angle θ3 between the long axis of the liquid crystal molecules in liquid crystal layer 132 and the tangent plane P3 at the position of the liquid crystal molecules on the second surface 112 ranges from 0 to 40 degrees. Thus, the long axis of the liquid crystal molecules can be approximately arranged along the second surface 112. The propagation direction of the light incident on the phase retardation layer 130 after passing through the first surface 111 is approximately perpendicular to the second surface 112, thereby the propagation direction of the incident light is approximately perpendicular to the long axis of the liquid crystal molecules. Of course, the embodiments of this disclosure do not limit the range of the angle θ3; it can be matched and designed according to the shape of the first lens 110, the position of the focal point F, and the size of the display screen 210.

[0145] In some examples, as shown in Figures 5 and 17, within plane P2, from the central region 110a to the edge region 110b of the first lens 110, the long axis direction of the liquid crystal molecules exhibits the same deflection trend. For instance, as shown in Figure 5, from the central region 110a to the edge region 110b of the first lens 110, the long axis direction of the liquid crystal molecules deflects towards the second surface 112, and the deflection angle increases from the central region 110a to the edge region 110b.

[0146] In some examples, as shown in Figures 5 and 17, the angle θ3 between the liquid crystal molecules and the sectional plane P3 along the optical axis OA is 0 degrees. Within plane P2, from the central region 110a of the first lens 110 to the edge region 110b, the angle θ3 between the long axis of the liquid crystal molecules and the sectional plane P3 gradually increases, and at the edge position, the angle θ3 between the long axis of the liquid crystal molecules and the sectional plane P3 is less than or equal to 40 degrees. Of course, the embodiments of this disclosure do not limit the value of the angle θ3 at the edge position.

[0147] In some examples, as shown in Figures 6 and 17, the orthographic projections of the long axis directions of the liquid crystal molecules in the liquid crystal layer 132 onto the plane P1 perpendicular to the optical axis OA are parallel to each other. Along the projected long axis direction, from the central region 110a of the first lens 110 to the edge region 110b, the projected length of the long axis of the liquid crystal molecules becomes smaller and smaller.

[0148] In some examples, the long axis of the liquid crystal molecules in the liquid crystal layer 132 is projected onto the plane P1 at an angle of 45 degrees or 135 degrees to the transmission axis of the polarizing reflective film 140.

[0149] In some examples, as shown in Figure 17, the optical structure 100 also includes a polarization absorption layer 150 and a first antireflection layer 160 located sequentially on the side of the polarization reflection film 140 away from the phase retardation layer 130.

[0150] Figure 18 is a cross-sectional schematic diagram of another optical structure provided in an embodiment of this disclosure. As shown in Figure 18, the phase retardation layer 130 of the optical structure 100 further includes an alignment layer 131 located between the liquid crystal layer 132 and the second surface 112. The alignment layer 131 is configured to be coated on the second surface 112 of the first lens 110, and the liquid crystal layer 132 is configured to be coated on the alignment layer 131. The liquid crystal layer 132 is coated on the alignment layer 131, thereby achieving the alignment of the liquid crystal layer 132 through the alignment layer 131. For example, the alignment layer 131 can be photoaligned, and the liquid crystal layer 132, after being coated on the already aligned alignment layer 131, can be arranged along the alignment direction of the alignment layer 131. For example, the alignment layer 131 can be aligned using the fabrication method of the optical structure 100 described above. Of course, the alignment method of the alignment layer 131 is not limited in the embodiments of this disclosure.

[0151] In some examples, the average thickness of the alignment layer 131 is 30-200 nanometers. For example, the average thickness of the liquid crystal layer 132 is 1-5 micrometers.

[0152] In some examples, as shown in FIG8, the optical structure 100 further includes a second lens 170, a third lens 180, a polarizing absorption layer 150, a second antireflection layer 161, and a third antireflection layer 162. The second lens 170 is located on the side of the first surface 111 away from the second surface 112, and the second antireflection layer 161 is located on the side of the second lens 170 away from the first lens 110. The side of the first lens 110 with the transmissive reflective coating 120 is attached to the side of the second lens 170 without the second antireflection layer 161. The third lens 180 is located on the side of the first lens 110 away from the second lens 170. The third lens 180 includes a third surface 181, the polarizing absorption layer 150 is located on the third surface 181 of the third lens 180, and the polarizing reflective coating 140 is located on the third lens 180 and on the side of the polarizing absorption layer 150 away from the third surface 181. The third antireflective layer 162 is located on the side of the third lens 180 away from the first lens 110, and the side of the first lens 110 where the liquid crystal layer 132 is formed is bonded to the side of the third lens 180 where the third antireflective layer 162 is not formed. In this example, the number of lenses, and the number of optical film layers, can be increased or decreased according to the optical or performance requirements of the optical structure 100. For example, the optical structure 100 may also include two or more lenses. For example, a hardening layer may also be deposited on the side of the third lens 180 away from the first lens 110.

[0153] Figure 8 schematically shows that the phase retardation layer 130 includes an alignment layer 131 and a liquid crystal layer 132. However, the present disclosure does not limit this, and the phase retardation layer 130 may also include only the liquid crystal layer 132.

[0154] Figure 19 is a cross-sectional schematic diagram of another optical structure provided in an embodiment of this disclosure. As shown in Figures 12 and 19, the optical structure 100 has an incident light side S1 and an exit light side S2. The optical structure 100 includes a first lens 110, a transmissive reflective film 120, a phase retardation layer 130, and a polarizing reflective film 140. The first lens 110 includes a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 is the surface of the incident light side S1 of the first lens 110 and the first surface 111 is curved. The transmissive reflective film 120 is located on the side of the first surface 111 away from the second surface 112. The phase retardation layer 130 is located on the side of the second surface 112 away from the first surface 111. The polarizing reflective film 140 is located on the side of the phase retardation layer 130 away from the first surface 111. A phase retardation layer 130 is configured to be coated on the second surface 112 of the first lens 110. The phase retardation layer 130 includes an alignment layer 131 and a liquid crystal layer 132. The alignment layer 131 is configured to be coated on the second surface 112 of the first lens 110, and the liquid crystal layer 132 is configured to be coated on the alignment layer 131. The orthographic projections of the long axis directions of the liquid crystal molecules in the liquid crystal layer 132 onto a plane P1 perpendicular to the optical axis OA of the first lens 110 are parallel to each other. The long axis directions of the liquid crystal molecules intersecting the optical axis OA are perpendicular to the optical axis OA. In the plane P2 formed by the long axis directions of the liquid crystal molecules and the direction X where the optical axis OA is located, from the central region 110a to the edge region 110b of the first lens 110, the angle θ2 between the long axis directions of the liquid crystal molecules and the optical axis OA gradually decreases. The orthographic projection of the long axis directions of the liquid crystal molecules in the liquid crystal layer 132 onto the plane P1 shown in Figure 19 is referenced in Figure 6 and will not be repeated here.

[0155] In the optical structure 100 provided in this embodiment, the phase retardation layer 130 is configured to be coated on the second surface 112 of the first lens 110. Therefore, the phase retardation layer 130 can be directly formed on the first lens 110 without the need for adhesive bonding. This avoids both the process of transferring the phase retardation layer 130 to the first lens 110 and the defects associated with bonding processes. In this example, the second surface 112 is curved; however, this embodiment does not impose any limitations on this.

[0156] In the optical structure 100 provided in this embodiment, the second surface 112 is planar. Referring to the optical path diagram shown in FIG11, when the light emitted from the display screen passes through the first surface 111 of the first lens 110 from the light incident side S1 to the second surface 112, the propagation direction of the incident light is not always perpendicular to the second surface 112. On the optical axis OA of the first lens 110, the propagation direction of the incident light is perpendicular to the second surface 112. From the central region 110a to the edge region 110b of the first lens 110, the angle between the propagation direction of the incident light and the second surface 112 becomes smaller and smaller. According to the changing trend of the propagation direction of the incident light used for display, by setting the angle θ2 between the long axis direction of the liquid crystal molecules and the optical axis OA to become smaller and smaller, the long axis direction of the liquid crystal molecules can always be perpendicular or nearly perpendicular to the propagation direction of the incident light. Thus, the phase retardation layer 130 can realize the conversion of light between fully linearly polarized light and fully circularly polarized light as much as possible, thereby improving the conversion efficiency of the phase retardation layer 130 between fully linearly polarized light and fully circularly polarized light.

[0157] Figure 19 schematically shows that the phase retardation layer 130 includes an alignment layer 131 and a liquid crystal layer 132. However, this embodiment of the present disclosure is not limited to this, and the phase retardation layer 130 may also include only the liquid crystal layer 132, which is configured to be coated on the second surface 112 of the first lens 110, and will not be described in detail here.

[0158] In some examples, as shown in Figures 12 and 19, the angle θ4 between the long axis of the liquid crystal molecules of the liquid crystal layer 132 and the second surface 112 in plane P2 ranges from 0 to 40 degrees.

[0159] In some examples, as shown in Figures 12 and 19, within plane P2, on the optical axis OA, the angle θ4 between the liquid crystal molecules and the second surface 112 is 0 degrees. Within plane P2, from the central region 110a of the first lens 110 to the edge region 110b, the angle θ4 between the long axis of the liquid crystal molecules and the second surface 112 gradually increases. At the edge, the angle θ4 between the long axis of the liquid crystal molecules and the tangent plane P3 is less than or equal to 40 degrees. Of course, the embodiments of this disclosure do not limit the range of values ​​for the angle θ4, and can be designed to match the shape of the first lens 110, the position of the focal point F, and the size of the display screen 210.

[0160] In some examples, as shown in Figures 12 and 19, within plane P2, from the central region 110a to the edge region 110b of the first lens 110, the long axis direction of the liquid crystal molecules exhibits the same deflection trend. For instance, from the central region 110a to the edge region 110b of the first lens 110, the long axis direction of the liquid crystal molecules deflects towards the second surface 112, and the deflection angle increases from the central region 110a to the edge region 110b.

[0161] In some examples, as shown in Figures 12 and 19, within plane P2, the line connecting the centers of the liquid crystal molecules in liquid crystal layer 132 is not parallel to the second surface 112; the center of this line is further away from the second surface 112 than its edge. It should be noted that this line is the connection of liquid crystal molecules within a sublayer in the figure, with its center on the optical axis OA, and its edge in the edge region 110b of the first lens 110.

[0162] Figure 20 is a cross-sectional schematic diagram of another optical structure provided in an embodiment of this disclosure; Figure 21 is a cross-sectional schematic diagram of the liquid crystal layer of the optical structure shown in Figure 20. As shown in Figures 20 and 21, the optical structure 100 has an incident light side S1 and an exit light side S2. The optical structure 100 includes a first lens 110, a transmissive reflective film 120, a phase retardation layer 130, and a polarizing reflective film 140. The first lens 110 includes a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 is the surface of the incident light side S1 of the first lens 110 and the first surface 111 is curved. The transmissive reflective film 120 is located on the side of the first surface 111 away from the second surface 112. The phase retardation layer 130 is located on the side of the second surface 112 away from the first surface 111. The polarizing reflective film 140 is located on the side of the phase retardation layer 130 away from the first surface 111. A phase retardation layer 130 is configured to be coated on the second surface 112 of the first lens 110. The phase retardation layer 130 includes a liquid crystal layer 132, the long axes of the liquid crystal molecules in the liquid crystal layer 132 being parallel to each other. Plane P2 is the plane formed by the long axis of the liquid crystal molecules and the direction X where the optical axis OA is located.

[0163] In the optical structure 100 provided in this embodiment, the phase retardation layer 130 is configured to be coated on the second surface 112 of the first lens 110. Therefore, the phase retardation layer 130 can be directly formed on the first lens 110 without the need for adhesive bonding. This avoids both the process of transferring the phase retardation layer 130 to the first lens 110 and the defects associated with bonding processes. Figure 21 schematically shows only one sublayer of the liquid crystal layer 132 and the second surface 112; the liquid crystal layer 132 may include multiple sublayers.

[0164] In this example, the phase retardation layer 130 includes a liquid crystal layer 132. However, the phase retardation layer 130 may also include an alignment layer 131, which is configured to be coated on the second surface 112 of the first lens 110, and the liquid crystal layer 132 is configured to be coated on the alignment layer 131.

[0165] For example, the long axis of the liquid crystal molecules is at a 45-degree or 135-degree angle to the transmission axis of the polarizing reflective film 140.

[0166] For example, the liquid crystal layer 132 can be aligned using the fabrication method of the embodiment corresponding to FIG15 above.

[0167] Figure 22 is a cross-sectional schematic diagram of another optical structure provided in an embodiment of this disclosure; Figure 23 is a cross-sectional schematic diagram of the liquid crystal layer of the optical structure shown in Figure 22. As shown in Figures 22 and 23, the optical structure 100 has an incident light side S1 and an exit light side S2. The optical structure 100 includes a first lens 110, a transmissive reflective film 120, a phase retardation layer 130, and a polarizing reflective film 140. The first lens 110 includes a first surface 111 and a second surface 112 disposed opposite to each other. The first surface 111 is the surface of the incident light side S1 of the first lens 110 and the first surface 111 is curved. The transmissive reflective film 120 is located on the side of the first surface 111 away from the second surface 112. The phase retardation layer 130 is located on the side of the second surface 112 away from the first surface 111. The polarizing reflective film 140 is located on the side of the phase retardation layer 130 away from the first surface 111. A phase retardation layer 130 is configured to be coated on the second surface 112 of the first lens 110. The phase retardation layer 130 includes a liquid crystal layer 132, the long axes of the liquid crystal molecules in the liquid crystal layer 132 being parallel to each other. Plane P2 is the plane formed by the long axis of the liquid crystal molecules and the direction X where the optical axis OA is located.

[0168] In the optical structure 100 provided in this embodiment, the phase retardation layer 130 is configured to be coated on the second surface 112 of the first lens 110. Therefore, the phase retardation layer 130 can be directly formed on the first lens 110 without the need for adhesive bonding. This avoids both the process of transferring the phase retardation layer 130 to the first lens 110 and the defects associated with the bonding process. Figure 23 only schematically shows one sublayer of the liquid crystal layer 132 and the second surface 112; the liquid crystal layer 132 may include multiple sublayers.

[0169] In this example, the phase retardation layer 130 includes a liquid crystal layer 132. However, the phase retardation layer 130 may also include an alignment layer 131, which is configured to be coated on the second surface 112 of the first lens 110, and the liquid crystal layer 132 is configured to be coated on the alignment layer 131.

[0170] For example, the long axis of the liquid crystal molecules is at a 45-degree or 135-degree angle to the transmission axis of the polarizing reflective film 140.

[0171] For example, the liquid crystal molecules can be aligned using the fabrication method of the embodiment corresponding to Figure 15 above.

[0172] This disclosure provides a display device according to one embodiment. FIG24 is a schematic diagram of a display device according to an embodiment of this disclosure. As shown in FIG24, the display device 200 includes a display screen 210 and the aforementioned arbitrary optical structure 100, with the display screen 210 located on the light-incident side of the optical structure 100. Thus, the display device 200 has the beneficial effects corresponding to the beneficial effects of the optical module, which will not be elaborated further here.

[0173] For example, the display device 200 may be a near-eye display device 200 of virtual reality (VR) or mixed reality (MR).

[0174] The following points need to be explained:

[0175] (1) The accompanying drawings of the embodiments of this disclosure only involve the structures involved in the embodiments of this disclosure. Other structures can be referred to the general design.

[0176] (2) Where there is no conflict, features of the same embodiment and different embodiments of this disclosure can be combined with each other.

[0177] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A method for fabricating an optical structure, wherein, The optical structure has an incident light side and an exit light side. The optical structure includes a first lens, a transmissive coating, a phase retardation layer, and a polarizing reflective coating. The first lens includes a first surface and a second surface disposed opposite to each other. The first surface is the incident light side surface of the first lens and is curved. The transmissive coating is located on the side of the first surface away from the second surface. The phase retardation layer is located on the side of the second surface away from the first surface. The polarizing reflective coating is located on the side of the phase retardation layer away from the first surface. The phase retardation layer includes an alignment layer and a liquid crystal layer. The fabrication method includes: coating the alignment layer on the second surface of the first lens; and using an alignment light source to... The light-incident side performs photo-alignment on the alignment layer; and the liquid crystal layer is coated on the side of the alignment layer away from the second surface. The photo-alignment of the alignment layer from the light-incident side using the alignment light source includes: linearly polarized light emitted from the alignment light source performs photo-alignment on the alignment layer from the light-incident side. The portion of the linearly polarized light whose propagation direction coincides with the optical axis of the first lens has a first polarization direction. This first polarization direction is perpendicular to the optical axis. In the plane formed by the first polarization direction and the direction of the optical axis, from the center region to the edge region of the first lens, the angle between the polarization direction of the linearly polarized light incident on the alignment layer and the optical axis gradually decreases.

2. The manufacturing method according to claim 1, wherein, When the optical structure is applied to a display device, a display screen is provided on the light-incident side of the optical structure, and the optical structure includes a focal point located at the position of the display screen. The process of using the alignment light source to perform optical alignment of the alignment layer from the light-incident side includes: using the alignment light source to emit light from the plane where the focal point is located to perform optical alignment of the alignment layer, wherein the plane is perpendicular to the optical axis of the first lens.

3. The manufacturing method according to claim 2, wherein, The light-emitting surface of the alignment light source is located in the plane where the focal point is located, and the size and shape of the light-emitting surface of the alignment light source are the same as the size and shape of the light-emitting surface of the display screen.

4. The manufacturing method according to claim 2, wherein, The area of ​​the light-emitting surface of the aligned light source is smaller than the area of ​​the phase retardation layer projected onto the plane.

5. The manufacturing method according to any one of claims 1-4, wherein, The angle between the long axis of the liquid crystal molecules in the liquid crystal layer and the tangent at the position of the liquid crystal molecule on the second surface ranges from 0 to 40 degrees.

6. The manufacturing method according to any one of claims 1-4, wherein, The average thickness of the alignment layer is 30-200 nanometers, and the average thickness of the liquid crystal layer is 1-5 micrometers.

7. The manufacturing method according to any one of claims 1-4, wherein, The second surface of the first lens includes a curved surface or a flat surface.

8. The manufacturing method according to any one of claims 1-4, further comprising: The transflective coating is formed on the first surface of the first lens; The polarizing reflective film is formed on the side of the liquid crystal layer away from the first surface; A polarization absorption layer is formed on the side of the polarization reflection film away from the first surface; and a first antireflection layer is formed on the side of the polarization absorption layer away from the first surface.

9. The manufacturing method according to any one of claims 1-4, further comprising: A second lens and a third lens are provided; a second antireflection layer is formed on one side of the second lens; and the transmissive film is formed on the first surface of the first lens. The side of the first lens with the transflective coating is bonded to the side of the second lens without the second antireflective layer; a polarizing absorption layer is formed on the third surface of the third lens; a polarizing reflection film is formed on the side of the polarizing absorption layer away from the third surface; a third antireflective layer is formed on the side of the third lens away from the third surface; and the surface of the first lens with the liquid crystal layer is bonded to the side of the third lens without the third antireflective layer.

10. A method for fabricating an optical structure, wherein, The optical structure has an incident light side and an exit light side. The optical structure includes a first lens, a transmissive coating, a phase retardation layer, and a polarizing reflective coating. The first lens includes a first surface and a second surface disposed opposite to each other. The first surface is the incident light side surface of the first lens and is curved. The transmissive coating is located on the side of the first surface away from the second surface. The phase retardation layer is located on the side of the second surface away from the first surface. The polarizing reflective coating is located on the side of the phase retardation layer away from the first surface. The phase retardation layer includes a liquid crystal layer. The fabrication method includes coating the first lens with the second surface of the first lens. A liquid crystal layer; and photoorientation of the liquid crystal layer from the light incident side using an alignment light source, wherein photoorientation of the liquid crystal layer from the light incident side using an alignment light source includes: photoorientation of linearly polarized light emitted by the alignment light source to the liquid crystal layer from the light incident side, wherein a portion of the linearly polarized light whose propagation direction coincides with the optical axis of the first lens has a first polarization direction, the first polarization direction being perpendicular to the optical axis, and within the plane formed by the first polarization direction and the direction of the optical axis, from the center region to the edge region of the first lens, the angle between the polarization direction of the linearly polarized light incident on the liquid crystal layer and the optical axis gradually decreases.

11. The manufacturing method according to claim 10, wherein, When the optical structure is applied to a near-eye display device, a display screen is provided on the light-incident side of the optical structure. The optical structure includes a focal point located at the position of the display screen. The process of photo-aligning the liquid crystal layer from the light-incident side using the alignment light source includes: emitting light from the plane where the focal point is located to photo-align the liquid crystal layer. The plane is perpendicular to the optical axis of the first lens. The light-emitting surface of the alignment light source is located in the plane where the focal point is located, and the size and shape of the light-emitting surface of the alignment light source are the same as the size and shape of the light-emitting surface of the display screen.

12. An optical structure having an incident light side and an exit light side, comprising: A first lens includes a first surface and a second surface disposed opposite to each other, the first surface being the light-incident surface of the first lens and the first surface being curved; a transflective film is located on the side of the first surface away from the second surface; A phase delay layer is located on the side of the second surface away from the first surface; And a polarizing reflective film, located on the side of the phase retardation layer away from the first surface, wherein the phase retardation layer is configured to be coated on the second surface of the first lens, the phase retardation layer includes a liquid crystal layer, the long axis directions of the liquid crystal molecules of the liquid crystal layer are parallel to each other in the orthographic projection on a plane perpendicular to the optical axis of the first lens, the long axis directions of the liquid crystal molecules intersecting the optical axis are perpendicular to the optical axis, and in the plane formed by the long axis directions of the liquid crystal molecules and the direction of the optical axis, from the center region to the edge region of the first lens, the angle between the long axis directions of the liquid crystal molecules and the optical axis becomes smaller and smaller.

13. The optical structure according to claim 12, wherein, The phase retardation layer further includes an alignment layer located between the liquid crystal layer and the second surface, the alignment layer being configured to be coated on the second surface of the first lens, and the liquid crystal layer being configured to be coated on the alignment layer.

14. The optical structure according to claim 12 or 13, wherein, The angle between the long axis of the liquid crystal molecules in the liquid crystal layer and the tangent at the position of the liquid crystal molecule on the second surface ranges from 0 to 40 degrees.

15. The optical structure according to claim 12 or 13, wherein, Within the plane formed by the long axis direction of the liquid crystal molecules and the direction of the optical axis, from the center region to the edge region of the first lens, the long axis direction of the liquid crystal molecules in the liquid crystal layer has the same deflection tendency.

16. The optical structure according to claim 13, wherein, The alignment layer has an average thickness of 30-200 nanometers, and the liquid crystal layer has an average thickness of 1-5 micrometers.

17. The optical structure according to claim 12 or 13, wherein, The second surface of the first lens includes a curved surface.

18. The optical structure according to claim 12 or 13, wherein, The second surface of the first lens includes a plane. In the plane formed by the long axis direction of the liquid crystal molecules and the direction of the optical axis, the line connecting the centers of the liquid crystal molecules of the liquid crystal layer is not parallel to the second surface, and the center of the line is farther away from the second surface than the edge of the line.

19. The optical structure according to claim 12 or 13, further comprising: The second lens is located on the side of the first surface away from the second surface; The second antireflection layer is located on the side of the second lens away from the first lens; A third lens, located on the side of the first lens away from the second lens, includes a third surface; a polarizing absorption layer, located on the third surface of the third lens; and a third antireflection layer, located on the side of the third lens away from the first lens. The polarizing reflective film is located on the third lens and on the side of the polarizing absorption layer away from the third surface. The side of the first lens with the reflective film is bonded to the side of the second lens without the second antireflection layer. The side of the first lens with the liquid crystal layer is bonded to the side of the third lens without the third antireflection layer.

20. A display device comprising a display screen and the optical structure according to any one of claims 12-19, wherein, The display screen is located on the light-incident side of the optical structure.

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