Polarized light conversion device and manufacturing method thereof

Abstract

The embodiment of the invention discloses a polarized light conversion device. The polarized light conversion device comprises a polarization splitting prism array and a polymer half-wave plate, the polarization splitting prism array is formed by bonding a plurality of first light-transmitting components; second light-transmitting components are adhered to the two ends of the polarization splitting prism array, a polarization splitting film is arranged between the first light-transmitting component and the adjacent first light-transmitting component or the second light-transmitting component, and the patterned polymer half-wave plate is arranged on a light emitting path of the polarization splitting prism array; according to the invention, the PBS plain film light path is utilized to directly process the required area patterned half-wave plate on the liquid crystal polymer layer, and the traditional wave plate laminating process is replaced, so that the processing and manufacturing are greatly reduced; the optical system can be applied to various precise and miniaturized practical application occasions, and miniaturization or microminiaturization of the optical system is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of processing and manufacturing optical devices, and in particular relates to a polarized light conversion device and a manufacturing method thereof. Background Art

[0002] The traditional illumination sources in polarized projection display systems are all non-polarized light sources, so polarizing devices are needed; commonly used polarizing devices are polarizing beam splitters (PBs) and polarization converters (PCS):

[0003] The polarization beam splitter prism PBs is made of a pair of isosceles right-angle prisms glued together. The inclined surface of one of the prisms is coated with a polarization beam splitter film. Converting non-polarized light into polarized light will lose at least 50% of the energy.

[0004] The polarization light converter PCS is made by gluing multiple PBS prisms together to convert P light into S light or S light into P light. It can maintain more than 80% of the energy of the original non-polarized light, which is of great help to the light utilization, contrast and image color saturation of the projection system.

[0005] In the processing of PCS, the sizes of PBS and quartz wave plates are very small (usually millimeter scale), but they can all be processed using conventional optical processing solutions. First, the PBS array and wave plate strips of corresponding specifications are processed, and the processing difficulty is relatively not great; the main processing difficulty lies in: accurately positioning and fitting many wave plate strips to the specified area of ​​the PBS array. The conventional process often involves positioning and bonding the half-wave plate strips one by one to the PBS array, which is difficult to operate, time-consuming and labor-intensive, and has a high efficiency and low cost. Summary of the invention

[0006] In the prior art, the purpose of the present invention is to provide a polarization light conversion device and a manufacturing method thereof to solve the problems of difficult operation, low efficiency and high cost when bonding a half-wave plate strip to a PBS array.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] In a first aspect, an embodiment of the present invention provides a polarization light conversion device, which includes a polarization beam splitter prism array and a half-wave plate;

[0009] The polarization beam splitter prism array is formed by bonding a plurality of first light-transmitting components; second light-transmitting components are bonded to both ends of the polarization beam splitter prism array, and a polarization beam splitter film is provided between the first light-transmitting component and the first light-transmitting component or the second light-transmitting component adjacent thereto; and a half-wave plate is provided on the light output path of the polarization beam splitter prism array.

[0010] The half-wave plate is a patterned polymer layer made of liquid crystal polymer.

[0011] Furthermore, the polarization beam splitter prism array includes two right-angle prisms and a plurality of rhombus prisms; a plurality of rhombus prisms are arranged between the two right-angle prisms, and a polarization beam splitter film is coated at the connection between each prism.

[0012] Furthermore, the rhombus prism and the adjacent rhombus prism or right-angle prism are bonded into a whole by optical adhesive technology.

[0013] In a second aspect, an embodiment of the present invention further provides a method for manufacturing a polarization light conversion device, which uses the above-mentioned polarization light conversion device; the method for manufacturing a polarization light conversion device comprises the following steps:

[0014] Step S1, PBS prism processing: quartz glass is used as the substrate material of the prism, and right-angle prism and rhombus prism are processed.

[0015] Step S2, PBS coating: coating a polarization beam splitting film on the inclined surface of the rhombus prism.

[0016] Step S3, PBS flat sheet processing: the inclined surfaces of two adjacent rhombus prisms are bonded together by optical adhesive technology, and several rhombus prisms are bonded into a whole by optical adhesive technology to form a polarization beam splitter prism array; both ends of the polarization beam splitter prism array are bonded with right-angle prisms by optical adhesive technology to form a PBS flat sheet structure.

[0017] Step S4, polymer coating and curing: coating a liquid crystal polymer on the light output path of the PBS flat sheet to form a polymer layer; and drying and curing the polymer layer by heating.

[0018] Step S5, photo-orientation: modulate the ultraviolet light source into S-polarized light with the same pattern as the patterned polymer half-wave plate, irradiate the S-polarized light on the incident light path of the polarization beam splitter prism array, and use photochemical reaction to align the liquid crystal molecules in the polymer layer to form a patterned polymer half-wave plate.

[0019] Step S6, post-processing: baking the polarized light conversion device after the photo-orientation, and performing optical performance inspection and appearance inspection on the baked polarized light conversion device.

[0020] Furthermore, the specific steps of step S1 are:

[0021] The prism uses quartz glass that can transmit both far ultraviolet light and visible light and near infrared light as the substrate material, and the substrate material is processed into right-angle prisms and rhombus prisms.

[0022] Furthermore, the specific steps of step S2 are:

[0023] Coating a polarization beam splitting film on the long inclined surface of the rhombus prism;

[0024] Among them, PBS film: Tp>99%@420-680nm; Rs>99%@350-680nm; AO I=45 degrees (incident on glass).

[0025] Furthermore, the specific steps of step S3 are:

[0026] A plurality of rhombus prisms are bonded between two right-angle prisms, the long inclined surfaces of the two adjacent rhombus prisms are bonded together by optical adhesive technology, and the long inclined surfaces of the rhombus prisms are bonded to the inclined surfaces of the right-angle prisms by optical adhesive technology; a plurality of rhombus prisms are bonded to the two right-angle prisms by optical adhesive technology into a whole, and a PBS flat sheet structure is formed.

[0027] Furthermore, the specific steps of step S4 are:

[0028] Liquid crystal polymer is coated on the light output path of the PBS flat sheet to form a polymer layer with a thickness of 100-600 nm, and the polymer layer is dried and solidified by heating;

[0029] The curing temperature of the polymer layer is 80-110° C., and the curing time is 1-2 hours.

[0030] Furthermore, the specific steps of step S5 are: modulating the ultraviolet light source into linear polarized light, and modulating the linear polarized light into S polarized light with the same pattern as the patterned polymer half-wave plate through a cylindrical lens array; irradiating the S polarized light on the incident light path of the polarization beam splitter prism array, and irradiating the S polarized light on the liquid crystal polymer layer through a PBS flat plate, and the part of the liquid crystal polymer layer irradiated by light undergoes a photo-controlled orientation effect; utilizing a photochemical reaction to make the polymer layer realize the directional arrangement of liquid crystal molecules, so as to form a patterned polymer half-wave plate;

[0031] Wherein, the ultraviolet light source is ultraviolet light with a wavelength of 330-400nm.

[0032] Furthermore, in step S6, the baking temperature is 90-130° C., and the baking time is 1-10 min.

[0033] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0034] The present invention improves the connection mode between the half-wave plate and the polarization beam splitter prism in the polarization light conversion device, and can effectively alleviate the problem in the prior art that the polarization beam splitter prism and the half-wave plate are relatively precise, which leads to difficult processing and thus affects the reliability of the polarization light converter and the light source when producing the polarization light conversion device; at the same time, the precise bonding steps between the wave plate and the PBS array are simplified, the forming is directly performed, the process is simplified, and the cost is reduced; and the problem of wave plate misalignment and bubbles caused by accurately positioning and bonding many wave plate strips to the specified area of ​​the PBS array is avoided.

[0035] The present invention utilizes the PBS flat plate optical path to directly process the patterned half-wave plate in the required area of ​​the liquid crystal polymer layer, replacing the traditional wave plate bonding process, greatly reducing the processing and manufacturing; it can be applied to various practical applications of precision miniaturization to achieve miniaturization or micro-miniaturization of optical systems. The processing method of the present invention has the characteristics of miniaturization, easy integration, and lightness, and has great application potential in the fields of display, optical communication, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0037] Figure 1 It is a schematic diagram of the overall structure of the polarization converter (PCS) of the present invention.

[0038] Figure 2 FIG. 1 is a schematic diagram of the optical path of the polarized light converter of the present invention and its light orientation.

[0039] Figure 3 The figure is a flow chart of the steps of the manufacturing method of the polarization light converter of the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] An embodiment of the present invention provides a polarized light conversion device, which includes a polarization beam splitting prism array and a half-wave plate;

[0042] Reference Figure 1As shown, the polarization beam splitter prism array is formed by bonding a plurality of first light-transmitting components; second light-transmitting components are bonded to both ends of the polarization beam splitter prism array, and a polarization beam splitter film is arranged between the first light-transmitting component and the adjacent first light-transmitting component or the second light-transmitting component; a half-wave plate is arranged on the light output path of the polarization beam splitter prism array.

[0043] The half-wave plate is a patterned polymer layer made of liquid crystal polymer.

[0044] Reference Figure 1 As shown, the polarization beam splitter prism array includes two right-angle prisms and a plurality of rhombus prisms; a plurality of rhombus prisms are arranged between the two right-angle prisms, and the connection between each prism is coated with a polarization beam splitter film; the rhombus prism and the adjacent rhombus prism or right-angle prism are bonded into a whole by optical adhesive technology.

[0045] Among them, the prism uses quartz glass material as the substrate material, which can transmit both far ultraviolet spectrum and visible light and near infrared spectrum; the specifications of polarization splitting film (PBS film) are: Tp>99%@420-680nm; Rs>99%@350-680nm; AO I=45 degrees (incident on glass).

[0046] In this embodiment, the specification of the right-angle prism is 2*2mm, the specification of the rhombus prism is 2mm wide, and the inclination angle is 45 degrees; so that the rhombus prism and the right-angle prism can be bonded by optical adhesive technology to form a PBS flat sheet structure. Among them, the first light-transmitting component and the second light-transmitting component can also be bonded by other adhesive materials to form a PBS flat sheet structure, as long as there is no absorption loss of the light-oriented ultraviolet light, and the connection relationship remains unchanged, the same effect can be achieved, and no further description is given here.

[0047] In addition, the second light-transmitting component is not limited to a right-angle prism. The second light-transmitting component can be an isosceles triangle, an isosceles trapezoid, an isosceles triangle, etc. The second light-transmitting component can also adopt other prism structures. As long as the first light-transmitting component and the second light-transmitting component are bonded to each other to form a PBS flat sheet structure, both the optical imaging application effect and the S-polarized ultraviolet light can pass through the designated area can be guaranteed. No further description is given here.

[0048] It should be noted that the optical adhesive technology relies on the molecular attraction between the polished surfaces of the parts to combine light-transmitting components into complex optical components; it enables the rhombus prism and the right-angle prism to be bonded at room temperature through the optical adhesive technology, and avoids the absorption loss of the glue to the light-oriented ultraviolet light; among them, the inclined surfaces of the rhombus prism and the right-angle prism have a relatively high surface flatness.

[0049] In addition, the polarization beam splitter prism array uses molecular attraction to achieve bonding between two adjacent prisms without using any adhesive; during the bonding process, pressure is applied to the two prisms so that two clean, smooth, and uniformly shaped prism optical surfaces are bonded together; among them, the friction of the smoother prism contact surface is reduced within a certain range, but when the smoothness exceeds a certain limit, the friction will increase.

[0050] The principle of optical bonding technology is that the molecules on the surfaces of two objects are closely adjacent to each other, and the distance between them is very small. Due to the electromagnetic force between the molecules, they attract each other. The smoother the surface of the object, the smaller the distance between the molecules, and the greater the attraction. Therefore, it becomes very difficult to separate the two objects. In this embodiment, the two objects are a first light-transmitting component and a second light-transmitting component. The first light-transmitting component and the second light-transmitting component can form a single piece without an obvious internal interface through the optical bonding technology.

[0051] On the other hand, an embodiment of the present invention further provides a method for manufacturing a polarization light conversion device, which uses the above-mentioned polarization light conversion device; Figure 3 As shown, the manufacturing method of the polarization light conversion device includes the following steps:

[0052] Step S1, PBS prism processing: select quartz glass material as the prism substrate material; first process a right-angle prism and an oblique square prism.

[0053] Among them, the prism preferably uses quartz glass material as the substrate material, which can transmit both far ultraviolet spectrum and visible light and near infrared spectrum; firstly, a right-angle prism and an oblique prism are processed, the specification of the right-angle prism is 2*2mm, the specification of the oblique prism is 2mm in width and the inclination angle is 45 degrees.

[0054] Step S2, PBS coating: coating a polarization beam splitting film on the inclined surface of the rhombus prism.

[0055] Among them, the long inclined surfaces on both sides of the rhombus prism are coated with polarization splitting films, which can not only ensure the optical imaging application effect, but also ensure that the S-polarized ultraviolet light can pass through the designated area.

[0056] In addition, the specifications of the polarization beam splitting film (PBS film) are: Tp>99%@420-680nm;

[0057] Rs>99%@350-680nm; AO I=45 degrees (incident on glass).

[0058] Step S3, PBS flat sheet processing: the inclined surfaces of two adjacent rhombus prisms are bonded together by bonding materials to form a polarization beam splitter prism array; both ends of the polarization beam splitter prism array are connected to the right-angle prism by optical bonding technology to form a PBS flat sheet structure.

[0059] Among them, a plurality of rhombus prisms are bonded between two right-angle prisms, the long inclined surfaces of the two adjacent rhombus prisms are bonded together by optical adhesive technology, and the long inclined surface of the rhombus prism is bonded to the inclined surface of the right-angle prism by optical adhesive technology; a plurality of rhombus prisms are bonded to the two right-angle prisms by optical adhesive technology into a whole, and a PBS flat sheet structure is formed.

[0060] It should be noted that optical bonding technology relies on the molecular attraction between the polished surfaces of parts to combine light-transmitting components into complex optical components; it enables rhombic prisms and right-angle prisms to be bonded at room temperature through optical bonding technology, and avoids the absorption loss of light-oriented ultraviolet light by the glue.

[0061] Among them, the inclined surfaces of rhombus prism and right-angle prism have relatively high surface flatness.

[0062] Step S4, polymer coating and curing: coating a liquid crystal polymer on the light output path of the PBS flat sheet to form a polymer layer; and drying and curing the polymer layer by heating.

[0063] The curing temperature of the polymer layer is 80-110° C., the curing time is 1-2 hours, and the thickness of the polymer layer is 100-600 nm.

[0064] In this embodiment, the present scheme preferably uses a spin coating method to coat the polymer on the PBS flat sheet, and after coating, the polarization light conversion device is baked at 100° C. for 1 hour through a hot plate to dry and solidify it to form a polymer layer with a thickness of 400 nm.

[0065] In addition, liquid crystal polymers can be coated on the PBS flat sheet by spin coating, spray coating, inkjet coating, screen printing, etc. As long as the same effect can be achieved, any method can be used and will not be described in detail here.

[0066] Step S5, photo-orientation: modulate the ultraviolet light source into S-polarized light with the same pattern as the patterned polymer layer, irradiate the S-polarized light on the incident light path of the polarization beam splitter prism array, and use photochemical reaction to align the liquid crystal molecules in the polymer layer to form a patterned polymer half-wave plate.

[0067] Among them, refer to Figure 2 As shown, the ultraviolet light source is modulated into linear polarized light, and the linear polarized light is modulated into S polarized light with the same pattern as the patterned polymer layer through a cylindrical lens array; the S polarized light is irradiated on the incident light path of the polarization beam splitter prism array, and the polymer layer is made to realize the directional arrangement of liquid crystal molecules by photochemical reaction, thereby forming a patterned polymer half-wave plate.

[0068] In addition, the ultraviolet light source is ultraviolet light with a wavelength of 330-400nm.

[0069] In this embodiment, a UV light source with a wavelength of 365 nm is selected and modulated into S polarized light by a polarizer, and then the linear polarized light is modulated into S polarized light with the same pattern as the patterned polymer layer through a cylindrical lens array, and the S polarized light is irradiated on the incident light path of the polarization beam splitter prism array; Figure 2 As shown, S-polarized light is irradiated onto the liquid crystal polymer layer through a PBS plate, and the portion of the liquid crystal polymer layer irradiated by light undergoes a photo-controlled orientation effect; anisotropy is generated by a photochemical reaction, that is, a photosensitive group parallel to the polarization direction of the polarized light undergoes a photochemical reaction, generating anisotropy to achieve directional arrangement of liquid crystal molecules, thereby forming a patterned polymer half-wave plate.

[0070] Photo-controlled orientation technology uses polarized light to change the microscopic arrangement direction of liquid crystal molecules; specifically, when polarized light is irradiated onto the liquid crystal material, the energy of the photons changes the arrangement state of the liquid crystal molecules, causing them to rearrange along the polarization direction of the light. Photo-controlled orientation technology is a method of achieving liquid crystal orientation through polarized light irradiation, causing them to be regularly arranged at a microscopic scale, thereby exhibiting macroscopic optical anisotropy.

[0071] It should be noted that the ultraviolet light source can generally be a high-pressure mercury lamp, a xenon lamp, a halogen lamp, etc., and then monochromatic polarized light is obtained through a filter device and a polarizing device. Polarized ultraviolet laser or a combination of non-polarized ultraviolet laser + polarizer can also be used; as long as the same effect can be achieved, it can be used and no further description will be given here.

[0072] Step S6, post-processing: baking the polarized light conversion device after the photo-orientation, and performing optical performance inspection and appearance inspection on the baked polarized light conversion device.

[0073] The polymer wave plate after photo-orientation is placed in an oven for baking to help the reaction of the polymer functional groups, further stabilize and eliminate the stress that may be caused during the photo-orientation process, achieve a more ideal photo-orientation effect, and enable the wave plate to achieve the expected optical delay performance.

[0074] The baking temperature is 90-130°C and the baking time is 1-10 minutes.

[0075] In this embodiment, the polarized light conversion device after photo-orientation is placed in an oven for baking at 110° C. for 5 minutes; thereafter, the polarized light conversion device is subjected to relevant optical performance and appearance inspections using relevant optical inspection equipment to ensure that the polarized light conversion device meets the design requirements.

[0076] In the present invention, a technology is used to induce photopolymerization, photoisomerization or photodecomposition reaction of the polymer layer on the substrate by irradiation with laser or polarized ultraviolet light, thereby generating surface anisotropy to induce the orientation of liquid crystal molecules. During the photo-orientation process, when the photosensitive liquid crystal polymer material is irradiated with polarized ultraviolet light, a photochemical reaction occurs on its surface, causing the surface properties of the material to change and generate anisotropy. This anisotropy then induces the liquid crystal molecules to align along a specific direction, thereby achieving the orientation of the liquid crystal wave plate. By precisely controlling the polarization direction of light and the irradiation area, a surface graphic structure can be obtained on the polymer surface, so that the liquid crystal molecules are oriented in the same direction in different areas, which is very beneficial for making patterned liquid crystal polymer wave plates.

[0077] Therefore, this technical solution can be used for the half-wave plate of the PBS plate to provide optical applications of phase delay; and the polarized light path of the PBS plate can be used to achieve local area exposure, thereby forming a patterned wave plate structure, which can greatly simplify the processing technology of the PBS plate; the PBS film is designed to reflect the specified linearly polarized ultraviolet light to ensure exposure of the designated area to form a patterned wave plate structure.

[0078] In summary, the present invention improves the connection method between the half-wave plate and the polarization beam splitter prism in the polarization light conversion device, which can effectively alleviate the problem in the prior art that the polarization beam splitter prism and the half-wave plate are relatively precise, which leads to difficult processing when producing the polarization light conversion device, thereby affecting the reliability of the polarization light converter and the light source; at the same time, the precise bonding steps between the wave plate and the PBS array are simplified, the forming is directly performed, the process is simplified, and the cost is reduced; and the problem of precisely positioning and bonding many wave plate strips to the specified area of ​​the PBS array, thereby avoiding the generation of problems such as wave plate misalignment and bubbles.

[0079] The present invention utilizes the PBS optical path to directly process the patterned half-wave plate in the required area of ​​the liquid crystal polymer layer, replacing the traditional wave plate bonding process, greatly reducing the processing and manufacturing; it can be applied to various practical applications of precision miniaturization to achieve miniaturization or micro-miniaturization of the optical system. The processing method of the present invention has the characteristics of miniaturization, easy integration, and lightness and thinness, and has great application potential in the fields of display, optical communication, etc.

[0080] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A polarization light conversion device, characterized in that: It includes: A polarization beam splitting prism array, which is formed by bonding a plurality of first light-transmitting components; The two ends of the polarization beam splitter prism array are bonded with a second light-transmitting member, and a polarization beam splitting film is provided between the first light-transmitting member and the first light-transmitting member or the second light-transmitting member adjacent thereto; and A half-wave plate, which is arranged on the light output path of the polarization beam splitting prism array; The half-wave plate is a patterned polymer layer made of liquid crystal polymer.

2. The polarization light conversion device according to claim 1, characterized in that: The polarization beam splitting prism array comprises two right-angle prisms and a plurality of oblique square prisms; a plurality of oblique square prisms are arranged between the two right-angle prisms, and a polarization beam splitting film is plated at the connection point of each prism.

3. The polarization light conversion device according to claim 2, characterized in that: The rhombus prism and the adjacent rhombus prism or right-angle prism are bonded into a whole by optical adhesive technology.

4. A method for manufacturing a polarization light conversion device, applied to the polarization light conversion device according to any one of claims 1 to 3, characterized in that: It includes the following steps: Step S1, PBS prism processing: quartz glass is used as the substrate material of the prism, and right-angle prism and rhombus prism are processed. Step S2, PBS coating: coating a polarization beam splitting film on the inclined surface of the rhombus prism. Step S3, PBS flat sheet processing: the inclined surfaces of two adjacent rhombus prisms are bonded together by optical adhesive technology; a plurality of rhombus prisms are bonded together into a whole by optical adhesive technology to form a polarization beam splitter prism array; both ends of the polarization beam splitter prism array are bonded with right-angle prisms by optical adhesive technology to form a PBS flat sheet structure. Step S4, polymer coating and curing: coating a liquid crystal polymer on the light output path of the PBS flat sheet to form a polymer layer, and drying and curing the liquid crystal polymer layer by heating. Step S5, photo-orientation: modulate the ultraviolet light source into S-polarized light with the same pattern as the patterned polymer half-wave plate, irradiate the S-polarized light on the incident light path of the polarization beam splitter prism array, and use photochemical reaction to align the liquid crystal molecules in the polymer layer to form a patterned polymer half-wave plate. Step S6, post-processing: baking the polarized light conversion device after the photo-orientation, and performing optical performance inspection and appearance inspection on the baked polarized light conversion device.

5. The method for manufacturing a polarization conversion device according to claim 4, wherein: The specific steps of step S1 are: The prism uses quartz glass that can transmit both far ultraviolet light and visible light and near infrared light as the substrate material, and the substrate material is processed into right-angle prisms and rhombus prisms.

6. The method for manufacturing a polarization conversion device according to claim 4, wherein: The specific steps of step S2 are: coating a polarization beam splitting film on the long inclined surface of the rhombus prism; Among them, PBS membrane: Tp>99%@420-680nm; Rs>99%@350-680nm.

7. The method for manufacturing a polarization conversion device according to claim 4, wherein: The specific steps of step S3 are: A plurality of rhombus prisms are bonded between two right-angle prisms, the long inclined surfaces of the two adjacent rhombus prisms are bonded together by optical adhesive technology, and the long inclined surfaces of the rhombus prisms are bonded to the inclined surfaces of the right-angle prisms by optical adhesive technology; a plurality of rhombus prisms are bonded to the two right-angle prisms by optical adhesive technology into a whole, and a PBS flat sheet structure is formed.

8. The method for manufacturing a polarization conversion device according to claim 4, wherein: The specific steps of step S4 are: Liquid crystal polymer is coated on the light output path of the PBS flat sheet to form a polymer layer with a thickness of 100-600 nm, and the polymer layer is dried and solidified by heating; The curing temperature of the polymer layer is 80-110° C., and the curing time is 1-2 hours.

9. The method for manufacturing a polarization conversion device according to claim 4, wherein: The specific steps of step S5 are: The ultraviolet light source is modulated into linear polarized light, and the linear polarized light is modulated into S polarized light with the same pattern as the patterned polymer half-wave plate through a cylindrical lens array; the S polarized light is irradiated on the light path of the polarization beam splitter prism array, and the S polarized light is irradiated on the liquid crystal polymer layer through a PBS flat plate, and the part of the liquid crystal polymer layer irradiated by light is subjected to a photo-controlled orientation effect; the liquid crystal polymer layer is oriented to form a patterned polymer half-wave plate by using a photochemical reaction; Wherein, the ultraviolet light source is ultraviolet light with a wavelength of 330-400nm.

10. The method for manufacturing a polarization conversion device according to claim 4, wherein: In step S6, the baking temperature is 90-130° C., and the baking time is 1-10 min.

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