WO2020093936A1

WO2020093936A1 - Miniature projection light engine, polarization multiplexing device, and method for improving light energy utilization rate

Info

Publication number: WO2020093936A1
Application number: PCT/CN2019/114930
Authority: WO
Inventors: 陈杭; 郝希应; 胡增新
Original assignee: 舜宇光学（浙江）研究院有限公司
Priority date: 2018-11-08
Filing date: 2019-11-01
Publication date: 2020-05-14

Abstract

A miniature projection light engine, a polarization multiplexing device (10), and a method for improving a light energy utilization rate. The polarization multiplexing device (10) is used to convert non-polarized light into polarized light having the same polarization state, and comprises a set of polarization multiplexing units (11). All of the polarization multiplexing units (11) are arranged in an end-to-end fashion, wherein each of the polarization multiplexing units (11) has an incident surface (1101) and an emergent surface (1102) disposed opposite to the incident surface (1101), and comprises an optical converter element (113), an optical splitter assembly (111), and an optical reflector assembly (112). The optical converter element (113) converts first polarized light (201) into second polarized light (202). The optical splitter assesmbly (111) is located on one side of the optical converter element (113), and splits non-polarized light incident on the incident surface (1101) into the second polarized light (202), emitted from the emergent surface (1102), and the first polarized light (201) directed toward the optical converter element (113). The reflector assembly (112) is located on the other side of the optical converter element (113), and reflects the second polarized light (202) converted by the optical converter element (113), such that the second polarized light (202) is emitted from the emergent surface (1102).

Description

Miniature projection light engine, polarization multiplexing device and method for improving light energy utilization rate

Technical field

The invention relates to the technical field of optical projection, in particular to a polarization multiplexing device for a projection system, a method for improving the light energy utilization rate of the projection system, and a miniature projection light engine for a near-eye display device.

Background technique

In the projection system based on LCOS, HTPS and other liquid crystal displays, in order to satisfy the polarized light illumination conditions, a polarization device is usually used in the projection system to convert the unpolarized light emitted by the light source system into polarized light. However, in the process of polarized light conversion, the projection system will have at least half of the light energy loss, undoubtedly reducing the light energy utilization rate of the projection system, and even unable to meet the projection system's high brightness and low power consumption imaging requirements. Therefore, in order to improve the light energy utilization rate of the projection system, a polarization multiplexing device is usually used to convert the unpolarized light emitted by the light source system into polarized light with the same polarization state.

At present, as shown in FIG. 1, the most common existing polarization multiplexing device 10P is to paste a 1/2 wave plate 12P after the polarization beam splitting array 11P, wherein the polarization beam splitting array 11P is provided with a polarization beam splitting film The prism 111P of the 112P and the reflective film 113P is composed periodically. In this way, when the incident light beam (unpolarized light) enters the corresponding prism 111P, due to the characteristics of the polarization beam splitting film 112P transmitting P-state polarized light and anti-S-state polarized light, the P-state polarization in the unpolarized light The light directly passes through the polarizing beam splitting film 112P, and the S-state polarized light in the unpolarized light is reflected to the adjacent reflective film 113P, after being reflected twice, it is converted to P-state polarized light. Therefore, finally, all light emitted from the existing polarization multiplexing device 10P is P-state polarized light.

However, although the existing polarization multiplexing device 10P can achieve the purpose of converting unpolarized light into polarized light of the same polarization state, it lays the foundation for further improving the energy utilization rate of the projection system. However, in the polarization multiplexing device 10P in the prior art, in order to make the light output through the polarization multiplexing device 10P have a uniform polarization state, the size and position of the 1/2 wave plate 12P must be The size and position of the mutually separated beam arrays obtained on the exit surface of the beam array 11P are perfectly matched. This undoubtedly greatly increased the difficulty of manufacturing the polarization multiplexing device 10P. In particular, the accuracy of periodic alignment of the 1/2 wave plate 12P and the polarization beam splitting array 11P is extremely high. Once there is a deviation between the 1/2 wave plate and the exiting polarized light area of the polarization beam splitting array 11P, the purity of the polarized light exiting from the polarization multiplexing device 10P will be reduced, and the brightness of the projection system will be reduced, which will affect The imaging quality of the projection system.

In addition, for the structure of the existing polarization multiplexing device 10P, the current manufacturing process cannot reach the level of small size, and cannot meet the development requirements of the small size of the current micro-miniature projection system. Augmented reality (AR), near-eye display (NED), wearable and other fields.

In addition, in recent years, the emergence of micro display chip technology has made it possible to miniaturize and high-resolution projection display. With the continuous development of projection display technology and market demand, the large field of view, high imaging quality, small size, and wearable miniature projection light engine are getting more and more attention, especially in the development of fierce augmented reality (Augmented reality, AR for short), Near-eye display (NED for short) and wearable.

However, existing miniature projection light engines usually include a light source system, a relay lens group, a display chip, and a projection imaging system, where the relay lens group is located in the emission path of the light source system, and the display chip and the projection imaging system are located The opposite side of the relay lens group, which leads to the large size and volume of the existing micro projection light engine, it is difficult to meet the market demand for a small volume micro projection light engine, especially in augmented reality, near-eye display And wearable and other fields have been widely used and popularized.

Summary of the invention

An object of the present invention is to provide a polarization multiplexing device for a projection system and a method for improving the light energy utilization rate of the projection system, which can effectively convert the unpolarized light emitted by the light source system into the same polarization state polarized light.

Another object of the present invention is to provide a polarization multiplexing device for a projection system and a method for improving the light energy utilization rate of the projection system, which can improve the purity of polarized light emitted through the polarization conversion system.

Another object of the present invention is to provide a polarization multiplexing device for a projection system and a method for improving the light energy utilization rate of the projection system, which can increase the brightness of the projection system.

Another object of the present invention is to provide a polarization multiplexing device for a projection system and a method for improving the light energy utilization rate of the projection system, which can improve the imaging quality of the projection system.

Another object of the present invention is to provide a polarization multiplexing device for a projection system and a method for improving the light energy utilization rate of the projection system, wherein, in an embodiment of the present invention, the polarization multiplexing device solves In order to reduce the difficulty in manufacturing the polarization conversion system, the problem of the alignment of the 1/2 wave plate and the polarization beam splitting array in the existing polarization multiplexing device is solved.

Another object of the present invention is to provide a polarization multiplexing device for a projection system and a method for improving the light energy utilization rate of the projection system, wherein, in an embodiment of the present invention, the polarization multiplexing device The manufacturing process is simplified, which helps reduce the manufacturing cost of the polarization conversion system.

Another object of the present invention is to provide a polarization multiplexing device for a projection system and a method for improving the light energy utilization rate of the projection system, wherein, in an embodiment of the present invention, the polarization multiplexing device can It is easy to accurately align the light conversion element with the separated first polarized light, which helps to convert all the first polarized light into the second polarized light, so as to improve the output of the first polarized light through the polarization multiplexing device. The purity of dipolarized light.

Another object of the present invention is to provide a polarization multiplexing device for a projection system and a method for improving the light energy utilization rate of the projection system, wherein, in an embodiment of the present invention, the polarization multiplexing device can Improve the light energy utilization rate of the projection system.

Another object of the present invention is to provide a polarization multiplexing device for a projection system and a method for improving the light energy utilization rate of the projection system, wherein, in an embodiment of the present invention, the polarization multiplexing device can On the basis of improving the utilization rate of light energy of the system, it has the characteristics of small size, which is beneficial to reduce the volume of the projection system to meet the needs of the industry.

Another object of the present invention is to provide a polarization multiplexing device for a projection system and a method for improving the light energy utilization rate of the projection system, wherein, in an embodiment of the present invention, the polarization multiplexing device is particularly It is suitable for applications and popularization in the fields of augmented reality, near-eye display and wearable.

Another object of the present invention is to provide a polarization multiplexing device for a projection system and a method for improving the light energy utilization rate of the projection system, wherein, in order to achieve the above purpose, no expensive materials or Complex structure. Therefore, the present invention successfully and effectively provides a solution that not only provides a simple polarization multiplexing device for a projection system and a method for improving the light energy utilization rate of the projection system, but also increases the The practicality and reliability of the polarization multiplexing device of the system and the method for improving the light energy utilization rate of the projection system.

An object of the present invention is to provide a miniature projection light engine for a near-eye display device, which can meet the market demand for a small-sized miniature projection light engine.

Another object of the present invention is to provide a miniature projection light engine for a near-eye display device, wherein, in an embodiment of the invention, the miniature projection light engine uses an innovative optical path design in order to achieve small size and light weight Demand.

Another object of the present invention is to provide a miniature projection light engine for a near-eye display device, wherein, in an embodiment of the invention, the relay system of the miniature projection light engine is designed in a reversal manner, which is conducive to making The relay system has a compact structure and a small size.

Another object of the present invention is to provide a miniature projection light engine for a near-eye display device, wherein, in an embodiment of the invention, the miniature projection light engine has a folding relay optical path to ensure In the case of a sufficiently long relay optical path, the size or volume of the micro projection light engine is further reduced.

Another object of the present invention is to provide a miniature projection light engine for a near-eye display device. In an embodiment of the present invention, the imaging system of the miniature projection light engine is designed in a reversal manner, which is beneficial to the The imaging system has a compact structure and a small size.

Another object of the present invention is to provide a miniature projection light engine for a near-eye display device, wherein, in an embodiment of the invention, the miniature projection light engine has a folding imaging optical path to ensure sufficient In the case of a long imaging optical path, the size or volume of the micro projection light engine is reduced.

Another object of the present invention is to provide a miniature projection light engine for a near-eye display device, wherein, in an embodiment of the present invention, the overall volume of the miniature projection light engine is sufficiently small to be suitable for augmented reality, near-eye Display and wearable fields have been applied and popularized.

Another object of the present invention is to provide a miniature projection light engine for a near-eye display device, wherein, in an embodiment of the invention, the miniature projection light engine has a linear structure, which helps reduce the miniaturization The horizontal dimension of the projection light engine.

Another object of the present invention is to provide a miniature projection light engine for a near-eye display device, wherein, in an embodiment of the invention, the miniature projection light engine has portability, which is helpful in the traditional projection field It is widely used.

Another object of the present invention is to provide a miniature projection light engine for a near-eye display device, wherein, in an embodiment of the invention, the miniature projection light engine is adapted to project polarized light carrying image information to the near-eye In the waveguide of the display device, the polarized light carrying image information is projected into the human eye through the waveguide for imaging.

Another object of the present invention is to provide a miniature projection light engine for a near-eye display device, wherein, in order to achieve the above-mentioned object, it is not necessary to use expensive materials or complicated structures in the present invention. Therefore, the present invention successfully and effectively provides a solution that not only provides a simple miniature projection light engine for near-eye display devices, but also increases the practicality and reliability of the miniature projection light engine for near-eye display devices. Sex.

In order to achieve at least one of the above objects of the invention or other objects and advantages, the present invention provides a polarization multiplexing device for converting unpolarized light into polarized light having the same polarization state, wherein the polarization multiplexing device includes:

A group of polarization multiplexing units, wherein all the polarization multiplexing units are arranged in an end-to-end manner, wherein each polarization multiplexing unit has an incident surface and an exit surface opposite to the incident surface, and includes:

A light conversion element, wherein the light conversion element is used to convert the first polarized light into the second polarized light;

An optical beam splitting assembly, wherein the optical beam splitting assembly is located on one side of the light conversion element, and is used to separate the unpolarized light incident from the incident surface into a second polarization emitted from the exit surface Light and the first polarized light directed to the light conversion element; and

A light reflection component, wherein the light reflection component is located on the other side of the light conversion element, and is used to reflect the second polarized light converted by the light conversion element so that the second polarized light is emitted from the exit Face shot.

In an embodiment of the present invention, the light splitting assembly of each polarization multiplexing unit includes a first beam splitting prism, a second beam splitting prism, and a light splitting element, wherein the light splitting element It is arranged between the first beam splitting prism and the second beam splitting prism, and is used to allow the first polarized light in the unpolarized light to pass through and prevent the second polarized light in the unpolarized light from passing through The second polarized light is reflected to the light conversion element.

In an embodiment of the present invention, the first and second beam splitting prisms are right-angle prisms, and the light splitting element is disposed between the slopes of the first and second beam splitting prisms to form The optical beam splitting assembly having a rectangular structure.

In an embodiment of the invention, the optical beam splitting element is a polarizing beam splitting film.

In an embodiment of the invention, the light conversion element is a 1/2 wave plate.

In an embodiment of the invention, the angle between the light conversion element and the light beam splitting element of each polarization multiplexing unit is 40-50 degrees.

In an embodiment of the invention, the first and second beam splitting prisms are both isosceles right-angled triangles.

In an embodiment of the present invention, the light reflecting component includes a first reflecting prism, a second reflecting prism, and a light reflecting element, wherein the light reflecting element is disposed on the first reflecting prism and the second reflecting Between the prisms, it is used to reflect the second polarized light converted by the light conversion element.

In an embodiment of the present invention, the first and second reflecting prisms are right-angle prisms, and the light reflecting element is disposed between the slopes of the first and second reflecting prisms to form a rectangular structure The light reflecting component.

In an embodiment of the invention, the light reflecting element is a reflecting film.

In an embodiment of the invention, the angle between the light conversion element and the light reflection element of each polarization multiplexing unit is 40-50 degrees.

In an embodiment of the present invention, the cross sections of the first and second reflecting prisms are both isosceles right triangles.

In an embodiment of the invention, the light reflecting element is parallel to the light beam splitting element.

In an embodiment of the present invention, the second beam splitting prism of the light splitting component of any one of the polarization multiplexing units and the light reflecting component of the adjacent polarization multiplexing unit The second reflecting prisms are bonded.

In an embodiment of the present invention, the second beam splitting prism of the light splitting component of any one of the polarization multiplexing units and the light reflecting component of the adjacent polarization multiplexing unit The second reflecting prisms are integrally connected to form a common prism having a parallelogram cross section by combining the second beam splitting prism and the second reflecting prism.

In an embodiment of the invention, the first polarized light is S-polarized light, and the second polarized light is P-polarized light.

In an embodiment of the invention, the first polarized light is P-polarized light, and the second polarized light is S-polarized light.

In an embodiment of the present invention, the polarization multiplexing device further includes at least one anti-reflection element, wherein the anti-reflection element is disposed on the incident surface and the exit surface of the polarization multiplexing unit, It is used to reduce the reflection of the unpolarized light and the second polarized light by the incident surface and the exit surface, respectively.

In an embodiment of the present invention, the anti-reflection element is an anti-reflection film plated on the incident surface and the exit surface of the polarization multiplexing unit, respectively.

According to another aspect of the present invention, the present invention further provides a method for improving the light energy utilization rate of the projection system, including the steps of:

S100: Separate unpolarized light to form separated first polarized light and separated second polarized light, wherein the separated first polarized light and the separated second polarized light propagate in different directions;

S200: Convert the separated first polarized light to form the converted second polarized light; and

S300: Reflect the converted second polarized light to form a reflected second polarized light, wherein the reflected second polarized light and the separated second polarized light propagate in the same direction so that the projection system is sufficiently Use this unpolarized light.

In an embodiment of the present invention, in the step S100:

By means of a beam splitting component of a polarization multiplexing unit of a polarization multiplexing device of the projection system, the unpolarized light incident from the incident surface of the polarization multiplexing unit is separated into the separated first polarization Light and the separated second polarized light, wherein the separated first polarized light is directed to a light conversion element of the polarization multiplexing unit, and the separated second polarized light is directed to the polarization multiplexing unit The exit surface is shot from the exit surface.

In an embodiment of the present invention, in the step S200:

With the light conversion element, the separated first polarized light is converted into the converted second polarized light, wherein the converted second polarized light is directed to a light reflection component of the polarization multiplexing unit.

In an embodiment of the present invention, in the step S300:

With the light reflection component, the converted second polarized light is reflected into the reflected second polarized light, wherein the reflected second polarized light is directed to the exit surface of the polarization multiplexing unit to The exit surface is shot.

In an embodiment of the invention, the method for improving the light energy utilization rate of the projection system further includes the steps of:

An anti-reflection material is plated on the incident surface of the polarization multiplexing unit to reduce the reflection of light from the incident surface.

An anti-reflection material is plated on the exit surface of the polarization multiplexing unit to reduce light reflection from the exit surface.

In an embodiment of the invention, the first polarized light is S-polarized light or P-polarized light, and the second polarized light is P-polarized light or S-polarized light.

In order to achieve at least one of the above objects of the invention or other objects and advantages, the present invention provides a miniature projection light engine, including:

A light source system for emitting polarized light with the same polarization state along a predetermined direction;

A display unit for modulating polarized light into polarized light carrying image information;

An imaging system for projecting polarized light carrying image information; and

A relay system, wherein the relay system is disposed between the light source system, the display unit, and the imaging system, and the light source system and the imaging system are respectively located opposite to the relay system Side, where the relay system is used to change the propagation direction of the polarized light from the light source system so that the polarized light propagates to the display unit; wherein the relay system is also used to change the light from the display unit The propagation direction of the polarized light carrying image information, so that the polarized light carrying image information can propagate to the imaging system along the predetermined direction.

In an embodiment of the present invention, the relay system includes a relay polarization beam splitting system and a relay folding system, wherein the relay polarization beam splitting system is disposed in the light source system and the imaging Between the systems, and the display unit and the relay folding system are respectively located on opposite sides of the relay polarization beam splitting system, wherein the display unit is also used to reflect the polarized light carrying image information back The relay polarization beam splitting system, and the relay folding system is used to fold back the polarized light emitted from the relay polarization beam splitting system back to the relay polarization beam splitting system, so that the light source A fold-back relay optical path forming the relay system is defined between the system and the display unit, so that the polarized light can propagate to the display unit along the fold-back relay optical path.

In an embodiment of the present invention, the relay folding system includes a relay light conversion element and a relay light reflection element, wherein the relay light conversion element is located in the relay polarization beam splitting system and Between the relay light reflecting elements, wherein the relay light reflecting elements are used to reflect the polarized light emitted from the relay polarizing beam splitting system back to the relay polarizing beam splitting system to make the polarized light secondary Passing through the relay light conversion element, wherein the relay light conversion element is used to convert polarized light passing through twice into polarized light having another polarization state.

In an embodiment of the invention, the relay light conversion element is a 1/4 wave plate, and the relay light reflection element is a concave mirror.

In an embodiment of the present invention, the relay polarization beam splitting system includes a first relay right angle prism, a second relay right angle prism, and a relay polarizing beam splitting film, wherein the relay polarizing beam splitting A film is provided between the slope of the first relay right-angle prism and the slope of the second relay right-angle prism to form the relay polarization beam splitting system having a rectangular cross section, wherein the relay polarized light The beam splitting film is used to allow P polarized light to pass through and reflect S polarized light to change the propagation direction of the S polarized light.

In an embodiment of the invention, the relay polarizing beam splitting film is a PBS film.

In an embodiment of the present invention, the relay polarization beam splitting system has a relay incidence surface, a relay exit surface parallel to the relay incidence surface, and a center perpendicular to the relay incidence surface A relay folding surface and a relay display surface perpendicular to the relay incident surface, wherein the light source system corresponds to the relay incident surface; wherein the relay folding system corresponds to the relay folding surface; Wherein the display unit corresponds to the relay display surface; wherein the imaging system corresponds to the relay exit surface.

In an embodiment of the present invention, the relay incident surface and the relay display surface of the relay polarization beam splitting system intersect the relay polarization beam splitting film, and the relay polarization beam splitting The relay exit surface and the relay folding surface of the system intersect the relay polarizing beam splitting film, so that the S polarized light from the light source system is first reflected by the relay polarizing beam splitting film to free itself The relay incident surface propagates to the relay folding surface, and then converted into P-polarized light by the relay folding system, and then folded back to the relay folding surface, the P-polarized light Passing through the relay polarizing beam splitting film to propagate from the relay folding surface to the display unit located on the relay display surface.

In an embodiment of the present invention, the relay system further includes a relay lens assembly, wherein the relay lens assembly is disposed on the relay incident surface of the relay polarization beam splitting system and the The light source systems are used to adjust the degree of convergence of polarized light from the light source systems.

In an embodiment of the present invention, the relay system further includes a relay polarization filter unit, wherein the relay polarization filter unit is disposed between the relay lens assembly and the relay polarization beam splitting system Between the relay incident surfaces is used to filter stray light in the S-polarized light.

In an embodiment of the invention, the relay polarization filter unit is an S polarizer.

In an embodiment of the present invention, the imaging system includes an imaging polarization beam splitting system and an imaging folding system, wherein the imaging polarization beam splitting system is located between the imaging folding system and the relay system , Wherein the imaging refraction system is used to revert the polarized light carrying image information emitted from the imaging polarization beam splitting system back to the imaging polarization beam splitting system to pass through the relay system and the imaging system A fold-back imaging optical path forming the imaging system is defined so that the miniature projection light engine can project the polarized light carrying image information along the fold-back imaging optical path.

In an embodiment of the present invention, the imaging folding system includes an imaging light conversion element and an imaging light reflection element, wherein the imaging light conversion element is located between the imaging light reflection element and the imaging polarization beam splitting system Between, wherein the imaging light reflecting element is used to reflect the polarized light carrying image information emitted from the imaging polarizing beam splitting system back to the imaging polarizing beam splitting system, so that the polarized light carrying image information is secondary Passing through the imaging light conversion element, wherein the imaging light conversion element is used to convert the polarized light carrying image information that has passed through twice into the polarized light having another polarization state carrying the image information.

In an embodiment of the invention, the imaging light conversion element is a 1/4 wave plate, and the imaging light reflection element is a concave mirror.

In an embodiment of the present invention, the imaging polarization beam splitting system includes a first imaging right-angle prism, a second imaging right-angle prism, and an imaging polarizing beam splitting film, wherein the imaging polarizing beam splitting film is disposed on the Between the inclined surface of the first imaging right-angle prism and the inclined surface of the second imaging right-angle prism to form the imaging polarization beam splitting system having a rectangular cross section, wherein the imaging polarization beam splitting film is used to allow image information to be carried The P-polarized light passes through and reflects the S-polarized light carrying image information to turn the S-polarized light carrying image information.

In an embodiment of the present invention, the imaging polarization beam splitting system has an imaging incident surface, an imaging exit surface perpendicular to the imaging incident surface, and an imaging reversal surface perpendicular to the imaging incident surface, wherein The imaging folding system corresponds to the imaging folding surface, and the relay system corresponds to the imaging incident surface, wherein the folding imaging optical path first extends from the relay display surface to the bending side A relay exit surface, and then extends from the relay exit surface to the imaging entrance surface, and then, the folding imaging optical path is reflected by the imaging polarizing beam splitting film to extend from the imaging entrance surface in a bent manner To the imaging folding surface, and finally after being folded back to the imaging folding surface by the relay folding system, it then passes through the imaging polarizing beam splitting film to extend from the imaging folding surface to the imaging exit surface.

In an embodiment of the present invention, the imaging system further includes an imaging polarization filter unit, wherein the imaging polarization filter unit is disposed on the imaging incident surface of the relay system and the imaging polarization beam splitting system In between, it is used to filter stray light from S-polarized light carrying image information from the relay system.

In an embodiment of the invention, the imaging polarizing filter unit is an S polarizing plate.

In an embodiment of the present invention, the imaging polarization beam splitting system has an imaging incident surface, an imaging exit surface perpendicular to the imaging incident surface, and an imaging folding surface parallel to the imaging incident surface, wherein The imaging folding system corresponds to the imaging folding surface, and the relay system corresponds to the imaging incident surface, wherein the folding imaging optical path first extends from the relay display surface to the bending side Relay exit surface, and then extend from the relay exit surface to the imaging entrance surface, and then, the folded imaging optical path passes through the imaging polarizing beam splitting film to extend from the imaging entrance surface to the The imaging reversal surface, and finally after being folded back to the imaging reversal surface by the imaging reversal system, is then reflected by the imaging polarizing beam splitting film to extend from the imaging refraction surface to the imaging exit surface .

In an embodiment of the present invention, the imaging system further includes an imaging conversion unit, wherein the imaging conversion unit is disposed between the imaging incident surface of the imaging polarization beam splitting system and the relay system , For converting S-polarized light carrying image information from the relay system into P-polarized light carrying image information incident from the imaging incident surface.

In an embodiment of the invention, the imaging conversion unit is a 1/2 wave plate or a pair of 1/4 wave plates.

In an embodiment of the invention, the imaging system further includes an imaging lens assembly, wherein the imaging lens assembly includes a first imaging lens group and a second imaging lens group, wherein the first imaging lens group is It is provided between the relay system and the imaging conversion unit, and the second imaging lens group is provided on the imaging exit surface of the imaging polarization beam splitting system.

In an embodiment of the present invention, the imaging system further includes an imaging polarization filter unit, wherein the imaging polarization filter unit is disposed on the imaging incident surface of the imaging conversion unit and the imaging polarization beam splitting system In order to filter stray light in the P-polarized light carrying image information converted by the imaging conversion unit.

In an embodiment of the invention, the imaging polarizing filter unit is a P polarizing plate.

In an embodiment of the invention, the light source system includes at least two light-emitting units, a color combination system and a polarization multiplexing system, wherein each light-emitting unit is used to emit monochromatic light, wherein the color combination system is located Between the at least two light emitting units and the polarization multiplexing system, for synthesizing the monochromatic light emitted by the at least two light emitting units into a monochromatic light, wherein the polarizing multiplexing system is used to convert the monochromatic light Into S polarized light.

In an embodiment of the present invention, the light source system further includes at least two collimating systems and a uniform light system, wherein each collimating system is disposed between the corresponding light-emitting unit and the color combination system , Used to collimate the monochromatic light emitted by the corresponding light-emitting unit; wherein the uniform light system is provided between the color combination system and the polarization multiplexing system for homogenizing the light Shades.

Through the understanding of the following description and drawings, further objects and advantages of the present invention will be fully realized.

These and other objects, features and advantages of the present invention are fully reflected in the following detailed description, drawings and claims.

BRIEF DESCRIPTION

FIG. 1 shows a schematic diagram of an existing polarization multiplexing device.

2 is a system schematic diagram of a projection system according to a first preferred embodiment of the present invention.

3 is a perspective schematic view of a polarization multiplexing device of the projection system according to the first preferred embodiment of the present invention.

4 is a partially enlarged schematic cross-sectional view of the polarization multiplexing device according to the first preferred embodiment of the present invention.

5 is a perspective schematic view of a polarization multiplexing unit of the polarization multiplexing device according to the first preferred embodiment of the present invention.

6 is an exploded schematic view of the polarization multiplexing unit according to the first preferred embodiment of the present invention.

FIG. 7 shows a modified implementation of the polarization multiplexing device according to the first preferred embodiment of the present invention.

8 is a schematic perspective view of a polarization multiplexing device according to a second preferred embodiment of the present invention.

9 is a partially enlarged schematic cross-sectional view of the polarization multiplexing device according to the second preferred embodiment of the present invention.

10 is a schematic perspective view of a beam splitting reflection unit of the polarization multiplexing device according to the second preferred embodiment of the present invention.

11 is an exploded schematic view of the beam splitting reflection unit according to the second preferred embodiment of the present invention.

FIG. 12 is a system schematic diagram of a miniature projection light engine according to a preferred embodiment of the present invention.

13 is a schematic diagram of the structure of the micro projection light engine according to the above preferred embodiment of the present invention.

14 is a schematic diagram of the light path of the micro projection light engine according to the above preferred embodiment of the present invention.

15 is an enlarged schematic view of a relay system of the micro projection light engine according to the above preferred embodiment of the present invention.

16A is an enlarged schematic view of an imaging system of the micro projection light engine according to the above preferred embodiment of the present invention.

FIG. 16B shows a modified embodiment of the imaging system according to the above-described preferred embodiment of the present invention.

17A is a schematic diagram of a near-eye display device according to the present invention.

17B is a schematic diagram of another near-eye display device according to the present invention.

detailed description

The following description is used to disclose the present invention to enable those skilled in the art to implement the present invention. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious modifications. The basic principles of the present invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalent solutions, and other technical solutions without departing from the spirit and scope of the present invention.

Those skilled in the art should understand that in the disclosure of the present invention, the terms "portrait", "horizontal", "upper", "lower", "front", "rear", "left", "right", " The orientation or positional relationship indicated by "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and The description is simplified, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore the above terms should not be construed as limiting the present invention.

In the present invention, the term "a" in the claims and the specification should be understood as "one or more", that is, in one embodiment, the number of an element may be one, and in other embodiments, the number of the element Can be multiple. Unless it is explicitly indicated in the disclosure of the present invention that the number of the element is only one, the term “one” cannot be understood as unique or single, and the term “one” cannot be understood as a limitation on the number.

In the description of the present invention, it should be understood that “first”, “second”, etc. are for descriptive purposes only, and cannot be understood as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection ; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through a medium. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the description of this specification, the description referring to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means specific features described in conjunction with the embodiment or examples , Structure, material or characteristic is included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. In addition, without contradicting each other, those skilled in the art may combine and combine different embodiments or examples and features of the different embodiments or examples described in this specification.

In recent years, with the emergence of LCOS, HTPS and other liquid crystal display technologies, the projection system has been able to develop rapidly in the direction of miniaturization and high resolution. In order to meet the polarized light illumination conditions of projection systems based on LCOS, HTPS, and other liquid crystal displays, existing projection systems usually require polarizing devices to convert unpolarized light emitted by the light source system into polarized light. However, in the process of polarized light conversion, the existing projection system will have at least half of the light energy loss, which undoubtedly reduces the light energy utilization rate of the projection system, and even cannot meet the high brightness and low power imaging of the projection system Claim.

Although, as shown in FIG. 1, the existing polarization multiplexing device 10P can use the cooperation between the polarization beam splitting array 11P and the 1/2 wave plate 12P to convert unpolarized light into polarized light with the same polarization state (such as P Polarized light), but the size and position of the 1/2 wave plate 12P must exactly match the size and position of the mutually separated beam array obtained on the exit surface of the polarization beam splitting array 11P. This undoubtedly greatly increased the difficulty of manufacturing the polarization multiplexing device 10P, in particular, the accuracy of the periodic alignment of the 1/2 wave plate 12P and the polarization beam splitting array 11P is extremely high, making the market The above polarization multiplexing device 10P has high manufacturing cost and size, and cannot be applied and popularized in the fields of augmented reality, near-eye display, and wearable. Therefore, a new polarization multiplexing device is urgently needed to reduce the difficulty of manufacturing, so as to be suitable for the needs of augmented reality, near-eye display, and wearable fields.

Referring to FIGS. 2 to 6 of the accompanying drawings, a polarization multiplexing device for a projection system according to a first preferred embodiment of the present invention is explained. As shown in FIG. 2, the projection system 1 includes a polarization multiplexing device 10, a light source system 20 and a projection imaging system 30. The light source system 20 is used to emit unpolarized light 200. The polarization multiplexing device 10 is disposed between the light source system 20 and the projection imaging system 30 for converting the unpolarized light 200 emitted by the light source system 20 into the same polarization state polarized light. The projection imaging system 30 is used to generate and project an image based on the polarized light having the same polarization state.

Those skilled in the art may understand that the unpolarized light 200 emitted by the light source system 20 may be natural light or partially polarized light. Generally, the unpolarized light 200 is composed of P-state polarized light and S-state polarized light. For ease of description, in the present invention, as shown in FIG. 2, the non-polarized light 200 includes first polarized light 201 and second polarized light 202, and the first and second polarized light in different embodiments of the present invention The

polarized light

201, 202 may be implemented as one of P-state polarized light or S-state polarized light, respectively. For example, in the preferred embodiment of the present invention, the first polarized light 201 is implemented as S-state polarized light, and the second polarized light 202 is implemented as P-state polarized light; In some other examples, the first polarized light 201 is implemented as P-state polarized light, and the second polarized light 202 is implemented as S-state polarized light.

In the preferred embodiment according to the present invention, as shown in FIGS. 3 and 4, the polarization multiplexing device 10 includes a group of polarization multiplexing units 11 arranged in an end-to-end manner, wherein each polarization The multiplexing unit 11 has an incident surface 1101 and an exit surface 1102 opposite to the incident surface 1101, and includes a beam splitting component 111, a light reflecting component 112 and a light conversion element 113. The beam splitting assembly 111 is located on one side of the light conversion element 113 and is used to separate the unpolarized light 200 incident from the incident surface 1101 into second polarized light 202 emitted from the exit surface 1102 And the first polarized light 201 directed to the light conversion element 113. The light conversion element 113 is used to convert the first polarized light 201 from the light splitting assembly 111 into the second polarized light 202 directed to the light reflecting assembly 112. The light conversion component 112 is located on the other side of the light conversion element 113, and is used to reflect the second polarized light 202 converted by the light conversion element 113 to make the second polarized light 202 from the The exit surface 1102 exits, thereby realizing the conversion of the unpolarized light 200 into polarized light having the same polarization state (ie, second polarized light 202).

In other words, as shown in FIG. 4, the light conversion element 113 is disposed between the light splitting component 111 and the light reflecting component 112 such that the light splitting component 111 passes from the unpolarized The first polarized light 201 separated from the light 200 is first converted into the second polarized light 202 by the light conversion element 113, and then reflected by the light reflection component 112 to be separated from the polarization multiplexing unit 11 The exit surface 1102 exits to convert all the unpolarized light 200 incident from the incident surface 1101 of the polarization multiplexing unit 11 into the exit surface 1102 of each polarization multiplexing unit 11 The emitted second polarized light 202 helps to improve the light energy utilization rate of the projection system 1.

It is worth noting that since the light conversion element 113 is disposed between the light splitting assembly 111 and the light reflecting assembly 112, it is not necessary to require the current In some polarization multiplexing devices 10P, the size and position of the 1/2 wave plate 12P must exactly match the size and position of the mutually separated beam arrays obtained on the exit surface of the polarization beam splitting array 11P. This undoubtedly greatly reduces the difficulty of processing and manufacturing the polarization multiplexing device 10, and helps to manufacture the polarization multiplexing device 10 with a smaller volume and a higher purity of polarized light.

It is worth mentioning that each of the light conversion elements 113 may be, but not limited to, implemented as a 1/2 wave plate for converting the first polarized light 201 into the second polarized light 202. Here, in the first preferred embodiment of the present invention, each of the light conversion elements 113 may be used to convert the S-polarized light into the P-polarized light. Of course, in some other embodiments of the present invention, the light conversion element 113 may also convert the P-polarized light into the S-polarized light.

Exemplarily, as shown in FIG. 4, the incident surface 1101 of each polarization multiplexing unit 11 is located on the left side of the corresponding polarization multiplexing device 10; the exit of each polarization multiplexing unit 11 The plane 1102 is located on the right side of the corresponding polarization multiplexing device 10; the optical beam splitting component 111 of each polarization multiplexing unit 11 is located on the lower side of the corresponding polarization multiplexing unit 11; each polarization The light reflection component 112 of the multiplexing unit 11 is located on the upper side of the corresponding polarization multiplexing unit 11. All the polarization multiplexing units 11 are longitudinally arranged in an end-to-end manner in a row, and the optical beam splitting assembly 111 of each polarization multiplexing unit 11 is adjacent to the adjacent polarization multiplexing unit 11 The light reflecting component 112 is opposite. Each light conversion element 113 is pasted between the light splitting component 111 and the light reflecting component 112 of the polarization multiplexing unit 11 respectively to form the polarization multiplexing device with an integrated structure 10. It is convenient to assemble the polarization multiplexing device 10 to the projection system 1.

In this way, when the projection system 1 works, the unpolarized light 200 emitted by the light source system 20 first enters the polarization multiplexing unit 11 from the incident surface 1101 of each polarization multiplexing unit 11 The optical beam splitting assembly 111; then, the non-polarized light 200 is separated by the optical beam splitting assembly 111 into the first polarized light directed to the light conversion element 113 of the polarization multiplexing unit 11 201 and the second polarized light 202 emitted from the exit surface 1102 of the polarization multiplexing unit 11; thereafter, the first polarized light 201 directed to the light conversion element 113 enters the light conversion element 113, to be converted by the light conversion element 113 into the second polarized light 202 directed to the light reflecting component 112; finally, the converted second polarized light 202 is converted by the polarization multiplexing unit 11 The light reflecting component 112 reflects the light exiting from the exit surface 1102 of the polarization multiplexing unit 11 so as to direct all the unpolarized light entering from the entrance surface 1101 of the polarization multiplexing unit 11 200 are all converted into those emitted from the exit surface 1102 of the polarization multiplexing unit 11 The second polarized light 202.

Further, as shown in FIGS. 4 and 5, the light beam splitting assembly 111 of each polarization multiplexing unit 11 includes a first beam splitting prism 1111, a second beam splitting prism 1112, and a light beam splitting element 1113, wherein the light beam splitting element 1113 is disposed between the first beam splitting prism 1111 and the second beam splitting prism 1112 to make the light beam splitting assembly 111 having an integrated structure. In this way, when the unpolarized light 200 enters from the first beam splitting prism 1111 of the polarization multiplexing unit 11 to be separated by the light splitting element 1113 into the first polarized light 201 and the first When the second polarized light 202 is separated, the separated second polarized light 202 passes through the light splitting element 1113 to pass through the second beam splitting prism 1112 and is emitted; the separated first polarized light 201 is reflected by the beam splitting element 1113 to be converted into the second polarized light 202 by the light conversion element 113 after exiting the first beam splitting prism 1111.

Exemplarily, as shown in FIGS. 5 and 6, in each polarization multiplexing unit 11, the first beam splitting prism 1111 and the second beam splitting prism 1112 of the optical beam splitting assembly 111 are both It is a right-angle prism, that is, each has a right-angle triangular cross-section, wherein the light splitting element 1113 is disposed between the inclined surface 11111 of the first beam splitting prism 1111 and the inclined surface 11121 of the second beam splitting prism 1112, In order to form the light splitting assembly 111 having a rectangular cross section. In this way, the right angle surface 11112 of the first beam splitting prism 1111 forms a part of the incident surface 1101 of the polarization multiplexing unit 11, and the other right angle surface 11112 of the first beam splitting prism 1111 corresponds to all The light conversion element 113; the right angle surface 11122 of the second beam splitting prism 1112 forms a part of the exit surface 1102 of the polarization multiplexing unit 11, and the other right angle surface of the second beam splitting prism 1112 11122 corresponds to the light reflection component 112 of the adjacent polarization multiplexing unit 11.

Preferably, as shown in FIG. 4, in the polarization multiplexing unit 11, the angle θ ₁ between the light splitting element 1113 and the light conversion element 113 is 40-50 degrees.

More preferably, the cross sections of the first and second

beam splitting prisms

1111, 1112 of the light splitting assembly 111 are implemented as isosceles right-angled triangles, so that the light splitting element 1113 and the light The angle θ ₁ between the conversion elements 113 is 45 degrees.

It is worth mentioning that in the first preferred embodiment of the present invention, the optical beam splitting element 1113 may be, but not limited to, implemented as a polarization beam splitting film (abbreviated as PBS film) for allowing P polarization The light transmits and blocks S polarized light from being transmitted to reflect the S polarized light, thereby separating the P polarized light and the S polarized light in the unpolarized light 202. Of course, in some examples of the present invention, the light splitting element 1113 may also be implemented as a polarizing beam splitter such as a polarizing beam splitter, a polarizing beam splitting block, etc., as long as the unpolarized light The P-polarized light and the S-polarized light in 200 may be separated, and the present invention does not further limit this. In addition, in some other examples of the present invention, the light splitting element 1113 may also be implemented to allow S polarized light to pass through, and block P polarized light from transmitting to emit other split beams of the P polarized light membrane.

It is worth noting that the polarizing beam splitting film may be disposed between the inclined surface 11111 of the first beam splitting prism 1111 and the inclined surface 11121 of the second beam splitting prism 1112 by coating or pasting, etc., The present invention does not further limit this.

According to the first preferred embodiment of the present invention, as shown in FIGS. 4 and 5, the light reflecting component 112 of each polarization multiplexing unit 11 includes a first reflecting prism 1121 and a second reflecting prism 1122 and a light reflecting element 1123, wherein the light reflecting element 1123 is disposed between the first reflecting prism 1121 and the second reflecting prism 1122 to make the light reflecting assembly 112 having an integrated structure . In this way, when the first polarized light 201 is converted into the second polarized light 202 by the light conversion element 113, the converted second polarized light 202 enters the first reflecting prism 1121 to The first reflecting prism 1121 is reflected by the light reflecting element 1123.

Exemplarily, as shown in FIG. 6, in each polarization multiplexing unit 11, the first reflecting prism 1121 and the second reflecting prism 1122 of the light reflecting component 112 are right-angle prisms, that is, both Having a right-angled triangular cross section, wherein the light reflecting element 1123 is disposed between the inclined surface 11211 of the first reflecting prism 1121 and the inclined surface 11221 of the second reflecting prism 1122 to form the rectangular cross section Light reflective component 112. In this way, the right-angled surface 11212 of the first reflecting prism 1121 forms another part of the exit surface 1102 of the polarization multiplexing unit 11, and the other right-angled surface 11212 of the first reflecting prism 1121 corresponds to the Light conversion element 113; the right angle surface 11222 of the second reflection prism 1122 forms another part of the incident surface 1102 of the polarization multiplexing unit 11, and the other right angle surface 11222 of the second reflection prism 1122 corresponds to The optical beam splitting assembly 111 adjacent to the polarization multiplexing unit 11.

In other words, one of the right-angle surfaces 11212 of the first reflecting prism 1121 and one of the right-angle surfaces 1112 of the second beam splitting prism 1112 together constitute the exit surface 1102 of the polarization multiplexing unit 11; And one of the right-angled surfaces 11222 of the second reflecting prism 1122 and one of the right-angled surfaces 11112 of the first beam splitting prism 1111 together constitute the incident surface 1101 of the polarization multiplexing unit 11 so that Both the separated second polarized light 202 and the converted second polarized light 202 can be emitted from the exit surface 1102 of the polarization multiplexing unit 11.

Preferably, as shown in FIG. 4, in the polarization multiplexing unit 11, the angle θ ₂ between the light reflection element 1123 and the light conversion element 113 is 40-50 degrees.

More preferably, the cross sections of the first and second reflecting

prisms

1121 and 1122 of the light reflecting assembly 112 are all implemented as isosceles right-angled triangles, so that the light reflecting element 1123 and the light converting element 113 The included angle θ ₂ is 45 degrees.

It is worth mentioning that, in the first preferred embodiment of the present invention, the light reflecting element 1123 may be, but not limited to, implemented as a reflecting film, such as a P light reflecting film (referred to as PM film) for The P polarized light 202 is reflected. Of course, in some examples of the present invention, the light reflecting element 113 may also be implemented as a reflecting member such as a reflecting sheet, a reflecting block, a reflecting mirror, etc., as long as it can reflect the second polarized light 202 The present invention does not further limit this. It can be understood that the reflective film may be disposed between the inclined surface 11211 of the first reflective prism 1121 and the inclined surface 11221 of the second reflective prism 1122 by methods such as coating or pasting, etc. No further restrictions.

It is worth noting that, in order to ensure that the exit directions of the separated and converted second polarized light 202 remain the same, in the polarization multiplexing device 10, as shown in FIG. The light splitting element 1113 is parallel to any of the light reflecting elements 113. In this way, the second polarized light 202 separated from the unpolarized light 200 will pass through the optical beam splitting element 1113 to propagate along the incident direction of the unpolarized light 200; The first polarized light 201 separated from the polarized light 200 passes through the reflection of the light splitting element 1113 to be directed to the light conversion element 113, and then is converted into the second by the light conversion element 113 The polarized light 202 is then reflected by the light reflecting element 113 to propagate along the incident direction parallel to the unpolarized light 200, so that all the second light emitted from the polarization multiplexing device 10 The propagation directions of the polarized light 202 are parallel to each other to maintain consistency.

In this way, when the unpolarized light 200 enters the polarization multiplexing unit 11 in a direction perpendicular to the incident surface 1101 of the polarization multiplexing unit 11, all the second polarized light 202 is along The light is emitted in a direction perpendicular to the exit surface 1102 of the polarization multiplexing unit 11, which can effectively prevent the unpolarized light 200 from entering the polarization multiplexing unit 11 and the second polarized light 202 Refraction occurs when exiting the polarization multiplexing unit 11.

In addition, as shown in FIG. 4, in each polarization multiplexing unit 11, one of the right-angle surfaces 11112 of the first beam splitting prism 1111 is parallel to one of the right-angle surfaces 11122 of the first reflection prism 1121 , So that the propagating direction of the separated first polarized light 201 and the converted second polarized light 202 is consistent, thereby ensuring that the converted second polarized light 202 is reflected by the light The exit direction of the element 1123 after reflection is consistent with the exit direction of the separated second polarized light 202. In this way, after the unpolarized light 200 enters the polarization multiplexing unit 11 in a direction perpendicular to the incident surface 1101, the optical beam splitting element 1113 separates the light from the unpolarized light 200. The first polarized light 201 and the second polarized light 202 converted by the light conversion element 113 are along a right angle plane 11112 perpendicular to the first beam splitting and first reflecting

prisms

1111, 1121 , 11212 in the propagation direction to prevent the first or second

polarized light

201, 202 from exiting the polarization multiplexing unit 11 in advance due to refraction inside the polarization multiplexing unit 11.

Further, as shown in FIG. 4, each of the light reflection element 1123 of the polarization multiplexing unit 11 and the corresponding light conversion element 113 intersect on the incident surface 1101 of the polarization multiplexing unit 11 to Avoiding unnecessary distance between the light conversion element 113 and the light reflection element 1123 is beneficial to reduce the height of the polarization multiplexing device 10. Accordingly, the light splitting element 1113 of each polarization multiplexing unit 11 intersects the corresponding light conversion element 113 on the exit surface 1102 of the polarization multiplexing unit 11 to avoid There is an unnecessary distance between the conversion element 113 and the optical beam splitting element 1113, which is beneficial to further reduce the height of the polarization multiplexing device 10.

It is worth mentioning that when the unpolarized light 200 enters the polarization multiplexing unit 11 of the polarization multiplexing device 10, the unpolarized light 200 is caused by the The reflection of the incident surface 1101 causes the loss of light energy of the unpolarized light 200, which reduces the light energy utilization rate of the polarization multiplexing device 10, which in turn affects the brightness and imaging quality of the projection system 1.

Therefore, in order to improve the light energy utilization rate of the polarization multiplexing device 10, FIG. 7 shows a modified embodiment of the polarization multiplexing device according to the preferred embodiment of the present invention, wherein the polarization The multiplexing device 10 further includes an anti-reflection element 12, wherein each anti-reflection element 12 is disposed on the incident surface 1101 of the polarization multiplexing unit 11 for reducing the polarization of the polarization multiplexing unit 11 The incident surface 1101 reflects the unpolarized light 200 to improve the light energy utilization rate of the unpolarized light 200 by the polarization multiplexing device 10.

Correspondingly, when the second polarized light 202 exits the polarization multiplexing unit 11, the second polarized light 202 is caused by the reflection of the exit surface 1102 of the polarization multiplexing unit 11 The second polarized light 202 generates light energy loss, which also reduces the light energy utilization rate of the polarization multiplexing device 10 to affect the brightness and imaging quality of the projection system 1. Therefore, in the preferred embodiment of the present invention, as shown in FIG. 7, the polarization multiplexing device 10 further includes another anti-reflection element 12, wherein the anti-reflection element 12 is disposed at each polarization The exit surface 1102 of the multiplexing unit 11 is used to reduce the reflection of the second polarized light 202 by the exit surface 1102 of the polarization multiplexing unit 11 to improve the polarization multiplexing device 10 to the The light energy utilization rate of the second polarized light 202.

It is worth noting that the anti-reflection element 12 may be, but not limited to, implemented as an anti-reflection film (referred to as AR film for short) provided on the incident surface 1101 and the exit surface 1102 of the polarization multiplexing unit 11, respectively , Used to further reduce the loss of light energy to improve the light energy utilization rate of the polarization multiplexing device 10. It can be understood that the anti-reflection film may be, but not limited to, plated on the incident surface 1101 and the exit surface 1102 of the polarization multiplexing unit 11, or may be pasted on the polarization multiplexing unit 11 The incident surface 1101 and the exit surface 1102 are not further limited by the present invention.

In addition, in some examples of the present invention, the anti-reflection material may also be plated on the right-angle planes of the first and second

beam splitting prisms

1111, 1112 and the second and The right-angle surfaces of the second reflecting

prisms

1121 and 1122 to form an anti-reflection film covering all the outer surfaces of the polarization multiplexing unit 11 not only helps to reduce the incident surface 1101 to the unpolarized light 200 Of the second polarized light 202 and the reflection of the second polarized light 202 by the exit surface 1102, and also helps to reduce the reflection of the first polarized light 201 and the first reflection of the first beam splitter prism 1111 The prism 1121 reflects the converted second polarized light 202 to minimize the loss of light energy due to the reflection, thereby further improving the light energy utilization rate of the polarization multiplexing device 10.

It is worth noting that in the existing polarization multiplexing device 10P, since the 1/2 wave plate 12P is periodically disposed on the exit surface of the polarization beam splitting array 11P, the size of the 1/2 wave plate 12P And position must match the size and position of the mutually separated beam array obtained on the exit surface of the polarization beam splitting array 11P, therefore, this undoubtedly greatly increases the manufacturing of the polarization multiplexing device 10P Difficulty leads to the problem that the existing polarization multiplexing device 10P has a large volume or the purity of the converted polarized light is not high.

In the preferred embodiment of the present invention, when manufacturing the polarization multiplexing device 10, a large 1/2 wave plate, the optical beam splitting component 111, and the light reflecting component 112 may be used first Paste and then perform uniform division to make the polarization multiplexing unit 11; finally, a group of the polarization multiplexing unit 11 is periodically bonded in a row to make the polarization multiplexing device 10. In this way, not only the process of separately dividing and pasting the large 1/2 wave plate in the manufacturing of the existing polarization multiplexing device 10P can be avoided, so as to simplify the manufacturing process of the polarization multiplexing device 10 and reduce the cost The manufacturing difficulty and manufacturing cost of the polarization multiplexing device 10 can also make the polarization multiplexing device 10 have the ability to be processed in the case of a small size to obtain the polarization multiplexing of a small size The device 10 is suitable for micro and small projection systems and meets the needs of augmented reality, near-eye display, and wearable fields. In addition, through the unified cutting method, the alignment accuracy between the light conversion element 113 and the polarization multiplexing unit 11 can be greatly improved, and the processing accuracy can be controlled above a very high level, which helps to improve the passing The purity and brightness of the polarized light converted by the polarization multiplexing device 10 can further improve the imaging quality of the projection system 1.

8 to 11, a polarization multiplexing device according to a second preferred embodiment of the present invention is explained. Compared with the above-mentioned first preferred embodiment according to the present invention, the polarization multiplexing device 10A according to the second preferred embodiment of the present invention is different in that: in the polarization multiplexing device 10A , The second beam splitting prism 1112A of the light splitting assembly 111A of any one of the polarization multiplexing unit 11A and the second of the light reflecting component 112A of the adjacent polarization multiplexing unit 11A The reflecting prism 1122A is integrally connected so that the second beam splitting prism 1112A and the second reflecting prism 1122A together form a common prism 1100A having a parallelogram cross section, that is, the second beam splitting prism 1112A Is a part of the common prism 1100A, and the second reflective prism 1122A is another part of the common prism 1100A. In this way, when manufacturing the polarization multiplexing device 10A, there is no need to additionally bond the second beam splitting prism 1112A and the second reflecting prism 1122A together, which helps to simplify the polarization multiplexing device 10A Manufacturing process.

In other words, as shown in FIGS. 8 and 9, the light splitting component 111A of any one of the polarization multiplexing units 11A and the light reflecting component 112A of the adjacent polarization multiplexing unit 11A are combined with each other , To form a beam splitting reflection unit 110A having an integrated structure, wherein the light conversion element 113 of each polarization multiplexing unit 11A is located between adjacent beam splitting reflection units 110A to form the polarization complex With device 10A.

Specifically, as shown in FIGS. 10 and 11, each beam splitting reflection unit 110A includes the first beam splitting prism 1111, the light splitting element 1113, the common prism 1100A, and the light reflecting element 1123 And the first reflecting prism 1121, wherein the light splitting element 1113 is located between the slope of the first beam splitting prism 1111 and the upper side of the common prism 1100A, and the light reflecting element 1123 is located at the Between the inclined surface of the first reflecting prism 1121 and the lower side of the common prism 1100A, to form the beam splitting reflecting unit 110A with an integrated structure, which helps to divide multiple sets of the beam splitting reflecting unit 110A and one group Large 1 / 2-wave plates are bonded to make semi-finished polarization multiplexing devices. After that, by cutting the large 1/2 wave plate, the polarization multiplexing device 10A is manufactured.

In the second preferred embodiment of the present invention, when manufacturing the polarization multiplexing device 10A, a large half-wave plate is firstly disposed between the adjacent beam splitting reflection units 110A, Then perform a unified division. In this way, not only the process of separately dividing and pasting the 1/2 wave plate in the manufacturing of the existing polarization multiplexing device 10P can be eliminated, so as to simplify the manufacturing process of the polarization multiplexing device 10A and reduce the polarization The manufacturing difficulty and manufacturing cost of the multiplexing device 10A, and the polarizing multiplexing device 10A can also have the ability to be processed when the size is small, so as to obtain the polarizing multiplexing device 10A of a small size , Suitable for micro and small projection systems, to meet the needs of augmented reality, near-eye display and wearable fields. In addition, through the unified cutting method, the alignment accuracy between the light conversion element 113 and the beam splitting reflection unit 110A can be greatly improved, and the processing accuracy can be controlled above a very high level, which helps to improve the passing The purity and brightness of the polarized light converted by the polarization multiplexing device 10A further improves the imaging quality of the projection system.

It is worth mentioning that, in an example of the present invention, an anti-reflection material is plated on the incident surface 1101 and the exit surface 1102 of each polarization multiplexing unit 11A separately, so that The anti-reflection element 12 (such as an AR film) is formed by the incident surface 1101 and the exit surface 1102 of the unit 11A for reducing the reflection of the incident surface 1101 and the exit surface 1102 to reduce the reflection The resulting loss of light energy improves the light energy utilization rate of the polarization multiplexing device 10A.

It can be understood that, in some other examples of the present invention, before the 1/2 wave plate is pasted, the anti-reflection material may be plated on the outer surface of each beam splitting reflection unit 110A to form The AR film coated on the outer surface of each beam splitting reflection unit 110A is not only beneficial to reduce the reflection of the unpolarized light 200 by the incident surface 1101 and the second polarized light by the exit surface 1102 202 reflection, and also helps to reduce the reflection of the first polarized light 201 by the first beam splitting prism 1111 in the beam splitting reflecting unit 110A and the first of the beam splitting reflecting unit 110A The reflection prism 1121 reflects the converted second polarized light 202 to minimize the loss of light energy due to the reflection, thereby further improving the light energy utilization rate of the polarization multiplexing device 10A.

It is worth noting that, in the second preferred embodiment of the present invention, in addition to the above-mentioned different structures, the other structures of the polarization multiplexing device 10A are the same as those of the first preferred embodiment according to the present invention The structure of the polarization multiplexing device 10 is the same, and the polarization multiplexing device 10A also has similar or identical modification implementations to the various modification implementations of the polarization multiplexing device 10 of the first preferred embodiment The method will not be repeated here.

According to another aspect of the present invention, an embodiment of the present invention further provides a method for improving light energy utilization of the projection system. Specifically, the method for improving the utilization rate of light energy of the projection system 1 includes the steps of:

S100: Separate the unpolarized light 200 to form the separated first polarized light 201 and the separated second polarized light 202, wherein the separated first polarized light 201 and the separated second polarized light 202 have different edges Direction propagation

S200: Convert the separated first polarized light 201 to form the converted second polarized light 202; and

S300: Reflect the converted second polarized light 202 to form a reflected second polarized light 202, wherein the reflected second polarized light 202 and the separated second polarized light 202 propagate in the same direction, so that The projection system 2 makes full use of the unpolarized light 200.

More specifically, in an example of the present invention, in the step S100:

By means of a beam splitting component 111 of a polarization multiplexing unit 11 of a polarization multiplexing device 10 of the projection system 2, the unpolarized light 200 incident from the incident surface 1101 of the polarization multiplexing unit 11 is separated into The separated first polarized light 201 and the separated second polarized light 202, wherein the separated first polarized light 201 is directed to a light conversion element 113 of the polarization multiplexing unit 11, and the separated The second polarized light 202 is incident on the exit surface 1102 of the polarization multiplexing unit 11 to exit from the exit surface 1102.

In an example of the present invention, in the step S200:

With the light conversion element 113, the separated first polarized light 201 is converted into the converted second polarized light 202, wherein the converted second polarized light 202 is directed to a part of the polarization multiplexing unit 11 Light reflective component 112.

In an example of the present invention, in the step S300:

With the light reflection component 112, the converted second polarized light 202 is reflected into the reflected second polarized light 202, wherein the reflected second polarized light 202 is directed to the polarization multiplexing unit 11 The exit surface 1102 is emitted from the exit surface 1102.

It is worth mentioning that, in an example of the present invention, the method for improving the light energy utilization rate of the projection system 1 further includes the steps of:

An anti-reflection material is plated on the incident surface 1101 of the polarization multiplexing unit 11 to reduce the reflection of light by the incident surface 1101.

In another example of the present invention, the method for improving the light energy utilization rate of the projection system 1 further includes the steps of:

An anti-reflection material is plated on the exit surface 1102 of the polarization multiplexing unit 11 to reduce the reflection of light by the exit surface 1102.

It is worth noting that in this embodiment of the present invention, the first polarized light 201 may be implemented as S-polarized light or P-polarized light, but correspondingly, the second polarized light 202 may be implemented as but not limited to It is P polarized light or S polarized light.

It is worth noting that in recent years, with the emergence of micro display chip technology, it has become possible to miniaturize and high-resolution projection display. However, in order to obtain a higher projection imaging quality, the existing miniature projection light engine has to be very large, which results in the existing miniature projection light engine being unable to meet the current augmented reality due to its large size or volume , Near-eye display and wearable products have strict requirements on volume and weight. Therefore, there is an urgent need for a miniature projection light engine that is small enough in size, light in weight, and has high imaging quality to meet market demand.

Referring to FIGS. 12 to 15A of the drawings, a miniature projection light engine according to a preferred embodiment of the present invention is illustrated. As shown in FIGS. 12 to 14, the micro projection light engine 1B includes a light source system 10B, a relay system 20B, an imaging system 30B, and a display unit 40B, wherein the relay system 20B is disposed on the The light source system 10B, the imaging system 30B, and the display unit 40B, and the light source system 10B and the imaging system 30B are respectively located on opposite sides of the relay system 20B. The light source system 10B is used to emit polarized light with a specific polarization state along a predetermined direction. The relay system 20B is used to change the propagation direction of the polarized light from the light source system 10B so that the polarized light propagates to the display unit 40B. The display unit 40B is used to modulate the polarized light into a polarized light carrying image information and reflect the polarized light carrying image information back to the relay system 20B. The relay system 20B is also used to change the propagation direction of the polarized light carrying image information so that the polarized light carrying image information can propagate to the imaging system 30B along the predetermined direction. The imaging system 30B is used to project the polarized light carrying image information.

In this way, the propagation direction of the polarized light carrying image information emitted from the relay system 20B is consistent with the propagation direction of the polarized light incident from the relay system 20B, that is, the light source system 10B , The relay system 20B and the imaging system 30B are on the same straight line, so that the micro projection light engine 1B has a linear structure, so as to reduce the volume or size of the micro projection light engine 1B, helps to meet The market demand for small-sized miniature projection light engines.

It is worth noting that, in the present invention, polarized light having an S polarization state is simply referred to as S polarized light, and polarized light having a P polarization state is simply referred to as P polarized light. For example, the polarized light with a specific polarization state emitted by the light source system 10B may be implemented as an S-polarized light, and the polarized light carrying image information may be, but not limited to, an S-polarized light carrying image information . Of course, in other examples of the present invention, the polarized light carrying image information may also be implemented as a P-polarized light carrying image information.

In addition, in order to clearly express the change of various polarization states of light in the optical path of the micro projection light engine 1B, in the drawings of the present invention: S is used to indicate the S polarized light; S ^{* is used to} indicate the carry S polarized light of image information; P represents the P polarized light; P ^* represents the P polarized light carrying the image information; and S + P represents unpolarized light (the unpolarized light may be natural light, monochromatic light or Partially polarized light, etc.).

Specifically, in the preferred embodiment of the present invention, as shown in FIGS. 13 and 14, the relay system 20B of the micro projection light engine 1B includes a relay polarization beam splitting system 21B and a middle Following the folding system 22B, the display unit 40B and the relay folding system 22B are respectively disposed on opposite sides of the relay polarization beam splitting system 22B. The display unit 40B is used to modulate the polarized light into polarized light carrying image information, and reflect the polarized light carrying image information back to the relay polarization beam splitting system 22B. The relay foldback system 22B is used to fold back the polarized light emitted from the relay polarization beam splitting system 22B back to the relay polarization beam splitting system 22B, so that the light source system 10B and the display Between the units 40B, a folded relay optical path 200B is defined so that the polarized light from the light source system 10B propagates along the folded relay optical path 200B to the display unit 40B. In this way, the fold-back relay optical path 200B enables the relay system 20B to provide a sufficiently long relay optical path in a small volume, so as to ensure that the micro projection light engine 1B has a high imaging quality Next, further reducing the volume or size of the micro-projection light engine 1B helps to meet the market demand for a small-volume micro-projection light engine.

It is worth noting that the display unit 40B may be, but not limited to, implemented as a reflective Lcos panel for modulating the polarized light into polarized light carrying image information and reflecting the polarized light carrying image information. Of course, in other examples of the present invention, the display unit 40B may also be implemented as other types of display chips, as long as the polarized light can be modulated and reflected, the present invention does not further limit this.

Exemplarily, in the preferred embodiment of the present invention, as shown in FIGS. 14 and 15, the relay folding system 22B of the relay system 20B includes a relay optical conversion element 221B and a The relay light reflection element 222B, wherein the relay light conversion element 221B is disposed between the relay light reflection element 222B and the relay polarization beam splitting system 22B. The relay light reflection element 222B is used to reflect the P or S polarized light emitted from the relay light conversion element 221B back to the relay light conversion element 221B, so that the P or S polarized light passes through the secondary The relay light conversion element 221B is described. The relay light conversion element 221B is used to convert the P or S polarized light that has passed through twice into S or P polarized light.

It is worth noting that in the preferred embodiment of the present invention, the relay light conversion element 221B may be, but not limited to, implemented as a 1/4 wave plate; the relay light reflection element 222B may but not Limited to being implemented as a concave mirror. Of course, in other examples of the present invention, the relay light conversion element 221B can also be implemented as other types of wave plates or light conversion members, as long as the P or S polarized light passing through the second time can be converted into the S or P polarized light is sufficient; the relay light reflecting element 222B may also be implemented as other types of mirrors or light reflecting members, as long as the P or S emitted from the relay polarization beam splitting system 21B can be emitted The polarized light is reflected back to the relay polarization beam splitting system 21B so that the P or S polarized light passes through the relay light conversion element 221B twice, and the present invention does not further limit this.

In addition, since the display unit 40B is used to modulate P or S polarized light into S or P polarized light carrying image information, and to reflect the S or P polarized light carrying image information back to the middle in a reflective manner Following the polarization beam splitting system 21B. The relay polarization beam splitting system 21B is used to reflect S-polarized light to change the propagation direction of the S-polarized light, and allow P-polarized light to pass through without changing the P-polarized light propagation direction. Therefore, according to the above characteristics of the display unit 40B, the relay polarization beam splitting system 21B, and the relay folding system 22B, a reasonable folding relay optical path 200B can be designed to achieve A sufficiently long relay optical path is obtained in a smaller volume, so that the volume or size of the micro-projection light engine 1B is reduced while ensuring that the micro-projection light engine 1B has a higher imaging quality.

Exemplarily, as shown in FIG. 15, the relay polarization beam splitting system 21B of the relay system 20B has a relay incident surface 2101B and a relay exit surface 2102B parallel to the relay incident surface 2101B , A relay folding surface 2103B perpendicular to the relay incident surface 2101B and a relay display surface 2104B perpendicular to the relay incident surface 2101B, wherein the relay light of the relay folding system 22B The conversion element 221B is provided between the relay light reflecting element 222B of the relay folding system 22B and the relay folding surface 2103B of the relay polarization beam splitting system 21B, wherein the display unit 40B The relay display surface 2104B of the relay polarization beam splitting system 21B is provided to define the folding relay by the relay polarization beam splitting system 21B and the relay folding system 22B Path 200B.

In addition, the relay incident surface 2101B of the relay polarization beam splitting system 21B corresponds to the light source system 10B, and the relay exit surface 2102B corresponds to the imaging system 30B to form a linear structure The micro projection light engine 1B helps to reduce the size of the micro projection light engine 1B.

In this way, when S-polarized light from the light source system 10B enters the relay polarization beam splitting system 21B from the relay incident surface 2101B, the S polarized light is reflected by the relay polarization beam splitting system 21B to Emitted from the relay folding surface 2103B; then, the S polarized light emitted from the relay folding surface 2103B is reflected back to the relay folding surface 2103B by the relay light reflecting element 222B to make the S polarized The light passes through the relay light conversion element 221B twice; at the same time, the S-polarized light is converted into P-polarized light by the relay light conversion element 221B, so that the P-polarized light converted from the middle After the folding plane 2103B enters the relay polarization beam splitting system 21B; after that, the P-polarized light incident from the relay folding plane 2103B passes through the relay polarization beam splitting system 21B to pass from the relay The display surface 2104B is emitted; finally, after the P-polarized light emitted from the relay display surface 2104B is modulated by the display unit 40B into S-polarized light carrying image information, the S-polarized light carrying image information is The display unit 40B reflects back to the relay display surface 2104B.

In other words, the fold-back relay optical path 200B of the relay system 20B is first reflected by the relay polarization beam splitting system 21B to escape from the relay incident surface of the relay polarization beam splitting system 21B 2101B extends bent to the relay folding surface 2103B; then, the folding relay optical path 200B is folded back to the relay folding surface 2103B by the relay folding system 22B, and then passes through The relay polarization beam splitting system 21B extends from the relay folding surface 2103B to the relay display surface 2104B, so that the polarized light can be propagated along the folding relay optical path 200B to all The display unit 40B is polarized light modulated by the display unit 40B to carry image information, thereby achieving a sufficiently long relay optical path in a small space.

It is worth noting that, as shown in FIG. 14, after the S-polarized light carrying image information is reflected back to the relay display surface 2104B by the display unit 40B, the S-polarized light carrying image information is relayed by the relay The polarization beam splitting system 21B reflects to bendly propagate from the relay display surface 2104B to the relay exit surface 2102B, and exit from the relay exit surface 2102B to propagate to the imaging system 30B, so that The display unit 40B and the imaging system 30B define a part of a folding imaging light path 300B, which can also extend the imaging light path of the micro projection light engine 1B to further improve the imaging of the micro projection light engine 1B quality.

More specifically, as shown in FIGS. 14 and 15, the relay polarization beam splitting system 21B of the relay system 20B includes a first relay right-angle prism 211B, a second relay right-angle prism 212B, and a middle Following the polarization beam splitting film 213B, wherein the relay polarizing beam splitting film 213B is disposed between the slope of the first relay rectangular prism 211B and the slope of the second relay rectangular prism 212B to form a rectangular shape The structure of the relay polarization beam splitting system 21B. The relay polarizing beam splitting film 213B is used to allow P polarized light to pass through, and to reflect S polarized light and S polarized light carrying image information to turn the S polarized light and the S polarized light carrying image information .

The two right-angle planes of the first relay right-angle prism 211B are respectively defined as the relay incident surface 2101B and the relay folding surface 2103B of the relay polarization beam splitting system 21B, and the second relay The two right-angle surfaces of the right-angle prism 212B are respectively defined as the relay exit surface 2102B and the relay display surface 2104B of the relay polarization beam splitting system 21B. At this time, the relay exit surface 2102B is parallel to the relay entrance surface 2101B, and the relay folding surface 2103B is parallel to the relay display surface 2104B, and the relay exit surface 2102B and the middle The secondary folding surface 2103B intersects the relay polarizing beam splitting film 213B, and the relay incident surface 2101B and the relay display surface 2104B intersect the relay polarizing beam splitting film 213B.

It is worth noting that the relay polarization beam splitting film 213B can be implemented as a PBS film, but is not limited to allow the transmission of P polarized light, and prevent the transmission of S polarized light and S polarized light carrying image information, The direction of propagation of the S-polarized light and the S-polarized light carrying image information is changed by reflecting the S-polarized light and the S-polarized light carrying image information.

In this way, the S-polarized light entering from the relay incident surface 2101B is reflected by the relay polarizing beam splitting film 213B to be emitted from the relay folding surface 2103B; then, it is emitted from the relay folding surface 2103B The S-polarized light is converted into the P-polarized light by the relay folding system 21B, and the P-polarized light is reflected back to the relay folding surface 2103B; after that, the light incident from the relay folding surface 2103B The P polarized light passes through the relay polarizing beam splitting film 213B to be emitted from the relay display surface 2104B; finally, the P polarized light emitted from the relay display surface 2104B is modulated by the display unit 40B into The S polarized light carrying image information.

In other words, after extending from the relay incident surface 2101B to the relay polarizing beam splitting film 213B, the folding relay optical path 200B extends from the relay polarizing beam splitting film 213B to the Relay folding surface 2103B; Then, the folding relay optical path 200B extends from the relay folding surface 2103B to the relay display surface 2104B, so as to extend the folding by folding The length of the relay optical path 200B helps to further reduce the volume or size of the micro projection light engine 1B.

It is worth noting that, as shown in FIGS. 14 and 15, the S-polarized light modulated by the display unit 40B and carrying image information will be reflected back to the relay display surface 2104B by the display unit 40B, and then, The S-polarized light carrying the image information incident from the relay display surface 2104B is reflected by the relay polarization beam splitting film 213B to be emitted from the relay exit surface 2102B so as to propagate to the imaging system 30B. In other words, a part of the folding imaging optical path 300B is first reflected by the relay polarizing beam splitting film 213B to bendly extend from the relay display surface 2104B to the relay exit surface 2102B, and then from The relay exit surface 2102B extends to the imaging system 30B in order to extend the length of the folding imaging optical path 300B, which helps to further reduce the volume or size of the micro projection light engine 1B.

Preferably, both the first and second relay right-

angle prisms

211B, 212B are implemented as an isosceles right-angle prism, so that the sandwich between the relay polarizing beam splitting film 213B and the relay incident surface 2101B The angle is 45 degrees. In this way, the angle between the relay polarizing beam splitting film 213B, the relay exit surface 2102B, the relay folding surface 2103B, and the relay display surface 2104B is also 45 degrees, so that the vertical incidence The S-polarized light of the relay incident surface 2101B is reflected by the relay polarizing beam splitting film 213B to perpendicularly exit the relay folding surface 2103B, and makes the vertically incident to the relay display surface 2104B S-polarized light carrying image information is reflected by the relay polarizing beam splitting film 213B to vertically exit the relay exit surface 2104B, which helps reduce polarized light along the folded relay optical path 200B and The light energy generated during the propagation of the folding imaging optical path 300B is lost.

According to the preferred embodiment of the present invention, as shown in FIG. 14, the relay system 20B further includes a relay lens assembly 23B, wherein the relay lens assembly 23B is disposed at the relay polarization beam splitting Between the relay incident surface 2101B of the system 21B and the light source system 10B, for adjusting the degree of convergence of the S-polarized light from the light source system 10B, so that the S-polarized light satisfies the display unit 40B The required irradiation area.

In addition, in the preferred embodiment according to the present invention, as shown in FIG. 15, the relay system 20B further includes a relay polarization filter unit 24B, wherein the relay polarization filter unit 24B is disposed on the Between the relay lens assembly 23B and the relay incident surface 2101B of the relay polarization beam splitting system 21B, for filtering stray light (ie non-S polarization) in the S polarized light from the light source system 10B Light) to ensure that the S-polarized light incident from the relay incident surface 2101B has high purity, which helps to improve the imaging quality of the micro-projection light engine 1B.

Exemplarily, the relay polarization filtering unit 24B may be implemented as an S polarizer, but is not limited to allow only S polarized light to pass, and block P polarized light or / and other stray light from passing, so as to filter P polarized light or / and other stray light among the S polarized light of the light source system 10B.

It is worth mentioning that, in other examples of the present invention, a 1/4 wave plate is also provided between the display unit 40B and the relay polarization beam splitting system 21B of the relay system 20B (in the figure (Not shown), used to improve the contrast of the system, and help to further improve the imaging quality of the micro projection light engine 1B.

However, existing miniature projection light engines usually include a light source system, a relay lens group, a display chip, and a projection imaging system, where the relay lens group is located in the emission path of the light source system, and the display chip and the projection imaging system are located The opposite sides of the relay lens group are defined by the display chip and the projection imaging system to form a linear imaging optical path. In order to obtain a high-quality projection effect, the existing miniature projection light engine needs to provide a sufficiently long imaging optical path, which will also cause the existing miniature projection light engine to have a large size and volume, and it is difficult to meet The demand for a volumetric miniature projection light engine cannot be widely used and popularized in the fields of augmented reality, near-eye display, and wearable.

Therefore, in the preferred embodiment of the present invention, the imaging system 30B includes an imaging polarization beam splitting system 31B and an imaging folding system 32B, wherein the imaging folding system 32B is used to The polarized light carrying the image information emitted by the polarization beam splitting system 31 is folded back to the imaging polarization beam splitting system 31B to define another part forming the folded imaging optical path 300B in the imaging system 30B, so that The micro projection light engine 1B can project the polarized light carrying image information along the folding imaging optical path 300B. In this way, the folding imaging optical path 300B enables the imaging system 30 to provide a sufficiently long imaging optical path in a small volume, so as to ensure that the micro projection light engine 1B has a high imaging quality, Reducing the volume or size of the micro-projection light engine 1B helps to meet the market demand for a small-volume micro-projection light engine.

Specifically, as shown in FIGS. 13 and 14, the imaging folding system 32B of the imaging system 30B includes an imaging light conversion element 321B and an imaging light reflection element 322B, wherein the imaging light conversion element 321B is provided Between the imaging light reflecting element 322B and the imaging polarization beam splitting system 31B. The imaging light reflection element 322B is used to reflect the P- or S-polarized light emitted from the imaging polarization beam splitting system 31B back to the imaging polarization beam splitting system 31B, so that the P carrying image information Or S polarized light passes through the imaging light conversion element 321B twice. The imaging light conversion element 321B is used to convert the second-pass P or S polarized light carrying image information into the S or P polarized light carrying image information.

It is worth noting that, in the preferred embodiment of the present invention, the imaging light conversion element 321B can be, but not limited to, implemented as a 1/4 wave plate; the imaging light reflection element 322B can be, but not limited to, Implemented as a concave mirror. Of course, in other examples of the present invention, the imaging light conversion element 321B can also be implemented as other types of wave plates or light conversion elements, as long as the P or S polarized light carrying image information that passes through the second time It can be converted into the S or P polarized light carrying image information; the imaging light reflecting element 322B can also be implemented as other types of mirrors or light reflecting members, as long as it can be emitted from the imaging polarization beam splitting system 31B The P or S polarized light carrying the image information is reflected back to the imaging polarization beam splitting system 31B, so that the P or S polarized light carrying the image information passes through the imaging light conversion element 321B twice. There is no further restriction.

In addition, the imaging polarization beam splitting system 31B of the imaging system 30B is used to reflect the S-polarized light carrying the image information to change the propagation direction of the S-polarized light carrying the image information, and allow the P-polarization of the carried image information Light transmits without changing the direction of propagation of the P-polarized light carrying image information. In this way, according to the above characteristics of the imaging polarization beam splitting system 31B and the imaging refraction system 32B, it is possible to design the reasonable another part of the refraction imaging optical path 300B, so as to obtain a smaller volume The imaging optical path is long enough to further reduce the volume or size of the micro-projection light engine 1B while ensuring that the micro-projection light engine 1B has a high imaging quality.

Exemplarily, as shown in FIG. 16A, the imaging polarization beam splitting system 31B of the imaging system 30B has an imaging incident surface 3101B, an imaging exit surface 3102B perpendicular to the imaging incident surface 3101B, and a parallel to all The imaging reversal surface 3103B of the imaging incidence surface 3101B, wherein the imaging light conversion element 321B of the imaging reflex system 32B is provided to the imaging light reflecting element 322B and the imaging polarization of the imaging reflex system 32B Between the imaging folding surface 3103B of the beam splitting system 31B, the folding imaging path 300B is defined by the imaging light reflecting element 322B of the imaging polarization beam splitting system 31B and the imaging folding system 32B Of the other part.

In this way, when P-polarized light carrying image information enters the imaging polarization beam splitting system 31B from the imaging incident surface 3101B, the P-polarized light carrying image information passes through the imaging polarization beam splitting system 31B The imaging folding surface 3103B is emitted; then, the P-polarized light carrying the image information emitted from the imaging folding surface 3103B is reflected back to the imaging folding surface 3103B by the imaging light reflecting element 322B, so that the image carrying P-polarized light passes through the imaging light conversion element 321B twice; at the same time, the P-polarized light carrying image information is converted into S-polarized light carrying image information by the imaging light conversion element 321B, so that the converted The S-polarized light carrying image information enters the imaging polarizing beam splitting system 31B from the imaging folding surface 3103B; finally, the S-polarized light carrying image information incident from the imaging folding surface 3103B is imaged by the imaging The polarization beam splitting system 31B reflects to emit from the imaging exit surface 3102B to project imaging, thereby realizing the P-polarized light carrying image information along the other side of the folding imaging optical path 300B Part of the projected image results.

In other words, in the imaging system 30B, the other part of the folding imaging optical path 300B first extends from the imaging incident surface 3101B of the imaging polarization beam splitting system 31B to the imaging polarization beam splitting The imaging refraction surface 3103B of the system 31B; then the folded imaging optical path 300B is folded by the imaging refraction system 32B to extend toward the imaging incidence surface 3101B of the imaging polarization beam splitting system 31B; finally, The folding imaging light path 300B is reflected by the imaging polarization beam splitting system 31B to extend to the imaging exit surface 3102B of the imaging polarization beam splitting system 31B, so that the P-polarized light carrying image information can Propagating along the folding imaging optical path 300B to project imaging, so as to achieve a sufficiently long imaging optical path in a small space.

It is worth noting that the folding imaging optical path 300B includes an imaging optical path between the display unit 40B and the imaging system 30B and an imaging optical path in the imaging system 30B, wherein the display unit The imaging optical path between 40B and the imaging system 30B first bends from the display unit 40B to the relay exit surface 2102B, and then linearly extends from the relay exit surface 2102B to the imaging entrance surface 3101B, and the imaging optical path in the imaging system 30B extends from the imaging incident surface 3101 to the imaging exit surface 3102B, thereby forming the complete folded imaging optical path 300B.

More specifically, as shown in FIGS. 14 and 16A, the imaging polarization beam splitting system 31B of the imaging system 30B includes a first imaging right-angle prism 311B, a second imaging right-angle prism 312B, and an imaging polarizing beam splitting film 313B, wherein the imaging polarization beam splitting film 313B is disposed between the slope of the first imaging right-angle prism 311B and the slope of the second imaging right-angle prism 312B to form the imaging polarization beam splitting having a rectangular structure System 31B. The imaging polarizing beam splitting film 313B is used to allow the P-polarized light carrying image information to pass through, and is used to reflect the S-polarized light carrying the image information to turn the S-polarized light carrying the image information. The right-angle surface of the first imaging right-angle prism 311B is defined as the imaging incident surface 3101B of the imaging polarization beam splitting system 31B, and the two right-angle surfaces of the second imaging right-angle prism 312B are respectively defined as the The imaging exit surface 3102B and the imaging folding surface 3103B of the imaging polarization beam splitting system 31B, and the imaging exit surface 3102B are both perpendicular to the imaging incident surface 3101B and the imaging folding surface 3103B.

In this way, the P-polarized light carrying image information incident from the imaging incident surface 3101B can pass through the imaging polarizing beam splitting film 313B to pass through the imaging polarizing beam splitting system 31B and exit from the imaging folding surface 3103B ; Next, the P-polarized light carrying the image information emitted from the imaging reversal surface 3103B is converted into the S-polarized light carrying the image information by the imaging reversal system 32B, and the S-polarized light carrying the image information is reflected Back to the imaging folding surface 3103B; finally, the S-polarized light carrying image information incident from the imaging folding surface 3103B is reflected by the imaging polarization beam splitting film 313B of the imaging polarization beam splitting system 31B The imaging exit surface 3102B exits for projection imaging. In other words, the other part of the folding imaging optical path 300B first extends from the imaging incident surface 3101B to the imaging folding surface 3103B, and extends from the imaging folding surface 3103B to the imaging After the polarizing beam splitting film 313B, it extends from the imaging polarizing beam splitting film 313B to the imaging exit surface 3102B, so as to extend the length of the folding imaging optical path 300B by folding, which helps In the case of the projection quality of the micro projection light engine 1B, the volume or size of the micro projection light engine 1B is reduced.

It is worth noting that the imaging polarization beam splitting film 313B may be, but not limited to, implemented as a PBS film for allowing the transmission of P-polarized light carrying image information and preventing the transmission and reflection of S-polarized light carrying image information The S polarized light carrying image information changes the propagation direction of the S polarized light carrying image information.

Preferably, both the first and second imaging right-

angle prisms

311B, 312B are implemented as an isosceles right-angle prism, so that the included angle between the imaging polarizing beam splitting film 313B and the imaging incident surface 3101B is 45 degree. In this way, the angle between the imaging polarizing beam splitting film 313B, the imaging exit surface 3102B, and the imaging folding surface 3103B is also 45 degrees, so that the carrying image information that enters the imaging folding surface 3103B vertically The S-polarized light is reflected by the imaging polarizing beam splitting film 313B to vertically exit the imaging exit surface 3102B, which helps reduce the light generated during the propagation of polarized light along the folding imaging optical path 300B Can be lost.

Further, in the preferred embodiment of the present invention, as shown in FIGS. 14 and 16A, the imaging system 30B further includes an imaging conversion unit 33B, wherein the imaging conversion unit 33B is provided in the imaging Between the imaging incident surface 3101B of the polarization beam splitting system 31B and the relay exit surface 2102B of the relay system 20B, for converting S-polarized light carrying image information from the relay system 20B into The P-polarized light carrying the image information, so that the P-polarized light carrying the image information enters the imaging polarization beam splitting system 31B from the imaging incident surface 3101B and follows the path of the folded imaging optical path 300B Another part spread.

For example, the imaging conversion unit 33B may be, but not limited to, implemented as a 1/2 wave plate for converting the S-polarized light carrying image information into the P-polarized light carrying image information. Of course, in other examples of the present invention, the imaging conversion unit 33B may also be implemented as a pair of 1/4 wave plates placed overlappingly, so that S-polarized light is converted into P-polarized light carrying image information.

According to the preferred embodiment of the present invention, as shown in FIG. 16A, the imaging system 30B further includes an imaging lens assembly 34B, wherein the imaging lens assembly 34B includes a first imaging lens group 341B, wherein the first An imaging lens group 341B is provided on the imaging exit surface 3102B of the imaging polarization beam splitting system 31B, and is used to adjust the degree of convergence of the S-polarized light carrying image information emitted from the imaging exit surface 3102B in order to satisfy The projection requirements of the micro projection light engine 1B.

Further, as shown in FIGS. 14 and 16A, the imaging lens assembly 34B further includes a second imaging lens group 342B, wherein the second imaging lens group 342B is disposed in the imaging conversion unit 33B and the middle Following the system 20B, it is used to adjust the degree of convergence of the S-polarized light carrying the image information from the relay system 20B, so as to reduce the convergence burden of the first imaging lens group 341B and help reduce the The thickness of the first imaging lens group 341B. It can be understood that, in other examples of the present invention, the second imaging lens assembly 342B may also be disposed between the imaging conversion unit 33B and the imaging incident surface 3101B of the imaging polarization beam splitting system 31B , For adjusting the degree of convergence of the P-polarized light carrying image information converted by the imaging conversion unit 33B.

In addition, in the preferred embodiment according to the present invention, as shown in FIG. 16A, the imaging system 30B further includes an imaging polarization filter unit 35B, wherein the imaging polarization filter unit 35B is disposed on the imaging conversion unit 33B and the imaging incident surface 3101B of the imaging polarization beam splitting system 31B, for filtering stray light (non-P polarization) in the P-polarized light carrying image information converted by the imaging conversion unit 33B Light) to ensure that the P-polarized light carrying image information incident from the imaging incident surface 3101B has a higher purity, which helps to improve the imaging quality of the micro projection light engine 1B.

Exemplarily, the imaging polarization filtering unit 35B may be, but not limited to, implemented as a P polarizer to allow only P polarized light carrying image information to pass, and block S polarized light carrying image information from passing to filter at S polarized light or other stray light in the P polarized light carrying image information converted by the imaging conversion unit 33B.

16B shows a modified embodiment of the imaging system 30B according to the preferred embodiment of the present invention, wherein the imaging polarization beam splitting system 31B of the imaging system 30B has an imaging incident surface 3101B, An imaging exit surface 3102B perpendicular to the imaging incident surface 3101B and an imaging folding surface 3103B perpendicular to the imaging incident surface 3101B, wherein the imaging light conversion element 321B of the imaging folding system 32B is disposed at Between the imaging light reflecting element 322B of the imaging and folding system 32B and the imaging and folding surface 3103B of the imaging polarization and beam splitting system 31B to pass the imaging polarization and beam splitting system 31B and the imaging and folding system The imaging light reflecting element 322B of 32B defines the other part of the folding imaging path 300B.

In this way, in this modified embodiment of the present invention, there is no need to first use the imaging conversion element 33B to convert the S-polarized light carrying the image information from the relay system 20B to the P-polarization carrying the image information Light, and then the P-polarized light carrying the image information enters the imaging polarization beam splitting system 31B from the imaging incident surface 3101B, but directly causes the S-polarized light carrying the image information from the relay system 20B It is sufficient to enter the imaging polarization beam splitting system 31B from the imaging incident surface 3101B, so as to further reduce the size of the micro projection light engine 1B.

In other words, since the polarized light incident from the imaging incident surface 3101B is the S-polarized light carrying image information, and the polarized light from the relay system 20B is also the S-polarized light carrying image information, so In this modified embodiment of the present invention, the imaging system 30B does not need to be provided with any of the imaging conversion units 33B, so that the S-polarized light carrying image information from the relay system 20B can be converted without conversion The imaging polarization beam splitting system 31B is incident from the imaging incident surface 3101B.

Exemplarily, as shown in FIG. 16B, first, the S-polarized light incident on the image information carrying the image information from the imaging incident surface 3101B is reflected by the imaging polarization beam splitting system 31B to exit from the imaging folding surface 3103B; , The S-polarized light carrying image information emitted from the imaging folding surface 3103B is reflected back to the imaging folding surface 3103B by the imaging light reflecting element 322B, so that the S-polarized light carrying image information passes through the secondary Imaging light conversion element 321B; at the same time, the S-polarized light carrying image information is converted into P-polarized light carrying image information by the imaging light conversion element 321B, so that the converted P-polarized light carrying image information The imaging polarization plane 3103B is incident on the imaging polarization beam splitting system 31B; finally, the P-polarized light carrying image information incident on the imaging plane 3103B passes through the imaging polarization beam splitting system 31B The imaging folding surface 3103B is emitted, thereby realizing the effect of projecting and imaging the S-polarized light carrying image information along the folding imaging optical path 300B.

In other words, in this modified embodiment, the two right-angle planes of the first imaging right-angle prism 311B are respectively defined as the imaging incidence plane 3101B and the imaging fold of the imaging polarization beam splitting system 31B The reverse surface 3103B, and the right-angle surface of the second imaging right-angle prism 312B is defined as the imaging exit surface 3102B of the imaging polarization beam splitting system 31B. In this way, the other part of the folding imaging optical path 300B first extends from the imaging incident surface 3101B to the imaging polarizing beam splitting film 313B, and extends from the imaging polarizing beam splitting film 313B to the imaging fold After the reverse surface 3102B, it extends from the imaging folding surface 3103B to the imaging exit surface 3102B, so as to extend the length of the folding imaging optical path 300B by folding, which helps to ensure the In the case of the projection quality of the micro projection light engine 1B, the volume or size of the micro projection light engine 1B is further reduced.

In addition, in this modified embodiment, as shown in FIG. 16B, the imaging polarization filter unit 35B of the imaging system 30B is provided at the position of the second imaging lens group 342B and the imaging polarization beam splitting system 31B Between the imaging incident surface 3101B, for filtering the stray light (ie non-S polarized light) in the S-polarized light carrying image information from the relay system 20B to ensure that the imaging incident surface 3101B enters The S-polarized light carrying image information has high purity, which helps to improve the imaging quality of the micro projection light engine 1B.

Exemplarily, the imaging polarization filter unit 35B may be implemented as an S polarizer, but is not limited to allow only S polarized light carrying image information to pass, and block P polarized light carrying image information from passing to filter P polarized light or other stray light in the S polarized light carrying image information of the relay system 20B.

It is worth mentioning that, according to the preferred embodiment of the present invention, as shown in FIGS. 12 to 14, the light source system 10B of the micro projection light engine 1B includes at least two light-emitting units 11B and a color combination system 12B and a polarization conversion system 13B, wherein each light-emitting unit 11B is used to emit monochromatic light, wherein the color combination system 12B is disposed between the at least two light-emitting units 11B and the polarization conversion system 13B, with In order to synthesize the monochromatic light emitted by the at least two light emitting units 11B into a monochromatic light, the polarization conversion system 13B is used to convert the monochromatic light into the S-polarized light. It can be understood that both the monochromatic light and the combined color light are implemented as unpolarized light, and the unpolarized light generally consists of P-polarized light and S-polarized light.

It is worth noting that the polarization conversion system 13B may be, but not limited to, implemented as a PCS array for converting unpolarized light into S-polarized light. Of course, in other examples of the present invention, the polarization conversion system 13B may also be implemented as a PCS array and a 1/2 wave plate, wherein the PCS array is disposed on the 1/2 wave plate and the Between the color combination systems 12B, wherein the PCS array is used to convert the unpolarized light into P-polarized light, and the 1/2 wave plate is used to convert the P-polarized light into the S-polarized light.

In addition, in the preferred embodiment of the present invention, the color combination system 12B may be, but not limited to, implemented as a decoy prism coated with a color selective transmission film, used to scale two monochromatic lights in proportion It is required to synthesize a light. Of course, in other examples of the present invention, the color combination system 12B can also be implemented as an X color combination prism or color combination sheet, which is used to synthesize multiple monochromatic lights into one light, and the present invention does not further limit this .

Further, as shown in FIGS. 12 and 14, the light source system 10B further includes at least two collimating systems 14B and a uniform light system 15B. Each collimating system 14B is disposed between the corresponding light-emitting unit 11B and the color combination system 12B for collimating the monochromatic light emitted by the light-emitting unit 11B. The uniform light system 15B is provided between the color combination system 12B and the polarization conversion system 13B for homogenizing the synthesized light. It can be understood by those skilled in the art that the collimating system 14B may be implemented as a collimating lens but not limited; the uniform light system 15B may be implemented as a compound eye or a micro-lens array group (Micro-lens array) , Referred to as MLA).

According to another aspect of the present invention, as shown in FIGS. 17A and 17B, the present invention further provides a near-eye display device. As shown in FIG. 17A, the near-eye display device includes a waveguide 500B and any of the above-mentioned miniature projection light engines 1B, wherein the miniature projection light engine 1B is used to project polarized light carrying image information to the waveguide 500B to pass The waveguide 500B projects the polarized light carrying image information into the human eye.

It is worth noting that in FIG. 17A, the micro projection light engine 1B and the human eye are located on the same side of the waveguide 500B. Of course, as shown in FIG. 17B, in another example of the present invention, the micro projection light engine 1B and the human eye may also be located on opposite sides of the waveguide 500B (ie, different sides of the waveguide 500B), similarly The projected polarized light carrying image information can be projected into human eyes. The present invention does not limit this. It only needs to ensure that the polarized light carrying image information from the micro-projection light engine 1B is projected to humans through the waveguide 500B. In your eyes. In addition, those skilled in the art may understand that the type of the near-eye display device is not limited, for example, the near-eye display device may be a head-mounted display device such as AR glasses.

Those skilled in the art should understand that the embodiments of the present invention shown in the above description and drawings are only examples and do not limit the present invention. The object of the present invention has been completely and effectively achieved. The functions and structural principles of the present invention have been shown and described in the examples. Without departing from the principles, the embodiments of the present invention may have any variations or modifications.

Claims

A polarization multiplexing device used in a projection system for converting unpolarized light into polarized light having the same polarization state, wherein the polarization multiplexing device includes:

A group of polarization multiplexing units, wherein all the polarization multiplexing units are arranged in an end-to-end manner, wherein each polarization multiplexing unit has an incident surface and an exit surface opposite to the incident surface, and includes:

A light conversion element, wherein the light conversion element is used to convert the first polarized light into the second polarized light;

An optical beam splitting assembly, wherein the optical beam splitting assembly is located on one side of the light conversion element, and is used to separate the unpolarized light incident from the incident surface into a second polarization emitted from the exit surface Light and the first polarized light directed to the light conversion element; and

A light reflection component, wherein the light reflection component is located on the other side of the light conversion element, and is used to reflect the second polarized light converted by the light conversion element so that the second polarized light is emitted from the exit Face shot.
The polarization multiplexing device according to claim 1, wherein the light splitting assembly of each polarization multiplexing unit includes a first beam splitting prism, a second beam splitting prism, and a light splitting element, wherein The beam splitting element is disposed between the first beam splitting prism and the second beam splitting prism, and is used to allow the first polarized light in the unpolarized light to pass through and prevent the first polarized light in the unpolarized light from passing through The two polarized light is transmitted to reflect the second polarized light to the light conversion element.
The polarization multiplexing device according to claim 2, wherein the first and second beam splitting prisms are right-angle prisms, and the light splitting element is provided on the first and second beam splitting prisms Between the inclined surfaces to form the optical beam splitting assembly with a rectangular structure.
The polarization multiplexing device of claim 3, wherein the optical beam splitting element is a polarization beam splitting film.
The polarization multiplexing device of claim 4, wherein the light conversion element is a 1/2 wave plate.
The polarization multiplexing device according to claim 5, wherein the angle between the light conversion element and the light splitting element of each polarization multiplexing unit is 40-50 degrees.
The polarization multiplexing device of claim 6, wherein the cross-sections of the first and second beam splitting prisms are both isosceles right-angled triangles.
The polarization multiplexing device of claim 1, wherein the light reflecting component comprises a first reflecting prism, a second reflecting prism, and a light reflecting element, wherein the light reflecting element is disposed on the first Between the reflecting prism and the second reflecting prism, the second polarized light converted by the light conversion element is reflected.
The polarization multiplexing device according to any one of claims 2 to 7, wherein the light reflecting component includes a first reflecting prism, a second reflecting prism, and a light reflecting element, wherein the light reflecting element is provided Between the first reflecting prism and the second reflecting prism, it is used to reflect the second polarized light converted by the light conversion element.
The polarization multiplexing device of claim 9, wherein the first and second reflecting prisms are right-angle prisms, and the light reflecting element is disposed between the inclined surfaces of the first and second reflecting prisms To form the light reflecting component with a rectangular structure.
The polarization multiplexing device of claim 10, wherein the light reflecting element is a reflecting film.
The polarization multiplexing device according to claim 11, wherein the angle between the light conversion element and the light reflection element of each polarization multiplexing unit is 40-50 degrees.
The polarization multiplexing device of claim 12, wherein the first and second reflecting prisms are both isosceles right-angled triangles.
The polarization multiplexing device of claim 13, wherein the light reflecting element is parallel to the light splitting element.
The polarization multiplexing device according to claim 14, wherein the second beam splitting prism of the optical beam splitting assembly of any one of the polarization multiplexing units and the adjacent of the polarization multiplexing unit The second reflecting prisms of the light reflecting component are bonded together.
The polarization multiplexing device according to claim 14, wherein the second beam splitting prism of the optical beam splitting assembly of any one of the polarization multiplexing units and the adjacent of the polarization multiplexing unit The second reflecting prisms of the light reflecting assembly are integrally connected to form a common prism having a parallelogram cross section by combining the second beam splitting prism and the second reflecting prism.
The polarization multiplexing device according to claim 9, wherein the second beam splitting prism of the optical beam splitting assembly of any one of the polarization multiplexing units and the adjacent of the polarization multiplexing unit The second reflecting prisms of the light reflecting assembly are integrally connected to form a common prism having a parallelogram cross section by combining the second beam splitting prism and the second reflecting prism.
The polarization multiplexing device according to any one of claims 1 to 8, wherein the first polarized light is S-polarized light and the second polarized light is P-polarized light.
The polarization multiplexing device according to any one of claims 1 to 8, wherein the first polarized light is P-polarized light, and the second polarized light is S-polarized light.
The polarization multiplexing device according to any one of claims 1 to 8, further comprising at least one anti-reflection element, wherein the anti-reflection element is provided on the incident surface and the exit surface of the polarization multiplexing unit , For reducing the reflection of the unpolarized light and the second polarized light by the incident surface and the exit surface, respectively.
The polarization multiplexing device of claim 20, wherein the anti-reflection element is an anti-reflection film plated on the incident surface and the exit surface of the polarization multiplexing unit, respectively.
A method for improving the utilization rate of light energy of a projection system is characterized in that it includes the steps of:

S100: Separate unpolarized light to form separated first polarized light and separated second polarized light, wherein the separated first polarized light and the separated second polarized light propagate in different directions;

S200: Convert the separated first polarized light to form the converted second polarized light; and

S300: Reflect the converted second polarized light to form a reflected second polarized light, wherein the reflected second polarized light and the separated second polarized light propagate in the same direction so that the projection system is sufficiently Use this unpolarized light.
The method for improving the light energy utilization rate of a projection system according to claim 22, wherein in said step S100:

By means of a beam splitting component of a polarization multiplexing unit of a polarization multiplexing device of the projection system, the unpolarized light incident from the incident surface of the polarization multiplexing unit is separated into the separated first polarization Light and the separated second polarized light, wherein the separated first polarized light is directed to a light conversion element of the polarization multiplexing unit, and the separated second polarized light is directed to the polarization multiplexing unit The exit surface is shot from the exit surface.
The method for improving the utilization rate of light energy of a projection system according to claim 23, wherein in said step S200:

With the light conversion element, the separated first polarized light is converted into the converted second polarized light, wherein the converted second polarized light is directed to a light reflection component of the polarization multiplexing unit.
The method for improving the light energy utilization rate of a projection system according to claim 24, wherein in said step S300:

With the light reflection component, the converted second polarized light is reflected into the reflected second polarized light, wherein the reflected second polarized light is directed to the exit surface of the polarization multiplexing unit to The exit surface is shot.
The method for improving the utilization of light energy of a projection system according to claim 25, further comprising the steps of:

An anti-reflection material is plated on the incident surface of the polarization multiplexing unit to reduce the reflection of light from the incident surface.
The method for improving the utilization of light energy of a projection system according to claim 25, further comprising the steps of:

An anti-reflection material is plated on the exit surface of the polarization multiplexing unit to reduce light reflection from the exit surface.
The method for improving the light energy utilization rate of a projection system according to any one of claims 22 to 27, wherein the first polarized light is S-polarized light or P-polarized light, and the second polarized light is P-polarized light Light or S polarized light.
A miniature projection light engine for a near-eye display device, characterized in that it includes:

A light source system for emitting polarized light with the same polarization state along a predetermined direction;

A display unit for modulating polarized light into polarized light carrying image information;

An imaging system for projecting polarized light carrying image information; and

A relay system, wherein the relay system is disposed between the light source system, the display unit, and the imaging system, and the light source system and the imaging system are respectively located opposite to the relay system Side, where the relay system is used to change the propagation direction of the polarized light from the light source system so that the polarized light propagates to the display unit; wherein the relay system is also used to change the light from the display unit The propagation direction of the polarized light carrying image information, so that the polarized light carrying image information can propagate to the imaging system along the predetermined direction.
The miniature projection light engine according to claim 29, wherein the relay system includes a relay polarization beam splitting system and a relay folding system, wherein the relay polarization beam splitting system is disposed on the light source Between the system and the imaging system, and the display unit and the relay folding system are respectively located on opposite sides of the relay polarization beam splitting system, wherein the display unit is also used to carry the image information Of the polarized light is reflected back to the relay polarization beam splitting system, and the relay folding system is used to fold the polarized light emitted from the relay polarization beam splitting system back to the relay polarization beam splitting system, To define a folding relay optical path forming the relay system between the light source system and the display unit, so that the polarized light can propagate to the display unit along the folding relay optical path .
The miniature projection light engine according to claim 30, wherein the relay folding system includes a relay light conversion element and a relay light reflection element, wherein the relay light conversion element is located at the relay polarization Between the beam splitting system and the relay light reflecting element, wherein the relay light reflecting element is used to reflect polarized light emitted from the relay polarizing beam splitting system back to the relay polarizing beam splitting system, The polarized light is passed through the relay light conversion element twice, wherein the relay light conversion element is used to convert the polarized light passed through twice into polarized light having another polarization state.
The miniature projection light engine of claim 31, wherein the relay light conversion element is a 1/4 wave plate, and the relay light reflection element is a concave mirror.
The miniature projection light engine of claim 32, wherein the relay polarization beam splitting system includes a first relay right angle prism, a second relay right angle prism, and a relay polarization beam splitting film, wherein the The relay polarizing beam splitting film is disposed between the slope of the first relay right-angle prism and the slope of the second relay right-angle prism to form the relay polarization beam splitting system having a rectangular cross section, wherein The relay polarizing beam splitting film is used to allow P polarized light to pass through and reflect S polarized light to change the propagation direction of the S polarized light.
The miniature projection light engine according to claim 33, wherein the relay polarizing beam splitting film is a PBS film.
The miniature projection light engine of claim 34, wherein the relay polarization beam splitting system has a relay incidence surface, a relay exit surface parallel to the relay incidence surface, and a perpendicular to the middle A relay folding surface following the incident surface and a relay display surface perpendicular to the relay incident surface, wherein the light source system corresponds to the relay incident surface; wherein the relay folding system corresponds to the A relay folding surface; wherein the display unit corresponds to the relay display surface; wherein the imaging system corresponds to the relay exit surface.
The miniature projection light engine of claim 35, wherein the relay incident surface and the relay display surface of the relay polarization beam splitting system intersect the relay polarization beam splitting film, and the The relay exit surface and the relay folding surface of the relay polarization beam splitting system intersect the relay polarizing beam splitting film, so that the S polarized light from the light source system is split by the relay polarizing beam first Film reflection propagates from the relay incident surface to the relay folding surface, and then is converted into P-polarized light by the relay folding system, and then folded back to the relay folding surface , The P-polarized light passes through the relay polarizing beam splitting film to propagate from the relay folding surface to the display unit located on the relay display surface.
The miniature projection light engine of claim 36, wherein the relay system further includes a relay lens assembly, wherein the relay lens assembly is disposed at the relay of the relay polarization beam splitting system Between the incident surface and the light source system, for adjusting the degree of convergence of polarized light from the light source system.
The miniature projection light engine according to claim 37, wherein the relay system further includes a relay polarization filter unit, wherein the relay polarization filter unit is disposed between the relay lens assembly and the relay Between the relay incident surfaces of the polarization beam splitting system, it is used to filter the stray light in the S-polarized light.
The miniature projection light engine of claim 38, wherein the relay polarization filter unit is an S polarizer.
The miniature projection light engine according to any one of claims 28 to 35, wherein the imaging system includes an imaging polarization beam splitting system and an imaging folding system, wherein the imaging polarization beam splitting system is located at the imaging folding Between an inversion system and the relay system, wherein the imaging refraction system is used to fold the polarized light carrying image information emitted from the imaging polarization beam splitting system back to the imaging polarization beam splitting system to pass The relay system and the imaging system define a folding imaging optical path forming the imaging system, so that the miniature projection light engine can project the polarized light carrying image information along the folding imaging optical path.
The miniature projection light engine according to any one of claims 36 to 39, wherein the imaging system includes an imaging polarization beam splitting system and an imaging folding system, wherein the imaging polarization beam splitting system is located at the imaging fold Between an inversion system and the relay system, wherein the imaging refraction system is used to fold the polarized light carrying image information emitted from the imaging polarization beam splitting system back to the imaging polarization beam splitting system to pass The relay system and the imaging system define a folding imaging optical path forming the imaging system, so that the miniature projection light engine can project the polarized light carrying image information along the folding imaging optical path.
The miniature projection light engine according to claim 41, wherein the imaging reversal system includes an imaging light conversion element and an imaging light reflection element, wherein the imaging light conversion element is located between the imaging light reflection element and the Between imaging polarization beam splitting systems, wherein the imaging light reflecting element is used to reflect the polarized light carrying image information emitted from the imaging polarization beam splitting system back to the imaging polarization beam splitting system, so that the carrying image The polarized light of the information passes through the imaging light conversion element twice, wherein the imaging light conversion element is used to convert the polarized light carrying the image information through the second time into the polarization of the image information carrying another polarization state Light.
The miniature projection light engine according to claim 42, wherein the imaging light conversion element is a 1/4 wave plate, and the imaging light reflection element is a concave mirror.
The miniature projection light engine of claim 43, wherein the imaging polarization beam splitting system includes a first imaging right angle prism, a second imaging right angle prism, and an imaging polarizing beam splitting film, wherein the imaging polarizing beam splitting A film is disposed between the slope of the first imaging right-angle prism and the slope of the second imaging right-angle prism to form the imaging polarization beam splitting system having a rectangular cross section, wherein the imaging polarization beam splitting film is used In order to allow P-polarized light carrying image information to pass through, and reflect S-polarized light carrying image information to turn the S-polarized light carrying image information.
The miniature projection light engine of claim 44, wherein the imaging polarization beam splitting system has an imaging incident surface, an imaging exit surface perpendicular to the imaging incident surface, and an imaging perpendicular to the imaging incident surface A folding surface, wherein the imaging folding system corresponds to the imaging folding surface, and the relay system corresponds to the imaging incident surface, wherein the folding imaging optical path is first bent from the relay display surface Extend to the relay exit surface, and then extend from the relay exit surface to the imaging entrance surface, and then, the folding imaging optical path is reflected by the imaging polarizing beam splitting film to enter from the imaging The surface is bent to extend to the imaging folding surface, and finally after being folded back to the imaging folding surface by the relay folding system, it then passes through the imaging polarizing beam splitting film to extend from the imaging folding surface To the imaging exit surface.
The miniature projection light engine according to claim 45, wherein the imaging system further comprises an imaging polarization filtering unit, wherein the imaging polarization filtering unit is disposed between the relay system and the imaging polarization beam splitting system Between the imaging incident surfaces, it is used to filter stray light from S-polarized light carrying image information from the relay system.
The miniature projection light engine of claim 46, wherein the imaging polarizing filter unit is an S polarizing plate.
The miniature projection light engine according to claim 44, wherein the imaging polarization beam splitting system has an imaging incident surface, an imaging exit surface perpendicular to the imaging incident surface, and an imaging parallel to the imaging incident surface A folding surface, wherein the imaging folding system corresponds to the imaging folding surface, and the relay system corresponds to the imaging incident surface, wherein the folding imaging optical path is first bent from the relay display surface Extend to the relay exit surface, and then extend from the relay exit surface to the imaging entrance surface, and then, the folding imaging optical path passes through the imaging polarizing beam splitting film to enter from the imaging The surface extends to the imaging folding surface, and finally after being folded back to the imaging folding surface by the imaging folding system, it is then reflected by the imaging polarizing beam splitting film to extend from the imaging folding surface to bending The imaging exit surface.
The miniature projection light engine according to claim 48, wherein the imaging system further includes an imaging conversion unit, wherein the imaging conversion unit is disposed on the imaging incident surface of the imaging polarization beam splitting system and the Between the relay systems, S-polarized light carrying image information from the relay system is converted into P-polarized light carrying the image information incident from the imaging incident surface.
The miniature projection light engine of claim 49, wherein the imaging conversion unit is a 1/2 wave plate or a pair of 1/4 wave plates.
The miniature projection light engine of claim 49, wherein the imaging system further includes an imaging lens assembly, wherein the imaging lens assembly includes a first imaging lens group and a second imaging lens group, wherein the first An imaging lens group is disposed between the relay system and the imaging conversion unit, and the second imaging lens group is disposed on the imaging exit surface of the imaging polarization beam splitting system.
The miniature projection light engine according to claim 51, wherein the imaging system further comprises an imaging polarization filtering unit, wherein the imaging polarization filtering unit is disposed between the imaging conversion unit and the imaging polarization beam splitting system Between the imaging incident surfaces, it is used to filter stray light in the P-polarized light carrying image information converted by the imaging conversion unit.
The miniature projection light engine of claim 52, wherein the imaging polarization filter unit is a P polarizer.
The miniature projection light engine according to claim 53, wherein the light source system includes at least two light-emitting units, a color combination system, and a polarization multiplexing system, wherein each of the light-emitting units is used to emit monochromatic light, wherein The color combination system is located between the at least two light emitting units and the polarization multiplexing system, and is used for synthesizing the monochromatic light emitted by the at least two light emitting units into a color combination light, wherein the polarization multiplexing system is used for This combined color light is converted into S polarized light.
The miniature projection light engine according to claim 54, wherein the light source system further comprises at least two collimating systems and a uniform light system, wherein each collimating system is provided in the corresponding light emitting unit and the Between the color combination systems, for collimating the monochromatic light emitted by the corresponding light-emitting unit; wherein the uniform light system is provided between the color combination system and the polarization multiplexing system for The combined color light is processed uniformly.