Projection system

Abstract

This application provides a projection system including an illumination component, a beam splitter, a pre-modulation component, a reflection component, and a main modulation component. The illumination component emits illumination light. The beam splitter is disposed in the emission light path of the illumination component and has a first emission light path, a second emission light path, and a third emission light path, used to split the illumination light into first polarized light and second polarized light. The pre-modulation component is disposed in the first emission light path and is used to pre-modulate the first polarized light to form pre-modulated light, and guide the pre-modulated light to the beam splitter. The reflection component is disposed in the second emission light path and is used to convert the polarization state of the second polarized light to form third polarized light, and guide the third polarized light to the beam splitter. The main modulation component is disposed in the third emission light path and is used to modulate the pre-modulated light and the third polarized light. The projection system provided by this application can achieve high image contrast and improve system light efficiency, solving the problem of insufficient system brightness.

Description

Technical Field

[0001] This application relates to the field of optical system technology, and more specifically to a projection system. Background Technology

[0002] Currently, the contrast ratio achievable by single-chip spatial light modulator projection display technology is roughly several hundred to one to one or two thousand to one, which is far lower than the brightness resolution of the human eye. Therefore, the brightness of the projected image is insufficient in bright areas and cannot be reduced in dark areas, resulting in poor image layering and loss of a large amount of detail.

[0003] The related technology provides a projection system that achieves HDR (High-Dynamic Range) display through dual-layer spatial light modulator technology. This projection system achieves high contrast by adding a second spatial light modulator after the first one, thus multiplying the contrast of the two modulators. However, the illumination light loses a significant amount of light energy after passing through the two spatial light modulators, resulting in a substantial reduction in the overall brightness of the projection system. Summary of the Invention

[0004] The purpose of this application is to provide a projection system to solve the aforementioned problems. This application achieves the above objective through the following technical solution.

[0005] This application provides a projection system, including: an illumination assembly for emitting illumination light; a beam splitter disposed on the emission light path of the illumination assembly, the beam splitter having a first emission light path, a second emission light path, and a third emission light path, the beam splitter being used to split the illumination light into first polarized light and second polarized light, and to emit the first polarized light through the first emission light path and the second polarized light through the second emission light path; and a premodulation assembly disposed on the first emission light path, used to premodulate the first polarized light to form premodulated light, and to guide the premodulated light to the beam splitter. The system includes an optical prism, wherein the polarization state of the pre-modulated light is opposite to that of the first polarized light; a reflective component, disposed on the second output optical path, for converting the polarization state of the second polarized light to form a third polarized light, and guiding the third polarized light to a beam splitter, wherein the polarization state of the third polarized light is opposite to that of the second polarized light; and a main modulation component, disposed on the third output optical path, wherein the beam splitter is also used to output the pre-modulated light and the third polarized light through the third output optical path to the main modulation component, and the main modulation component is used to modulate the pre-modulated light and the third polarized light.

[0006] The projection system provided in this application embodiment can pre-modulate the input light field of the main modulation component through the pre-modulation component, thereby achieving a higher image contrast. At the same time, the second polarized light is converted into a third polarized light by the reflection component, and the beam splitter can combine the third polarized light with the pre-modulated light and then emit it to the main modulation component, which is beneficial to improving the light efficiency of the projection system and solving the problem of insufficient brightness of the projection system. Attached Figure Description

[0007] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 This is the optical path diagram of the projection system provided in the embodiments of this application.

[0009] Figure 2 This is the optical path diagram of a projection system in modulated light field mode provided in another embodiment of this application.

[0010] Figure 3 yes Figure 2 The light path diagram of the projection system provided in the embodiment shown in the substrate light field mode.

[0011] Figure 4 This is a schematic diagram of the structure of the polarizer in the projection system provided in the embodiments of this application. Detailed Implementation

[0012] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0013] In projection imaging systems, the contrast of the final displayed image is primarily limited by the characteristics of spatial stray light and the spatial light modulator. For the spatial light modulator, due to the low reflectivity of the substrate material, complete beam shut-off cannot be achieved in the OFF state. Therefore, even when the spatial light modulator switches to the OFF state (dark field), a certain dark field pattern still exists on the projected screen. Thus, the intrinsic properties of the spatial light modulator directly limit the contrast of the projected image.

[0014] Related technologies provide an optical path design method using cascaded spatial light modulators. By connecting two stages of spatial light modulators in series, multiple shutdowns of the dark field can be achieved, thereby realizing extremely high intrinsic contrast. However, using two stages of spatial light modulators to process the optical signal results in a significant loss of light energy, thus reducing the overall brightness of the system.

[0015] To address brightness loss under high contrast conditions, related technologies offer a solution using optical circulation to improve the efficiency of pre-modulated light sources. Specifically, after the illumination source emits an illumination beam, it passes through a relay system and is pre-modulated in a first spatial light modulator. The ON-state beam is imaged through an optomechanical system to a second spatial light modulator for imaging modulation, ultimately forming an image on the screen. The OFF-state beam re-enters the light source homogenizing system via an optical circulation relay system and is again pre-modulated in the first spatial light modulator system, achieving the recycling of OFF light. Using an optical circulation system can compensate for the light energy loss caused by the two-stage spatial light modulator to some extent. However, this solution also increases the complexity of the optical path, resulting in relatively large device size and cost, and presents significant challenges in the fabrication and assembly of the optical path.

[0016] In view of this, the inventors have proposed a projection system, including an illumination component, a beam splitter, a pre-modulation component, a reflection component, and a main modulation component. The pre-modulation component can pre-modulate the input light field of the main modulation component, thereby achieving higher image contrast. Simultaneously, the reflection component converts the polarization state of the second polarized light to form a third polarized light. The beam splitter combines the third polarized light with the pre-modulated light before projecting it onto the main modulation component, which helps improve the light efficiency of the projection system and compensates for insufficient brightness. In addition, the light-emitting surface of the illumination component to the pre-modulation component and the light-emitting surface to the reflection component have equivalent optical paths and optical lengths, resulting in smaller aberrations and lower device costs in the combined light path of the pre-modulation component and the reflection component.

[0017] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0018] Please see Figure 1This application provides a projection system 100, including an illumination component 110, a beam splitter 120, a pre-modulation component 130, a reflection component 140, and a main modulation component 150. The illumination component 110 emits illumination light. The beam splitter 120 is disposed in the light path of the illumination component 110, and the beam splitter 120 has a first light-emitting path, a second light-emitting path, and a third light-emitting path. The light-emitting directions of the first light-emitting path, the second light-emitting path, and the third light-emitting path are different from each other. For example, the first light-emitting path... The light output directions of the first and third light output paths are opposite, and the second light output path is perpendicular to the first and third light output paths. The beam splitter 120 is used to split the illumination light into first polarized light and second polarized light, and to output the first polarized light through the first light output path and the second polarized light through the second light output path. The polarization states of the first polarized light and the second polarized light are opposite. For example, the first polarized light can be either P-polarized light or S-polarized light, and the second polarized light can be either P-polarized light or S-polarized light.

[0019] The pre-modulation component 130 is disposed in the first light output path of the beam splitter 120, and is used to pre-modulate the first polarized light to form pre-modulated light and guide the pre-modulated light to the beam splitter 120. The polarization state of the pre-modulated light is opposite to that of the first polarized light, and the polarization state of the pre-modulated light is the same as that of the second polarized light.

[0020] The reflective component 140 is disposed on the second light output path of the beam splitter 120, and is used to convert the polarization state of the second polarized light to form the third polarized light, and guide the third polarized light to the beam splitter 120. The polarization state of the third polarized light is opposite to that of the second polarized light, and the polarization state of the third polarized light is the same as that of the first polarized light.

[0021] The main modulation component 150 is disposed on the third output optical path of the beam splitter 120. The beam splitter 120 is also used to output the pre-modulated light and the third polarized light through the third output optical path to the main modulation component 150. The main modulation component 150 is used to modulate the pre-modulated light and the third polarized light.

[0022] The projection system 100 provided in this application embodiment can pre-modulate the input light field of the main modulation component 150 through the pre-modulation component 130, thereby achieving a higher image contrast. At the same time, the second polarized light is converted into a third polarized light by the reflection component 140. The beam splitter prism 120 can combine the third polarized light with the pre-modulated light and then emit it to the main modulation component 150 for modulation and imaging, which is beneficial to improving the light efficiency of the projection system 100 and compensating for the problem of insufficient brightness of the projection system 100.

[0023] In this embodiment, the beam splitter 120 is a polarization beam splitter (PBS), which can be formed by bonding two right-angle prisms together. The inclined surfaces of the right-angle prisms are coated with a multilayer film structure to form a beam-splitting surface. The optical axis of the illumination component 110 forms a 45° angle with the beam-splitting surface. The optical axis of the pre-modulation component 130 is parallel to the first output light path of the beam splitter 120, and its optical axis forms a 45° angle with the beam-splitting surface and is perpendicular to the optical axis of the illumination component 110. The optical axis of the reflection component 140 is parallel to the second output light path of the beam splitter 120, and its optical axis forms a 45° angle with the beam-splitting surface and is coaxial with the optical axis of the illumination component 110. The third output light path of the beam splitter 120 forms a 45° angle with the beam-splitting surface and is perpendicular to the optical axis of the illumination component 110.

[0024] The beam-splitting surface of the beam-splitting prism 120 can be coated with a film structure that reflects first polarized light and transmits second polarized light. Therefore, when the illumination light is incident on the beam-splitting surface, it can be split into first polarized light and second polarized light. The first polarized light is reflected to the pre-modulation component 130, and the second polarized light is transmitted to the reflection component 140. The polarization state of the pre-modulated light is opposite to that of the first polarized light. Therefore, after returning to the beam-splitting surface of the beam-splitting prism 120, the pre-modulated light can be transmitted to the main modulation component 150. The polarization state of the third polarized light is opposite to that of the second polarized light. Therefore, after returning to the beam-splitting surface of the beam-splitting prism 120, the third polarized light can be reflected to the main modulation component 150.

[0025] In some embodiments, the illumination component 110 may include a laser light source 111, an optical scattering device 112, and a light homogenizing device 113. The optical scattering device 112 and the light homogenizing device 113 are sequentially disposed in the output light path of the laser light source 111. The laser light source 111 is used to emit laser light as illumination light. The laser has advantages such as stable performance, high clarity at the same lumen, and small brightness decay over long-term use. The illumination light passes through the optical scattering device 112 and the light homogenizing device 113 and then enters the beam splitter 120. The optical scattering device 112 is used to depolarize and decohere the illumination light, and the light homogenizing device 113 is used to homogenize the illumination light.

[0026] In this embodiment, the illumination assembly 110 may further include one or more first light source lenses 114 and one or more second light source lenses 115. The first light source lens 114 is disposed in the optical path between the laser light source 111 and the optical scattering device 112, and can be used to relay the illumination light to the optical scattering device 112. The second light source lens 115 is disposed in the optical path between the optical scattering device 112 and the light homogenizing device 113, and can be used to relay the illumination light emitted from the optical scattering device 112 to the light homogenizing device 113.

[0027] The optical scattering device 112 can be a scattering wheel, which can scatter the incident laser beam by rotating at high speed, achieving depolarization and decoherence. The beam homogenizing device 113 can be a dispersion plate, the surface of which is processed with hundreds of tiny protrusions, which can re-segment and superimpose the laser beam to make the uniformity of the laser beam meet the requirements. In some other embodiments, the illumination component 110 can also be a light source such as a light-emitting diode or an ultra-high pressure mercury bulb; the beam homogenizing device 113 can also be a convex lens array or a conical beam homogenizing device 113 such as a solid conical light guide rod.

[0028] In some embodiments, the projection system 100 may further include an optical-mechanical relay system 160, which is disposed in the optical path between the illumination component 110 and the beam splitter 120, for relaying the illumination light emitted from the illumination component 110 to the beam splitter 120. The optical-mechanical relay system 160 may include one or more lenses. When the optical-mechanical relay system 160 includes multiple lenses, the multiple lenses may be sequentially disposed in the optical path between the illumination component 110 and the beam splitter 120.

[0029] In some embodiments, the reflecting component 140 may include a quarter-wave plate 141 and a reflector 142, which are sequentially disposed in the second output optical path of the beam splitter 120. The quarter-wave plate 141, also known as a phase retarder, can change the polarization state of light. Utilizing the reflection effect of the reflector 142, the second polarized light emitted from the beam splitter 120 can pass through the quarter-wave plate 141 twice, thereby changing the polarization state of the second polarized light to form a third polarized light, and the third polarized light can return to the beam splitter 120.

[0030] In some embodiments, the premodulation component 130 may include a premodulation spatial light modulator 131, which may be an LCOS (Liquid Crystal on Silicon) spatial light modulator. This modulator can be used to premodulate the first polarized light to form premodulated light and directly reflect the premodulated light back to the beam splitter 120. This eliminates the need for other optical elements to guide the premodulated light to the beam splitter 120, resulting in a simpler optical path system and lower device costs. Furthermore, the LCOS spatial light modulator uses reflective technology, which does not significantly reduce light utilization due to light penetration through the panel. Therefore, it has high light utilization and can produce high display brightness. Moreover, the premodulation spatial light modulator 131 can be a common LCOS spatial light modulator, which can effectively reduce control difficulty and equipment costs.

[0031] In this embodiment, the premodulation component 130 may further include a polarizer 132, which is disposed in the optical path between the beam splitter 120 and the premodulation spatial light modulator 131, and is used to analyze the polarization of the light beam incident on the premodulation spatial light modulator 131 to ensure that the incident light beam is polarized light.

[0032] In some embodiments, the main modulation component 150 may include a main spatial light modulator 151, which may be a non-polarized spatial light modulator such as a DMD (Digital Micromirror Device). DMDs have high reliability and are suitable for high-brightness projection systems.

[0033] In this embodiment, the main modulation component 150 may further include a TIR prism 152 and a projection lens (not shown in the figure). The TIR prism 152 and the projection lens are sequentially disposed on the outgoing light path of the main spatial light modulator 151. The main modulation component 150 is used to modulate the pre-modulated light and the third polarized light to form image light. The image light is projected after passing through the TIR prism 152 and the projection lens.

[0034] The projection system 100 also includes a pre-imaging lens group 170, which is disposed in the optical path between the beam splitter 120 and the main modulation component 150, and the optical axis of the pre-imaging lens group 170 can be parallel to the third output optical path of the beam splitter 120. The pre-imaging lens group 170 is used to pre-image the pre-modulated light and the third polarized light emitted from the beam splitter 120 into the main spatial light modulator 151. The pre-imaging lens group 170 may include one or more pre-imaging lenses, and the multiple pre-imaging lenses can be sequentially disposed in the optical path between the beam splitter 120 and the main modulation component 150.

[0035] In some embodiments, the illumination component 110 has an end light-emitting surface 116, through which the illumination light is emitted to the beam splitter 120. The optical path from the end light-emitting surface 116 to the pre-modulation component 130 and the optical path from the end light-emitting surface 116 to the reflection component 140 have equivalent optical paths and optical paths, that is, the optical path from the end light-emitting surface 116 to the pre-modulation component 130 and the optical path from the end light-emitting surface 116 to the reflection component 140 have the same optical path, so that the pre-modulated light and the third polarized light have small aberrations after combining, and the device cost can be saved.

[0036] The term "end-emitting surface 116" refers to the optical surface located at the very end of the optical path of the illumination assembly 110. For example, if the homogenizing device 113 is located at the very end of the optical path of the illumination assembly 110, then the end-emitting surface 116 is the emitting surface of the homogenizing device 113. The optical path from the end-emitting surface 116 to the pre-modulation assembly 130 refers to the optical path from the end-emitting surface 116 to the pre-modulation spatial light modulator 131, and the optical path from the end-emitting surface 116 to the reflection assembly 140 refers to the optical path from the end-emitting surface 116 to the reflector 142.

[0037] Please refer to the following: Figure 2 and Figure 3 In some embodiments, the projection system 100 may further include a polarization state adjustment component 180, which is disposed in the optical path between the illumination component 110 and the beam splitter 120. The illumination light emitted by the illumination component 110 is a uniform beam containing all polarization states (including the polarization states corresponding to the first polarized light and the second polarized light). The polarization state adjustment component 180 is used to adjust the ratio of the first polarized light and the second polarized light in the illumination light.

[0038] The ratio of the first polarized light to the second polarized light in the illumination light can be adjusted within the range of 1:0 to 0:1. For example, the ratio of the first polarized light to the second polarized light is 1:0, meaning the proportion of the first polarized light in the illumination light is 100%, and the proportion of the second polarized light is 0%. In this case, the projection system 100 is in modulated light field mode (see details). Figure 2 All beams are reflected by the beam splitter 120 and enter the pre-modulated spatial light modulator 131 for light field pre-modulation. Therefore, the modulated light field mode can greatly improve the optical contrast and display effect of the final projection system 100.

[0039] When the ratio of the first polarized light to the second polarized light is 0:1, that is, the proportion of the first polarized light in the illumination light is 0% and the proportion of the second polarized light is 100%, the projection system 100 is in the substrate light field mode (see details). Figure 3 All beams are transmitted through beam splitter 120, enter quarter-wave plate 141 and mirror 142 and return to beam splitter 120, and are reflected by beam splitter 120 to main spatial light modulator 151 for modulation and imaging. Since the beams do not enter pre-modulated spatial light modulator 131 for pre-modulation, the substrate light field mode has high optical efficiency.

[0040] When the ratio of the first polarized light to the second polarized light is greater than 0:1 and less than 1:0, for example, when the ratio is 0.3:0.7, 0.5:0.5, or 0.8:0.2, the illumination light incident on the beam splitter 120 includes both the first and second polarized light, and the projection system 100 is in a combined light field mode (see details). Figure 1The first polarized light is reflected by the beam splitter 120 and enters the pre-modulated spatial light modulator 131 to pre-modulate the light field and form pre-modulated light. The second polarized light is transmitted through the beam splitter 120, enters the quarter-wave plate 141 and the reflector 142 to form the third polarized light, and then returns to the beam splitter 120. For details, please refer to the section on... Figure 1 The illustrated embodiment is described below. The integrated light field mode combines the advantages of the modulated light field mode and the substrate light field mode, achieving high display contrast and high luminous efficiency, thus compensating for the insufficient brightness of the projection system 100.

[0041] In this embodiment, the polarization state adjustment component 180 can adjust the ratio of the first polarized light and the second polarized light in the illumination light, so that the projection system 100 can be adjusted between different light effects and contrasts to meet different user needs and obtain a better visual experience. At the same time, the combined light path of the modulated light field mode and the substrate light field mode is simple and the light path cost is relatively small.

[0042] In some embodiments, the polarization state adjustment component 180 is used to selectively transmit or eliminate the first polarized light in the illumination light to achieve switching display of HDR (High-Dynamic Range) or SDR (Standard Dynamic Range).

[0043] Specifically, when the polarization state adjustment component 180 transmits the first polarized light in the illumination light, at least a portion of the illumination light enters the pre-modulated spatial light modulator 131 for light field pre-modulation, and then enters the main spatial light modulator 151 for imaging modulation. After modulation by these two stages of spatial light modulators, HDR display can be achieved, meeting the requirements for high contrast. Furthermore, when the polarization state adjustment component 180 transmits the first polarized light in the illumination light, the illumination light may or may not include second polarized light, as long as light can undergo two stages of modulation by the pre-modulated spatial light modulator 131 and the main spatial light modulator 151.

[0044] When the polarization state adjustment component 180 is used to eliminate the first polarized light in the illumination light, the ratio of the first polarized light to the second polarized light in the illumination light is 0:1. All beams are transmitted through the beam splitter 120, enter the quarter-wave plate 141 and the reflector 142, and return to the beam splitter 120. The beam splitter 120 reflects the beams to the main spatial light modulator 151 for modulation and imaging. This is equivalent to the beams being modulated by only one spatial light modulator, which can realize SDR display and is suitable for playing SDR sources.

[0045] In some embodiments, the projection system 100 further includes a data processor, which is signal-connected to the polarization state adjustment component 180, for receiving video data and controlling the polarization state adjustment component 180 to adjust the ratio of the first polarized light and the second polarized light in the illumination light according to the video data.

[0046] The data processor can also be connected to the laser light source 111, the pre-modulated spatial light modulator 131 and the main spatial light modulator 151 for video data control of the laser light source 111, the pre-modulated spatial light modulator 131 and the main spatial light modulator 151.

[0047] The data processor can be an FPGA (Field Programmable Gate Array) or other controllers with video signal processing capabilities. The video signal can be SDR or HDR video data. HDR video data can be original HDR source data or data specially fabricated for the HDR display module. After acquiring the video data, the FPGA determines whether it is SDR or HDR video data. If the video data is original HDR source data, it calculates the brightness of each frame based on the relationship between the light source characteristics, illumination light diffusion characteristics, and spatial light modulator of the projection system 100. The calculated brightness, pre-modulated spatial light modulator control signal, and main spatial light modulator control signal are then output by the FPGA. Finally, the FPGA outputs the brightness signal to the laser light source 111, selects the polarization ratio adjustment signal for the HDR optical path, outputs it to the polarization state adjustment component 180 to transmit the first polarized light in the illumination light, outputs the pre-modulated spatial light modulator control signal to the pre-modulated spatial light modulator 131, and outputs the main spatial light modulator control signal to the main spatial light modulator 151. If the video data is HDR formatting data, the formatting data is directly separated into individual signals and then output to the corresponding modules in sequence. Of course, the polarization ratio adjustment signal is the same as that of the original HDR source material, which selects the HDR optical path.

[0048] If the video data is SDR data, the FPGA calculates the light source brightness and the main spatial light modulator control signal based on the light source characteristics, and then outputs them to the laser light source 111 and the main spatial light modulator 151 respectively. The FPGA also selects the polarization ratio adjustment signal for the SDR optical path and outputs it to the polarization state adjustment component 180. The polarization state adjustment component 180 eliminates the first polarization in the illumination light, ensuring that the beam does not pass through the pre-modulated spatial light modulator 131, but is modulated only by the main spatial light modulator 151. Because it does not require multiple stages of spatial light modulators, its brightness is greatly improved.

[0049] In some embodiments, the polarization state adjustment component 180 may include a polarizer 181 and a polarization state controller 182, which are sequentially disposed in the outgoing light path of the illumination component 110. Specifically, the polarizer 181 and the polarization state controller 182 may be sequentially disposed in the optical path between the homogenizing device 113 and the optomechanical relay system 160. The polarizer 181 is used to convert the illumination light into polarized light, and the polarization state controller 182 is used to adjust the polarization direction of the polarized light, thereby adjusting the ratio of the first polarized light and the second polarized light in the illumination light. Through the cooperation of the polarizer 181 and the polarization state controller 182, the ratio of the first polarized light and the second polarized light in the illumination light can be adjusted accurately and conveniently.

[0050] In this embodiment, the polarizer 181 can be a polarizer, a Nicol prism, etc. After the illumination light passes through the polarizer 181 for polarization conversion, it is emitted as polarized light in a certain polarization state. The polarization state controller 182 can be an electro-optic polarization state controller, such as a ferroelectric liquid crystal polarization controller. Utilizing the fast response characteristics of ferroelectric liquid crystal materials, the switching of polarized light between two polarization states can be quickly achieved by switching the level signal.

[0051] In some other embodiments, the polarization state adjustment component 180 can also be a waveplate-type polarization controller. The waveplate-type polarization controller includes a linear polarizer, a quarter-wave plate, and a half-wave plate, which are sequentially arranged in the output light path of the illumination component 110. The linear polarizer 181 is used to polarize the illumination light to form linearly polarized light. By rotating the quarter-wave plate and the half-wave plate with a motor, their fast axis can be rotated at any angle relative to the vibration direction of the linearly polarized light, thereby obtaining any desired polarization state and realizing the ratio adjustment of the first polarized light and the second polarized light in the illumination light.

[0052] Please combine Figure 4As shown, in some other embodiments, the polarization state adjustment component 180 may also include a polarizer 183 and a driver (not shown in the figure). The polarizer 183 may be a strip polarizer. The polarizer 183 includes a first polarization part 1831 and a second polarization part 1832. The first polarization part 1831 and the second polarization part 1832 are arranged sequentially along a direction perpendicular to the optical axis of the illumination component 110. The first polarization part 1831 is used to polarize the illumination light to form first polarized light, such as P-polarized light. The second polarization part 1832 is used to polarize the illumination light to form second polarized light, such as S-polarized light. The driver is used to drive the polarizer 183 to move so as to selectively move the first polarization part 1831 or the second polarization part 1832 to the outgoing light path of the illumination component 110. When the first polarization unit 1831 moves into the optical path of the illumination light, the second polarization unit 1832 is located outside the optical path of the illumination light, and the first polarization unit 1831 can convert the illumination light into first polarized light; when the second polarization unit 1832 moves into the optical path of the illumination light, the first polarization unit 1831 is located outside the optical path of the illumination light, and the second polarization unit 1832 can switch the illumination light into second polarized light, thereby achieving the same polarization state switching of the illumination light.

[0053] In some embodiments, the projection system 100 may further include an optical path circulation device for collecting the light beam as an optical loop and reflecting it back to the pre-modulated spatial light modulator 131 to provide illumination light when the pre-modulated spatial light modulator 131 is in the OFF state, thereby achieving the purpose of reusing the originally unused illumination light and realizing energy saving.

[0054] In some embodiments, the pre-modulated spatial light modulator 131 is a liquid crystal spatial light modulator such as LCOS or LCD (Liquid Crystal Display). The polarization state adjustment component 180 is used to adjust the ratio of the first polarized light and the second polarized light in the illumination light to 0:1 within the response time of the liquid crystal spatial light modulator, so that the projection system 100 can be switched to the substrate light field mode to continue imaging within the response time of the liquid crystal spatial light modulator, which is beneficial to improving the time utilization rate and light energy utilization rate of the illumination component 110.

[0055] In a liquid crystal spatial light modulator, each pixel is composed of a liquid crystal. The light beam displays an image by switching between the "transparent state" and "blocked state" of the liquid crystal. The time it takes for the liquid crystal to switch from the transparent state to the blocked state (or from the blocked state to the transparent state) is the response time of the liquid crystal spatial light modulator.

[0056] about Figure 2 and Figure 3Other optical components of the projection system 100 in the illustrated embodiment, such as the illumination assembly 110, beam splitter 120, pre-modulation assembly 130, reflection assembly 140, and main modulation assembly 150, can be found in reference to [other components]. Figure 1 The relevant descriptions of the embodiments shown will not be repeated here.

[0057] The above description is merely a preferred embodiment of this application and is not intended to limit this application in any way. Although this application has been disclosed above with reference to preferred embodiments, it is not intended to limit this application. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this application. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A projection system, characterized in that, include: Lighting components for emitting illumination light; A beam splitter is disposed on the output light path of the illumination component. The beam splitter has a first output light path, a second output light path, and a third output light path. The beam splitter is used to split the illumination light into a first polarized light and a second polarized light, and to output the first polarized light through the first output light path and the second polarized light through the second output light path. A pre-modulation component is disposed on the first output light path to pre-modulate the first polarized light to form pre-modulated light and guide the pre-modulated light to the beam splitter, wherein the polarization state of the pre-modulated light is opposite to that of the first polarized light. A reflecting component, disposed on the second light-emitting path, is used to convert the polarization state of the second polarized light to form a third polarized light, and guide the third polarized light to the beam-splitting prism, wherein the polarization state of the third polarized light is opposite to that of the second polarized light; and The main modulation component is disposed on the third output optical path. The beam splitter is also used to output the pre-modulated light and the third polarized light through the third output optical path to the main modulation component. The main modulation component is used to modulate the pre-modulated light and the third polarized light.

2. The projection system according to claim 1, characterized in that, The projection system further includes a polarization state adjustment component, which is disposed in the optical path between the illumination component and the beam splitter, and is used to adjust the ratio of the first polarized light and the second polarized light in the illumination light.

3. The projection system according to claim 2, characterized in that, The polarization state adjustment component includes a polarizer and a polarization state controller. The polarizer and the polarization state controller are sequentially disposed in the output light path of the illumination component. The polarizer is used to convert the illumination light into polarized light, and the polarization state controller is used to adjust the polarization direction of the polarized light.

4. The projection system according to claim 3, characterized in that, The polarization state controller is a ferroelectric liquid crystal polarization controller.

5. The projection system according to claim 2, characterized in that, The polarization state adjustment component includes a polarizer and a driver. The polarizer includes a first polarization section and a second polarization section. The driver is used to selectively move the first polarization section or the second polarization section to the outgoing light path of the illumination component. The first polarization section is used to polarize the illumination light to form first polarized light, and the second polarization section is used to polarize the illumination light to form second polarized light.

6. The projection system according to claim 2, characterized in that, The ratio of the first polarized light to the second polarized light in the illumination light is adjustable within the range of 1:0 to 0:

1.

7. The projection system according to claim 6, characterized in that, The pre-modulation component includes a pre-modulation spatial light modulator, which is a liquid crystal spatial light modulator. The polarization state adjustment component is used to adjust the ratio of the first polarized light and the second polarized light in the illumination light to 0:1 within the response time of the liquid crystal spatial light modulator.

8. The projection system according to claim 2, characterized in that, The polarization state adjustment component is used to selectively transmit or eliminate the first polarized light in the illumination light.

9. The projection system according to claim 2, characterized in that, The projection system further includes a data processor, which receives video data and controls the polarization state adjustment component to adjust the ratio of the first polarized light and the second polarized light in the illumination light based on the video data.

10. The projection system according to claim 1, characterized in that, The lighting component has an end light-emitting surface, and the optical path from the end light-emitting surface to the pre-modulation component has an equivalent optical path and optical path length to the optical path from the end light-emitting surface to the reflection component.

11. The projection system according to any one of claims 1-10, characterized in that, The reflective component includes a quarter-wave plate and a reflector, which are sequentially disposed on the second light-emitting path.

12. The projection system according to any one of claims 1-10, characterized in that, The premodulation component includes a premodulation spatial light modulator, which is an LCOS spatial light modulator.

13. The projection system according to any one of claims 1-10, characterized in that, The illumination assembly includes a laser source, an optical scattering device, and a light homogenizing device. The optical scattering device and the light homogenizing device are sequentially disposed in the output light path of the laser source. The laser source is used to emit laser light as the illumination light. The illumination light passes through the optical scattering device and the light homogenizing device and then enters the beam splitter.

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