A projection system

Abstract

The application discloses a projection system, which comprises a light source assembly, a dispersion light splitting device, a first liquid crystal modulator, a second liquid crystal modulator and a light combination assembly. The light source assembly is used for generating a first illumination light and a second illumination light. The first illumination light is light of one color of three primary colors, and the second illumination light is composed of light of other colors of the three primary colors. The dispersion light splitting device is used for splitting the second illumination light into a first sub-illumination light and a second sub-illumination light. The first liquid crystal modulator is used for receiving and modulating the first illumination light to generate a first image light. The second liquid crystal modulator is used for generating a second image light by modulating the first sub-illumination light and the second sub-illumination light. The light combination assembly is used for combining the first image light and the second image light to generate an image light. A projection lens is arranged on an outgoing light path of the light combination assembly and is used for projecting the image light. In the above manner, the application can improve the system efficiency and the total output lumens.

Description

Technical Field

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

[0002] To achieve projection display, a projection scheme based on a liquid crystal display (LCD) panel can be adopted. LCD panel-based projection schemes include projection display using a single LCD or projection display using three LCDs, but they have problems such as large heat load, low system efficiency, or low light output lumens. Summary of the Invention

[0003] This application provides a projection system that can improve system efficiency and total output lumens.

[0004] To solve the above-mentioned technical problems, the technical solution adopted in this application is as follows: A projection system is provided, comprising: a light source assembly, a dispersion beam splitter, a first liquid crystal modulator, a second liquid crystal modulator, and a light combining assembly. The light source assembly generates a first illumination light and a second illumination light. The first illumination light is light of one of the three primary colors, and the second illumination light is light synthesized from other colors of the three primary colors. The dispersion beam splitter is disposed in the output light path of the light source assembly and is used to split the second illumination light into a first sub-illumination light and a second sub-illumination light. The first liquid crystal modulator receives the first illumination light and modulates it to generate a first image light. The second liquid crystal modulator combines the first sub-illumination light and the second sub-illumination light to generate a second image light. The light combining assembly is disposed in the output light path of the first and second liquid crystal modulators and is used to combine the first image light and the second image light to generate an image light. A projection lens is disposed in the output light path of the light combining assembly and is used to project the image light.

[0005] The beneficial effects of this application through the above solution are as follows: The projection system provided by this application includes: a light source assembly, a dispersion beam splitter, two liquid crystal modulators, and a light combining assembly. The light source assembly generates a first illumination light and a second illumination light. The first illumination light contains light of one of the three primary colors, and the second illumination light contains light of other colors among the three primary colors. The first illumination light enters the first liquid crystal modulator to be modulated to generate a first image light. The second illumination light is split into a first sub-illumination light and a second sub-illumination light by the dispersion beam splitter. The first sub-illumination light and the second sub-illumination light enter the second liquid crystal modulator and are modulated into a second image light. The first image light and the second image light pass through the light combining assembly... The image light is obtained by combining the horizontal beams in the projection space. This image light is then projected onto a projection screen or projection wall through a projection lens to achieve projection display. Because two liquid crystal modulators are used, the overall size is smaller compared to 3LCD projection systems, as fewer liquid crystal modulators are used. In addition, compared to single-LCD projection systems, the increased number of liquid crystal modulators that bear the heat load improves the problems of low light efficiency and high heat load on a single liquid crystal modulator. Moreover, since it is a combination of two beams, the light spot is more uniform compared to the combination of three beams. Furthermore, the use of a dispersive beam splitter before beam combining maximizes the utilization of the spectrum, which helps to improve system efficiency and total output lumens. Attached Figure Description

[0006] 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 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. Wherein:

[0007] Figure 1 This is a schematic diagram of the structure of the first embodiment of the projection system provided in this application;

[0008] Figure 2 This is a schematic diagram of the structure of the second embodiment of the projection system provided in this application;

[0009] Figure 3(a) is a schematic diagram of the structure of the first display panel provided in this application;

[0010] Figure 3(b) is a schematic diagram of the structure of the second display panel provided in this application;

[0011] Figure 4 This is a schematic diagram of the spectral dispersion principle of the prism film provided in this application;

[0012] Figure 5 This is a schematic diagram illustrating the fabrication of the prism film provided in this application;

[0013] Figure 6This is a graph showing the relationship between the tilt angle of the prism film and the beam deflection angle provided in this application;

[0014] Figure 7 This is a graph showing the relationship between the tilt angle of the prism film and the required number of prism film layers when red light is deflected by 4 degrees, as provided in this application.

[0015] Figure 8 This is a graph showing the relationship between the pitch size and the diffraction angle distance provided in this application;

[0016] Figure 9 This is a schematic diagram of the third embodiment of the projection system provided in this application;

[0017] Figure 10 This is a schematic diagram of the structure of the light source assembly provided in this application;

[0018] Figure 11(a) is a schematic diagram of the structure of the light source assembly and light collection device provided in this application;

[0019] Figure 11(b) is a schematic diagram of the structure of the shaping device provided in this application;

[0020] Figure 12 This is a schematic diagram of the fourth embodiment of the projection system provided in this application;

[0021] Figure 13 This is a schematic diagram of the fifth embodiment of the projection system provided in this application;

[0022] Figure 14 This is a schematic diagram of the sixth embodiment of the projection system provided in this application;

[0023] Figure 15 This is a schematic diagram of the structure of the seventh embodiment of the projection system provided in this application;

[0024] Figure 16 This is a schematic diagram of the structure of the eighth embodiment of the projection system provided in this application;

[0025] Figure 17 This is a schematic diagram of the structure of the ninth embodiment of the projection system provided in this application;

[0026] Figure 18 This is a schematic diagram of the tenth embodiment of the projection system provided in this application;

[0027] Figure 19 This is a schematic diagram of the eleventh embodiment of the projection system provided in this application;

[0028] Figure 20 This is a schematic diagram of the structure of the twelfth embodiment of the projection system provided in this application;

[0029] Figure 21 This is a schematic diagram of the structure of the thirteenth embodiment of the projection system provided in this application;

[0030] Figure 22 This is a schematic diagram of the fourteenth embodiment of the projection system provided in this application;

[0031] Figure 23 This is a schematic diagram of the fifteenth embodiment of the projection system provided in this application. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0033] Because projection systems based on reflective digital micromirror devices (DMDs) and liquid crystal on silicon (LCoS) employ reflective optical paths, their optical paths are complex, resulting in larger overall sizes and higher costs. Therefore, LCD-based projection systems are more commonly used. LCD panels are manufactured using two processes: Low Temperature Poly-Silicon (LTPS) and High Temperature Poly-Silicon (HTPS). HTPS offers higher precision but requires more sophisticated manufacturing processes, leading to higher costs. Therefore, LTPS is typically used, as it offers lower costs but lower precision and larger pixel sizes (usually above 25μm).

[0034] Although single-LCD projection systems are slightly smaller than DMD-based and LCoS-based projection systems, they suffer from low efficiency and high heat load due to the presence of color filters and polarizers on the display panel. To address these issues, a 3LTPS-LCD projection architecture has been proposed, which minimizes the heat load on the display panel and increases the system's maximum output lumens. However, the system's size is relatively large because it requires three separate illumination channels. Furthermore, the need to combine the light from the three display panels, with the three illumination beams originating from different optical systems, leads to uneven illumination. The problems of projection systems based on single LCDs and 3LTPS-LCDs are addressed by using a projection architecture based on 2LTPS-LCDs. This architecture solves the problems of low efficiency and high heat load on the panel that exist in single LCD projection architectures. It is also smaller in size and has a more uniform light spot than the 3LTPS-LCD projection architecture. However, in this solution, the LCD in the dual-color light path still needs to pass through a color filter, which results in a large heat load. Moreover, while using a beam splitter in conjunction with a microlens array to improve the efficiency of illumination light passing through the LCD panel, the inconsistent dispersion angles of red, green, and blue light lead to excessive spectral loss between red and green light during beam splitting, and the spectral gap between green and blue light is not fully utilized, ultimately resulting in low system efficiency and low output lumens.

[0035] Based on the problems existing in the current solution, this application provides an improved solution: using a two-panel LCD, one color of light is split to the other panel. This not only maximizes the utilization of the spectrum when using a dispersive beam splitter, but also reduces the burden on the panel, improves system efficiency and total output lumens. The solution is described in detail below.

[0036] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of the first embodiment of the projection system provided in this application. The projection system includes: a light source assembly 101, a first liquid crystal modulator 102, a second liquid crystal modulator 103, a light combining assembly 104, a projection lens 105, and a dispersion beam splitter 121.

[0037] The light source assembly 101 is used to generate illumination light. The light source assembly 101 can be a light-emitting diode (LED), a laser phosphor light source, or a pure laser light source. Specifically, the illumination light includes a first illumination light and a second illumination light. The first illumination light is light of one of the three primary colors, and the second illumination light is light synthesized from the other colors of the three primary colors. The light source assembly 101 illuminates the first liquid crystal modulator 102 and the second liquid crystal modulator 103 using a non-imaging illumination method.

[0038] Furthermore, the first illumination light can be blue light, and the second illumination light can be yellow light. Yellow light can be obtained by exciting yellow phosphor with blue light or by combining red and green light sources; or the first illumination light can be red light, and the second illumination light can be cyan light, which can be obtained by exciting green phosphor with blue light or by combining blue and green light sources; or the first illumination light can be green light, and the second illumination light can be magenta light, which can be obtained by exciting red phosphor with blue light or by combining blue and red light sources.

[0039] The dispersive beam splitter 121 is disposed on the output light path of the light source assembly 101. The dispersive beam splitter 121 is used to split the second illumination light into a first sub-illumination light and a second sub-illumination light. Specifically, the dispersive beam splitter 121 can be a prism film, which can be a single-layer structure or a multi-layer structure. The first sub-illumination light and the second sub-illumination light can be red light and green light, or blue light and green light, or green light and blue light, respectively.

[0040] A first liquid crystal modulator 102 is disposed in the outgoing light path of the light source assembly 101, and is used to receive and modulate the first illumination light to generate the first image light. A second liquid crystal modulator 103 is disposed in the outgoing light path of the light source assembly 101, and is used to modulate the first sub-illumination light and the second sub-illumination light to generate the second image light.

[0041] In one specific embodiment, such as Figure 2 As shown, the first liquid crystal modulator 102 includes a first polarizer 21, a first display panel 22, and a first analyzer 23. The first polarizer 21 is disposed in the optical path of the first illumination light and is used to obtain light with a first polarization state from the first illumination light emitted from the light source assembly 101. The first polarization state can be a P polarization state. The first display panel 22 is disposed in the output optical path of the first polarizer 21 and is used to receive the light emitted from the first polarizer 21. The first analyzer 23 is disposed in the output optical path of the first display panel 22 and is used to convert the light emitted from the first display panel 22 into first image light.

[0042] The second liquid crystal modulator 103 includes a second polarizer 31, a second display panel 32, and a second analyzer 33. The second polarizer 31 is disposed in the optical path of the second illumination light and is used to obtain light with a first polarization state from the second illumination light emitted from the light source assembly 101. The second display panel 32 is disposed in the output optical path of the second polarizer 31 and is used to receive the light emitted from the second polarizer 31. The second analyzer 33 is disposed in the output optical path of the second display panel 32 and is used to convert the light emitted from the second display panel 32 into second image light.

[0043] Furthermore, the first display panel 22 and the second display panel 32 are LTPS-LCD panels, such as... Figures 3(a)-3(b)As shown, the first display panel 22 includes a plurality of first pixel units 221, and the second display panel 32 includes a plurality of second pixel units 321, and the number of first pixel units 221 is the same as the number of second pixel units 321. Each second pixel unit 321 includes a first sub-pixel 3211 and a second sub-pixel 3212; for example, the first pixel unit 221 is a blue sub-pixel, the first sub-pixel 3211 is a green sub-pixel, and the second sub-pixel 3212 is a red sub-pixel.

[0044] Understandably, the two LTPS-LCD panels are illuminated by two separate optical paths. When the blue light path is a separate path, the heat load on the first display panel 22 can be reduced, thereby increasing its lifespan. When system efficiency is affected by red light excitation efficiency, red light can be placed in a separate optical path, resulting in greater optical expansion and panel transmittance. When system output lumens are limited by green light, green light can be placed in a separate optical path, maximizing system output efficiency.

[0045] Preferably, due to the limitations of LTPS-LCD process precision, if a certain aperture ratio is required while ensuring high resolution, the display panel (including the first display panel 22 and the second display panel 32) needs to be made relatively large. Typically, the size of a 1080P resolution display panel is 2 inches or 1 inch. If factors such as dispersion or pixels are considered, using imaging for illumination would make the system too bulky. Therefore, in this embodiment, a non-imaging illumination method is used to illuminate the first display panel 22 and the second display panel 32.

[0046] The light combining component 104 is disposed in the output light path of the first liquid crystal modulator 102 and the second liquid crystal modulator 103. It is used to combine the first image light and the second image light to generate image light. Specifically, the light combining component 104 can be a dichroic light combining prism or a polarizing light combining prism.

[0047] The projection lens 105 is disposed on the outgoing light path of the light combining component 104 and is used to project image light; furthermore, the projection lens 105 can use a mobile phone architecture or a field lens architecture.

[0048] The following example, using the dispersive beam splitter 121 as a prism film, illustrates the beam splitting principle.

[0049] The principle of prism film spectral dispersion is as follows: Figure 4 As shown, the dispersive beam splitter 121 includes a first structural layer 71 and a second structural layer 72 disposed on the first structural layer 71. The first structural layer 71 has a periodic structure, and the material of the first structural layer 71 is different from that of the second structural layer 72. Dispersive beam splitting can be achieved through the first structural layer 71 and the second structural layer 72.

[0050] Furthermore, the Abbe number of the first structural layer 71 is less than a preset value, and the Abbe number of the second structural layer 72 is greater than a preset value. That is, the materials of the first structural layer 71 and the second structural layer 72 can be low Abbe number materials and high Abbe number materials, respectively. The preset value can be set according to experience or application needs. The preset wavelength can be the dominant wavelength of green light, that is, the refractive index of the first structural layer 71 and the second structural layer 72 is the same at the dominant wavelength of green light.

[0051] The structure of the prism membrane is as follows Figure 5 As shown, it is a periodic angular structure made of optical adhesive (or glass). The first structural layer 71 can be prepared by photopolymerization molding. Specifically, since the greater the deviation of angle β from 90 degrees, the more stray light is generated after the incident light passes through the prism film, and the lower the system efficiency, the preferred angle β is 90 degrees. However, considering the draft angle, the angle β can be slightly less than 90 degrees. The selection of the tilt angle α is related to the light deflection capability of the prism film, and its effect on the deflection of red light is as follows: Figure 6 As shown, it can be seen that the larger the tilt angle of the prism film, the larger the deflection angle of the light beam.

[0052] After obtaining the angular periodic structure made of the first structural layer 71, the angular periodic structure is filled in with the second structural layer 72 to obtain the desired result. Figure 5 The prism film shown. Since green light experiences the same refractive index when passing through the first structural layer 71 and the second structural layer 72, no beam deflection occurs. However, for red and blue light, the refractive indices of the first structural layer 71 and the second structural layer 72 are different, and due to the presence of the periodic prism structure, the beam is deflected to a certain extent.

[0053] Furthermore, to increase the deflection angles of red and blue light, one could consider increasing the tilt angle of the periodic prism structure or using multiple prism layers. When achieving a 4-degree deflection of red light, the relationship between the tilt angle of the periodic prism structure and the required number of prism layers is as follows: Figure 7 As shown, the larger the tilt angle, the fewer prism film layers are required.

[0054] Furthermore, the pitch size affects the overall thickness of the prism film, its geometric optical efficiency (a larger pitch results in fewer defects at sharp corners and roots), and its diffraction optical efficiency. However, an excessively large pitch can also lead to an overly thick film, material waste, and beam dispersion. Structurally, the prism film can be viewed as a transmission-type blazed grating. The center of its diffraction distribution depends on the direction of the principal ray deflection, its zero-order interference depends on the direction of the incident light, and its diffraction model is multi-slit Fraunhofer diffraction. Its diffraction distribution formula is:

[0055] I = I0 × (sinα / α) 2

[0056] Where α=π×a×θ x / 2, a is the seam width, θ x The diffraction angle is α = 0 (i.e., θ). x At point (=0), there exists a principal order large value, and the center of this zero-order diffraction spot is the geometric optical image point.

[0057] Multislit diffraction is the result of the combined effects of diffraction and interference. The angle of its interference order can be calculated by the following formula:

[0058] d×sinθ=m×λ

[0059] Where m = 0, ±1, ±2, ...

[0060] Since a = d in the prism film, the angular distance of each interference order can be approximated by θ = mλ / a. The relationship between the pitch of two adjacent prisms in the prism film and the diffraction angular distance is as follows: Figure 8 As shown, when the pitch is too small, the angular distance of each interference order is 0.6°; light of a specific wavelength has a specific deflection angle after passing through the prism film, and two interference orders show high energy distribution, and the two angles differ greatly (even more than the light deflection angle), which causes many angles to exceed the collection range, resulting in wasted efficiency.

[0061] If a pure laser is chosen as the light source, the pitch and deflection angle can be optimized to ensure that the interference order coincides with the 0th order of the diffraction distribution, maximizing energy utilization. If a broadband light source (such as LEDs and laser fluorescence) is chosen, a larger pitch is required to reduce the angle between orders and narrow the diffraction distribution. Alternatively, the light deflection angle of each prism film can be appropriately increased to reduce the proportion of diffraction, thus minimizing the dilution of the spread.

[0062] Understandably, the master mold for the prism film can be directly fabricated using methods such as laser direct writing or precision lathe machining. If the demand is large, a large-area thin mold can also be fabricated, and then the structure can be replicated using a roll-to-roll method to facilitate the large-area fabrication of the prism film.

[0063] In another embodiment, see reference Figure 1 , Figure 2As shown in Figure 3(b), in order to improve the efficiency of the second illumination light passing through the second liquid crystal modulator 103, a second microlens array (not shown in the figure) can also be set in the dual-color light path to cooperate with the dispersive beam splitter 121. Specifically, the second liquid crystal modulator 103 also includes a second microlens array that is attached to the second display panel 32. The second microlens array is set in the outgoing light path of the dispersive beam splitter 121, that is, the second microlens array is set on the side surface of the second display panel 32 facing the dispersive beam splitter 121. The second microlens array is used to process the first sub-illumination light and the second sub-illumination light (e.g., collect or homogenize the light) and project them into the corresponding second pixel unit 321.

[0064] Continue reading Figure 1 The illumination light is divided into two paths: a monochromatic path (which can be one of the colors R, G, or B) and a dual-color path (containing two other colors different from the monochromatic path). In the dual-color path, the second illumination light, after being polarized and collimated, passes through a dispersive beam splitter 121, which separates the two colors of the second illumination light into illumination spots that are angularly separated but overlap on the surface. After passing through the second microlens array in front of the second display panel 32, the second illumination light allows light at different angles to pass through their respective pixels. The image light emitted from the two display panels passes through corresponding analyzers to filter out the image information, and then is combined by the light combining assembly 104 before being projected onto the screen by the projection lens 105.

[0065] In other embodiments, since the use of a second microlens array in the dual-color optical path dilutes the system's spread, the monochromatic optical path will have a surplus of spread. To further improve the system's efficiency, transmittance, and display panel reliability, a first microlens array and / or another dispersive beam splitter (not shown in the figure) can be added to the monochromatic optical path; specifically, refer to... Figure 1 , Figure 2 As shown in Figure 3(a), the first liquid crystal modulator 102 also includes a first microlens array bonded to the first display panel 22. The first microlens array is disposed in the outgoing light path of the light source assembly 101, and is used to process the first illumination light and direct it into the corresponding first pixel unit 221, thereby making full use of the system's expansion capacity. Alternatively, the first microlens array and the second microlens array can be respectively disposed in the monochromatic light path and the dual-color light path to collect the illumination light.

[0066] Understandably, in addition to using the dispersive beam splitter 121, dispersive beam splitting can also be achieved using geometric or diffractive methods.

[0067] This embodiment proposes a projection architecture based on a 2LTPS-LCD with non-imaging illumination. By using two LTPS-LCDs, it solves the problems of low efficiency and high panel heat load of single LCD projection systems. At the same time, it is smaller in size than a 3LTPS-LCD, achieving a balance between heat load and size, and the light spot is more uniform. Moreover, it can maximize the utilization of the spectrum when using a prism film, reduce the burden on the display panel, and improve system efficiency and total output lumens.

[0068] Please see Figure 9 , Figure 9 This is a schematic diagram of the third embodiment of the projection system provided in this application. The projection system includes: a light source assembly 101, a first liquid crystal modulator 102, a second liquid crystal modulator 103, a light combining assembly 104, a projection lens 105, and a dispersion beam splitter 121.

[0069] The light source assembly 101 is used to generate illumination light, which includes a first illumination light and a second illumination light. Specifically, the light source assembly 101 includes a first light-emitting component 1011 and a second light-emitting component 1012. The first light-emitting component 1011 is used to generate the first illumination light, which is light of one of the three primary colors. The second light-emitting component 1012 is used to generate the second illumination light, which is synthesized from light of other colors among the three primary colors.

[0070] Furthermore, the first light-emitting component 1011 is a monochrome LED, and the second light-emitting component 1012 is a dual-color LED, such as a yellow LED, a cyan LED, a magenta LED, or two colors of light source closely spaced. In this embodiment, the first light-emitting component 1011 is a blue LED, and the second light-emitting component 1012 is a yellow LED.

[0071] In another embodiment, the light source assembly 101 can also be replaced with a reflective laser fluorescent light source, that is, the first illumination light is a blue laser, the first light-emitting assembly 1011 is a blue laser, which is used to generate blue laser; the second illumination light is a received laser, the second light-emitting assembly 1012 is a color wheel, a fixed phosphor sheet or an LED with phosphor coating on its surface, and the second light-emitting assembly 1012 is used to receive blue laser and generate received laser, which includes yellow light, cyan light or magenta light.

[0072] In other embodiments, the light source assembly 101 can also be replaced with a transmission-type laser fluorescence light source, such as... Figure 10 As shown, the light source assembly 101 includes a blue laser 41, a first homogenizing assembly 42, an imaging lens 43, and a second wavelength conversion device 44.

[0073] Blue laser 41 is used to generate blue laser light, i.e., the first illumination light is blue laser light. A first homogenizing component 42 is disposed in the output optical path of the blue laser 41, and is used to homogenize the blue laser light. An imaging lens 43 is disposed in the output optical path of the first homogenizing component 42, and is used to image the blue laser light output by the first homogenizing component 42 onto the second wavelength conversion device 44, so that the second wavelength conversion device 44 generates the second illumination light.

[0074] Furthermore, the blue laser emitted by the blue laser 41 is first homogenized by the first homogenizing component 42, and then the imaging lens 43 images the uniform rectangular light spot onto the second wavelength conversion device 44.

[0075] In another specific embodiment, such as Figure 9 As shown, the projection system also includes a light collection device (not shown in the figure). The light collection device is disposed on the output light path of the light source assembly 101 and is used to collect the illumination light and direct it into the first liquid crystal modulator 102 and the second liquid crystal modulator 103. Specifically, the light collection device includes a second light homogenizing component and a lens assembly (not shown in the figure) disposed along the transmission direction of the illumination light. The second light homogenizing component is used to homogenize the illumination light, and the lens assembly is used to collimate the illumination light emitted by the second light homogenizing component.

[0076] In one implementation, such as Figure 9 As shown, there are two light collection devices, referred to as the first light collection device and the second light collection device, respectively. The second light homogenizing assembly includes the first light homogenizing device 1061 and the second light homogenizing device 1062, and the lens assembly includes the first lens device 1081 and the second lens device 1082.

[0077] A first light-collecting device is disposed in the output light path of the first light-emitting component 1011. It collects the first illumination light and directs it into the first liquid crystal modulator 102. The device includes a first light-diffusing device 1061 and a first lens device 1081 arranged along the transmission direction of the illumination light. The first lens device 1081 can be a collimating lens or a Fresnel lens. A second light-collecting device is disposed in the output light path of the second light-emitting component 1012. It collects the second illumination light and directs it into the second liquid crystal modulator 103. The device includes a second light-diffusing device 1062 and a second lens device 1082 arranged along the transmission direction of the illumination light. The second lens device 1082 can be a collimating lens or a Fresnel lens. Specifically, the first light-diffusing device 1061 and the second light-diffusing device 1062 can be cones, i.e., the light-collecting device is a cone-and-lens system or a cone-and-Fresnel lens system. The collimating lens can collimate the illumination light, allowing it to smoothly enter the downstream optical elements in the light path. It is understood that in other embodiments of this application, a collimating lens may not be provided, for example, when the illumination light from the upstream optical path satisfies a small divergence angle.

[0078] Furthermore, the smaller end of the cone is the incident surface, and the larger end is the exit surface, so that the illumination light emitted by the light source assembly 101 enters the cone through the incident surface, is reflected by the side wall of the cone, and exits through the exit surface or directly, making the area of ​​the exit light spot larger than the area of ​​the incident light spot, thereby reducing the divergence angle of the beam.

[0079] Understandably, in this embodiment, the cone is a solid conical light guide rod, and the light beam is reflected from the side of the cone by total internal reflection. In other embodiments, the cone may also be a hollow cone composed of a reflector / reflective surface, which will not be elaborated here.

[0080] In another embodiment, the light collection device is a circular collecting lens system, as shown in FIG11(a). The light collection device includes a first collecting lens 51 and a second collecting lens 52. The first collecting lens 51 is disposed on the outgoing light path of the light source assembly 101 and is used to collect the illumination light; the second collecting lens 52 is used to collect the light emitted from the first collecting lens 51.

[0081] Understandably, the light collection device can also be a freeform surface shaping system or a discrete form of the aforementioned collection system; by setting up a light collection device, the uniformity of the illumination light can be ensured, the size of the system can be reduced, and a certain level of efficiency can be guaranteed.

[0082] See also Figures 11(a)-11(b) The projection system also includes a shaping device 53, which is used to shape the illumination light emitted from the second collecting lens 52 so that the light spot emitted from the shaping device 53 is a preset shape, which can be rectangular, and the shaping device 53 can be a polarizing shaping film.

[0083] Furthermore, since the surface distribution of the illumination light emitted from the second collecting lens 52 is circular, while the part of the display panel that needs to be illuminated is rectangular, it is necessary to cut out a rectangle from the circular light spot, as shown in FIG11(b). The shaping device 53 includes a first region 531 and a second region 532. The first region 531 is used to transmit the illumination light emitted from the second collecting lens 52; the second region 532 is used to reflect the illumination light emitted from the second collecting lens 52 to the light source assembly 101. 533 is a circular light spot surface distribution.

[0084] Preferably, the first region 531 is a light circulation film layer, and the second region 532 is a specular reflection film layer. The portion of the circular light spot that does not participate in the illumination of the display panel is reflected back to the corresponding light collection device to perform light circulation. In addition, the first region 531 can also perform polarized light circulation. For example, the first region 531 transmits P-polarized illumination light and reflects S-polarized illumination light to further improve system efficiency.

[0085] In another specific embodiment, the projection system further includes an adjustment component (not shown in the figure), which is disposed in the outgoing light path of the light source component 101 and is used to shape the illumination light and direct it into the first liquid crystal modulator 102 and the second liquid crystal modulator 103.

[0086] Furthermore, the adjustment components include a first adjustment component and a second adjustment component. The first adjustment component is disposed in the light path emitted by the first light-emitting component 1011, and the second adjustment component is disposed in the light path emitted by the second light-emitting component 1012. The first and second adjustment components can be field lenses, lenses, or Fresnel lenses. By adding a field lens, lens, or Fresnel lens between the display panel and the illumination light, telecentric illumination is transformed into non-telecentric illumination, thereby further reducing the difficulty and cost of lens design.

[0087] The first liquid crystal modulator 102 is disposed in the outgoing light path of the light source assembly 101, and is used to receive the first illumination light and modulate it to generate the first image light.

[0088] The second liquid crystal modulator 103 is disposed in the outgoing light path of the light source assembly 101, and is used to receive the second illumination light and modulate it to generate the second image light.

[0089] Furthermore, a light recovery film (not shown in the figure) can be added before the polarizer (including the first polarizer 21 and the second polarizer 31). This light recovery film is a polarized light recovery film. The illumination light in the first polarization state is transmitted through the polarized light recovery film, and the illumination light in the second polarization state is reflected back to the light source assembly 101 for light circulation. The second polarization state can be an S-polarization state.

[0090] A light combining component 104 is disposed in the outgoing light path of the first liquid crystal modulator 102 and the second liquid crystal modulator 103, and is used to combine the first image light and the second image light to generate image light. A projection lens 105 is disposed in the outgoing light path of the light combining component 104, and is used to project the image light.

[0091] Continue reading Figure 9 The projection system also includes a first pixel expansion device 107, which is disposed on the outgoing light path of the light combining component 104 and is used to expand the image light and project it into the projection lens 105.

[0092] Furthermore, the light combining component 104 can be a light combining prism. By placing a first pixel expansion device 107, such as birefringent crystal pixel expansion (E-SHIFT) or expanded pixel resolution (XPR), between the light combining prism and the projection lens 105, the resolution of the display panel can be further improved.

[0093] The working principle of this embodiment will be explained below using the following example: the light combining component 104 is a dichroic light combining prism, the first light-emitting component 1011 is a blue LED, the second light-emitting component 1012 is a yellow LED, and the first lens device 1081 and the second lens device 1082 are collimating lenses. The collimating lens in the blue light path (i.e., the light path where the blue LED is located) is referred to as the first collimating lens; the collimating lens in the yellow light path (i.e., the light path where the yellow LED is located, which can be called the dual-color light path) is referred to as the second collimating lens.

[0094] For the blue light path, the first illumination light emitted by the blue LED is collected by the conical first light homogenizing device 1061, and then collimated into parallel blue light by the first collimating lens. A first polarizer 21 is placed at the exit of the first collimating lens to polarize the parallel blue light. The polarized blue light illuminates the first display panel 22, and then the image light to be displayed is filtered out by the first analyzer 23 to obtain the first image light.

[0095] For Huang Guanglu, combining Figure 3(b) and Figure 9 The second illumination light emitted by the yellow LED is collected by the conical second homogenizing device 1062 and then collimated into parallel yellow light by the second collimating lens. A second polarizer 31 is placed at the exit of the second collimating lens to polarize the parallel yellow light. The polarized yellow light is split into red and green light by the dispersive beam splitter 121. They are separated in angle but overlap on the surface. The green light enters the first sub-pixel 3211 in the second pixel unit 321 and is modulated by the first sub-pixel 3211. The red light enters the second sub-pixel 3212 in the second pixel unit 321 and is modulated by the second sub-pixel 3212. The modulated red light and the modulated green light enter the second analyzer 33. The second analyzer 33 filters out the image information to be displayed to obtain the second image light.

[0096] After the first image light in the blue light path and the second image light in the yellow light path are combined by the dichroic light combining prism, the image light is generated and enters the first pixel expansion device 107 to further improve the display resolution. Finally, the image light emitted from the first pixel expansion device 107 is projected onto the projection screen or projection wall (not shown in the figure) through the projection lens 105.

[0097] In another specific embodiment, such as Figure 12 As shown, Figure 12 This is a schematic diagram of the fourth embodiment of the projection system provided in this application, and... Figure 9 The difference between the embodiments shown is that the projection system in this embodiment also includes a first folding prism 109.

[0098] The first folding prism 109 is disposed in the light path of the first light-emitting component 1011 and is used to adjust the transmission direction of the first illumination light. Specifically, the first folding prism 109 can adjust the transmission direction of the first illumination light from a first direction to a second direction, wherein the first direction and the second direction are perpendicular to each other, for example, the first direction is vertical and the second direction is horizontal. Since it can change the transmission direction of the first illumination light, it can compress the length in the horizontal direction.

[0099] Continue reading Figure 12 The projection system also includes a first hollow conduit 110, which is disposed on the outgoing light path of the first light-emitting component 1011 and is used to transmit the first illumination light to the first folding prism 109 without loss.

[0100] Understandably, the transmission direction of the second illumination light in the dual-color light path can also be adjusted. That is, the first hollow conduit 110 is disposed on the outgoing light path of the second light-emitting component 1012, which is used to transmit the second illumination light to the first folding prism 109; the first folding prism 109 is disposed on the outgoing light path of the first hollow conduit 110, which is used to adjust the transmission direction of the second illumination light.

[0101] Continue reading Figure 12 The projection system also includes a polarization light recovery device 122, which is disposed in the outgoing light path of the first light-emitting component 1011. The polarization light recovery device 122 is used to transmit illumination light with a first polarization state to the first hollow conduit 110 and reflect illumination light with a second polarization state to the first light-emitting component 1011. Specifically, the polarization light recovery device 122 can be an antireflection film (DBEF, dual brightness enhancement film).

[0102] Furthermore, the polarization light recovery device 122 is disposed between the first lens device 1081 and the first hollow conduit 110. The first illumination light emitted from the first light-emitting component 1011 sequentially enters the first homogenizing device 1061, the first lens device 1081, and the polarization light recovery device 122. Part of the light is transmitted through the polarization light recovery device 122 and continues to be emitted in a single polarization state, while the other part of the light is reflected by the polarization light recovery device 122 and returns to the polarization light recovery device 122. It is reflected back and forth within the polarization light recovery device 122 and then emitted through the exit surface of the polarization light recovery device 122, thereby improving the utilization rate of the illumination light. In order to reduce the number of times the recovered illumination light is recovered, a structure such as a quarter-wave plate can be provided in the first homogenizing device 1061 to change the polarization state of the beam.

[0103] In this embodiment, a first folding prism 109 and a first hollow conduit 110 are set in an optical path. The cooperation of the two can change the transmission direction of the illumination light in the optical path, reduce the length of the projection system in a certain direction, and make the system more compact as a whole.

[0104] In another specific embodiment, please refer to Figure 13 , Figure 13 This is a schematic diagram of the fifth embodiment of the projection system provided in this application. This embodiment is similar to... Figure 9 The embodiments shown are similar, except that: in this embodiment, the light source component 101 further includes a third light-emitting component 1013 and a first beam-splitting component 111, and the second light-emitting component 1012 can be an LED light source with phosphor coating on its surface.

[0105] The third light-emitting component 1013 is used to generate blue laser; the first beam splitter 111 is disposed in the output light path of the third light-emitting component 1013, and is used to reflect the blue laser generated by the third light-emitting component 1013 to the second light-emitting component 1012, and transmit the blue laser generated by the second light-emitting component 1012 to the second liquid crystal modulator 103.

[0106] The working principle of this embodiment will be explained below using the example of a blue laser and a yellow phosphor in the first light-emitting component 1011:

[0107] The blue laser emitted from the third light-emitting component 1013 is collected by the third light-collecting device (including the third light-diffusing device 1063 and the third lens device 1083), enters the first beam-splitting component 111, and after reflection by the first beam-splitting component 111 and collection by the second light-collecting device, it is incident on the yellow phosphor, generating yellow fluorescence. The blue laser emitted from the first light-emitting component 1011 is reflected by the light-combining component 104 and enters the second liquid crystal modulator 103, and then after transmission by the first beam-splitting component 111 and collection by the second light-collecting device, it is incident on the yellow phosphor, generating yellow fluorescence. The yellow fluorescence sequentially passes through the second light-collecting device, the first beam-splitting component 111, and the second liquid crystal modulator 103 before entering the light-combining component 104. The subsequent working principle is similar to that of the third embodiment, and will not be described again here.

[0108] In this embodiment, the phosphor in the dual-color optical path is excited from both sides by two blue lights, which helps to improve the excitation efficiency of the laser and thus improve the light efficiency.

[0109] In another specific embodiment, due to Figure 13 The method of adding an extra laser path, as shown, may impose a burden on the volume. Therefore, a two-optical-path, dual-surface excitation architecture is proposed, such as... Figure 14 As shown, Figure 14 This is a schematic diagram of the sixth embodiment of the projection system provided in this application, and... Figure 13The difference between the embodiments shown is that the light source component 101 in this embodiment also includes a second beam splitting component 112 and a third beam splitting component 113, and no third light-emitting component and a first beam splitting component are provided.

[0110] In this embodiment, the first light-emitting component 1011 is a blue laser, and the second light-emitting component 1012 is a white LED coated with yellow phosphor or a fixed phosphor sheet, which can achieve double-sided excitation. On one side, the second light-emitting component 1012 generates white light, and on the other side, the blue laser generated by the first light-emitting component 1011 excites the yellow phosphor to generate yellow light. The first illumination light enters the second beam splitter 112 in an upward direction, and the second illumination light enters the third beam splitter 113 in an upward direction.

[0111] Furthermore, the second beam splitter 112 is disposed in the output light path of the blue laser, and is used to transmit light with the first polarization state in the blue laser to form the first illumination light and enter the first liquid crystal modulator 102. The third beam splitter 113 is disposed in the reflection light path of the second beam splitter 112, and is used to reflect light with the second polarization state in the blue laser to the second light-emitting component 1012, and transmit the laser light generated by the second light-emitting component 1012 to the second liquid crystal modulator 103.

[0112] Continue reading Figure 14 The projection system also includes a second hollow conduit 114, which is disposed on the output light path of the second beam splitter 112. It is used to transmit the light with the second polarization state in the blue laser to the third beam splitter 113, that is, the third beam splitter 113 is disposed on the output light path of the second beam splitter 112.

[0113] The working principle of this embodiment is as follows: Blue light enters the second beam splitter 112 and is split into two paths. One path passes sequentially through the first hollow conduit 110, the first folding prism 109, and the first liquid crystal modulator 102 into the beam combining assembly 104. The other path passes through the second hollow conduit 114 into the third beam splitter 113, where it is reflected onto the yellow phosphor, causing the yellow phosphor to produce yellow fluorescence. This yellow fluorescence enters the third beam splitter 113, is transmitted through it to the second liquid crystal modulator 103, and after modulation by the second liquid crystal modulator 103, enters the beam combining assembly 104. The subsequent working principle is the same as... Figure 9 The embodiments shown operate on a similar principle and will not be described again here.

[0114] In another specific embodiment, a 2LTPS-LCD architecture with a reflective laser phosphor light source can also be used, such as... Figure 15 As shown, Figure 15 This is a structural schematic diagram of the seventh embodiment of the projection system provided in this application, and... Figure 14The difference between the embodiments shown is that in this embodiment, the first illumination light enters the second beam splitter 112 in a downward direction, and the second illumination light enters the third beam splitter 113 in a left-to-right direction.

[0115] The second beam splitter 112 is disposed in the output light path of the blue laser and is used to reflect the light with the first polarization state in the blue laser to form the first illumination light and enter the first liquid crystal modulator 102; the third beam splitter 113 is disposed in the transmission light path of the second beam splitter 112 and is used to transmit the light with the second polarization state in the blue laser to the second light-emitting component 101 and transmit the laser light generated by the second light-emitting component 101 to the second liquid crystal modulator 103.

[0116] Microlens arrays (not shown in the figure) are provided on the first display panel 22 and the second display panel 32, and the first display panel 22 and the second display panel 32 are respectively attached to the first analyzer and the second analyzer (not shown in the figure); or the analyzer may not be attached to the corresponding display panel and may exist independently in the optical path.

[0117] The working principle of this embodiment will be explained below using the following example: the first light-emitting component 1011 is a blue laser; the first folding prism 109 is a right-angle prism; the first wavelength conversion device is a color wheel 61 (with yellow phosphor on the color wheel 61); the second beam-splitting component 112 is a P-polarized and S-polarized prism; the third beam-splitting component 113 is a prism with a blue-reflecting and yellow-transmitting coating (denoted as a blue-reflecting and yellow-transmitting prism); and the beam-combining component 104 is a P-polarized and S-polarized blue light-transmitting and S-polarized blue light-reflecting coating (denoted as a P-polarized and S-polarized prism).

[0118] The polarized blue light (usually P-polarized blue light) emitted by the blue laser passes through the P-transmitting and S-reflecting prism, then enters the second hollow conduit 114, and is reflected by the blue-reflecting and yellow-transmitting prism to the second light collection device. After being collected by the second light collection device, it enters the color wheel 61, exciting the yellow phosphor on the color wheel 61 to emit Lambertian white light. The excited white light is collected by the second light collection device and then split by the blue-reflecting and yellow-transmitting prism to generate yellow light, which enters the first hollow conduit 110 and the right-angle prism in sequence, and then exits from the other side of the right-angle prism. A second polarizer 31 is placed on the exit surface of the right-angle prism. Preferably, a reflective polarizer (not shown in the figure), such as a DBEF, can be placed here to achieve light circulation, thereby improving the polarization efficiency. The polarized yellow light illuminates the second display panel 32.

[0119] The blue light reflected by the blue-reflecting yellow prism enters the P-reflecting S prism after passing through the second hollow conduit 114. The S-component of the blue light (i.e., S-polarized blue light) is reflected and emitted. A first polarizer 21 is placed between the emission surface and the first display panel 22 to perform polarization purification in order to improve the contrast of the system.

[0120] The polarized yellow light is split into red and green light by the dispersive beam splitter 121. The two colors are separated at an angle but overlap on the surface. After passing through the microlens array, the different colors of light fall into their respective pixels. After passing through the second display panel 32, the second illumination light is filtered out by the second analyzer to extract the image information to be displayed.

[0121] The principles of the blue light path and the yellow light path are roughly the same, the difference being that there is no need to set up a dispersive beam splitter 121; after the first illumination light emitted from the first display panel 22 passes through the first analyzer, the image light is filtered out to generate the first image light, which is then combined with the second image light from the yellow light path in the light combining component 104, and finally projected onto the projection screen by the projection lens 105.

[0122] Preferably, a first pixel expansion device 107 can be added between the light combining component 104 and the projection lens 105 to further improve the display resolution.

[0123] Understandably, in this embodiment, the color wheel 61 can also be replaced by a fixed fluorescent sheet 62 (such as...). Figure 16 (as shown) or LEDs with phosphor coating on the surface can be used as alternatives.

[0124] In another specific embodiment, such as Figure 17 As shown, Figure 17 This is a structural schematic diagram of the ninth embodiment of the projection system provided in this application, and... Figure 9 The embodiment shown differs in that the projection system further includes a fourth beam splitter 115, a second folding prism 116, and a third folding prism 117, and the light source assembly 101 is a white light source.

[0125] The fourth beam splitter 115 is disposed on the outgoing light path of the light source assembly 101, and is used to split the illumination light into a first illumination light and a second illumination light.

[0126] The second folding prism 116 is disposed in the optical path of the first illumination light, and is used to adjust the transmission direction of the first illumination light from the first direction to the second direction, and then project it into the first liquid crystal modulator 102.

[0127] The third folding prism 117 is disposed in the optical path of the second illumination light, and is used to adjust the transmission direction of the second illumination light from the second direction to the first direction, and then project it into the second liquid crystal modulator 103.

[0128] Continue reading Figure 17The projection system also includes a polarization light recovery device 122, which is disposed in the outgoing light path of the light source assembly 101. The device transmits illumination light with a first polarization state to the fourth beam splitter 115 and reflects illumination light with a second polarization state back to the light source assembly 101. Specifically, the polarization light recovery device 122 can be a DBEF (Diverterless Optimizer-Defined Optimizer), and it can be disposed between the lens assembly 108 and the fourth beam splitter 115, or between the first polarizer 21 and the second folding prism 116.

[0129] Furthermore, taking the example of a polarization light recovery device 122 positioned between the lens assembly 108 and the fourth beam splitter 115, white light emitted from the white light source sequentially enters the second homogenizing assembly 106, the lens assembly 108, and the polarization light recovery device 122. Part of the light is transmitted through the polarization light recovery device 122 and continues to exit with a single polarization state, while the other part is reflected back into the polarization light recovery device 122, undergoing repeated reflections within it before exiting through its exit surface. This improves the utilization rate of the illumination light. To reduce the number of times the recovered illumination light is recovered, a structure such as a quarter-wave plate can be provided within the second homogenizing assembly 106 to change the polarization state of the beam.

[0130] Continue reading Figure 17 The projection system also includes a third hollow guide tube 118 and a fourth hollow guide tube 119. The third hollow guide tube 118 is disposed on the reflected light path of the fourth beam splitter 115 and is used to transmit light with a second polarization state in the illumination light to the third folding prism 117. The fourth hollow guide tube 119 is disposed on the transmitted light path of the fourth beam splitter 115 and is used to transmit light with a first polarization state in the illumination light to the second folding prism 116.

[0131] The working principle of this embodiment will be explained below using the following example: a white light source is a white LED; the light combining component 104 is a dichroic light combining prism (coated with a blue-transparent, yellow-reflective film); the second light homogenizing component 106 is a conical light homogenizing device; the lens component 108 is a collimating lens; the third beam splitting component 113 is a blue-reflective, yellow-transparent prism (the dichroic beam splitting prism is coated with a blue-transparent, yellow-reflective film); and the fourth beam splitting component 115 is a dichroic beam splitting prism.

[0132] The illumination light emitted by the white LED is collected by the conical second homogenizing component 106 and collimated into parallel light by the lens component 108. This parallel light enters the polarization light recovery device 122, which polarizes the white light. After polarization, the parallel white light is split by a dichroic beam splitter into reflected yellow light (i.e., the second illumination light) and transmitted blue light (i.e., the first illumination light). The polarized yellow light is split into red and green light by the dispersive beam splitter 121. These colors are separated angularly but overlap on the surface. The light emitted from the dispersive beam splitter 121 passes through the second display panel 32 and is filtered out by the second analyzer 33 to obtain the image information to be displayed, thus obtaining the second illumination light.

[0133] The principles of the blue light path and the yellow light path are roughly the same. Blue light passes through the fourth hollow guide tube 119 and the second folding prism 116, and exits from the exit surface of the second folding prism 116. A first polarizer 21 is placed on the exit surface to further purify the polarization of the first illumination light (if a polarization recovery device 122 was not previously placed, it can be placed here for light circulation). The polarized blue light directly illuminates the first display panel 22, and the polarized yellow light directly illuminates the second display panel 32. The light passing through the first display panel 22 and the second display panel 32 is filtered by the first analyzer 23 and the second analyzer 33 respectively to extract the image light. After being combined by a dichroic light combining prism, the light is projected onto the projection screen by the projection lens 105. This scheme, based on white light splitting, has the advantages of high efficiency and good color uniformity.

[0134] Understandably, the lighting section in the above embodiments can also employ discrete multi-area lighting, such as using a discrete cone-bar lens array or a discrete collecting lens array, in order to further reduce the system size.

[0135] This embodiment proposes a projection architecture based on non-imaging illumination for a 2LTPS-LCD, which solves the problems of low efficiency and high panel heat load in single-LCD projection systems. It is also smaller in size and has a more uniform light spot than the projection architecture of a 3LTPS-LCD. In addition, all three colors of light are present on the projection screen at the same time, which can effectively reduce rainbow effect and color separation effect and improve display effect. Furthermore, this embodiment uses a two-panel LCD, which distributes one color of light to another display panel. This not only maximizes the utilization of the spectrum when using a prism film, but also reduces the burden on the display panel, improves system efficiency and total output lumens.

[0136] To improve the resolution of the display panel, a second pixel expansion device can be placed between the light combining component and the projection lens, or between the second display panel and the light combining component, as will be described in detail below. Understandably, since the dispersive beam splitter has been described in detail in the above embodiments, it will not be repeated in the following embodiments and is not shown in the figures.

[0137] Please see Figure 18 , Figure 18 This is a structural schematic diagram of the tenth embodiment of the projection system provided in this application, and... Figure 9 The difference between the embodiments shown is that the projection system in this embodiment also includes a second pixel expansion device 120.

[0138] The second pixel expander 120 is disposed in the outgoing light path of the light source assembly 101, and is used to expand the image light and direct it into the light combining assembly 104; specifically, the second pixel expander 120 is disposed in the outgoing light path of the second liquid crystal modulator 103, and is used to expand the second image light and direct it into the light combining assembly 104. Understandably, the working principle of this projection system is similar to... Figure 9 The embodiments shown operate on a similar principle and will not be described again here.

[0139] A second pixel expansion device 120 is placed at the light-emitting end of the second display panel 32 in the red-green dual-color light path. For a specific pixel position in space, red and green pixel light will pass through in sequence and combine with the blue pixel light of the first display panel 22 in the blue light path to ultimately present the image light. By using the second pixel expansion device 120, the resolution of the second display panel 32 is improved. By utilizing the current frame resolution of the second display panel 32, the display effect can be further enhanced.

[0140] In another specific embodiment, please refer to Figure 19 , Figure 19 This is a schematic diagram of the eleventh embodiment of the projection system provided in this application, and... Figure 18 The difference between this embodiment and the previous one is that the projection system in this embodiment also includes a first folding prism 109 and a first hollow conduit 110. The working principle of this projection system is the same as... Figure 12 as well as Figure 18 The embodiments shown operate on a similar principle and will not be described again here.

[0141] In another specific embodiment, please refer to Figure 20 , Figure 20 This is a schematic diagram of the structure of the twelfth embodiment of the projection system provided in this application, and... Figure 18 The difference between this embodiment and the previous one is that the projection system in this embodiment also includes a second beam splitter 112, a third beam splitter 113, and a second hollow conduit 114. The working principle of this projection system is the same as... Figure 14 as well as Figure 18 The embodiments shown operate on a similar principle and will not be described again here.

[0142] In another specific embodiment, please refer to Figure 21 , Figure 21 This is a schematic diagram of the thirteenth embodiment of the projection system provided in this application, and... Figure 20 The difference between the embodiments shown is that in this embodiment, the first illumination light enters the second beam splitter 112 in a downward direction, and the second illumination light enters the third beam splitter 113 in a left-to-right direction.

[0143] The first light-emitting component 1011 can be a blue LED or a blue laser, used to emit blue light. After being collected and polarized, the blue light passes through the second beam splitter 112 (for example, the second beam splitter 112 reverses the S-polarized state of blue light and transmits the P-polarized state of blue light, and the blue light emitted by the first light-emitting component 1011 is P-polarized) and reaches the third beam splitter 113 (for example, the third beam splitter 113 reverses the blue light and transmits the yellow light). After being reflected by the third beam splitter 113, the light enters the color wheel 61, exciting the phosphor on the color wheel 61 to obtain white light. The yellow light in the white light is transmitted through the third beam splitter 113, then passes through the first hollow conduit 110 and the first folding prism 109 to reach the second liquid crystal modulator 103; the blue light in the white light is reflected by the third beam splitter 113 to reach the second beam splitter 112, the S-polarized blue light is reflected by the second beam splitter 112 into the first liquid crystal modulator 102, and the P-polarized blue light enters the first light-emitting component 1011 for recycling. The light emitted from the first liquid crystal modulator 102 and the second liquid crystal modulator 103 is combined by the light combining component 104 to generate image light, which is then emitted after passing through the first pixel expansion device 107 and the projection lens 105.

[0144] In another specific embodiment, please refer to Figure 22 , Figure 22 This is a schematic diagram of the fourteenth embodiment of the projection system provided in this application, and... Figure 21 The difference between the illustrated embodiment and the actual embodiment is that the second light-emitting component in this embodiment is a fixed fluorescent sheet 62, and the working principle of the projection system is the same as... Figure 21 The embodiments shown operate on a similar principle and will not be described again here.

[0145] In another specific embodiment, please refer to Figure 23 , Figure 23 This is a schematic diagram of the structure of the fifteenth embodiment of the projection system provided in this application, and... Figure 18 The difference between the embodiments shown is that the projection system in this embodiment also includes a fourth beam splitter 115, a second folding prism 116 and a third folding prism 117, and the light source assembly 101 is a white light source.

[0146] Understandably, the working principle of this projection system is similar to... Figure 17 as well as Figure 18 The working principle of the embodiment shown is similar, except that after the dual-color image light is emitted from the second liquid crystal modulator 103, it is expanded by the second pixel expansion device 120 to improve the resolution, and then combined by the light combining component 104 before being projected onto the projection screen by the projection lens 105. This will not be described in detail here.

[0147] This embodiment proposes a projection architecture for a 2LTPS-LCD based on non-imaging illumination, which solves the problems of low efficiency and high panel heat load in single LCD projection systems, reduces the rainbow effect, and is smaller in size and has a more uniform light spot than a 3LTPS-LCD projection system, with higher system efficiency; moreover, due to the use of pixel expansion devices for pixel expansion, the resolution is higher.

[0148] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A projection system, characterized in that, include: A light source assembly for generating a first illumination light and a second illumination light, wherein the first illumination light is light of one of the three primary colors, and the second illumination light is light synthesized from other colors of the three primary colors; A dispersive beam splitter is disposed in the output light path of the light source assembly to split the second illumination light into a first sub-illumination light and a second sub-illumination light; A first liquid crystal modulator is disposed in the outgoing light path of the light source assembly, and is used to receive the first illumination light and modulate it to generate the first image light; A second liquid crystal modulator is disposed in the outgoing light path of the light source assembly and is used to modulate the first sub-illumination light and the second sub-illumination light to generate a second image light; A light combining component is disposed in the light output path of the first liquid crystal modulator and the second liquid crystal modulator, and is used to combine the first image light and the second image light to generate image light; A projection lens is disposed on the outgoing light path of the light combining component and is used to project the image light.

2. The projection system according to claim 1, characterized in that, The dispersive beam splitter includes a first structural layer and a second structural layer disposed on the first structural layer. The first structural layer has a periodic structure, and the material of the first structural layer is different from that of the second structural layer.

3. The projection system according to claim 2, characterized in that, The Abbe number of the first structural layer is less than a preset value, and the Abbe number of the second structural layer is greater than the preset value; the refractive index of the first structural layer and the second structural layer is the same at a preset wavelength.

4. The projection system according to claim 1, characterized in that, The first liquid crystal modulator includes a first display panel and a first microlens array. The first display panel includes a plurality of first pixel units. The first microlens array is disposed in the outgoing light path of the light source assembly and is used to process the first illumination light and direct it into the corresponding first pixel unit. And / or, the second liquid crystal modulator includes a second display panel and a second microlens array, the second display panel including a plurality of second pixel units; the first microlens array is disposed in the outgoing light path of the dispersive beam splitter, for processing the first sub-illumination light and the second sub-illumination light and injecting them into the corresponding second pixel units.

5. The projection system according to claim 4, characterized in that, The first display panel and the second display panel are LTPS-LCD.

6. The projection system according to claim 1, characterized in that, The light source assembly includes a first light-emitting component and a second light-emitting component, wherein the first light-emitting component is used to generate the first illumination light and the second light-emitting component is used to generate the second illumination light; The first illumination light is a blue laser, and the second illumination light is a laser-receiving light; the first light-emitting component is a blue laser generator, which is used to generate the blue laser; the second light-emitting component is a color wheel, a fixed phosphor sheet, or an LED with phosphor coating on its surface, which is used to receive the blue laser and generate the laser-receiving light. Alternatively, the first light-emitting component may be a blue LED, and the second light-emitting component may be a yellow LED.

7. The projection system according to claim 6, characterized in that, The light source assembly further includes a third light-emitting component and a first beam-splitting component. The third light-emitting component is used to generate blue laser light. The first beam-splitting component is disposed in the output light path of the third light-emitting component and is used to reflect the blue laser light generated by the third light-emitting component to the second light-emitting component and transmit the blue laser light generated by the second light-emitting component to the second liquid crystal modulator.

8. The projection system according to claim 6, characterized in that, The projection system further includes a first folding prism and a first hollow conduit. The first hollow conduit is disposed in the light path of the first light-emitting component and is used to transmit the first illumination light to the first folding prism. The first folding prism is disposed on the outgoing light path of the first hollow duct to adjust the transmission direction of the first illumination light.

9. The projection system according to claim 8, characterized in that, The projection system further includes a second beam splitter, a third beam splitter, and a second hollow conduit. The second beam splitter is disposed in the output light path of the blue laser and is used to transmit / reflect light with a first polarization state in the blue laser to form the first illumination light and inject it into the first liquid crystal modulator. The second hollow conduit is disposed in the output light path of the second beam splitter and is used to transmit the light with the second polarization state in the blue laser to the third beam splitter; the third beam splitter is disposed in the output light path of the second hollow conduit and is used to reflect / transmit the light with the second polarization state in the blue laser to the second light-emitting component and transmit the laser generated by the second light-emitting component to the second liquid crystal modulator.

10. The projection system according to claim 9, characterized in that, The first illumination light enters the second beam splitter in an upward direction, and the second illumination light enters the third beam splitter in an upward direction; Alternatively, the first illumination light enters the second beam splitter in a downward direction, and the second illumination light enters the third beam splitter in a left-to-right direction.

11. The projection system according to claim 1, characterized in that, The projection system also includes: The fourth beam splitter is disposed in the output light path of the light source assembly and is used to split the illumination light into the first illumination light and the second illumination light; The second folding prism is disposed in the optical path of the first illumination light to adjust the transmission direction of the first illumination light from the first direction to the second direction and to project it into the first liquid crystal modulator. A third folding prism is disposed in the optical path of the second illumination light to adjust the transmission direction of the second illumination light from the second direction to the first direction and then project it into the second liquid crystal modulator.

12. The projection system according to claim 11, characterized in that, The projection system further includes a polarization light recovery device, which is disposed in the outgoing light path of the light source assembly and is used to transmit the illumination light with a first polarization state to the fourth beam splitter and reflect the illumination light with a second polarization state to the light source assembly.

13. The projection system according to claim 11, characterized in that, The projection system further includes a third hollow guide tube and a fourth hollow guide tube. The third hollow guide tube is disposed in the reflected light path of the fourth beam splitter and is used to transmit light with a second polarization state in the illumination light to the third folding prism. The fourth hollow guide tube is disposed in the transmitted light path of the fourth beam splitter and is used to transmit light with a first polarization state in the illumination light to the second folding prism.

14. The projection system according to claim 1, characterized in that, The first illumination light is a blue laser. The light source assembly includes a blue laser, a first homogenizing component, an imaging lens, and a second wavelength conversion device. The blue laser is used to generate the blue laser. The first homogenizing component is disposed in the output light path of the blue laser and is used to homogenize the blue laser. The imaging lens is disposed in the output light path of the first homogenizing component and is used to image the blue laser output by the first homogenizing component onto the second wavelength conversion device, so that the second wavelength conversion device generates the second illumination light.

15. The projection system according to claim 1, characterized in that, The projection system further includes a light collection device, which is disposed in the outgoing light path of the light source assembly and is used to collect the illumination light and project it into the first liquid crystal modulator and the second liquid crystal modulator.

16. The projection system according to claim 1, characterized in that, The projection system further includes a first pixel expansion device, which is disposed in the outgoing light path of the light combining component and is used to expand the image light and project it into the projection lens.

17. The projection system according to claim 1, characterized in that, The projection system further includes a second pixel expansion device, which is disposed in the outgoing light path of the light source assembly and is used to expand the image light and project it into the light combining assembly.

18. The projection system according to claim 1, characterized in that, The second liquid crystal modulator includes a plurality of second pixel units, each second pixel unit including a first sub-pixel and a second sub-pixel, wherein the first sub-illumination light corresponds to the first sub-pixel and the second sub-illumination light corresponds to the second sub-pixel.

19. The projection system according to claim 1, characterized in that, The light source assembly illuminates the first liquid crystal modulator and the second liquid crystal modulator using a non-imaging illumination method.

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