CN216118360U - Light combining device and projection system - Google Patents

Abstract

The utility model provides a light combining device which is used for combining illumination light, wherein the illumination light comprises first light, second light and third light, and the light combining device comprises a first light deflection component, a second light deflection component and a light combining component. The first light deflection component is arranged on a light-emitting light path of the first light and is used for deflecting the first light to form first deflection light; the second light deflection component is arranged on a light-emitting light path of the second light and is used for deflecting the second light and forming second deflection light; the light combining component is arranged on a light emitting light path of the third light and used for combining and emitting the first deflection light, the second deflection light and the third light. The light combining device provided by the utility model can process the illumination light to form the first deflection light, the second deflection light and the third light which are separated in the angular direction and still overlapped on the surface, and can reduce the angle difference between the included angle of the first deflection light and the third light and the included angle of the second deflection light and the third light. The utility model also provides a projection system.

Description

Light combining device and projection system

Technical Field

The utility model relates to the technical field of optics, in particular to a light combining device and a projection system.

Background

In the field of optical projection, it is often necessary to separate incident light into a plurality of light beams for emission through a light processing device to meet the requirements of optical instruments. The existing light processing device has the problems of low efficiency, large angle difference between the included angle of red light and green light and the included angle of blue light and green light and the like, and is difficult to meet the requirement.

SUMMERY OF THE UTILITY MODEL

An embodiment of the utility model provides a light combining device and a projection system to solve the above problems. The embodiment of the utility model achieves the aim through the following technical scheme.

In a first aspect, the present invention provides a light combining device for combining illumination light, the illumination light including a first light, a second light and a third light, the light combining device including a first light deflecting element, a second light deflecting element and a light combining element. The first light deflection component is arranged on a light-emitting light path of the first light and is used for deflecting the first light to form first deflection light; the second light deflection component is arranged on a light-emitting light path of the second light and is used for deflecting the second light and forming second deflection light; the light combining component is arranged on a light emitting light path of the third light and used for combining and emitting the first deflection light, the second deflection light and the third light.

In a second aspect, the present invention further provides a projection system, which includes a light source device, a spatial light modulator, and any of the light combining devices. The light source device is used for emitting illumination light; the spatial light modulator comprises a plurality of light modulation unit groups, the light modulation unit groups are located on the same plane, each light modulation unit group comprises a first light modulation unit, a second light modulation unit and a third light modulation unit, first deflection light enters the first light modulation unit and is emitted after being modulated by the first light modulation unit, second deflection light enters the second light modulation unit and is emitted after being modulated by the second light modulation unit, and third light enters the third light modulation unit and is emitted after being modulated by the third light modulation unit.

Compared with the prior art, the light combining device and the projection system provided by the utility model can process the illumination light to form the first deflection light, the second deflection light and the third light which are separated in the angular direction and still overlapped on the surface, have high light combining efficiency, and can reduce the angle difference between the included angle of the first deflection light and the third light and the included angle of the second deflection light and the third light. When the light combining device is used for the spatial light modulator, the efficiency of the illumination light penetrating through the spatial light modulator can be improved, the spatial light modulator can respectively modulate the first deflection light, the second deflection light and the third light and then emit the first deflection light, the second deflection light and the third light, high-efficiency illumination is realized, the heat load of the spatial light modulator is reduced, the service life of the spatial light modulator is prolonged, and the maximum output lumen of the spatial light modulator is improved.

These and other aspects of the utility model are apparent from and will be elucidated with reference to the embodiments described hereinafter.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a color liquid crystal panel provided in the prior art.

Fig. 2 is a schematic structural diagram of a color filter structure of the color liquid crystal panel shown in fig. 1.

Fig. 3 is a schematic structural diagram of a light combining device according to an embodiment of the present application.

Fig. 4 is a schematic structural view of the first light deflecting element of the light combining device shown in fig. 3 being a prism film.

Fig. 5 is a schematic structural view of the base layer and the first functional layer of the light combining device shown in fig. 3.

Fig. 6 is a graph showing the relationship between the tilt angle α of the prism film of the light combining device shown in fig. 3 and the deflection angle of the light beam (red light with a main wavelength of 615 nm).

Fig. 7 is a graph showing the relationship between the size of a single edge angle and the diffraction angle distance of the prism film of the light combining device shown in fig. 3.

Fig. 8 is a schematic structural diagram of the first light deflecting element of the light combining device shown in fig. 3 being a prism array.

Fig. 9 is a relationship between the inclination angle α of the prism film (when the red light is deflected by 4 degrees) and the number of layers required for the prism film in the light combining device shown in fig. 3.

Fig. 10 is a schematic structural diagram of a projection system provided in an embodiment of the present application.

Fig. 11 is a schematic diagram of a single pixel area in the spatial light modulator of the projection system shown in fig. 10.

Detailed Description

In order to facilitate an understanding of the embodiments of the present invention, the embodiments of the present invention will be described more fully hereinafter with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the examples of the present invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model.

The inventors of the present application have discovered that in recent years projection systems have emerged that employ monolithic color liquid crystals. The color liquid crystal panel has been widely used in the display fields of televisions, computer monitors, mobile phone screens and the like for decades. As shown in fig. 1, when a white light source W enters a color liquid crystal panel, polarized light is first formed by a polarizer 410, and then passes through structures such as a transparent electrode 420, a liquid crystal layer 430, and an alignment film 440 in sequence, and light modulated by a pixelized liquid crystal finally passes through a color filter film 450 and is analyzed and polarized by a polarizer 460. The color filter structures of the adjacent pixels are shown in FIG. 2, i.e., the adjacent color filters are a red filter 510, a green filter 520, and a blue filter 530, respectively. Therefore, the color liquid crystal panel not only can regulate and control the light intensity, but also can regulate and control the color of the pixel to form the adjacent red, green and blue color sub-pixel arrangement. Although the three color pixels are spatially separated, due to the limited angular resolution of the human eye, beyond a certain distance, the observer cannot distinguish the three separated color pixels, but rather each group of red, green and blue three sub-pixels is regarded as one integral display unit, i.e. a color display image formed by spatial integration is observed. In addition, because the color liquid crystal panel can simultaneously display the pixels of three colors of red, green and blue at the same time, the rainbow effect is avoided in principle. In addition, due to the wide application of the color liquid crystal panel, the cost of the color liquid crystal panel is greatly reduced, which has a very high cost advantage, and the color liquid crystal panel is gradually applied to a projection display system in recent years, that is, an image on the color liquid crystal panel is directly enlarged through a lens for projection display.

However, the use of a single-piece color liquid crystal panel as a light valve device in a projection system still has the following problems:

(1) the illumination light will use a white light source to form different color sub-pixels through a color filter film on top of the color liquid crystal panel. Since the color filter only transmits light of a specific color, 2/3 light cannot pass through the pixel and is completely absorbed, resulting in a large loss of light energy, for example, more than 60%. Meanwhile, absorbed light is converted into heat, so that the temperature of the color liquid crystal panel is increased, and the display effect and the service life of a display chip are further influenced;

(2) the LCD panel is manufactured by two processes, namely, Low Temperature Poly-Silicon (LTPS) and High Temperature Poly-Silicon (HTPS), wherein the HTPS process has High precision, the size of a liquid crystal pixel can reach less than 10 μm, but the process requirement is High, and thus the cost is High. The color liquid crystal panel generally employs an LTPS process. LTPS processes are less costly but less accurate and have larger pixel sizes, e.g., pixel sizes typically above 25 um. Under the condition of a certain resolution, the size of the whole LCD panel is larger, so that the size of a subsequent lens is larger, and finally, the size of the whole projection system is larger;

(3) the color pixels on the color liquid crystal panel are separated from each other, although in television, computer monitor or mobile phone screen display, the observer cannot distinguish the spatial color separation in consideration of the angular resolution limit of human eyes and the observation distance. However, in the projection display, since the size of the projection is usually much larger than that of the solid display screen, the phenomenon of color pixel separation is more obvious, and the viewing effect is affected.

In addition, the projection system based on the color liquid crystal panel has the following problems:

(1) in the liquid crystal panel, a matrix type conductive electrode, that is, a TFT (Thin Film Transistor) circuit, for driving liquid crystal of each individual pixel is present. The TFT circuit is made of opaque materials, so that incident light at corresponding positions can be shielded, and partial light effect loss is caused. In addition, part of the light energy is absorbed by the TFT circuit and converted into heat. In addition, due to the existence of the TFT circuit and process limitations, in order to ensure the aperture ratio of the panel, that is, to ensure the light transmittance of the panel, the size of the liquid crystal panel is large, which results in a large size and volume of the projection system;

(2) the color liquid crystal panel adopts a group of red, green and blue pixels which are equivalent to one color pixel, so that the resolution of the liquid crystal panel is reduced to 1/3 of the intrinsic resolution;

(3) the liquid crystal panel has a low aperture ratio, and a lot of incident light is absorbed by Black Matrix between pixels, resulting in low efficiency of LCD projection.

To solve the above problems, the prior art proposes to implement a high efficiency projection system by attaching cylindrical microlens arrays on an LCD, one of which covers three pixels in the horizontal dimension, so that RGB illumination light, which is angularly separated in one dimension but overlapped in the plane, is used. However, angular separation of the three RGB wavelengths of light is a difficult problem.

The prior art also discloses an optical scheme that RGB pure laser is matched with a diffraction optical device to realize separation of RGB three-color light in angle, and a single micro-transparent LCD panel is matched to realize high-efficiency illumination. From the viewpoint of light sources, light sources based on RGB three-color lasers have problems of speckle and excessive cost. From the perspective of optical devices, the diffraction optical device has the problems of low efficiency due to efficiency loss caused by wide light source spectrum width or wavelength temperature drift, and the like, and the diffraction optical device also has high processing precision requirement.

In order to solve the problem of low efficiency in the conventional optical device, the inventor of the present application proposes a light combining device and a single LCD projection system based on the light combining device and a single micro-transparent panel. The light combining device and the projection system provided by the utility model are described in detail below with reference to the detailed description and the drawings.

Referring to fig. 3, the present invention provides a light combining device 10 for combining illumination light, wherein the illumination light includes a first light, a second light and a third light, and the light combining device 10 includes a first light deflecting element 100, a second light deflecting element 200 and a light combining element 300. The first light-deflecting component 100 is disposed on an outgoing light path of the first light, and is configured to deflect the first light and form a first deflection light; the second light-deflecting component 200 is disposed on a light-emitting path of the second light, and is configured to deflect the second light and form a second deflection light; the light combining component 300 is disposed on the light emitting path of the third light, and is configured to combine and emit the first deflection light, the second deflection light, and the third light.

In this embodiment, the first light is red light, the second light is blue light, and the third light is green light.

The first light deflecting component 100 is disposed on the light-emitting path of the first light, and is configured to deflect the first light and form a first deflection light, that is, an angle of the first light incident on the first light deflecting component 100 is different from an angle of the first deflection light exiting from the first light deflecting component 100, and the light is deflected. In this embodiment, the first light deflecting element 100 is an angular deflecting device for red light.

The first light deflecting element 100 may be a discrete structure, and the discrete first light deflecting element 100 does not cause an excessive optical path difference, so that uniformity of the illumination spot can be ensured. For example, the first light deflecting element 100 may be a prism array or a prism film with a discrete structure, and the prism array or the prism film deflects light rays in a geometric manner, so that loss of efficiency due to wavelength temperature drift and the like can be avoided, and the deflection efficiency is high.

Referring to fig. 4 and 5, in the present embodiment, the first light deflecting element 100 is a prism film. The prism film comprises a substrate layer 110, a first functional layer 120 and a second functional layer 130, wherein the first functional layer 120 comprises a plurality of corner units 121, the plurality of corner units 121 are convexly arranged on the substrate layer 110, and the first functional layer 120 is made of a first material; the second functional layer 130 is filled between the plurality of corner units 121, and the second functional layer 130 is made of a second material, and the abbe number of the second material is different from the abbe number of the first material.

The base layer 110 may be used to provide the first functional layer 120. In this embodiment, the substrate layer 110 may be directly prepared by laser direct writing or precision lathing. If the substrate layer 110 is in high demand, a large-area thin mold can be prepared, and then a roll-to-roll method is adopted to perform structure repeated etching, so as to prepare a large-area prism film. The material of the substrate layer 110 may be a transparent organic material such as PC (Polycarbonate) or PMMA (poly methyl methacrylate).

The base layer 110 comprises a bottom surface 111, the bottom surface 111 being provided with a first functional layer 120. In addition, the substrate layer 110 further includes a back surface 112, and the back surface 112 is opposite to the bottom surface 111 and can be connected to other optical elements, for example, the back surface 112 can be adhered to other optical elements, such as an optical lens, by a back adhesive.

The first functional layer 120 is used to deflect light. The first functional layer 120 may be prepared by a method of performing an overmolding process by photocuring. The first functional layer 120 is made of a first material. In this embodiment, the first material may be different from the material of the base layer 110, for example, the first material may be optical glue or glass. In other embodiments, the first material may be the same as the material of the base layer 110, i.e., may be a transparent organic material such as PC or PMMA.

The first functional layer 120 includes a plurality of corner units 121, the corner units 121 are protruded from the base layer 110, and the corner units 121 are protruded from the bottom surface 111, for example. The plurality of corner units 121 are in a corner periodic structure and are distributed on the bottom surface 111 in a linear array, the plurality of corner units 121 can be connected in sequence, and the distance between two adjacent corner units 121 can be 0.05mm-1 mm. In the present embodiment, the cross section of the corner unit 121 is triangular, for example, the corner unit 121 has a substantially triangular prism structure.

Each corner element 121 includes a first surface 1211 and a second surface 1213 that are connected, the first surface 1211 and the second surface 1213 being connected to the bottom surface 111. An angle between the first surface 1211 and the second surface 1213 is defined as α, an angle between the first surface 1211 and the bottom surface 111 is defined as β, and an angle between the second surface 1213 and the bottom surface 111 is defined as γ, and α + β + γ is defined as 180 °. In this embodiment, the angle between the first surface 1211 and the second surface 1213 is less than 90 °, i.e., α < 90 °, wherein the angle α is selected to be related to the light deflection capability of the prism film, and the magnitude of the angle α has a deflection effect on the red light rays as shown in fig. 6. Therefore, for the incident light of a specific color, the deflection of the emergent light at different angles can be realized by setting different angles alpha.

In the embodiment, β is less than or equal to 90 °, when β deviates more than 90 °, i.e., β is smaller, the more stray light is generated after the light passes through the prism film, and the system efficiency is lower. However, since β is 90 ° affects the mold release efficiency of the corner element 121, β may be slightly smaller than 90 °, for example, β is 85 ° in consideration of the draft.

In the present invention, the size of the edge unit 121 affects the film thickness and the diffraction optical efficiency of the prism film, and also affects the geometrical optical efficiency of the prism film, for example, the larger the edge, the smaller the defect ratio of the sharp corner to the root. However, too large an angle also causes the prism film to have too thick film layer, waste material and dispersion of light spots. The size of the corner refers to the size of the volume of the corner unit 121.

The structure of the prism film can be regarded as a transmission type blazed grating, the center of diffraction distribution of the prism film depends on the deflection direction of the principal ray, and the interference 0 level of the prism film depends on the direction of incident light. The prism film diffraction model is multislice fraunhofer diffraction. The prism film diffraction distribution formula is as follows:

wherein α ═ π a sin θ_xA is the slit width, θ_xIs the diffraction angle. With main step large at 0, i.e. theta_xThe center of the zero-order diffraction spot is the geometric optical image point, which is 0.

Multi-slit diffraction is the result of the combined effects of diffraction and interference, and the angle of the interference order can be calculated by the formula d sin θ ═ m λ (m ═ 0, ± 1, ± 2), where d denotes the distance between the slits. Since a is d in the prism film, the angular distance of each interference order can be approximated by sin θ m λ/a. The relationship between the size of each corner of the prism film and the diffraction angle distance is shown in fig. 7. It can be seen that when the edge angle is too small, the angular distance of each interference order of the prism film is 0.6 °, for a specific deflection angle after light with a specific wavelength passes through the prism film, high energy distribution occurs in two interference orders, the difference between the two angles is large, and even the two angles are larger than the light deflection angle, so that a lot of angles exceed the collection range of a single micro-transparent panel, and the efficiency is wasted.

If the light source selects RGB pure laser, the size of the edge angle and the deflection angle can be optimized, so that the interference order is superposed with the 0 level of diffraction distribution, and the highest energy utilization rate is achieved.

If the light source is selected to be a broad spectrum light such as LED or laser fluorescence, it is necessary to select a larger angle size to reduce the angle between orders and make the diffraction distribution narrower, or to appropriately increase the light deflection angle of each prism film layer to reduce the specific gravity of diffraction, thereby minimizing the dilution of the expansion.

With continued reference to fig. 4 and fig. 5, the second functional layer 130 is filled between the corner units 121. In this embodiment, after obtaining a plurality of corner elements 121 made of a first material, the corner elements 121 may be filled with a second material. The flat filling means that the filled second functional layer 130 is flush with the top line of the corner unit 121 of the first functional layer 120, or the top surface of the second functional layer 130 is a plane and higher than the top line of the corner unit 121, wherein the top line means the intersection line of the first surface 1211 and the second surface 1213, and the intersection line is parallel to the bottom surface 111.

The second functional layer 130 is made of a second material having an abbe number greater than that of the first material, and thus, the refractive index of the first material is different from that of the second material. When the illumination light of the color lights with different wavelengths is incident on the prism film, the edge unit 121 deflects the color lights with different wavelengths to different degrees.

In one embodiment, the first light deflecting element 100 is a prism array, and the prism array is opposite to the light combining element 300, so that the efficiency of the first light incident on the light combining element 300 can be improved. Similar to the corner unit 121, the prism array performs deflection of light rays by using the principle of refraction of light. Because the refractive index of the material of the prism array is different from that of air, the first light can be deflected after being emitted from the prism array and entering the air. The material of the prism array may be a transparent organic material such as PC or PMMA.

Referring to fig. 8, the prism array includes a prism base layer 140 and a plurality of prism units 150, the prism units 150 are convexly disposed on the prism base layer 140, and each prism unit 150 has a triangular cross-section, for example, the prism units 150 are substantially triangular prism structures. The prism array may be made by nanoimprint or injection molding.

In other embodiments, the first light deflecting component 100 may also be a slide driven by an XPR (Extended Pixel Resolution) actuator, or an E-shift device.

Referring to fig. 3 and 5, the second light deflecting element 200 is disposed on the light emitting path of the second light, and is configured to deflect the second light to form a second deflecting light, that is, an angle of the second light incident on the second light deflecting element 200 is different from an angle of the second deflecting light exiting from the second light deflecting element 200. In this embodiment, the second light deflecting element 200 is an angular deflecting device for blue light.

In this embodiment, the second light deflecting member 200 is also a prism film, like the first light deflecting member 100. In one embodiment, the second light deflecting assembly 200 may be the same as the first light deflecting assembly 100, and the second light deflecting assembly 200 may also be a prism array. In other embodiments, the second light deflecting assembly 200 may be different from the first light deflecting assembly 100, e.g., the first light deflecting assembly 100 is a prismatic film and the second light deflecting assembly 200 is a prismatic array; alternatively, the first light deflecting element 100 is a prism array, and the second light deflecting element 200 is an E-shift device, etc.

The light combining component 300 is disposed on the light emitting path of the third light, and is configured to combine and emit the first deflection light, the second deflection light, and the third light. The emergent first, second and third deflected lights are angularly separated, but still coincide at the face. In the present embodiment, the light combining component 300 is an X-CUBE (light combining prism).

The light combining assembly 300 includes a first light incident surface 310, a second light incident surface 320 and a third light incident surface 330, wherein the first light incident surface 310 and the second light incident surface 320 are opposite to each other, and the first light incident surface 310 is opposite to the first light deflecting assembly 100 and is used for incidence of first deflection light; the second light incident surface 320 is opposite to the second light deflecting element 200 and is used for incidence of second deflection light; the third light incident surface 330 is connected between the first light incident surface 310 and the second light incident surface 320, and is used for the incidence of third light. In addition, the light combining component 300 further includes a light emitting surface 340, where the light emitting surface 340 is opposite to the third light incident surface 330, and is used for emitting the combined light of the first polarized light, the second polarized light, and the third light.

The combined light of the first deflection light, the second deflection light and the third light exits through the light exit surface 340. In one embodiment, the angle between the first deflected light and the third light emitted from the light emitting surface 340 is equal to the angle between the second deflected light and the third light, that is, the angle between the red light and the green light is equal to the angle between the blue light and the green light. The angle of the edge, which refers to the angle α between the first surface 1211 and the second surface 1213 when the first light deflection assembly 100 is a prism film, may be designed by matching the angle of the edge in the first light deflection assembly 100 and the second light deflection assembly 200 with the dominant wavelength of the red light and the blue light, so that the included angle between the red light and the green light is equal to the included angle between the blue light and the green light; when the first light deflecting member 100 is a prism array, the edge angle refers to a vertex angle of the prism unit 150. Therefore, the purpose of reducing the angle difference between the included angle of the first light deflection component 100 and the included angle of the second light deflection component 200 and the included angle of the third light deflection component and the included angle of the second light deflection component and the third light deflection component can be achieved by setting the angle of the first light deflection component 100 and the angle of the second light deflection component 200.

Referring to fig. 4 and 5, in the embodiment, if the deflection angle of the red light and the blue light is to be increased, the included angle α between the first surface 1211 and the second surface 1213 of the corner unit 121 may be increased, or a prism film with a multi-layer structure is adopted, when the prism film is a single-layer structure, the first functional layer 120 and the second functional layer 130 are both single-layers, and when the prism film is a multi-layer structure, the first functional layer 120 and the second functional layer 130 are both multi-layers, and the number of layers is the same, and the first functional layers 120 and the second functional layers 130 are stacked alternately in sequence. For example, when a deflection angle of 4 ° for red light is to be achieved, the relationship between the α angle of the edge unit 121 and the number of layers of prism films is as shown in fig. 9. In other embodiments, the number of layers of the prism film may be determined according to the angle at which the light needs to be refracted, or the value of the α angle of the edge unit 121. It is therefore also possible to achieve the purpose of reducing the angle difference between the angle of the first and third light and the angle of the second and third light by setting the number of layers of the first light deflecting element 100 (fig. 3) and the number of layers of the second light deflecting element 200 (fig. 3).

Referring to fig. 3, in the present embodiment, the light combining element 300 employs dichroic light combination. The light combining element 300 is further provided with a first dichroic film 350 and a second dichroic film 360, wherein the first dichroic film 350 is disposed between the first light incident surface 310 and the second light incident surface 320, and is used for reflecting the first polarized light and transmitting the second polarized light and the third light. The first dichroic film 350 and the second dichroic film 360 may be plated on the surface of the x-prism. In the present embodiment, the first dichroic film 350 has a function of transmitting red light and blue light, that is, transmitting red light and reflecting green and blue light. The second dichroic film 360 is disposed between the first light incident surface 310 and the second light incident surface 320, and is configured to reflect the second polarized light and transmit the first polarized light and the third light. In the present embodiment, the second dichroic film 360 has a function of transmitting blue and yellow, that is, transmitting blue light and reflecting green and red light.

In summary, in the light combining device 10 provided by the present invention, the first light is deflected by the first light deflecting element 100 to form a first deflected light, the second light is deflected by the second light deflecting element 200 to form a second deflected light, and the light combining element 300 combines and emits the first deflected light, the second deflected light, and the third light, which are separated in an angular direction but still overlapped on a surface, so that the first deflected light, the second deflected light, and the third light can be formed, the light combining efficiency is high, and the angle difference between the included angle of the first deflected light and the third light and the included angle of the second deflected light and the third light can be reduced. For example, the purpose of reducing the angle difference between the included angle of the first light deflection component and the included angle of the second light deflection component and the third light can be achieved by setting only the number of layers or the edge angle of the first light deflection component 100, or only the number of layers or the edge angle of the second light deflection component 200, or setting both the number of layers or the edge angle of the first light deflection component 100 and the number of layers or the edge angle of the second light deflection component 200.

Referring to fig. 10 and fig. 11, the present invention further provides a projection system 1, which includes a light combining device 10, a light source device 40, and a spatial light modulator 50. The light source device 40 is used for emitting illumination light; the spatial light modulator 50 includes a plurality of light modulation unit groups 51, the plurality of light modulation unit groups 51 are located on the same plane, each light modulation unit group 51 includes a first light modulation unit 511, a second light modulation unit 512, and a third light modulation unit 513, the first deflection light enters the first light modulation unit 511 and is emitted after being modulated by the first light modulation unit 511, the second deflection light enters the second light modulation unit 512 and is emitted after being modulated by the second light modulation unit 512, and the third light enters the third light modulation unit 513 and is emitted after being modulated by the third light modulation unit 513.

The light source device 40 is used to emit illumination light, for example, parallel white light. In the present embodiment, the light source device 40 forms the illumination light by a non-imaging manner, for example, the illumination light may be a light emitting source plus a collecting lens, or a light emitting source with a conrod plus a lens, or a light emitting source plus a free-form surface lens, or a light emitting source plus a reflector. In other embodiments, the illumination light is not limited to the manner of realizing the illumination light, and the purpose of finally emitting the illumination light is satisfied, and the illumination light can be formed in a non-imaging manner, for example, after the light source is homogenized by the square rod, the image at the outlet of the square rod is amplified by the optical system to form parallel white light illumination spots; or the light source is subjected to compound eye dodging, and then subjected to surface angle change through a subsequent optical system to form parallel white light illuminating spots; the image of the luminous surface can be directly amplified to form parallel white light illuminating spots and the like. The light emitting source of the light source device 40 may emit LED light, laser fluorescence or RGB pure laser light.

In the present embodiment, the light source device 40 includes a light source assembly 41 and a tapered light uniformizing device 43, the light source assembly 41 is a light emitting source of the light source device 40 and is used for emitting illumination light, and the tapered light uniformizing device 43 is disposed between the light source assembly 41 and the spatial light modulator 50 and is used for uniformizing the illumination light.

In the present embodiment, the illumination light is RGB pure laser light. Since the light entering the tapered light uniformizing device 43 needs a larger divergence angle and the RGB pure laser needs to eliminate the speckle, an angular gaussian scattering wheel needs to be enlarged at the entrance of the tapered light uniformizing device 43, for example, a scattering wheel with a higher roughness is used, or a material layer with a larger scattering angle such as a micro-structural layer is added.

The light source assembly 41 includes a first laser 411, a second laser 413, and a third laser 415, where the first laser 411 is configured to emit a first light, the second laser 413 is configured to emit a second light, and the third laser 415 is configured to emit a third light, and in this embodiment, the first light, the second light, and the third light are lasers. The number of the first laser 411, the second laser 413 and the third laser 415 may be multiple, and multiple different lasers may form a corresponding laser array to increase the light emitting area of the laser. For example, the plurality of first lasers 411 may form a first laser array, the plurality of second lasers 413 may form a second laser array, and the plurality of third lasers 415 may form a third laser array.

The light source device 40 further includes a fresnel lens 45 and a light uniformizing prism 47, the fresnel lens 45 is disposed between the light uniformizing prism 47 and the tapered light uniformizing device 43, and the light uniformizing prism 47 is disposed between the fresnel lens 45 and the spatial light modulator 50. The fresnel lens 45 and the light-equalizing prism 47 may form a light collection device with the tapered light-equalizing device 43, and are configured to collect the first deflection light, the second deflection light, and the third light emitted from the light-emitting surface 340 of the light-combining assembly 300, collimate the collected light, and adjust the light-combining spot of the first deflection light, the second deflection light, and the third light into a rectangle to adapt to a rectangular LCD panel that is mainstream in the market. In one embodiment, the light collecting means may also be composed of the tapered light unifying device 43 and the fresnel lens 45, i.e., without the light unifying prism 47. In another embodiment, the light collecting device may also be composed of a tapered dodging device 43 and a lens assembly.

In one embodiment, the fresnel lens 45 and the dodging prism 47 are of an integral structure, and the fresnel lens 45 and the dodging prism 47 of the integral structure can be manufactured by nano-imprinting or injection molding.

The spatial light modulator 50 includes a plurality of light modulation unit groups 51, the plurality of light modulation unit groups 51 are located on the same plane, as shown in fig. 11, each light modulation unit group 51 includes a first light modulation unit 511, a second light modulation unit 512, and a third light modulation unit 513, a first deflection light enters the first light modulation unit 511 and is emitted after being modulated by the first light modulation unit 511, a second deflection light enters the second light modulation unit 512 and is emitted after being modulated by the second light modulation unit 512, and a third light enters the third light modulation unit 513 and is emitted after being modulated by the third light modulation unit 513.

In the present embodiment, the spatial light modulator 50 is a single transmissive liquid crystal panel, and the illumination light is polarized illumination light, so as to improve the light extraction efficiency of the transmissive liquid crystal panel. The first light modulation unit 511, the second light modulation unit 512, and the third light modulation unit 513 are pixels of the corresponding color light, respectively, and each light modulation unit group 51 corresponds to one pixel region.

The projection system 1 further comprises a microlens array 60, the microlens array 60 is disposed between the prism film and the spatial light modulator 50, is located on the light incident side of the spatial light modulator 50, and is used for guiding the first polarized light, the second polarized light and the third light separated from each other in the angular direction to the first light modulation unit 511, the second light modulation unit 512 and the third light modulation unit 513 respectively. The microlens array 60 and the spatial light modulator 50 are collectively considered a single micro-transparent panel.

The microlens array 60 includes a plurality of microlenses 61, and in an embodiment, each microlens 61 corresponds to one light modulation unit group 51, so that each microlens 61 can process the first deflection light, the second deflection light and the third light, the efficiency of processing the colored lights with different wavelengths by the microlenses 61 is improved, and the light energy utilization rate of the projection system 1 is improved. In the present embodiment, the microlens 61 is made of glass.

The projection system 1 further comprises a polarizing element 70, the polarizing element 70 being arranged between the light source device 40 and the spatial light modulator 50, the polarizing element 70 being adapted to convert the illumination light into polarized light. In this embodiment, the polarizing element 70 may be a polarizer, for example, the polarizing element 70 is a reflective polarizing film, which can transmit light with a desired polarization state and reflect light with other polarizations. E.g., transmitting p-polarized light and reflecting s-polarized light. In the present embodiment, the light emitting surface of the light source device 40 is provided with a wavelength conversion material, after part of the polarized light is reflected by the reflective polarizing film, the reflected polarized light is incident to the wavelength conversion material on the light emitting surface through the tapered light uniformizing device 43, the wavelength conversion material is excited to generate the received laser light, and the received laser light is incident to the reflective polarizing film and participates in the light circulation of the projection system 1. By this light recycling, the efficiency of the projection system 1 can be improved. For example, yellow phosphor is disposed on the light emitting surface, and the yellow phosphor will re-scatter the returned polarized light into natural light, and then participate in the light cycle of the projection system 1. In other embodiments, the polarizing element 70 may also be a polarizer or a nicol prism.

The projection system 1 further includes a projection lens 80, the projection lens 80 is disposed in the emergent light path of the spatial light modulator 50, and the projection lens 80 is configured to project and image the light emitted from the spatial light modulator 50.

The projection system 1 further comprises a polarization analyzing element (not shown), which can analyze the light emitted from the spatial light modulator 50 to filter out the desired signal light, and then project the signal light through the projection lens 80, for example, to a projection screen. In this embodiment, the polarization analyzing element may be provided to the spatial light modulator 50.

In this embodiment, the illumination light emitted from the light source device 40 includes a first light, a second light and a third light, wherein the first light forms a first deflection light through the first light deflection assembly 100, the second light forms a second deflection light through the second light deflection assembly 200, the first deflection light, the second deflection light and the third light are emitted after being combined by the light combining assembly 300 and are separated in an angular direction, but RGB three-color light which is still overlapped on a surface (can be located on the same plane) is emitted after being sequentially passed through the cone-shaped dodging device 43, the fresnel lens 45 and the dodging prism 47, and is converted into polarized light through the polarizing element 70, and after passing through the micro lens array 60, the polarized light is subjected to surface angle conversion and is respectively incident to corresponding RGB pixels on the transmissive liquid crystal panel, so that light loss of the light beam passing through the spatial light modulator 50 is minimized, and high-efficiency illumination is realized, the thermal load of the spatial light modulator 50 can be reduced, and after the light beam exits from the transmissive liquid crystal panel, the required signal light is filtered by the analyzer and then projected to the projection screen by the projection lens 80.

In summary, the projection system 1 provided by the embodiment of the present invention includes the light combining device 10, the light source device 40 and the spatial light modulator 50, the light combining device 10 combines and emits the first deflection light, the second deflection light and the third light, and the illumination light can be divided into the first deflection light, the second deflection light and the third light which are separated from each other in the angle direction, so that the first deflection light is emitted after being modulated by the first light modulation unit 511 of the spatial light modulator 50, the second deflection light is emitted after being modulated by the second light modulation unit 512 of the spatial light modulator 50, and the third light is emitted after being modulated by the third light modulation unit 513 of the spatial light modulator 50, thereby realizing high-efficiency illumination and reducing the thermal load of the spatial light modulator 50. The light combining device 10 also reduces the angle difference between the included angle of the first deflection light and the third light and the included angle of the second deflection light and the third light, and can further improve the transmittance of the spatial light modulator 50, thereby prolonging the service life of the spatial light modulator 50 and improving the maximum output lumen of the spatial light modulator 50.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (12)

1. A light combining device for combining illumination light including first light, second light, and third light, the light combining device comprising:

the first light deflection component is arranged on a light emitting light path of the first light and is used for deflecting the first light to form a first deflection light;

the second light deflection component is arranged on a light emitting light path of the second light and is used for deflecting the second light to form second deflection light; and

and the light combining component is arranged on a light emitting light path of the third light and is used for combining and emitting the first deflection light, the second deflection light and the third light.

2. A light combining device according to claim 1, wherein the first light deflecting element is a prism array located opposite the light combining element, the prism array comprising a plurality of prism units, each prism unit having a triangular cross-section.

3. A light combining device according to claim 1, wherein the first light deflecting component is a prismatic film, the prismatic film comprises a substrate layer, a first functional layer and a second functional layer, the first functional layer comprises a plurality of corner units, the plurality of corner units are protruded from the substrate layer, and the first functional layer is made of a first material; the second functional layer is filled among the corner units and is made of a second material, and the Abbe number of the second material is different from that of the first material.

4. A light combining device according to claim 3, wherein each of the corner units comprises a first surface and a second surface connected to each other, the substrate layer comprises a bottom surface, the first surface and the second surface are both connected to the bottom surface, and the first surface and the second surface form an included angle of less than 90 °.

5. The light combining device of claim 1, wherein the light combining assembly comprises a first light incident surface, a second light incident surface and a third light incident surface, the first light incident surface and the second light incident surface are opposite to each other, the third light incident surface is connected between the first light incident surface and the second light incident surface, the first light deflecting assembly is opposite to the first light incident surface, and the second light deflecting assembly is opposite to the second light incident surface.

6. The light combining device according to claim 5, wherein the light combining component further comprises a first dichroic film and a second dichroic film, the first dichroic film being disposed between the first light incident surface and the second light incident surface for reflecting the first polarized light and transmitting the second polarized light and the third light; the second two-way film is arranged between the first light incoming surface and the second light incoming surface, and is used for reflecting the second deflection light and transmitting the first deflection light and the third light.

7. The light combining device according to claim 5, wherein the light combining component further comprises a light emitting surface, the light emitting surface is opposite to the third light incident surface, the combined light of the first polarized light, the second polarized light and the third light exits through the light emitting surface, and an included angle between the first polarized light and the third light exiting from the light emitting surface is equal to an included angle between the second polarized light and the third light.

8. A projection system comprising light source means for emitting said illumination light, a spatial light modulator, and light combining means according to any one of claims 1 to 7; the spatial light modulator comprises a plurality of light modulation unit groups, the light modulation unit groups are located on the same plane, each light modulation unit group comprises a first light modulation unit, a second light modulation unit and a third light modulation unit, first deflection light enters the first light modulation unit and is emitted after being modulated by the first light modulation unit, second deflection light enters the second light modulation unit and is emitted after being modulated by the second light modulation unit, and third light enters the third light modulation unit and is emitted after being modulated by the third light modulation unit.

9. The projection system of claim 8, wherein the light source device comprises a light source assembly for emitting the illumination light and a tapered dodging device disposed between the light source assembly and the spatial light modulator for dodging the illumination light.

10. The projection system of claim 9, wherein the light source assembly comprises a first laser for emitting the first light, a second laser for emitting the second light, and a third laser for emitting the third light.

11. The projection system of claim 9, wherein the light source device further comprises a fresnel lens and an dodging prism, the fresnel lens is disposed between the dodging prism and the tapered dodging device, and the dodging prism is disposed between the fresnel lens and the spatial light modulator.

12. The projection system of claim 11, wherein the fresnel lens and the integrator prism are a unitary structure.

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