CN216286123U - Projection system - Google Patents

Abstract

The application discloses projection system, this projection system includes: the liquid crystal display device comprises a light source assembly, a first liquid crystal modulator, a second liquid crystal modulator and a light combination assembly, wherein the light source assembly is used for generating first illumination light and second illumination light, the first illumination light is light of one color of three primary colors, and the second illumination light is synthesized by light of other colors of the three primary colors; the first liquid crystal modulator is used for receiving and modulating the first illumination light to generate first image light; the second liquid crystal modulator is used for receiving and modulating the second illumination light to generate second image light; the light combining component is arranged on the emergent light path of the first liquid crystal modulator and the second liquid crystal modulator and is used for combining the first image light and the second image light to generate image light; the projection lens is arranged on an emergent light path of the light combination component and is used for projecting image light; and the first liquid crystal modulator is not provided with a color film, and the second liquid crystal modulator is provided with a color film. Through the mode, the problem that the optical efficiency is low and the heat load is large can be improved, and the whole volume is small.

Description

Projection system

Technical Field

The application relates to the technical field of projection display, in particular to a projection system.

Background

At present, when projection Display is performed, a projection architecture based on a single Liquid Crystal Display (LCD) and a projection architecture based on three LCDs may be adopted, but the projection architecture based on the single LCD has the problems of low optical efficiency and rainbow effect, and the projection architecture based on the three LCDs has the problems of complex optical path system, high hardware cost, large system volume and the like.

SUMMERY OF THE UTILITY MODEL

The application provides a projection system, can improve the great problem of optical efficiency low and heat load, and whole volume is less.

In order to solve the technical problem, the technical scheme adopted by the application is as follows: there is provided a projection system comprising: the liquid crystal display device comprises a light source assembly, a first liquid crystal modulator, a second liquid crystal modulator and a light combination assembly, wherein the light source assembly is used for generating illuminating light, the illuminating light comprises first illuminating light and second illuminating light, the first illuminating light is light of one color of three primary colors, and the second illuminating light is synthesized by light of other colors of the three primary colors; the first liquid crystal modulator is arranged on an emergent light path of the light source component and used for receiving and modulating the first illuminating light to generate first image light; the second liquid crystal modulator is arranged on an emergent light path of the light source component and used for receiving and modulating second illuminating light to generate second image light; the light combining component is arranged on the emergent light path of the first liquid crystal modulator and the second liquid crystal modulator and is used for combining the first image light and the second image light to generate image light; the projection lens is arranged on the emergent light path of the light combination component and is used for projecting the image light.

Through the scheme, the beneficial effects of the application are that: the projection system provided by the application comprises: the light source assembly generates first illumination light and second illumination light, the first illumination light comprises light of one color of three primary colors, the second illumination light comprises light of other colors of the three primary colors, the first illumination light and the second illumination light are respectively emitted into the corresponding liquid crystal modulators to be modulated to generate first image light and second image light, the first image light and the second image light are subjected to spatial light combination through the light combination assembly to obtain image light, and the image light is projected onto a projection screen or a projection wall through a projection lens to realize projection display; because two liquid crystal modulators are adopted, a color film for modulating second image light is only required to be arranged on the second liquid crystal modulator, and the first liquid crystal modulator does not need to be provided with the color film, compared with a 3LCD projection system, the number of the liquid crystal modulators is less, and the whole volume is smaller; in addition, compared with a single LCD projection system, due to the adoption of two panels, the number of liquid crystal modulators capable of bearing heat loads is increased, the problems of low light efficiency and large heat load on a single liquid crystal modulator can be solved, and due to the fact that light is combined by two paths of light, compared with light combined by three paths of light, light spots are more uniform.

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.

Wherein:

FIG. 1 is a schematic diagram of a first embodiment of a projection system provided herein;

FIG. 2 is a schematic diagram of a second embodiment of a projection system provided herein;

fig. 3(a) is a schematic structural diagram of a first display panel provided in the present application;

fig. 3(b) is a schematic structural diagram of a second display panel provided in the present application;

FIG. 4 is a schematic diagram of a third embodiment of a projection system provided herein;

FIG. 5 is a schematic view of a light source module provided herein;

FIG. 6(a) is a schematic view of a light source module and a light collection device provided herein;

fig. 6(b) is a schematic structural diagram of a shaping device provided in the present application;

FIG. 7 is a schematic diagram of a fourth embodiment of a projection system provided herein;

FIG. 8 is a schematic diagram of a fifth embodiment of a projection system provided herein;

FIG. 9 is a schematic diagram of a sixth embodiment of a projection system provided herein;

FIG. 10 is a schematic diagram of a seventh embodiment of a projection system provided herein;

FIG. 11 is a schematic diagram of an eighth embodiment of a projection system provided in the present application;

FIG. 12 is a schematic diagram of a ninth embodiment of a projection system provided in the present application;

FIG. 13 is a schematic diagram of a tenth embodiment of a projection system provided herein;

FIG. 14 is a schematic diagram of an eleventh embodiment of a projection system provided in the present application;

FIG. 15 is a schematic diagram of a twelfth embodiment of a projection system provided in the present application;

FIG. 16 is a schematic diagram of a thirteenth embodiment of a projection system provided in the present application;

FIG. 17 is a schematic diagram of a fourteenth embodiment of a projection system provided in the present application;

FIG. 18 is a schematic diagram illustrating a fifteenth embodiment of a projection system provided herein;

FIG. 19 is a schematic diagram of a sixteenth embodiment of a projection system provided by the present application;

FIG. 20 is a schematic illustration of the light splitting principle of the prismatic film provided herein;

FIG. 21 is a schematic illustration of the preparation of a prismatic film provided herein;

FIG. 22 is a graph of the angular dependence of the tilt angle of the prism film on the beam deflection angle provided by the present application;

FIG. 23 is a graph of the prism film tilt angle versus the number of layers of prism film required when red light is deflected by 4 degrees, as provided herein;

FIG. 24 is a plot of Pitch size versus diffraction angle distance as provided herein;

FIG. 25 is a schematic diagram illustrating a seventeenth embodiment of a projection system provided herein;

FIG. 26 is a schematic diagram illustrating an eighteenth embodiment of a projection system provided by the present application;

FIG. 27 is a schematic diagram of a nineteenth embodiment of a projection system provided in the present application;

FIG. 28 is a schematic block diagram of a twentieth embodiment of a projection system provided by the present application;

FIG. 29 is a schematic block diagram of a twenty-first embodiment of a projection system provided by the present application;

fig. 30 is a schematic structural diagram of a twenty-second embodiment of a projection system provided by the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Since a projection system based on a reflective Digital Micromirror Device (DMD) and a projection system based on a Liquid Crystal on Silicon (LCoS) are systems using a reflective optical path, the optical path is complicated, the overall size is large, and the cost is high, a projection system based on an LCD is often used. The LCD panel is manufactured by two processes of Low Temperature Poly-Silicon (LTPS) LTPS and High Temperature Poly-Silicon (HTPS), wherein the HTPS process has High precision, but has High requirements on the process, so the cost is High; therefore, the LTPS process is usually adopted, and has low cost, but low precision and large pixel size (usually above 25 μm).

Although the volume of a single LCD projection system is slightly smaller than that of a DMD-based projection system and that of a LCoS-based projection system, there are problems in that efficiency is low and a thermal load of a display panel is high because a color film and a polarizer are present on the display panel. In order to solve the problems of a projection system of a single LCD, the related technical scheme provides a projection framework of a 3LTPS-LCD, which can reduce the heat load of a display panel to the maximum extent and improve the maximum output lumen number of the system; however, the display panel needs three channels of illumination light to illuminate respectively, so that the problem of large system volume exists; furthermore, since light combination of three display panels is required, and three illumination lights come from different optical systems, there is a problem that the illumination light is not uniform.

Based on the problems existing in the existing scheme, the application provides a projection framework of a 2LTPS-LCD based on non-imaging illumination, the problems of low efficiency and large panel heat load existing in the projection framework of a single LCD can be solved, and meanwhile, the projection framework is smaller in size and more uniform in light spot compared with the projection framework of a 3 LTPS-LCD.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a projection system according to a first embodiment of the present disclosure, the projection system including: a light source module 101, a first liquid crystal modulator 102, a second liquid crystal modulator 103, a light combining module 104, and a projection lens 105.

The light source assembly 101 is used for generating illumination light, and the light source assembly 101 may be a light-emitting diode (LED), a laser fluorescent 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 three primary colors, the second illumination light is light synthesized by other colors of the three primary colors, the light source assembly 101 irradiates the first liquid crystal modulator 102 and the second liquid crystal modulator 103 in a non-imaging illumination manner, wherein a color film is not disposed in the first liquid crystal modulator 102 and is used for modulating a single color light, and the second liquid crystal modulator 103 is provided with color films (not shown) for respectively modulating light of other colors of the second illumination light, that is, the second liquid crystal modulator 103 is used for modulating broad spectrum light.

Further, the first illumination light can be blue light, the second illumination light can be yellow light, and the yellow light can be obtained by exciting yellow fluorescent powder by the blue light or closely splicing a red light source and a green light source; or the first illumination light is red light, the second illumination light is cyan light, and the green light can be obtained by exciting green fluorescent powder by blue light or closely splicing a blue light source and a green light source; or the first illumination light is green light, the second illumination light is pinkish light, and the red light can be obtained by exciting red fluorescent powder by blue light or closely splicing a blue light source and a red light source.

The first liquid crystal modulator 102 is disposed on an emitting light path of the light source assembly 101, and is configured to receive and modulate the first illumination light to generate a first image light. The second liquid crystal modulator 103 is disposed on an emitting light path of the light source assembly 101, and is configured to receive the second illumination light and modulate the second illumination light to generate a second image light, where the first liquid crystal modulator 102 and the second liquid crystal modulator 103 are LTPS-LCDs.

In a specific embodiment, as shown in fig. 2, 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 on the optical path of the first illumination light and is used for obtaining light with a first polarization state from the first illumination light emitted from the light source assembly 101, and the first polarization state may be a P polarization state; the first display panel 22 is disposed on an emergent light path of the first polarizer 21, and is configured to receive light emitted from the first polarizer 21; the first analyzer 23 is disposed on the light emitting path of the first display panel 22, and is configured to convert light emitted from the first display panel 22 into first image light.

The second liquid crystal modulator 103 includes a second polarizer 31, a second display panel 32, and a second analyzer 33, where the second polarizer 31 is disposed on the optical path of the second illumination light and is used for obtaining light with the first polarization state from the second illumination light emitted from the light source assembly 101; the second display panel 32 is disposed on the outgoing light path of the second polarizer 31, and is configured to receive light outgoing from the second polarizer 31; the second analyzer 33 is disposed on the light path of the second display panel 32, and is configured to convert the light emitted from the second display panel 32 into second image light.

Further, the first display panel 22 and the second display panel 32 are LTPS-LCD panels, as shown in fig. 3(a) -3(b), the first display panel 22 includes a plurality of first pixel units 221, the second display panel 32 includes a plurality of second pixel units 321, the number of the first pixel units 221 is the same as that of the second pixel units 321, and each of the second pixel units 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.

It is understood that the 2LTPS-LCD panels are respectively illuminated by two separate light paths, and when the light path of the blue light is a separate light path, the thermal load of the first display panel 22 can be reduced, thereby improving the lifetime of the first display panel 22. When the system efficiency is affected by the red excitation efficiency, the red light can be placed in a separate light path, which allows for greater etendue and panel transmittance. When the system is limited in lumen by green light, the green light can be placed in a separate light path, which maximizes the output efficiency of the system.

Preferably, due to the limitation of the LTPS-LCD process precision, if a certain aperture ratio is to be ensured while ensuring high resolution, the display panels (including the first display panel 22 and the second display panel 32) need to be made larger, and the size of the display panel with 1080P resolution is usually 2 inches or 1 inch, at this time, if the dispersion or the pixel is considered, the system volume is too large by adopting the imaging illumination, so the embodiment adopts the non-imaging illumination to illuminate the first display panel 22 and the second display panel 32.

The light combining component 104 is disposed on the light emitting paths of the first liquid crystal modulator 102 and the second liquid crystal modulator 103, and is configured to combine the first image light and the second image light to generate image light; specifically, the light combining component 104 may be a dichroic light combining prism or a polarization light combining prism.

The projection lens 105 is disposed on an exit light path of the light combining component 104, and is configured to project image light; further, the projection lens 105 may use a cell phone architecture or a field lens architecture.

The embodiment provides a projection framework of a 2LTPS-LCD based on non-imaging illumination, and due to the fact that two LTPS-LCDs are adopted, the problems that a single-LCD projection system is low in efficiency and high in panel heat load are solved, meanwhile, the size of the projection framework is smaller than that of a 3LTPS-LCD, heat load and size are considered, and light spots are uniform.

Referring to fig. 4, fig. 4 is a schematic structural diagram of a projection system according to a third embodiment of the present application, the projection system including: a light source module 101, a first liquid crystal modulator 102, a second liquid crystal modulator 103, a light combining module 104, and a projection lens 105.

The light source module 101 is configured 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 assembly 1011 and a second light emitting assembly 1012, the first light emitting assembly 1011 is configured to generate a first illumination light, and the first illumination light is light of one of three primary colors; the second light emitting assembly 1012 is used to generate a second illumination light composed of the other colors of the three primary colors.

Further, the first light emitting assembly 1011 is a single color LED, and the second light emitting assembly 1012 is a two-color LED, such as: yellow light LED, cyan light LED, magenta light LED or light sources of two colors are closely spliced, in this embodiment, the first light emitting component 1011 is a blue light LED, and the second light emitting component 1012 is a yellow light LED.

In another embodiment, the light source module 101 may also be replaced by a reflective laser fluorescence light source, that is, the first illumination light is blue laser, and the first light emitting module 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 fluorescent sheet or an LED with a surface coated with fluorescent powder, and the second light emitting assembly 1012 is used for receiving blue laser and generating a received laser, where the received laser includes yellow light, cyan light or magenta light.

In other embodiments, the light source module 101 may be replaced by a transmissive laser fluorescence light source, as shown in fig. 5, the light source module 101 includes a blue laser 41, a first dodging module 42, an imaging lens 43 and a second wavelength conversion device 44.

The blue laser 41 is an array laser for generating blue laser light, i.e., the first illumination light is blue laser light. The first dodging assembly 42 is disposed on an outgoing light path of the blue laser 41, and is configured to dodge blue laser light. The imaging lens 43 is disposed on the exit light path of the first dodging assembly 42, and is used for imaging the blue laser light output by the first dodging assembly 42 onto the second wavelength conversion device 44, so that the second wavelength conversion device 44 generates second illumination light.

Further, the blue laser emitted from the blue laser 41 is first homogenized by the first light homogenizing assembly 42, and then the uniform rectangular spot is imaged on the second wavelength conversion device 44 by the imaging lens 43.

In another specific embodiment, as shown in fig. 4, the projection system further includes a light collection device (not shown), disposed on the light path exiting from the light source assembly 101, for collecting the illumination light and injecting the illumination light into the first liquid crystal modulator 102 and the second liquid crystal modulator 103; specifically, the light collection device includes a second light unifying assembly and a lens assembly (not shown) arranged along the transmission direction of the illumination light, the second light unifying assembly is used for unifying the illumination light, and the lens assembly is used for collimating the illumination light emitted by the second light unifying assembly.

In one embodiment, as shown in fig. 4, the number of the light collecting devices is two, which are respectively referred to as a first light collecting device and a second light collecting device, the second light unifying assembly includes a first light unifying device 1061 and a second light unifying device 1062, and the lens assembly includes a first lens device 1081 and a second lens device 1082.

The first light collecting device is disposed on an emergent light path of the first light emitting assembly 1011, is used for collecting the first illumination light and emitting the first illumination light into the first liquid crystal modulator 102, and includes a first dodging device 1061 and a first lens device 1081 disposed along a transmission direction of the illumination light, and the first lens device 1081 may be a collimating lens or a fresnel lens. The second light collecting device is disposed on the light emitting path of the second light emitting assembly 1012, is used for collecting the second illumination light and emitting the second illumination light into the second liquid crystal modulator 103, and includes a second dodging device 1062 and a second lens device 1082 disposed along the transmission direction of the illumination light, and the second lens device 1082 may be a collimating lens or a fresnel lens. Specifically, the first light uniformizing device 1061 and the second light uniformizing device 1062 may be cone barrels, that is, the light collecting device is a cone barrel plus lens system or a cone barrel plus fresnel lens system; the collimating lens can collimate the illumination light so that the illumination light can smoothly enter the optical element at the downstream of the optical path. It is to be understood that, in other embodiments of the present application, when the illumination light from the upstream optical path satisfies a small divergence angle, the collimator lens may not be provided.

Furthermore, the smaller one end of area of awl bucket is the incident surface, and the great one end of area is the exit surface to make the illumination light that light source subassembly 101 launched after the incident surface incides awl bucket inside, by exit surface outgoing or direct outgoing after the lateral wall reflection of awl bucket, make the area of emergent facula be greater than the area of incident facula, thereby reduced the divergence angle of light beam.

It can be understood that the cone-shaped barrel in the embodiment is a solid cone-shaped light guide rod, and the light beam is reflected on the side surface of the cone-shaped barrel in a total reflection manner. In other embodiments, the cone may also be a hollow cone composed of a reflective plate/surface, which is not described herein again.

In another embodiment, the light collection device is a circular collection lens system, as shown in fig. 6(a), the light collection device includes a first collection lens 51 and a second collection lens 52, the first collection lens 51 is disposed on the light path exiting from the light source assembly 101 and is used for collecting the illumination light; the second collecting lens 52 is used for collecting the light emitted from the first collecting lens 51.

It will be appreciated that the light collection means may also be in the form of a free form shaping system and a discrete version of the collection system described above; through setting up light collection device, can guarantee the homogeneity of illumination light, reduce the volume of system, guarantee certain efficiency simultaneously.

Referring to fig. 6(a) -6(b), the projection system further includes a shaping device 53, the shaping device 53 is configured to shape the illumination light emitted from the second collecting lens 52, so that the light spot of the illumination light emitted from the shaping device 53 has a preset shape, which may be a rectangle, and the shaping device 53 may be a polarizing shaping film.

Further, since the surface distribution of the illumination light emitted from the second collecting lens 52 is circular, and the portion of the display panel to be illuminated is rectangular, it is necessary to cut out a rectangle from the circular spot, as shown in fig. 6(b), the shaping device 53 includes a first region 531 and a second region 532, and the first region 531 is used for transmitting the illumination light emitted from the second collecting lens 52; the second region 532 is used for reflecting the illumination light emitted from the second collecting lens 52 to the light source assembly 101, 533 as a circular spot distribution.

Preferably, the first region 531 is a light recycling film layer, the second region 532 is a mirror reflection film layer, and the portion of the circular light spot not participating in the illumination of the display panel is reflected back to the corresponding light collecting device for light recycling; in addition, the first region 531 may also be used for recycling polarized light, such as: the first region 531 transmits the illumination light of P polarization and reflects the illumination light of S polarization to further improve the system efficiency.

In another embodiment, the projection system further includes an adjusting component (not shown) disposed on the light-emitting path of the light source module 101, for shaping the illumination light and emitting the illumination light into the first liquid crystal modulator 102 and the second liquid crystal modulator 103.

Further, the adjusting component includes a first adjusting component and a second adjusting component, the first adjusting component is disposed on the emergent light path of the first light emitting component 1011, and the second adjusting component is disposed on the emergent light path of the second light emitting component 1012. The first adjusting component and the second adjusting component can be field lenses, lenses or Fresnel lenses, and the field lenses, the lenses or the Fresnel lenses are added between the display panel and the illuminating light to integrate telecentric illumination into non-telecentric illumination, so that the design difficulty and cost of the lens are further reduced.

The first liquid crystal modulator 102 is disposed on an emitting light path of the light source assembly 101, and is configured to receive and modulate the first illumination light to generate a first image light. The second liquid crystal modulator 103 is disposed on an emitting light path of the light source assembly 101, and is configured to receive the second illumination light and modulate the second illumination light to generate second image light.

Further, a light recycling film (not shown) may be added before the polarizers (including the first polarizer 21 and the second polarizer 31), the light recycling film is a polarized light recycling film, the illumination light of the first polarization state is transmitted through the polarized light recycling film, the illumination light of the second polarization state is reflected back to the light source assembly 101 for light recycling, and the second polarization state may be the S polarization state.

The light combining component 104 is disposed on the light emitting paths of the first liquid crystal modulator 102 and the second liquid crystal modulator 103, and is configured to combine the first image light and the second image light to generate image light. The projection lens 105 is disposed on an exit light path of the light combining component 104, and is configured to project image light.

With continued reference to fig. 4, the projection system further includes a first pixel expanding device 107, where the first pixel expanding device 107 is disposed on the light emitting path of the light combining component 104, and is used to expand the image light and emit the image light into the projection lens 105.

Further, the light combining component 104 may be a light combining prism, and by placing a first pixel expansion device 107 between the light combining prism and the projection lens 105, for example: the Resolution of the display panel can be further improved by Pixel expansion (E-SHIFT) or extended Pixel Resolution (XPR) of the birefringent crystal.

The working principle of the present embodiment is described below by taking the light combining component 104 as a dichroic light combining prism, the first light emitting component 1011 as a blue light LED, the second light emitting component 1012 as a yellow light LED, and the first lens device 1081 and the second lens device 1082 as collimating lenses as examples, where the collimating lens in the blue light path (i.e., the light path where the blue light LED is located) is referred to as a first collimating lens; the collimating lens in the yellow light path (i.e., the light path in which the yellow LED is located, which may be referred to as the bi-color light path) is referred to as the second collimating lens.

For a blue light path, first illumination light emitted by the blue LED is collected by the tapered first dodging device 1061, and then is collimated by the first collimating lens to be parallel blue light, a first polarizer 21 is placed at an outlet of the first collimating lens to polarize the parallel blue light, the polarized blue light is irradiated onto the first display panel 22, and then image light to be displayed is filtered out by the first analyzer 23 to obtain first image light.

For the yellow light path, with reference to fig. 3(b) and fig. 4, the second illumination light emitted by the yellow LED is collected by the tapered second light uniformizing device 1062, and then collimated by the second collimating lens to parallel yellow light, 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 irradiated onto the second display panel 32, the green light of the yellow light is incident on the first subpixel 3211 in the second pixel unit 321 and modulated by the first subpixel 3211, the red light of the yellow light is incident on the second subpixel 3212 in the second pixel unit 321 and modulated by the second subpixel 3212, and the modulated red light and the modulated green light are incident on the second analyzer 33; the image light to be displayed is filtered out by the second analyzer 33 to obtain second image light.

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, and then image light is generated and enters the first pixel expansion device 107 to further improve the display resolution, and finally the image light emitted from the first pixel expansion device 107 is projected onto a projection screen or a projection wall (not shown in the figure) through the projection lens 105.

In another specific embodiment, as shown in fig. 7, fig. 7 is a schematic structural diagram of a fourth embodiment of the projection system provided in the present application, and different from the embodiment shown in fig. 4, the embodiment includes: the projection system in this embodiment further comprises a first folding prism 109.

The first turning prism 109 is disposed on an emitting light path of the first light emitting assembly 1011, and is used for adjusting a 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, the first direction and the second direction being perpendicular to each other, such as: the first direction is a vertical direction, and the second direction is a horizontal direction, and since the transmission direction of the first illumination light can be changed, the length in the horizontal direction can be compressed.

With continued reference to fig. 7, the projection system further includes a first hollow guiding tube 110, the first hollow guiding tube 110 is disposed on the light emitting path of the first light emitting element 1011, and is used for transmitting the first illumination light to the first folding prism 109 without loss.

It is understood that the transmission direction of the second illumination light in the two-color light path can be adjusted, that is, the first hollow conduit 110 is disposed on the light emitting path of the second light emitting assembly 1012, and is used for transmitting the second illumination light to the first folding prism 109; the first turning prism 109 is disposed on the outgoing light path of the first hollow conduit 110, and is used for adjusting the transmission direction of the second illumination light.

With continued reference to fig. 7, the projection system further includes a polarized light recycling device 122, and the polarized light recycling device 122 is disposed on the light emitting path of the first light emitting module 1011, and is configured to transmit the illumination light with the first polarization state in the illumination light to the first hollow guide tube 110, and reflect the illumination light with the second polarization state in the illumination light to the first light emitting module 1011. Specifically, the polarized light recycling device 122 may be a Dual Brightness Enhancement Film (DBEF).

Further, the polarized light recycling 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 assembly 1011 sequentially enters the first dodging device 1061, the first lens device 1081 and the polarized light recycling device 122, a part of the light is transmitted by the polarized light recycling device 122 and then continuously emitted in a single polarization state, another part of the light is reflected by the polarized light recycling device 122 and then returns to the polarized light recycling device 122, and is reflected back and forth in the polarized light recycling device 122 and emitted through the emitting surface of the polarized light recycling device 122, so that the utilization rate of the illumination light is improved. In order to reduce the number of times of recycling of the recycled illumination light, a structure such as an 1/4 wave plate may be provided in the first light unifying device 1061 to change the polarization state of the light beam.

In the present embodiment, the first folding prism 109 and the first hollow conduit 110 are disposed in a light path, and the transmission direction of the illumination light in the light path can be changed by the cooperation of the two, so as to reduce the length of the projection system in a certain direction, and make the whole system more compact.

In another specific embodiment, as shown in fig. 8, fig. 8 is a schematic structural diagram of a fifth embodiment of the projection system provided in the present application, and this embodiment is similar to the embodiment shown in fig. 4, except that: the light source assembly 101 of this embodiment further includes a third light emitting assembly 1013 and a first light splitting assembly 111, and the second light emitting assembly 1012 can be an LED light source with a surface coated with phosphor.

The third light emitting assembly 1013 is used to generate blue laser light; the first light splitting element 111 is disposed on an emitting light path of the third light emitting element 1013, and is configured to reflect the blue laser light generated by the third light emitting element 1013 to the second light emitting element 1012 and transmit the received laser light generated by the second light emitting element 1012 to the second liquid crystal modulator 103.

The working principle of this embodiment will be described below by taking the first light emitting element 1011 as a blue laser and the phosphor as a yellow phosphor as an example:

the blue laser light emitted from the third light emitting assembly 1013 is collected by a third light collecting device (including a third dodging device 1063 and a third lens device 1083), enters the first light splitting assembly 111, is reflected by the first light splitting assembly 111, and is collected by the second light collecting device to be incident on the yellow phosphor, so as to generate yellow fluorescent light; the blue laser light emitted from the first light emitting element 1011 is reflected by the light combining element 104 and enters the second liquid crystal modulator 103, and then is transmitted by the first light splitting element 111 and collected by the second light collecting device and enters the yellow fluorescent powder to generate yellow fluorescent light, and the yellow fluorescent light sequentially passes through the second light collecting device, the first light splitting element 111 and the second liquid crystal modulator 103 and enters the light combining element 104.

In this embodiment, the two-sided excitation is carried out to the phosphor powder in the double-colored light path through two way blue lights, helps promoting the excitation efficiency who receives laser, and then promotes optical efficiency.

In another specific embodiment, since the manner of adding one laser beam and one laser beam shown in fig. 8 may bring a burden to the volume, a two-sided excitation architecture with two optical paths is proposed, as shown in fig. 9, fig. 9 is a schematic structural diagram of a sixth embodiment of the projection system provided by the present application, which is different from the embodiment shown in fig. 8: in this embodiment, the light source module 101 further includes a second light splitting module 112 and a third light splitting module 113, and the third light emitting module and the first light splitting module are not disposed.

In this embodiment, the first light emitting element 1011 is a blue laser, the second light emitting element 1012 is a yellow LED or a fixed phosphor plate coated with yellow phosphor, double-sided excitation can be achieved, one side is that the second light emitting element 1012 generates yellow light, the other side is that the blue laser generated by the first light emitting element 1011 excites the yellow phosphor to generate yellow light, the first illumination light is emitted into the second light splitting element 112 along the direction from bottom to top, and the second illumination light is emitted into the third light splitting element 113 along the direction from bottom to top.

Further, the second light splitting component 112 is disposed on the outgoing light path of the blue laser, and is configured to transmit light having the first polarization state in the blue laser, so as to form first illumination light and emit the first illumination light into the first liquid crystal modulator 102. The third light splitting element 113 is disposed on the reflection light path of the second light splitting element 112, and is configured to reflect light with the second polarization state in the blue laser light to the second light emitting element 1012, and transmit the received laser light generated by the second light emitting element 1012 to the second liquid crystal modulator 103.

With reference to fig. 9, the projection system further includes a second hollow guide tube 114, where the second hollow guide tube 114 is disposed on the light emitting path of the second light splitting assembly 112, and is used to transmit the light with the second polarization state in the blue laser to the third light splitting assembly 113, that is, the third light splitting assembly 113 is disposed on the light emitting path of the second light splitting assembly 112.

The working principle of the embodiment is as follows: blue light is emitted into the second light splitting assembly 112 and is divided into two paths, one path sequentially passes through the first hollow guide tube 110, the first turning prism 109 and the first liquid crystal modulator 102 to enter the light combining assembly 104, the other path enters the third light splitting assembly 113 through the second hollow guide tube 114 and is reflected to yellow fluorescent powder by the third light splitting assembly 113, so that the yellow fluorescent powder generates yellow fluorescent light, the yellow fluorescent light enters the third light splitting assembly 113, is transmitted to the second liquid crystal modulator 103 by the third light splitting assembly 113 and enters the light combining assembly 104 after being modulated by the second liquid crystal modulator 103, the subsequent working principle is similar to that of the embodiment shown in fig. 4, and the description is omitted.

In another specific embodiment, a 2LTPS-LCD architecture of a reflective laser fluorescence light source can also be adopted, as shown in fig. 10, fig. 10 is a schematic structural diagram of a seventh embodiment of the projection system provided in the present application, and different from the embodiment shown in fig. 9, the structure diagram of the seventh embodiment is as follows: in this embodiment, the first illumination light enters the second light splitting assembly 112 from the top to the bottom, and the second illumination light enters the third light splitting assembly 113 from the left to the right.

The second light splitting component 112 is disposed on an emitting light path of the blue laser, and is configured to reflect light with a first polarization state in the blue laser to form first illumination light and emit the first illumination light into the first liquid crystal modulator 102; the third light splitting element 113 is disposed on the transmission light path of the second light splitting element 112, and is configured to transmit light with the second polarization state in the blue laser light to the second light emitting element 101, and transmit the received laser light generated by the second light emitting element 101 to the second liquid crystal modulator 103.

The working principle of the present embodiment is described below by taking as an example that the first light emitting element 1011 is a blue laser, the first turning prism 109 is a right-angle prism, the first wavelength conversion device is a color wheel 61, the second light splitting element 112 is a P-transparent inverse S prism, the third light splitting element 113 is a prism with a blue-transparent coating (referred to as a blue-transparent prism), and the light combining element 104 is a P-transparent inverse S prism with a P-transparent polarized blue-light-reflective S-polarized blue-light coating (referred to as a P-transparent inverse S prism):

the blue polarized light (usually P polarized blue light) emitted by the blue laser is transmitted into the second hollow conduit 114 after passing through the P-transparent reverse S prism, and then reflected to the second light collecting device by the blue-transparent yellow prism, and enters the color wheel 61 after being collected by the second light collecting device, the yellow phosphor on the excitation color wheel 61 emits lambert white light, the white light after excitation is collected by the second light collecting device and then split by the blue-transparent yellow prism, and then the yellow light is emitted from the other surface of the right-angle prism, and the second polarizer 31 is placed on the emitting surface of the right-angle prism, preferably, a reflective polarizer (not shown in the figure) can be placed therein, such as: DBEF to achieve light recycling to improve polarization efficiency; the polarized yellow light illuminates the second display panel 32.

The blue light reflected by the anti-blue yellow-transmitting prism is scattered and then changed into blue light containing light of a P component and light of an S component, and then enters the anti-P S-transmitting prism through the second hollow duct 114, wherein the blue light of the S component (namely the S-polarized blue light) is reflected and then emitted, and a first polarizer 21 is arranged between the emitting surface and the first display panel 22 for polarization purification, so that the contrast of the system is improved.

The analyzer (including the first analyzer 23 and the second analyzer 33) filters out the image lights of the two display panels, combines the image lights by the light combining component 104, and projects the combined light onto the projection screen through the projection lens 105.

It is understood that the color wheel 61 in this embodiment may be replaced by a fixed fluorescent sheet 62 (as shown in fig. 11) or an LED with phosphor powder coated on the surface.

In another embodiment, please refer to fig. 12, fig. 12 is a schematic structural diagram of a ninth embodiment of a projection system provided in the present application, which is different from the embodiment shown in fig. 4: the projection system further comprises: a fourth light-splitting assembly 115, a second turning prism 116 and a third turning prism 117, and the light source assembly 101 is a white light source.

The fourth light splitting assembly 115 is disposed on an exit light path of the light source assembly 101, and is configured to split the illumination light into a first illumination light and a second illumination light.

The second turning prism 116 is disposed on the optical path of the first illumination light, and is used for adjusting the transmission direction of the first illumination light from the first direction to the second direction, and emitting the first illumination light to the first liquid crystal modulator 102.

The third turning prism 117 is disposed on 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 to emit the second illumination light into the second liquid crystal modulator 103.

With continued reference to fig. 12, the projection system further includes a polarized light recycling device 122, where the polarized light recycling device 122 is disposed on an exit light path of the light source module 101, and is configured to transmit the illumination light with the first polarization state in the illumination light to the fourth light splitting module 115, and reflect the illumination light with the second polarization state in the illumination light to the light source module 101. Specifically, the polarization recycling device 122 may be DBEF, and the polarization recycling device 122 may be disposed between the lens assembly 108 and the fourth light splitting assembly 115, or between the first polarizer 21 and the second turning prism 116.

Further, taking the example that the polarized light recycling device 122 is disposed between the lens assembly 108 and the fourth light splitting assembly 115, the white light emitted from the white light source sequentially enters the second light homogenizing assembly 106, the lens assembly 108 and the polarized light recycling device 122, a part of the light is transmitted from the polarized light recycling device 122 and then continuously emitted in a single polarization state, and the other part of the light is reflected by the polarized light recycling device 122 and then returns to the polarized light recycling device 122, is reflected back and forth in the polarized light recycling device 122 and is emitted through the emitting surface of the polarized light recycling device 122, so that the utilization rate of the illumination light is improved. In order to reduce the recycling times of the recycled illumination light, a structure such as 1/4 wave plate can be arranged in the second dodging assembly 106 to change the polarization state of the light beam.

With continued reference to fig. 12, the projection system further includes a third hollow conduit 118 and a fourth hollow conduit 119, the third hollow conduit 118 is disposed on the reflection light path of the fourth light splitting element 115, and is used for transmitting the light with the second polarization state in the illumination light to the third turning prism 117; a fourth hollow conduit 119 is disposed on the transmission light path of the fourth light splitting assembly 115 for transmitting light of the first polarization state in the illumination light to the second turning prism 116.

The working principle of the present embodiment will be described below by taking a white light source as a white light LED, the fourth light splitting assembly 115 as a dichroic splitting prism (a blue-transmitting and yellow-reflecting film is coated on the dichroic splitting prism), and the light combining assembly 104 as a dichroic light combining prism (a blue-transmitting and yellow-reflecting film is coated on the dichroic splitting prism):

the illumination light emitted by the white light LED is collected by the second light homogenizing assembly 106 and collimated into parallel light by the lens assembly 108, the parallel light enters the polarized light recycling device 122, and the polarized light recycling device 122 polarizes the white light. The polarized parallel white light is split by the dichroic beam splitter prism into reflected yellow light (i.e., the second illumination light) and transmitted blue light (i.e., the first illumination light). The blue light is emitted from the exit surface of the second turning prism 116 after passing through the fourth hollow guide tube 119 and the second turning prism 116, and the first polarizer 21 is disposed on the exit surface to further polarize and purify the first illumination light. The yellow light is emitted from the emitting surface of the second turning prism 116 after passing through the third hollow guide tube 118 and the second turning prism 116, and the second polarizer 31 is placed on the emitting surface to further perform polarization purification on the second illumination light.

The polarized blue light is directly illuminated onto the first display panel 22 and the polarized yellow light is directly illuminated onto 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, and then is combined by the dichroic light-combining prism and projected onto the projection screen by the projection lens 105. The scheme is based on white light splitting, and has the advantages of high efficiency and good color uniformity.

It is understood that the illumination portion in the above embodiments may also adopt discrete multi-area illumination, such as: a discrete conical rod lens array or a discrete collection lens array is used to further reduce the system volume.

The embodiment provides a projection framework of a 2LTPS-LCD based on non-imaging illumination, solves the problems of low efficiency and high panel heat load of a single LCD projection system, and has smaller volume and more uniform light spots compared with the projection framework of a 3 LTPS-LCD; in addition, at the same moment, light of three colors on the projection screen is available, so that the rainbow effect and the color separation effect can be effectively reduced, and the display effect is improved.

In order to improve the resolution of the display panel, a second pixel expansion device may be further disposed between the light combining component and the projection lens or between the second display panel and the light combining component, which is described in detail below.

Referring to fig. 13, fig. 13 is a schematic structural diagram of a tenth embodiment of a projection system provided in the present application, which is different from the embodiment shown in fig. 4: the projection system in this embodiment further comprises a second pixel extension device 120.

The second pixel expanding device 120 is disposed on an emergent light path of the light source module 101, and is configured to expand the image light and inject the image light into the light combining module 104; specifically, the second pixel expanding device 120 is disposed on an emitting light path of the second liquid crystal modulator 103, and is configured to expand the second image light and inject the second image light into the light combining component 104. It will be appreciated that the working principle of the projection system is similar to that of the embodiment shown in fig. 4, and will not be described herein again.

The second pixel expansion device 120 is disposed at the light-emitting position of the second display panel 32 in the red-green light path, and for a specific pixel position in the space, the red pixel light and the green pixel light pass through in time sequence, and are combined with the blue pixel light of the first display panel 22 in the blue light path to finally present image light. The resolution of the second display panel 32 is improved by using the second pixel expansion device 120, and the display effect can be further improved by using the resolution of the current frame of the second display panel 32.

In another embodiment, please refer to fig. 14, fig. 14 is a schematic structural diagram of an eleventh embodiment of a projection system provided in the present application, which is different from the embodiment shown in fig. 13: the projection system of this embodiment further includes a first folding prism 109 and a first hollow duct 110, and the working principle of the projection system is similar to that of the embodiment shown in fig. 7 and 13, and will not be described again here.

In another embodiment, please refer to fig. 15, fig. 15 is a schematic structural diagram of a twelfth embodiment of a projection system provided in the present application, which is different from the embodiment shown in fig. 13: the projection system in this embodiment further includes a second light splitting assembly 112, a third light splitting assembly 113, and a second hollow conduit 114, and the working principle of the projection system is similar to that of the embodiment shown in fig. 9 and 13, and is not described herein again.

In another specific embodiment, please refer to fig. 16, fig. 16 is a schematic structural diagram of a thirteenth embodiment of a projection system provided in the present application, which is different from the embodiment shown in fig. 15: in this embodiment, the first illumination light enters the second light splitting assembly 112 from the top to the bottom, and the second illumination light enters the third light splitting assembly 113 from the left to the right.

The first light emitting assembly 1011 may be a blue LED or a blue laser, and is configured to emit blue light, and after the blue light is collected and polarized, the blue light passes through the second light splitting assembly 112 (for example, the second light splitting assembly 112 reflects the blue light in the S polarization state, and transmits the blue light in the P polarization state, and the blue light emitted by the first light emitting assembly 1011 is in the P polarization state), reaches the third light splitting assembly 113 (for example, the third light splitting assembly 113 reflects the blue light and transmits yellow light), and is reflected by the third light splitting assembly 113 and enters the color wheel 61, so as to excite the phosphor on the color wheel 61 to obtain white light. Yellow light in the white light is transmitted by the third light splitting component 113, and reaches the second liquid crystal modulator 103 through the first hollow conduit 110 and the first turning prism 109; the blue light in the white light is reflected by the third light splitting component 113 and then reaches the second light splitting component 112, the blue light in the S state is reflected by the second light splitting component 112 and enters the first liquid crystal modulator 102, and the blue light in the P polarization state 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, and the image light is emitted after passing through the first pixel expansion device 107 and the projection lens 105.

In another specific embodiment, please refer to fig. 17, fig. 17 is a schematic structural diagram of a fourteenth embodiment of a projection system provided in the present application, which is different from the embodiment shown in fig. 16: the second light-emitting component in this embodiment is a fixed fluorescent sheet 62, and the working principle of the projection system is similar to that of the embodiment shown in fig. 16, and will not be described again.

In another specific embodiment, please refer to fig. 18, fig. 18 is a schematic structural diagram of a fifteenth embodiment of a projection system provided in the present application, which is different from the embodiment shown in fig. 13: the projection system in this embodiment further includes a fourth light-splitting assembly 115, a second turning prism 116 and a third turning prism 117, and the light source assembly 101 is a white light source.

It can be understood that the operation principle of the projection system is similar to that of the embodiment shown in fig. 12 and 13, and the difference is that the bi-color image light is emitted from the second liquid crystal modulator 103, and then is subjected to pixel expansion by the second pixel expanding device 120 to improve the resolution, and then is combined by the light combining component 104 and projected onto the projection screen by the projection lens 105, which is not described herein again.

The embodiment provides a projection framework of a 2LTPS-LCD based on non-imaging illumination, solves the problems of low efficiency and large panel thermal load of a single LCD projection system, reduces rainbow effect, and has smaller volume, more uniform light spots and high system efficiency compared with a 3LTPS-LCD projection system; and because the pixel expansion device is adopted for pixel expansion, the resolution is higher.

One panel (panel in a two-color light path) in a projection scheme based on a 2LTPS-LCD still needs to be filtered by a color film, and a large thermal load is generated. In addition, in order to solve the problems of low efficiency and large panel heat load of a single LCD projection system, the efficiency of illuminating light transmitting the LCD panel is improved by matching a light splitter with a micro-lens array, but the dispersion angles of red light, green light and blue light are not consistent; further, the angle between red light (620 nm wavelength) and green light (530 nm wavelength) is smaller than the angle between green light and blue light (455 nm wavelength), which results in excessive spectral loss between red light and green light during light splitting, and the spectral gap between green light and blue light is not fully utilized, resulting in low system efficiency and low lumen output. Based on this, this application provides the improvement: using a 2-piece LCD to split one of the colors into the other panel not only maximizes the spectral utilization when using the dispersive light splitting device, but also reduces the panel load and increases the system efficiency and total output lumens, as will be described in detail below.

Referring to fig. 19, fig. 19 is a schematic structural diagram of a sixteenth embodiment of a projection system provided by the present application, which is different from the embodiment shown in fig. 1: the projection system further comprises a dispersive beam splitter device 121.

The dispersion light splitting device 121 is disposed on an exit light path of the light source assembly 101, and the dispersion light splitting device 121 is configured to split the second illumination light into first sub-illumination light and second sub-illumination light; the second liquid crystal modulator 103 is disposed on an exit light path of the light source module 101, and the second liquid crystal modulator 103 is configured to modulate the first sub-illumination light and the second sub-illumination light to generate a second image light.

The principle of the dispersion will be described below by taking the dispersion spectrometer 121 as a prism film.

As shown in fig. 20, the principle of prism film dispersion is that a dispersion spectroscopic device 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 is a periodic structure, the material of the first structural layer 71 is different from that of the second structural layer 72, and dispersion spectroscopy can be realized by the first structural layer 71 and the second structural layer 72.

Further, the abbe number of the first structural layer 71 is smaller than a preset value, and the abbe number of the second structural layer 72 is larger than the preset value, that is, the material of the first structural layer 71 and the material of the second structural layer 72 may be a low abbe number material and a high abbe number material, respectively, and the preset value may be set according to experience or application requirements; the predetermined wavelength may be the dominant wavelength of green light, i.e., the refractive indices of first structural layer 71 and second structural layer 72 at the dominant wavelength of green light are the same.

The structure of the prism film is shown in fig. 21, which is an angular periodic structure made of optical cement (or glass), and the first structural layer 71 can be prepared by a method of light curing and performing overmolding; specifically, since the more the angle β deviates from 90 degrees, the more stray light is generated from incident light after passing through the prism film, and the lower the system efficiency, the angle β is preferably 90 degrees, but the angle β may be slightly smaller than 90 degrees in consideration of draft; the tilt angle α is selected in relation to the light deflection ability of the prism film, and the effect of the tilt on the red light is shown in fig. 22, and it can be seen that the larger the tilt angle of the prism film, the larger the deflection angle of the light beam.

After the angular periodic structure made with the first structural layer 71 was obtained, the angular periodic structure was filled in with the second structural layer 72 to obtain a prism film shown in fig. 21. Since green light experiences the same refractive index when passing through the first and second structural layers 71 and 72, no beam deflection occurs. For red light and blue light, the refractive indexes of the first structural layer 71 and the second structural layer 72 are different, and the light beam is deflected to a certain degree due to the existence of the angular periodic structure.

Further, if the deflection angle of the red light and the blue light is to be increased, it is considered to increase the tilt angle of the angular periodic structure or to use a multilayer prism film in combination. When deflection of 4 degrees of red light is to be achieved, the relationship between the inclination angle of the angular periodic structure and the required number of prism film layers is shown in fig. 23, and it can be seen that the larger the inclination angle, the smaller the required number of prism film layers.

In addition, the Pitch size affects the overall prism film thickness, geometric-optical efficiency (the larger the Pitch, the smaller the ratio of sharp-angled to root defects), and diffractive-optical efficiency. However, too large Pitch also causes problems of too thick film, waste of material and spot dispersion. From the structure of the prism film, the prism film can be regarded as a transmission type blazed grating, the center of the diffraction distribution of the prism film depends on the deflection direction of the principal ray, the interference 0 level depends on the direction of the incident light, the diffraction model of the prism film is multi-slit Fraunhofer diffraction, and the formula of the diffraction distribution of the prism film is as follows:

I＝I₀×(sinα/α)²

wherein α ═ π × a × θ_xA is the slit width, θ_xIs the diffraction angle. At α ═ 0 (i.e. θ)_x0) is present, the center of this zero-order diffraction spot is the geometric optical image point.

The multi-slit diffraction is the result of the combined action of two effects of diffraction and interference, and the angle of the interference order can be calculated by the following formula:

d×sinθ＝m×λ

wherein m is 0, ± 1, ± 2, ….

Since a is d in the prism film, the angular distance of each interference order can be approximated by θ m λ/a. The relationship between the size of the Pitch (Pitch) of two adjacent prisms in the prism film and the diffraction angular distance is shown in fig. 24, and it can be seen that when Pitch is too small, the angular distance of each interference order is 0.6 °; after light with specific wavelength passes through the prism film, a specific deflection angle is formed, two interference levels generate high energy distribution, and the difference between the two angles is large (even larger than the light deflection angle), so that a plurality of angles exceed the collection range, and the efficiency is wasted.

If the light source selects pure laser, the size and deflection angle of the Pitch 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 selects a broad spectrum light (such as LED and laser fluorescence), it is necessary to select a larger Pitch 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 proportion of diffraction, so as to minimize the dilution of the expansion.

It is understood that the master mold of the prism film can be directly prepared by laser direct writing or precision lathing. If the demand is large, a large-area thin die can be prepared, and then the structure is repeatedly engraved by adopting a roll-to-roll method, so that the large-area preparation of the prism film can be conveniently carried out.

In another embodiment, referring to fig. 2, fig. 3(b) and fig. 19 in combination, 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) may be further disposed in the two-color light path to cooperate with the dispersive optical splitter 121; specifically, the second liquid crystal modulator 103 further includes a second microlens array attached to the second display panel 32, the second microlens array is disposed on the light exiting path of the dispersive light splitting device 121, that is, a second microlens array is disposed on a side surface of the second display panel 32 facing the dispersive light splitting device 121, and the second microlens array is used for processing (for example, collecting or homogenizing) the first sub-illumination light and the second sub-illumination light and emitting the processed light into the corresponding second pixel unit 321.

With continued reference to fig. 25, the illumination light is divided into two paths, one of which is a single color light path (which may be R, G or B), and the second of which is a dual color light path (which is another two colors different from the single color light path). In the two-color light path, the polarized and collimated second illumination light passes through the dispersion splitting device 121, and the dispersion splitting device 121 splits the two colors of second illumination light into illumination spots which are separated in angle but overlapped in surface. The second illumination light passes through the respective pixels at different angles after passing through the second microlens array before the second display panel 32. Image light emitted by the two display panels passes through corresponding analyzers, image information is filtered out, and then the image light is combined by the light combining component 104, and then the image light is projected to a picture by the projection lens 105.

In other embodiments, since the second microlens array is used in the two-color optical path to dilute the expansion of the system, the single-color optical path has the surplus of the expansion, and in order to further improve the efficiency of the system, the transmittance of the system, and the reliability of the display panel, the first microlens array and/or another dispersive optical splitter (not shown in the figure) may be added in the single-color optical path; specifically, referring to fig. 2, fig. 3(a) and fig. 19, the first liquid crystal modulator 102 further includes a first microlens array attached to the first display panel 22, and the first microlens array is disposed on the light emitting path of the light source assembly 101 and is used for processing the first illumination light and emitting the first illumination light into the corresponding first pixel unit 221, so as to fully utilize the expansion amount of the system. Alternatively, a first microlens array and a second microlens array may be provided in the monochromatic light path and the dichroic light path, respectively, to collect the illumination light.

In a specific embodiment, as shown in fig. 25, fig. 25 is a schematic structural diagram of a seventeenth embodiment of the projection system provided in the present application, which is different from the embodiment shown in fig. 4: the projection system further comprises a dispersive beam splitter device 121.

The dispersive light splitting device 121 is disposed on the outgoing optical path of the second polarizer 31, and is configured to split the light output by the second polarizer 31 into first sub-illumination light and second sub-illumination light; specifically, the dispersive light splitting device 121 may be a prism film, the prism film may be a single-layer structure or a multi-layer structure, and the first sub-illumination light and the second sub-illumination light may be red light and green light, or blue light and green light, or green light and blue light, respectively.

The working principle of this embodiment will be described below by taking the first light emitting element 1011 as a blue LED and the second light emitting element 1012 as a yellow LED as an example:

the second illumination light emitted by the yellow LED is collected by the second light homogenizing device 1062, and then collimated into parallel light by the second lens device 1082, and a second polarizer 31 is placed at the light exit of the second lens device 1082 to polarize the parallel yellow light. The polarized yellow light is split into two colors of red and green light by the dispersive light-splitting device 121, which are angularly separated but are coincident in plane. The second illumination light passes through the second display panel 32 and is filtered by the second analyzer 33 to obtain image information to be displayed.

The principle of the blue optical path is substantially the same as that of the yellow optical path, and after the first illumination light emitted from the first display panel 22 passes through the first analyzer 23, the image light is filtered out to obtain the first image light, and the first image light and the second image light of the yellow optical path are combined in the light combining component 104 and finally projected onto the projection screen by the projection lens 105.

It is understood that the dispersive splitting may be implemented by using a geometric optical waveguide or a diffractive optical waveguide, in addition to the dispersive splitting device 121.

In another embodiment, please refer to fig. 26, fig. 26 is a schematic structural diagram of an eighteenth embodiment of a projection system provided in the present application, which is different from the embodiment shown in fig. 25: the projection system further comprises a first turning prism 109 and a first hollow duct 110, which operate in a similar manner to the embodiment shown in fig. 7 and 25, and are not described in detail herein.

This embodiment makes the overall system more compact by using the first folding prism 109 and the first hollow duct 110 in one optical path.

In another specific embodiment, please refer to fig. 27, fig. 27 is a schematic structural diagram of a nineteenth embodiment of a projection system provided in the present application, which is similar to the embodiment shown in fig. 25 except that: the light source assembly 101 in this embodiment further includes a third light emitting assembly 1013, a third light homogenizing device 1063, a third lens device 1083 and a first light splitting assembly 111, and the operation principle thereof is similar to that of the embodiment shown in fig. 8 and fig. 25, and is not described herein again.

This embodiment is through adding blue light all the way in projection system and doing two-sided excitation to the phosphor powder on first wavelength conversion device surface in the double-colored light path more, can promote the excitation efficiency who receives the laser, and then the luminous efficiency of promotion system.

In another specific embodiment, since the way of adding one more path will bring burden to the volume, the present application further proposes a two-sided excitation architecture with two optical paths, as shown in fig. 28, fig. 28 is a schematic structural diagram of a twentieth embodiment of the projection system provided by the present application, and this embodiment is similar to the embodiment shown in fig. 27, except that: in this embodiment, the projection system further includes a second light splitting element 112, a third light splitting element 113 and a second hollow conduit 114, and the third light emitting element and the first light splitting element are not disposed.

In another specific embodiment, a 2LTPS-LCD architecture using a reflective laser fluorescence light source is disclosed, as shown in fig. 29, fig. 29 is a schematic structural diagram of a twenty-first embodiment of a projection system provided in the present application, and this embodiment is similar to the embodiment shown in fig. 28 except that: in this embodiment, the first illumination light enters the second light splitting assembly 112 from the top to the bottom, and the second illumination light enters the third light splitting assembly 113 from the left to the right.

The first display panel 22 and the second display panel 32 are provided with a micro lens array (not shown in the figure), 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 in the optical path alone.

The working principle of the present embodiment will be described below by taking the first turning prism 109 as a right-angle prism, the third light splitting component 113 as a blue-reflecting yellow-transmitting prism, the first light emitting component 1011 as a blue laser, the first wavelength conversion device as a color wheel 61 (yellow fluorescent powder is disposed on the color wheel 61), and the second light splitting component 112 as a P-transmitting reverse S prism as an example:

the polarized blue light (usually P polarized blue light) emitted by the blue laser is transmitted into the second hollow conduit 114 after passing through the P-transparent reverse S prism, and then is reflected to the second light collecting device by the blue-transparent yellow prism, and enters the color wheel 61 after being collected by the second light collecting device, the yellow phosphor on the color wheel 61 is excited to emit lambert white light, the excited white light is split by the blue-transparent yellow prism after being collected by the second light collecting device, and then is emitted from the other surface of the right-angle prism, the second polarizer 31 is placed on the emitting surface of the right-angle prism, and the polarized yellow light illuminates the second display panel 32.

The blue light reflected by the blue-reflecting yellow-transmitting prism enters the P-reflecting S-transmitting prism after passing through the second hollow conduit 114, the blue light of the S component is reflected and then emitted, and the first polarizer 21 is arranged between the emitting surface and the first display panel 22 for polarization purification, so that the contrast of the system is improved.

The polarized yellow light is split into two colors of red and green light by the dispersive light-splitting device 121, which are angularly separated but are coincident in plane. After passing through the microlens array, the second illumination light with different colors falls into the respective pixels, and after passing through the second display panel 32, the second illumination light is filtered out by the second analyzer for image information to be displayed.

The principle of the blue optical path is substantially the same as that of the yellow optical path, and 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, and then the first image light and the second image light of the yellow optical path are combined in the light combining component 104, and finally projected onto the projection screen by the projection lens 105.

Preferably, a first pixel expansion device 107 may be added between the light combining component 104 and the projection lens 105 to achieve further improvement of the display resolution.

It is understood that the color wheel 61 in the present embodiment may be replaced by a fixed type fluorescent sheet.

In another specific embodiment, as shown in fig. 30, fig. 30 is a schematic structural diagram of a twenty-second embodiment of the projection system provided in the present application, and this embodiment is similar to the embodiment shown in fig. 25, except that: the projection system in this embodiment further includes a fourth light-splitting assembly 115, a second turning prism 116 and a third turning prism 117, and the light source assembly 101 is a white light source.

The working principle of the present embodiment is described below by taking, as an example, a white light source as a white light LED, a second light homogenizing assembly 106 as a tapered light homogenizing device, a lens assembly 108 as a collimating lens, a fourth light-splitting assembly 115 as a dichroic light-splitting prism, a third light-splitting assembly 113 as a blue-reflecting yellow-transmitting prism, and a light-combining assembly 104 as a dichroic light-combining prism:

the light emitted from the white light LED is collected by the conical light homogenizing device and then collimated into parallel light by the collimating lens, and preferably, a polarized light recycling device (not shown in the figure) may be disposed between the dichroic beam splitter prism and the collimating lens to polarize the white light. The polarized parallel white light is split into reflected yellow light and transmitted blue light after being split by the dichroic beam splitter prism. The polarized yellow light is separated into red and green lights by the dispersion beam splitter 121, the red and green lights are separated in angle but overlapped on the surface, and the light emitted from the dispersion beam splitter 121 passes through the second display panel 32 and then is filtered by the second analyzer 33 to obtain the second illumination light.

The principle of the blue light path is substantially the same as that of the yellow light path, the blue light passes through the fourth hollow conduit 119 and the second turning prism 116, and then exits at the exit surface of the second turning prism 116, and the first polarizer 21 is placed on the exit surface to further perform polarization purification on the first illumination light (if no polarization recovery device is placed before, a polarization recovery device can also be placed at the position to perform light circulation); after the first illumination light emitted from the first display panel 22 passes through the first analyzer 23, the image light is filtered to obtain the first illumination light, and the first illumination light is combined with the image information of the yellow optical path in the dichroic light-combining prism, and finally projected onto the projection screen by the projection lens 105.

It is understood that in other embodiments, a second pixel expansion device (not shown in the figures) may be further disposed in the embodiments of fig. 19 and fig. 25 to fig. 30 to increase the resolution of the display panel, so as to improve the display effect.

Based on the pain point of the projection system of the single LTPS-LCD, the 2LTPS-LCD and the 3LTPS-LCD, the embodiment uses the 2-piece LCD, divides light of one color into another display panel, and uses the dispersion light splitting device to perform dispersion light splitting before light combination, so that not only the utilization rate of the spectrum can be maximized when the prism film is used, but also the burden of the display panel can be reduced, and the system efficiency and the total output lumens can be improved.

The above description is only an example of the present application and is not intended to limit the scope of the present application, and all modifications of equivalent structures and equivalent processes, which are made by the contents of the specification and the drawings, or which are directly or indirectly applied to other related technical fields, are intended to be included within the scope of the present application.

Claims (19)

1. A projection system, comprising:

the light source component is used for generating first illumination light and second illumination light, wherein the first illumination light is light of one of the three primary colors, and the second illumination light is synthesized by light of other colors of the three primary colors;

the first liquid crystal modulator is arranged on an emergent light path of the light source component and used for receiving and modulating the first illumination light to generate first image light;

the second liquid crystal modulator is arranged on an emergent light path of the light source assembly and used for receiving and modulating the second illumination light to generate second image light;

the light combining component is arranged on the emergent light paths of the first liquid crystal modulator and the second liquid crystal modulator and is used for combining the first image light and the second image light to generate image light;

the projection lens is arranged on an emergent light path of the light combination component and is used for projecting the image light;

the first liquid crystal modulator is not provided with a color film, and the second liquid crystal modulator is provided with color films for respectively modulating lights of other colors in the second illumination light.

2. The projection system of claim 1,

the projection system further comprises a first pixel expansion device, wherein the first pixel expansion device is arranged on an emergent light path of the light combination component and is used for expanding the image light and emitting the image light into the projection lens.

3. The projection system of claim 1,

the light source assembly comprises a first light-emitting assembly and a second light-emitting assembly, wherein the first light-emitting assembly is used for generating the first illumination light, and the second light-emitting assembly is used for generating the second illumination light;

the first illumination light is blue laser, and the second illumination light is stimulated light; the first light-emitting component is a blue laser, the blue laser is used for generating blue laser, the second light-emitting component is a color wheel, a fixed fluorescent sheet or an LED with the surface coated with fluorescent powder, and the second light-emitting component is used for receiving the blue laser and generating the received laser;

or, the first light-emitting component is a blue light LED, and the second light-emitting component is a yellow light LED.

4. The projection system of claim 3,

the light source assembly further comprises a third light-emitting assembly and a first light-splitting assembly, the third light-emitting assembly is used for generating blue laser, and the first light-splitting assembly is arranged on an emergent light path of the third light-emitting assembly and used for reflecting the blue laser generated by the third light-emitting assembly to the second light-emitting assembly and transmitting the laser generated by the second light-emitting assembly to the second liquid crystal modulator.

5. The projection system of claim 3,

the projection system further comprises a first turning prism and a first hollow guide tube, wherein the first hollow guide tube is arranged on an emergent light path of the first light-emitting assembly and is used for transmitting the first illuminating light to the first turning prism; the first turning prism is arranged on the emergent light path of the first hollow guide tube and used for adjusting the transmission direction of the first illuminating light.

6. The projection system of claim 5,

the projection system further comprises a second light splitting assembly, a third light splitting assembly and a second hollow guide pipe, wherein the second light splitting assembly is arranged on an emergent light path of the blue laser and is used for transmitting/reflecting light with a first polarization state in the blue laser to form first illumination light which is emitted into the first liquid crystal modulator; the second hollow guide pipe is arranged on an emergent light path of the second light splitting assembly and is used for transmitting light with a second polarization state in the blue laser to the third light splitting assembly; the third light splitting assembly is arranged on an emergent light path of the second hollow guide tube and used for reflecting/transmitting light with a second polarization state in the blue laser to the second light emitting assembly and transmitting the received laser generated by the second light emitting assembly to the second liquid crystal modulator.

7. The projection system of claim 6,

the first illumination light is emitted into the second light splitting assembly along the direction from bottom to top, and the second illumination light is emitted into the third light splitting assembly along the direction from bottom to top;

or, the first illumination light is emitted into the second light splitting assembly along a direction from top to bottom, and the second illumination light is emitted into the third light splitting assembly along a direction from left to right.

8. The projection system of claim 1, further comprising:

the fourth light splitting assembly is arranged on an emergent light path of the light source assembly and is used for splitting the illuminating light into the first illuminating light and the second illuminating light;

the second turning prism is arranged on the light path of the first illumination light, is used for adjusting the transmission direction of the first illumination light from a first direction to a second direction, and emits the first illumination light into the first liquid crystal modulator;

and the third turning prism is arranged on the light path of the second illumination light and used for adjusting the transmission direction of the second illumination light from the second direction to the first direction and emitting the second illumination light into the second liquid crystal modulator.

9. The projection system of claim 8,

the projection system further comprises a polarized light recycling device, wherein the polarized light recycling device is arranged on the emergent light path of the light source assembly and used for transmitting the illuminating light with the first polarization state in the illuminating light to the fourth light splitting assembly and reflecting the illuminating light with the second polarization state in the illuminating light to the light source assembly.

10. The projection system of claim 8,

the projection system further comprises a third hollow guide tube and a fourth hollow guide tube, wherein the third hollow guide tube is arranged on the reflection light path of the fourth light splitting assembly and is used for transmitting the light with the second polarization state in the illumination light to the third turning prism; the fourth hollow conduit is arranged on the transmission light path of the fourth light splitting assembly and used for transmitting the light with the first polarization state in the illumination light to the second turning prism.

11. The projection system of claim 1,

the first illumination light is blue laser, the light source assembly comprises a blue laser, a first dodging assembly, an imaging lens and a second wavelength conversion device, and the blue laser is used for generating the blue laser; the first dodging assembly is arranged on an emergent light path of the blue laser and is used for dodging the blue laser; the imaging lens is arranged on an emergent light path of the first dodging assembly and is used for imaging the blue laser output by the first dodging assembly onto the second wavelength conversion device so that the second wavelength conversion device generates the second illumination light.

12. The projection system of claim 1,

the projection system further comprises a light collecting device, wherein the light collecting device is arranged on an emergent light path of the light source assembly and is used for collecting the illuminating light and emitting the illuminating light into the first liquid crystal modulator and the second liquid crystal modulator.

13. The projection system of claim 12,

the light collection device comprises a second dodging assembly and a lens assembly, wherein the second dodging assembly and the lens assembly are arranged along the transmission direction of the illuminating light, the second dodging assembly is used for dodging the illuminating light, and the lens assembly is used for collimating the illuminating light emitted by the second dodging assembly.

14. The projection system of claim 13,

the light collecting device comprises a first collecting lens and a second collecting lens, the projection system further comprises a shaping device, and the first collecting lens is arranged on an emergent light path of the light source component and used for collecting the illuminating light; the second collecting lens is used for collecting the light emitted by the first collecting lens; the shaping device is used for shaping the illuminating light emitted by the second collecting lens, so that the light spot of the illuminating light emitted by the shaping device is in a preset shape.

15. The projection system of claim 14,

the shaping device comprises a first area and a second area, and the first area is used for transmitting the illumination light emitted by the second collecting lens; the second region is used for reflecting the illumination light emitted by the second collecting lens to the light source component.

16. The projection system of claim 1,

the projection system further comprises an adjusting component, wherein the adjusting component is arranged on an emergent light path of the light source component and used for shaping the illuminating light and emitting the illuminating light into the first liquid crystal modulator and the second liquid crystal modulator so as to shape telecentric illumination into non-telecentric illumination.

17. The projection system of claim 1,

the projection system further comprises a second pixel expanding device, wherein the second pixel expanding device is arranged on an emergent light path of the light source component and is used for expanding the image light and emitting the image light into the light combining component.

18. The projection system of claim 1,

the light source assembly illuminates the first liquid crystal modulator and the second liquid crystal modulator in a non-imaging illumination mode.

19. The projection system of claim 1,

the first liquid crystal modulator and the second liquid crystal modulator are LTPS-LCDs.

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