Double-LCD projector

Abstract

The invention discloses a double-LCD projector, two paths of LED light sources which are vertically arranged are adopted for illumination, the first path of LED light source in the two paths of LED light sources comprises a first LED light source, fluorescent powder, a light hopper, a first rear Fresnel lens, a first light filter, a first polaroid, a first LCD screen and a first front Fresnel lens which are sequentially arranged from back to front, and the fluorescent powder is arranged on the first LED light source; the second path of LED light source comprises a second LED light source, an aspherical lens, a reflector, a second rear Fresnel lens, a second optical filter, a second polaroid, a second LCD screen and a second front Fresnel lens which are sequentially arranged from back to front; the double-LCD projector further comprises a double-gluing two-phase-color light combining mirror, and the double-gluing two-phase-color light combining mirror, the first front Fresnel lens and the second front Fresnel lens are arranged in a 45-degree mode. According to the invention, the length-width ratio of a horizontal light path and a vertical light path can be effectively avoided, and the light deviation after light combination is reduced.

Description

Technical Field

[0001] This invention relates to the field of projector technology, and in particular to a dual LCD projector. Background Technology

[0002] Dual LCD optical systems typically use two optical paths: a vertical path and a horizontal path. These two paths are converged using a dichroic mirror or a beam combiner. Because LTPS LCD screens are relatively large, using a beam combiner would require a large beam combiner, which would be expensive and heavy. Therefore, a dichroic mirror is used to combine the light. Light from the horizontal path passes through the dichroic mirror, while light from the vertical path is reflected by the dichroic mirror.

[0003] When using a single-layer dichroic mirror, light from the horizontal path passes through the mirror, which is placed at a 45-degree angle. Refraction occurs inside the mirror, causing a slight misalignment of the light rays and resulting in a larger overall light spot. Because the angle of incidence varies, the misalignment after refraction also varies, leading to a difference in the aspect ratio between the horizontal and vertical light paths. This results in a large deviation in the combined light. For example, adding a 0.7mm thick dichroic mirror results in a 0.04mm difference in edge image height and a 0.2mm deviation in centerline, leading to an overall deviation of 0.24mm, or 4 pixels. Summary of the Invention

[0004] The main objective of this invention is to propose a dual LCD projector that avoids the aspect ratio of the horizontal and vertical light paths and reduces the light deviation after light combination.

[0005] To achieve the above objectives, the present invention proposes a dual LCD projector, wherein the dual LCD projector uses two vertically arranged LED light sources for illumination. The first LED light source of the two LED light sources includes, from back to front, a first LED light source, phosphor, light source, a first rear Fresnel lens, a first filter, a first polarizer, a first LCD screen, and a first front Fresnel lens, wherein the phosphor is disposed on the first LED light source.

[0006] The second LED light source in the two LED light sources includes, from back to front, a second LED light source, an aspherical lens, a reflector, a second rear Fresnel lens, a second filter, a second polarizer, a second LCD screen, and a second front Fresnel lens;

[0007] The dual LCD projector also includes a cemented binary color combining mirror, which is set at a 45° angle to the first front Fresnel lens and the second front Fresnel lens;

[0008] The light emitted by the first LED light source is excited by the phosphor, passes through the light source and the first rear Fresnel lens to the first filter, then passes through the first polarizer to become P-light, and then passes through the first LCD screen to produce an image. It then passes through the first front Fresnel lens, through the cemented doublet dichroic mirror, and through the projection lens to image the image onto the screen. The light emitted by the second LED light source is focused by the aspherical lens, reflected by the mirror, then passes through the second Fresnel lens to the second filter, then passes through the second polarizer to become S-light, then passes through the second LCD screen, and then through the second front Fresnel lens to reach the cemented doublet dichroic mirror. The light passes through the first surface of the cemented doublet dichroic mirror, is reflected by the second surface, passes through the first surface again, and then through the projection lens to image the image onto the screen.

[0009] A further technical solution of the present invention is that the first LED light source is a blue LED light source, the phosphor is a yellow phosphor, the first filter is a blue light band filter, the first LCD screen is a red-green LCD screen, the second LED light source is a blue LED light source, the second filter is a red-green band filter, and the second LCD screen is a black-and-white LCD screen.

[0010] A further technical solution of the present invention is that the first LED light source is a blue LED light source, the phosphor is a red phosphor, the first filter is a green band filter, the first LCD screen is a red-blue LCD screen, the second LED light source is a blue LED light source, the second LED light source is provided with green phosphor, the second filter is a green band filter, and the second LCD screen is a black-and-white LCD screen.

[0011] A further technical solution of the present invention is that the first LED light source is a blue LED light source, the phosphor is a green phosphor, the first filter is a red light segment filter, the first LCD screen is a blue-green LCD screen, the second LED light source is a red LED light source, the second filter is a red filter, and the second LCD screen is a black-and-white LCD screen.

[0012] The beneficial effects of the dual LCD projector of this invention are:

[0013] The present invention, through the above technical solution, describes a dual-LCD projector that uses two vertically arranged LED light sources for illumination. The first LED light source comprises, from back to front, a first LED light source, phosphor, a light source, a first rear Fresnel lens, a first filter, a first polarizer, a first LCD screen, and a first front Fresnel lens, with the phosphor disposed on the first LED light source. The second LED light source comprises, from back to front, a second LED light source, an aspherical lens, a reflector, a second rear Fresnel lens, a second filter, a second polarizer, a second LCD screen, and a second front Fresnel lens. The dual-LCD projector also includes a cemented doublet dichroic mirror, which is positioned at a 45° angle to the first and second front Fresnel lenses. Light emitted from the first LED light source passes through the phosphor... The light emitted by the second LED light source is excited after passing through the light source and the first rear Fresnel lens to reach the first filter. After passing through the first polarizer, it is converted into P-light. After passing through the first LCD screen, it produces an image. After passing through the first front Fresnel lens, it passes through the cemented doublet dichroic light combining mirror and is projected onto the screen by the projection lens. The light emitted by the second LED light source is focused by the aspherical lens, reflected by the mirror, and then passes through the second Fresnel lens to reach the second filter. After passing through the second polarizer, it becomes S-light. After passing through the second LCD screen, it passes through the second front Fresnel lens and reaches the cemented doublet dichroic light combining mirror. After passing through the first surface of the cemented doublet dichroic light combining mirror, it is reflected by the second surface. After passing through the first surface, it is projected onto the screen by the projection lens. This effectively avoids the aspect ratio of the horizontal and vertical light paths and reduces the deviation of the light after combining. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the optical path structure of a preferred embodiment of the dual LCD projector of the present invention;

[0016] Figure 2 This is a schematic diagram illustrating the working principle of a double-cemented dichroic optical mirror.

[0017] Explanation of icon numbers:

[0018] First LED light source 1;

[0019] Fluorescent powder 2;

[0020] Guangdou 3;

[0021] First rear Fresnel lens 4;

[0022] First filter 5;

[0023] First polarizer 6;

[0024] First LCD screen 7;

[0025] First front Fresnel lens 8;

[0026] Second LED light source 9;

[0027] Aspherical lens 10;

[0028] Mirror 11;

[0029] Second rear Fresnel lens 12;

[0030] Second filter 13;

[0031] Second polarizer 14;

[0032] Second LCD screen 15;

[0033] Second front Fresnel lens 16;

[0034] Double-cemented dichroic optical mirror 17;

[0035] Projection lens 18. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] This invention proposes a dual LCD projector, such as... Figure 1 As shown, in a preferred embodiment of the dual LCD projector of the present invention, two vertically arranged LED light sources are used for illumination. The first LED light source includes a first LED light source 1, phosphor 2, light source 3, first rear Fresnel lens 4, first filter 5, first polarizer 6, first LCD screen 7 and first front Fresnel lens 8 arranged sequentially from back to front. The phosphor 2 is disposed on the first LED light source 1.

[0038] The second LED light source in the two LED light sources includes, from back to front, a second LED light source 9, an aspherical lens 10, a reflector 11, a second rear Fresnel lens 12, a second filter 13, a second polarizer 14, a second LCD screen 15, and a second front Fresnel lens 16.

[0039] The dual LCD projector also includes a cemented dichroic mirror 17, which is set at a 45° angle to the first front Fresnel lens 8 and the second front Fresnel lens 16.

[0040] The light emitted by the first LED light source 1 is excited by the phosphor 2, passes through the light tube 3 and the first rear Fresnel lens 4, reaches the first filter 5, then passes through the first polarizer 6 and is converted into P light, then passes through the first LCD screen 7 to produce an image, passes through the first front Fresnel lens 8, passes through the cemented doublet dichroic mirror 17, and passes through the projection lens 18 to image the image onto the screen; the light emitted by the second LED light source 9 is focused by the aspherical lens 10, reflected by the reflector 11, then passes through the second Fresnel lens to reach the second filter 13, then passes through the second polarizer 14 and is converted into S light, passes through the second LCD screen 15, passes through the second front Fresnel lens 16 and reaches the cemented doublet dichroic mirror 17, the light passes through the first surface of the cemented doublet dichroic mirror 17 and is reflected by the second surface, then passes through the first surface and is imaged onto the screen by the projection lens 18.

[0041] like Figure 2 As shown, when the two central light rays are aligned, the first LED light source experiences different refractions due to the different angles at which it is incident on the dichroic mirror, thus preventing it from completely coinciding with the light from the second LED light source. The double-cemented dichroic mirror 17 avoids this problem by ensuring that both light paths have the same incident angle and the same refraction angle.

[0042] As one implementation scheme, this embodiment can employ a red-green plus blue light combining method. Specifically, in this embodiment, the first LED light source 1 of the two LED light sources is a blue LED light source, the phosphor 2 is a yellow phosphor, the first filter 5 is a blue light band filter, the first LCD screen 7 is a red-green LCD screen, the second LED light source 9 is a blue LED light source, the second filter 13 is a red-green band filter, and the second LCD screen 15 is a black-and-white LCD screen.

[0043] The blue light emitted by the first LED light source 1 is excited into yellow light after passing through the phosphor on the surface of the first LED light source 1. After passing through the light chamber 3 and the first rear Fresnel lens 4, it reaches the first filter 5. The function of the first filter 5 is to filter out the incompletely excited blue light, so as to avoid the LCD temperature from being too high and improve the overall lifespan. Then, the light from the first polarizer 6 is converted to P-light, and after passing through the first LCD screen 7, it produces a red-green image. After passing through the first front Fresnel lens 8, it passes through the cemented doublet dichroic mirror 17 and is projected onto the screen by the projection lens 18. The light from the second LED light source 9 is focused by the aspherical lens 10, reflected by the mirror 11, and after passing through the second rear Fresnel lens 12, it reaches the second filter 13. After passing through the second polarizer 14, it becomes S-light and passes through the second LCD screen 15. The second LCD screen 15 receives the blue signal and produces a blue image. After passing through the second front Fresnel lens 16, it reaches the cemented doublet dichroic mirror 17. After passing through the first surface of the cemented doublet dichroic mirror 17, the light is reflected by the second surface, passes through the first surface, and is then projected onto the screen by the projection lens 18.

[0044] As a second implementation scheme, this embodiment can adopt a red-blue plus green light combining method. Specifically, in this embodiment, the first LED light source 1 is a blue LED light source, the phosphor 2 is a red phosphor 2, the first filter 5 is a green light band filter, the first LCD screen 7 is a red-blue LCD screen, the second LED light source 9 is a blue LED light source, the second LED light source 9 is provided with green phosphor (not shown in the figure), the second filter 13 is a green band filter, and the second LCD screen 15 is a black and white LCD screen.

[0045] The blue light emitted by the first LED light source 1 is excited into purple light after passing through the phosphor 2 on its surface. This purple light is then filtered out by a first filter to remove any incompletely excited blue light. After passing through a first polarizer 6, it is converted into P-light. This P-light then passes through a first LCD screen 7 to produce a red-blue image. The image then passes through a first front Fresnel lens 8, a cemented doublet dichroic lens 17, and a projection lens 18 to project the image onto the screen. The blue light emitted by the second LED light source 9 is excited into green light after passing through the phosphor on its surface. After being focused by the aspherical lens 10, the light is reflected by the mirror 11, passes through the second rear Fresnel lens 12, reaches the second filter 13, then passes through the second polarizer 14 and becomes S-light, then passes through the second LCD screen 15, the second LCD screen 15 receives the green light signal and generates a green image, then passes through the second front Fresnel lens 16 and reaches the cemented doublet dichroic mirror 17. After passing through the first surface of the cemented doublet dichroic mirror 17, the light is reflected by the second surface, passes through the first surface again, and then passes through the projection lens 18 to form an image on the screen.

[0046] As a third implementation scheme, this embodiment can adopt a blue-green plus red light combining method. Specifically, in this embodiment, the first LED light source 1 is a blue LED light source, the phosphor 2 is a green phosphor 2, the first filter 5 is a red light segment filter, the first LCD screen 7 is a blue-green LCD screen, the second LED light source 9 is a red LED light source, the second filter 13 is a red filter, and the second LCD screen 15 is a black and white LCD screen.

[0047] The blue light emitted by the first LED light source 1 is excited into cyan light after passing through the phosphor 2 on the surface of the first LED light source 1. After passing through the light tube 3 and the first rear Fresnel lens 4, it reaches the first filter 5, which filters out a portion of the excited green and red light. Then, after passing through the first polarizer 6, it is converted into P light. After passing through the first LCD screen 7, it produces a blue-green image. After passing through the first front Fresnel lens 8, it passes through the cemented doublet dichroic mirror 17 and the projection lens 18 to image the blue-green image onto the screen. The second LED light source 9 uses a red LED light source. The red light of the second LED light source 9 is focused by the aspherical lens 10, reflected by the mirror 11, and after passing through the second rear Fresnel lens 12, it reaches the second filter 13 to filter out light other than red light. Then, after passing through the second polarizer 14, it becomes S light. The light then passes through the second LCD screen 15, which receives the red signal and generates a red image. After passing through the second front Fresnel lens 16, the light reaches the cemented doublet dichroic mirror 17. After passing through the first surface of the cemented doublet dichroic mirror 17, the light is reflected by the second surface, passes through the first surface again, and then passes through the projection lens 18 to form an image on the screen.

[0048] It is worth emphasizing that, firstly, in the dual LCD projector of the present invention, because the light from the first LED light source passes through the double-cemented dichroic mirror 17, the image will be larger than the image of the reflected second light path due to the refraction of light inside the double-cemented dichroic mirror 17. Therefore, software scaling and functions are added to control the image of the first LED light source to reduce the image of the first LED light source to match the image of the second LED light source, thus ensuring that the images of the first LED light source and the second LED light source overlap.

[0049] The specific solution involves comparing the image deviations between the first and second LED light sources, scaling the image of the first LED light source according to the deviation data using an algorithm, and inputting the signal to the LCD of the first LED light source. The larger portion of the LCD of the first LED light source will be displayed as black. The signals from the first and second LED light sources are input synchronously.

[0050] Secondly, the present invention uses a double-cemented two-phase color combining mirror 17, where the combining surface is a cemented surface. In this way, the light in the horizontal light path passes through two layers of glass, and the light in the vertical light path passes through this layer of glass and is reflected on the second surface of the glass, and then passes through the first layer of glass again. In this way, the light rays in the two light paths are misaligned and consistent.

[0051] The beneficial effects of the dual LCD projector of this invention are:

[0052] The present invention, through the above technical solution, describes a dual-LCD projector that uses two vertically arranged LED light sources for illumination. The first LED light source comprises, from back to front, a first LED light source, phosphor, a light source, a first rear Fresnel lens, a first filter, a first polarizer, a first LCD screen, and a first front Fresnel lens, with the phosphor disposed on the first LED light source. The second LED light source comprises, from back to front, a second LED light source, an aspherical lens, a reflector, a second rear Fresnel lens, a second filter, a second polarizer, a second LCD screen, and a second front Fresnel lens. The dual-LCD projector also includes a cemented doublet dichroic mirror, which is positioned at a 45° angle to the first and second front Fresnel lenses. Light emitted from the first LED light source passes through the phosphor... The light emitted by the second LED light source is excited after passing through the light source and the first rear Fresnel lens to reach the first filter. After passing through the first polarizer, it is converted into P-light. After passing through the first LCD screen, it produces an image. After passing through the first front Fresnel lens, it passes through the cemented doublet dichroic light combining mirror and is projected onto the screen by the projection lens. The light emitted by the second LED light source is focused by the aspherical lens, reflected by the mirror, and then passes through the second Fresnel lens to reach the second filter. After passing through the second polarizer, it becomes S-light. After passing through the second LCD screen, it passes through the second front Fresnel lens and reaches the cemented doublet dichroic light combining mirror. After passing through the first surface of the cemented doublet dichroic light combining mirror, it is reflected by the second surface. After passing through the first surface, it is projected onto the screen by the projection lens. This effectively avoids the aspect ratio of the horizontal and vertical light paths and reduces the deviation of the light after combining.

[0053] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A dual LCD projector, characterized in that, The dual LCD projector uses two vertically arranged LED light sources for illumination. The first LED light source includes, from back to front, a first LED light source, phosphor, light source, first rear Fresnel lens, first filter, first polarizer, first LCD screen, and first front Fresnel lens. The phosphor is disposed on the first LED light source. The second LED light source in the two LED light sources includes, from back to front, a second LED light source, an aspherical lens, a reflector, a second rear Fresnel lens, a second filter, a second polarizer, a second LCD screen, and a second front Fresnel lens; The dual LCD projector also includes a cemented binary color combining mirror, which is set at a 45° angle to the first front Fresnel lens and the second front Fresnel lens; The light emitted by the first LED light source is excited by the phosphor, passes through the light source and the first rear Fresnel lens to the first filter, then passes through the first polarizer to become P-light, and then passes through the first LCD screen to produce an image. It then passes through the first front Fresnel lens, through the cemented doublet dichroic mirror, and through the projection lens to image the image onto the screen. The light emitted by the second LED light source is focused by the aspherical lens, reflected by the mirror, then passes through the second Fresnel lens to the second filter, then passes through the second polarizer to become S-light, then passes through the second LCD screen, and then through the second front Fresnel lens to reach the cemented doublet dichroic mirror. The light passes through the first surface of the cemented doublet dichroic mirror, is reflected by the second surface, passes through the first surface again, and then through the projection lens to image the image onto the screen.

2. The dual LCD projector according to claim 1, characterized in that, The first LED light source is a blue LED light source, the phosphor is a yellow phosphor, the first filter is a blue light band filter, the first LCD screen is a red-green LCD screen, the second LED light source is a blue LED light source, the second filter is a red-green band filter, and the second LCD screen is a black-and-white LCD screen.

3. The dual LCD projector according to claim 1, characterized in that, The first LED light source is a blue LED light source, the phosphor is a red phosphor, the first filter is a green band filter, the first LCD screen is a red-blue LCD screen, the second LED light source is a blue LED light source, the second LED light source is provided with green phosphor, the second filter is a green band filter, and the second LCD screen is a black-and-white LCD screen.

4. The dual LCD projector according to claim 1, characterized in that, The first LED light source is a blue LED light source, the phosphor is a green phosphor, the first filter is a red light segment filter, the first LCD screen is a blue-green LCD screen, the second LED light source is a red LED light source, the second filter is a red filter, and the second LCD screen is a black-and-white LCD screen.

Images