LCD (Liquid Crystal Display) projection optical structure with reflective polaroid and LCD ray machine

Abstract

The invention relates to an LCD projection optical structure with a reflection type polaroid and an LCD light machine. The LCD projection optical structure comprises a light emitting source, a condensation element, a first polaroid, an LCD screen, a second polaroid, a projection lens and a heat conduction frame which are sequentially arranged in the light propagation direction. The polarization direction of the first polaroid is perpendicular to the polarization direction of the second polaroid, and at least one of the first polaroid and the second polaroid is a reflective polaroid. According to the embodiment of the invention, the reflective polaroid is used for replacing an absorption type iodine polaroid in the prior art, and the reflective polaroid can reflect one kind of linearly polarized light and does not absorb light basically, so that the temperature of the polaroid can be reduced, the chemical performance of the polaroid is stable, and the polaroid is not easy to lose efficacy under a high-temperature condition.

Description

Technical Field

[0001] The present invention relates to the technical field of LCD projection, and in particular to an LCD projection optical structure with a reflective polarizing plate and an LCD optical machine. Background Art

[0002] Projectors can be divided into three types according to the different display elements: DLP, LCOS, and LCD. The imaging principle of LCD projection display is to use light source to project onto the liquid crystal display panel, and synthesize a color image by independently controlling the transmittance of light by the liquid crystal in each pixel of the liquid crystal display panel. The color image is projected onto the display plane through a projection assembly composed of a reflective lens, a collimating lens, etc. to achieve image projection. Liquid crystal projection displays have the advantages of low cost, small size of optical machine, and simple principle, and are widely used in more and more places.

[0003] In LCD projection displays, a layer of polarizer is required on both the light input side and the light output side of the LCD. Natural light passes through the polarizer to form polarized light. The polarizers on both sides work together with the liquid crystal molecules to control the rotation of the liquid crystal molecules through the electric field, change the direction of light travel, form a light-dark contrast, and thus display the image. Currently, the polarizers used on the market are iodine-based polarizers, which are absorption-type polarizers. Light that is consistent with the polarization direction of the polarizer is transmitted, and light that is not polarized is absorbed. After the polarizer absorbs a large amount of light, its temperature will rise. Under long-term high temperature conditions, the polarizer will turn yellow and fail, resulting in abnormal LCD display. Summary of the invention

[0004] Based on this, the purpose of the present invention is to overcome the deficiencies of the prior art and provide an LCD projection optical structure and an LCD optical machine with a reflective polarizer.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] An LCD projection optical structure with a reflective polarizer, comprising a light source, a focusing element, a first polarizer, an LCD screen, a second polarizer, a projection lens and a heat-conducting frame arranged in sequence along the light propagation direction;

[0007] The polarization direction of the first polarizer is perpendicular to the polarization direction of the second polarizer, and at least one of the first polarizer and the second polarizer is a reflective polarizer.

[0008] A first heat dissipation channel is provided between the first polarizer and the LCD screen, and a second heat dissipation channel is provided between the second polarizer and the LCD screen;

[0009] A first heat-conductive film layer is arranged between the first polarizer and the LCD screen, a second heat-conductive film layer is arranged between the second polarizer and the LCD screen, the heat-conductive frame is arranged around the edges of the LCD screen, the first polarizer and the second polarizer, and the first heat-conductive film layer, the second heat-conductive film layer and the LCD screen contact the heat-conductive frame.

[0010] This embodiment uses a reflective polarizer to replace the absorptive iodine-based polarizer in the prior art. The reflective polarizer can reflect one type of linear polarized light and basically does not absorb light. Therefore, this solution can reduce the temperature of the polarizer, and its chemical properties are stable and it is not easy to fail under high temperature conditions.

[0011] As an implementation manner, the first polarizer and / or the second polarizer are attached to glass.

[0012] As an implementation manner, a heat dissipation hole connecting the first heat dissipation channel and the second heat dissipation channel is provided at an edge of the heat conduction frame.

[0013] As an implementation manner, the first heat-conductive film layer is attached to the first polarizer, and the second heat-conductive film layer is attached to the second polarizer.

[0014] As an implementation method, the LCD screen includes a display area and a non-display area arranged around the display area;

[0015] The first heat-conducting film layer and the second heat-conducting film layer each include at least one opening, and the orthographic projection of the opening on the LCD screen is located in the display area.

[0016] As an implementation manner, the LCD projection optical structure further includes an anti-reflection layer, and the anti-reflection layer is located on a side of the first polarizer facing away from the LCD screen and / or a side of the second polarizer facing away from the LCD screen;

[0017] The anti-reflection layer includes a first film layer and a second film layer which are alternately stacked along the light propagation direction. The material of the first film layer is silicon nitride material, and the material of the second film layer is silicon oxide material.

[0018] As an embodiment, the anti-reflection layer includes a bottom layer film, a second layer film, a second top layer film and a top layer film arranged along the direction of light propagation, and the thickness ratio of the bottom layer film, the second layer film, the second top layer film and the top layer film is 1: (2 to 2.3): (2.4 to 3.9): (2.3 to 4).

[0019] As an embodiment, the bottom layer film has a thickness of 10nm to 15nm, the second layer film has a thickness of 20nm to 34nm, the second top layer film has a thickness of 25nm to 58nm, and the top layer film has a thickness of 23nm to 59nm.

[0020] An LCD optical engine comprises the LCD projection optical structure with a reflective polarizer as described above.

[0021] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of an LCD projection optical structure with a reflective polarizer in one embodiment of the present application;

[0023] Figure 2 In one embodiment of this application Figure 1 The enlarged structural diagram at B in the middle;

[0024] Figure 3 This is a schematic diagram of the structure of an anti-reflection layer in one embodiment of the present application;

[0025] Figure 4 In another embodiment Figure 1 The enlarged structural diagram at B in the middle;

[0026] Description of reference numerals:

[0027] 1. Light source; 2. Focusing element; 3. First polarizer; 31. First thermal conductive film layer; 4. LCD screen; 5. Second polarizer; 51. Second thermal conductive film layer; 61. Projection lens; 62. Reflector; 7. Glass; 8. Thermal conductive frame; 9. Anti-reflection layer; 91. First film layer; 92. Second film layer; 901. Bottom film; 902. Second film layer; 903. Sub-top film; 904. Top film. DETAILED DESCRIPTION

[0028] To further illustrate each embodiment, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in the field should be able to understand other possible implementation methods and advantages of the present invention.

[0029] In the description of the present invention, it is necessary to understand that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "left", "right", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] See also Figures 1 to 4 This embodiment provides an LCD projection optical structure with a reflective polarizer, which can be applied to an LCD optical machine. The LCD projection optical structure includes a light source 1, a focusing element 2, a first polarizer 3, an LCD screen 4, a second polarizer 5 and a projection lens 61, which are arranged in sequence along the propagation direction of light. The polarization direction of the first polarizer 3 is perpendicular to the polarization direction of the second polarizer 5.

[0031] In the LCD projection optical structure, the light emitted by the light source 1 is converged by the focusing element 2 and projected onto the first polarizer 3. The light is converted into the first linear polarized light by the first polarizer 3. The first linear polarized light is deflected by the pixel liquid crystal in the LCD screen 4, carries the image grayscale information, and is then colored by the color filter layer of the LCD screen 4 and presented in grayscale by the second polarizer 5, forming a target display image. Finally, it is projected through the projection lens 61 and forms a clear image on the target projection surface. A reflector 62 is also provided between the second polarizer 5 and the projection lens 61, and the reflector 62 is used to change the direction of light propagation.

[0032] Preferably, at least one of the first polarizer 3 and the second polarizer 5 is a reflective polarizer. The principle of the reflective polarizer is mainly to use two materials with different high and low refractive indices to form a multilayer film. When white light passes through the multilayer film, the unpolarized white light is divided into a first linear polarized light parallel to the incident plane and a second linear polarized light perpendicular to the incident plane. The first linear polarized light penetrates and the second linear polarized light is reflected, so it basically does not absorb light, so it will not cause a significant increase in temperature. It can be seen that this embodiment uses a reflective polarizer to replace the absorption type iodine polarizer in the prior art. The reflective polarizer can reflect one of the linear polarized lights and basically does not absorb light. Therefore, this solution can reduce the temperature of the polarizer, and its chemical properties are stable and it is not easy to fail under high temperature conditions.

[0033] Specifically, in some embodiments, the first polarizer 3 is an absorptive polarizer, and the second polarizer 5 is a reflective polarizer; in other embodiments, the first polarizer 3 is a reflective polarizer, and the second polarizer 5 is an absorptive polarizer; in still other embodiments, the first polarizer 3 and the second polarizer 5 are both reflective polarizers, at which time the temperatures of the first polarizer 3 and the second polarizer 5 are the lowest, which can greatly improve durability.

[0034] Since the LCD screen 4 is a component with a relatively high temperature, in order to reduce the influence of the temperature of the LCD screen 4 on the first polarizer 3 or the second polarizer 5, optionally, the first polarizer 3 and the second polarizer 5 are arranged at a predetermined distance from the LCD screen 4. By such arrangement, a first heat dissipation channel (not shown) is formed between the first polarizer and the LCD screen, and a second heat dissipation channel (not shown) is formed between the second polarizer and the LCD screen, so that the heat dissipation effect can be better.

[0035] Preferably, in some embodiments, the first polarizer 3 and / or the second polarizer 5 are attached to the glass 7. The polarizer is attached to the glass 7 to reduce the influence of heat accumulation on the LCD screen 4. In some embodiments, the first polarizer 3 is attached to the glass 7, and the second polarizer 5 is attached to the LCD screen 4. In other embodiments, the first polarizer 3 is attached to the LCD screen 4, and the second polarizer 5 is attached to the glass 7; in still other embodiments, both the first polarizer 3 and the second polarizer 5 are attached to the glass 7.

[0036] Furthermore, in order to improve the transmittance and the imaging effect, the LCD projection optical structure of this embodiment further includes an anti-reflection layer 9, which is located on the side of the first polarizer 3 facing away from the LCD screen 4 and / or the side of the second polarizer 5 facing away from the LCD screen 4. The anti-reflection layer 9 includes a first film layer 91 and a second film layer 92 which are staggered and stacked along the propagation direction of the light, the material of the first film layer 91 is silicon nitride (SiNx) material, and the material of the second film layer 92 is silicon oxide (SiO2) material. Since the first polarizer 3 and the second polarizer 5 can be arranged on the glass 7, the anti-reflection layer 9 can effectively reduce the reflectivity of the light on the surface of the glass 7, thereby improving the overall light transmittance and reducing the interference of the reflected light on the projection imaging.

[0037] Specifically, the anti-reflection layer 9 includes a bottom film 901, a second film 902, a sub-top film 903 and a top film 904 arranged along the propagation direction of the light, and the thickness ratio of the bottom film 901, the second film 902, the sub-top film 903 and the top film 904 is 1: (2 to 2.3): (2.4 to 3.9): (2.3 to 4). Among them, the material of the bottom film 901 and the sub-top film 903 is silicon nitride material, and the material of the second film 902 and the top film 904 is silicon oxide material. The thickness of the bottom film 901 is 10nm to 15nm, the thickness of the second film 902 is 20nm to 34nm, the thickness of the sub-top film 903 is 25nm to 58nm, and the thickness of the top film 904 is 23nm to 59nm, which can better reduce reflected light.

[0038] In order to improve installation convenience and thermal conductivity, preferably, the LCD projection optical structure of this embodiment also includes a thermally conductive frame 8, a first thermally conductive film layer 31 is arranged between the first polarizer 3 and the LCD screen 4, a second thermally conductive film layer 51 is arranged between the second polarizer 5 and the LCD screen 4, and the thermally conductive frame 8 is arranged around the edges of the LCD screen 4, the first polarizer 3 and the second polarizer 5, and the first thermally conductive film layer 31, the second thermally conductive film layer 51 and the LCD screen 4 contact the thermally conductive frame 8.

[0039] By such arrangement, when the light incident side of the LCD screen 4 is irradiated with a high-brightness light source, since the first heat-conducting film layer 31 is arranged between the first polarizer 3 and the LCD screen 4, and the heat-conducting frame 8 is arranged around the edges of the LCD screen 4, the first polarizer 3 and the second polarizer 5, the heat-conducting frame 8 is in contact with the first heat-conducting film layer 31 and the second heat-conducting film layer 51, and a heat conduction path can be formed through the first heat-conducting film layer 31 and the heat-conducting frame 8. Heat is quickly transferred to the outer heat-conducting frame 8 through the first heat-conducting film layer 31 and the second heat-conducting film layer 51, thereby accelerating the heat dissipation speed, effectively reducing the temperature of the display area of ​​the LCD screen 4, avoiding bending and wrinkling of the polarizer caused by uneven accumulation of heat on the polarizer, and thus eliminating the resulting display unevenness and overheating of the LCD screen 4, thereby improving the display quality and display life.

[0040] Preferably, the first heat-conducting film layer 31 is attached to the first polarizer 3, and the second heat-conducting film layer 51 is attached to the second polarizer 5. In this way, heat conduction is faster, heat dissipation speed is accelerated, and uneven heat accumulation on the polarizer is avoided. Compared with the related art, fans and air channels are not required, thereby reducing the overall structure and solving the problem of excessive volume. The first heat-conducting film layer 31 and the second heat-conducting film layer 51 are both attached to the LCD screen 4, and the structure is simple and easy to manufacture.

[0041] Furthermore, a heat dissipation hole (not shown) connecting the first heat dissipation channel and the second heat dissipation channel is provided on the edge of the heat conduction frame, thereby accelerating the heat dissipation speed and improving the heat dissipation performance.

[0042] During the manufacturing process, the first heat-conductive film layer 31 and the second heat-conductive film layer 51 can be respectively manufactured on the first polarizer 3 and the second polarizer 5, and the first heat-conductive film layer 31 and the second heat-conductive film layer 51 can replace the original pressure-sensitive adhesive layer on the first polarizer 3 and the second polarizer 5, and then the first polarizer 3, the LCD screen 4 and the second polarizer 5 can be installed in the heat-conductive frame in sequence, and the first heat dissipation channel and the second heat dissipation channel can be made the same as the heat dissipation hole.

[0043] Specifically, in order to ensure the transmittance of the first polarizer 3 and the second polarizer 5 , the first heat-conducting film layer 31 and the second heat-conducting film layer 51 are transparent film layers.

[0044] Specifically, the material of the heat-conducting frame 8 may be a heat-conducting metal material, for example, aluminum, copper and other metals.

[0045] In this embodiment, the LCD screen 4 includes a display area and a non-display area arranged around the display area; wherein the first heat-conducting film layer 31 and the second heat-conducting film layer 51 each include at least one opening, and the orthographic projection of the opening on the LCD screen 4 is located in the display area. Since the provision of the first heat-conducting film layer 31 and the second heat-conducting film layer 51 will reduce the transmittance of the LCD screen 4, the transmittance of the LCD screen 4 can be improved by providing openings on the first heat-conducting film layer 31 and the second heat-conducting film layer 51. Specifically, the first heat-conducting film layer 31 and the second heat-conducting film layer 51 can have an opening, and the first heat-conducting film layer 31 and the second heat-conducting film layer 51 are coated in a frame shape, and the orthographic projections of the first heat-conducting film layer 31 and the second heat-conducting film layer 51 on the LCD screen 4 can be located in the non-display area.

[0046] This embodiment also provides an LCD optical engine, which includes the LCD projection optical structure with a reflective polarizer as described above. This LCD optical engine has all the beneficial effects of the LCD projection optical structure of this embodiment, so it will not be described in detail here.

[0047] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. An LCD projection optical structure with a reflective polarizer, characterized in that: It includes a light source, a focusing element, a first polarizer, an LCD screen, a second polarizer, a projection lens and a heat-conducting frame which are sequentially arranged along the light propagation direction; The polarization direction of the first polarizer is perpendicular to the polarization direction of the second polarizer, and at least one of the first polarizer and the second polarizer is a reflective polarizer. A first heat dissipation channel is provided between the first polarizer and the LCD screen, and a second heat dissipation channel is provided between the second polarizer and the LCD screen; A first heat-conductive film layer is arranged between the first polarizer and the LCD screen, a second heat-conductive film layer is arranged between the second polarizer and the LCD screen, the heat-conductive frame is arranged around the edges of the LCD screen, the first polarizer and the second polarizer, and the first heat-conductive film layer, the second heat-conductive film layer and the LCD screen contact the heat-conductive frame.

2. The LCD projection optical structure with a reflective polarizer according to claim 1, characterized in that: The first polarizer and / or the second polarizer are attached to the glass.

3. The LCD projection optical structure with a reflective polarizer according to claim 2, characterized in that: The edge of the heat-conducting frame is provided with a heat dissipation hole connecting the first heat dissipation channel and the second heat dissipation channel.

4. The LCD projection optical structure with a reflective polarizer according to claim 3, characterized in that: The first heat-conductive film layer is attached to the first polarizer, and the second heat-conductive film layer is attached to the second polarizer.

5. The LCD projection optical structure with a reflective polarizer according to claim 4, characterized in that: The LCD screen includes a display area and a non-display area arranged around the display area; The first heat-conducting film layer and the second heat-conducting film layer each include at least one opening, and the orthographic projection of the opening on the LCD screen is located in the display area.

6. The LCD projection optical structure with a reflective polarizer according to claim 3, characterized in that: It also includes an anti-reflection layer, and the anti-reflection layer is located on a side of the first polarizer facing away from the LCD screen and / or a side of the second polarizer facing away from the LCD screen; The anti-reflection layer includes a first film layer and a second film layer which are alternately stacked along the light propagation direction. The material of the first film layer is silicon nitride material, and the material of the second film layer is silicon oxide material.

7. The LCD projection optical structure with a reflective polarizer according to claim 6, characterized in that: The anti-reflection layer includes a bottom layer film, a second layer film, a second top layer film and a top layer film arranged along the light propagation direction, and the thickness ratio of the bottom layer film, the second layer film, the second top layer film and the top layer film is 1: (2 to 2.3): (2.4 to 3.9): (2.3 to 4).

8. The LCD projection optical structure with a reflective polarizer according to claim 7, characterized in that: The thickness of the bottom layer film is 10nm to 15nm, the thickness of the second layer film is 20nm to 34nm, the thickness of the second top layer film is 25nm to 58nm, and the thickness of the top layer film is 23nm to 59nm.

9. An LCD optical machine, characterized in that: The invention comprises an LCD projection optical structure with a reflective polarizer as described in any one of claims 1 to 8.

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