LCD projection screen and projection equipment

Abstract

The utility model belongs to the technical field of projectors, and discloses a liquid crystal display (LCD) projection screen, which realizes pixel-level backlight partition by arranging a single-color LCD screen on the light incident side of a color film LCD screen, thereby avoiding obvious light leakage problem through finer brightness control, and further improving contrast ratio. The utility model also discloses projection equipment with the LCD projection screen.

Description

Technical Field

[0001] This utility model belongs to the field of projector technology, and in particular relates to an LCD projection screen and projection device. Background Technology

[0002] LCD projectors are inexpensive, high-resolution projectors with rich colors and good image detail, currently dominating the market. Furthermore, recent data on projector shipments and market share show that the proportion of DLP projectors is gradually declining, and they will face even greater challenges from the LCD projector market in the future.

[0003] LCD projectors utilize the photoelectric effect of liquid crystals, where the arrangement of liquid crystal molecules changes under the influence of an electric field, affecting the transmittance or reflectance of the liquid crystal cells and thus their optical properties. This results in light emitted from each pixel cell having different gray levels and colors, thereby forming a richly colored projected image.

[0004] However, since light leakage is inevitable when liquid crystal pixels obstruct light passage, there is still much room for improvement in image contrast. Utility Model Content

[0005] To address the aforementioned technical issues, this utility model discloses an LCD projection screen that uses a control layer to achieve pixel-level backlight partitioning of the display layer, thereby avoiding significant light leakage through more precise brightness control and further improving contrast.

[0006] The specific technical solution of this utility model is as follows:

[0007] An LCD projection screen includes a control layer and a display layer, wherein the display layer is disposed on the light-emitting side of the control layer; the control layer is a non-color film liquid crystal screen for modulation according to the brightness and darkness information of the displayed image, and the display layer is a color film liquid crystal layer for modulation according to the color information of the displayed image.

[0008] In existing technologies, the contrast of the projected image is typically adjusted by illuminating the display layer with matrix lamps and adjusting the brightness of the matrix lamps. Generally, the contrast ratio of the projected image emitted in this way is only between 400:1 and 600:1, with a maximum of only 1000:1. Therefore, it is difficult to effectively improve the contrast ratio of the projected image using existing technologies. Based on this, this application adds a light control layer on the light-incident side of the display layer. When the projection beam illuminates the control layer, each pixel unit of the control layer can be individually controlled. Compared with existing technologies, the number of pixel units in the control layer is much greater than the number of lamps in the matrix lamps. Therefore, the light control of this application is more precise, thereby giving the projected image a higher contrast ratio.

[0009] Preferably, a microlens array is provided on the light-incident side of the control layer, the microlens array comprising multiple microlens units, each microlens unit corresponding to a pixel unit of the control layer.

[0010] Since the control layer consists of a metal matrix driving pixel glass plate and a glass plate coated with a black matrix, with the liquid crystal between the two glass plates, when the projection beam is collimated and incident on the control layer, part of the projection beam is blocked by the metal matrix and / or the black matrix and cannot completely pass through the control layer. This reduces the utilization rate of the projection beam and also causes the temperature of the LCD projection screen to rise, affecting the projection image quality. Therefore, by using a microlens array, the projection beam can be effectively converged, allowing the projection beam to avoid the metal matrix and / or the black matrix, thereby effectively improving the utilization rate of the projection beam and preventing the LCD projection screen from overheating.

[0011] Preferably, the microlens array is attached to the light-incident side of the control layer.

[0012] This structure effectively ensures the structural stability of the microlens array relative to the control layer, ensuring that each microlens unit can accurately converge the projected beam onto the light-transmitting area of ​​the control layer pixel unit.

[0013] Preferably, the microlens array is made of resin material.

[0014] Microlens arrays made of resin materials have advantages in terms of portability, durability, optical performance, ease of processing, safety, and environmental friendliness.

[0015] Preferably, the microlens array is fabricated using nanoimprinting or photolithography.

[0016] Preferably, one pixel unit of the control layer corresponds to one or more pixel units of the display layer.

[0017] Based on the actual situation and the pixel correspondence between the control layer and the display layer, this application presents different display requirements for the projected image.

[0018] Preferably, the control layer and the display layer are bonded together, or there is a gap between the control layer and the display layer.

[0019] Preferably, the size of the control layer is greater than or equal to the size of the display layer; or the size of the control layer is less than the size of the display layer, and a beam expander is disposed between the control layer and the display layer.

[0020] When the size of the control layer is smaller than the size of the display layer, a beam expander can be placed between the control layer and the display layer to enlarge the small image into a relatively large image, thereby meeting the actual usage requirements.

[0021] Preferably, the light-emitting side of the control layer and the light-incident side of the display layer share a single polarizer.

[0022] This structure reduces the number of components, which helps to reduce size and control costs.

[0023] Projection devices, including:

[0024] The LCD projection screen described above;

[0025] A light source that emits a projection beam, the projection beam being guided to a control layer, the control layer adjusting the light and dark intensity of its pixel units, and the projection beam illuminating the display layer; and

[0026] A lens is used to project a beam of light emitted from the display layer.

[0027] Compared with existing technologies, this invention achieves pixel-level partitioning, which can compensate for the light leakage problem caused by the shutdown of the pixel units of the liquid crystal, thereby effectively improving the contrast of the projected image. Compared with ordinary backlight partitioning, this invention provides higher projection image quality and lower cost through a higher number of pixel units. This invention can also solve the problem of projection beam loss, better achieve light control consistency, and further optimize the display effect of the projected image. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the projection device in an embodiment of the present utility model;

[0029] Figure 2 This is a schematic diagram of the projection device in an embodiment of this utility model;

[0030] Figure 3 These are renderings of an embodiment of the present utility model;

[0031] Figure 4 This is a schematic diagram of the LCD projection screen in an embodiment of the present utility model;

[0032] Figure 5 This is a schematic diagram showing the correspondence between pixel units in the control layer and pixel units in the display layer in some embodiments of this utility model;

[0033] Figure 6 This is a schematic diagram of an LCD projection screen in some embodiments of the present invention.

[0034] In the diagram: 100-LCD projection screen; 200-light source; 300-lens; 1-control layer; 2-display layer; 3-metal matrix driving pixel glass plate; 4-black matrix glass plate; 5-light transmission section one; 6-light transmission section two; 7-microlens array; 8-beam expander; 9-polarizer one; 10-polarizer two; 11-polarizer three. Detailed Implementation

[0035] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to specific embodiments.

[0036] like Figure 1 and Figure 2 As shown, this embodiment discloses a projection device, including an LCD projection screen 100, a light source 200, and a lens 300. The LCD projection screen 100 includes a control layer 1 and a display layer 2. The light source 200 emits a projection beam, which is guided to the control layer 1. After the control layer 1 adjusts the light and dark intensity of its pixel units, the projection beam illuminates the display layer 2. The lens 300 is used to project the projection beam emitted from the display layer 2. In this embodiment, the control layer 1 is a non-color film LCD screen, and the display layer 2 is a color film LCD layer. This embodiment achieves pixel-level backlight partitioning of the display screen by adding a controllable dimming monochrome LCD screen (control layer 1) in front of the color film LCD screen (display layer 2). By dividing the screen into millions of individual dimmable areas, more precise brightness control can be achieved within a sub-millimeter range, thereby effectively improving the contrast of the projected image.

[0037] For HDR technology, the most important aspect of HDR for displays is the implementation of backlight zoning. If an LCD has over 95% DCI-P3 color gamut and a peak brightness of 1000 nits, the entire projected image will be poorly displayed without backlight zoning. In this embodiment, by using a stacked control layer 1 and display layer 2, the resolution of control layer 1 can be increased to 1920*1080, and the resolution of display layer 2 can be increased to true 4K level. Therefore, after using the stacked control layer 1 and display layer 2, the LCD projection screen 100 can achieve the effect of at least 2 million backlight zones. Compared to conventional Mini LED displays, which typically achieve only 1000-2000 backlight zones, this embodiment achieves a much higher order of magnitude of backlight zones. Figure 3 As shown, since the monochrome LCD screen (control layer 1) is used to turn light on / off, the black areas on the projected image can achieve a near-pure black effect, thus effectively avoiding the appearance of trace amounts of black images on the projected image and improving the viewing experience. Therefore, in this embodiment, pixel-level dimming can match the brightness value corresponding to each color according to the different brightness levels displayed by the light valve of the color filter LCD screen (display layer 2), achieving true color reproduction.

[0038] Specifically, such as Figure 4As shown, an LCD projection screen 100 includes a control layer 1 and a display layer 2, wherein the display layer 2 is disposed on the light-emitting side of the control layer 1; the control layer 1 is a non-color film liquid crystal screen used for modulation according to the brightness and darkness information of the displayed image, and the display layer 2 is a color film liquid crystal layer used for modulation according to the color information of the displayed image.

[0039] It should be noted that non-color LCD screens are usually called monochrome LCD screens or black and white LCD screens, and can also be LCD screens without color filters on the light-emitting side. Color LCD screens refer to LCD screens that include multiple color filters in a single pixel unit to display color images.

[0040] In this embodiment, the control layer 1 includes a metal matrix driving pixel glass plate 3 and a black matrix glass plate 4, as well as a liquid crystal disposed between the two glass plates. The metal matrix driving pixel glass plate 3 has a plurality of light-transmitting parts 5, and the black matrix glass plate 4 has a plurality of light-transmitting parts 6. The pixel units on the liquid crystal correspond one-to-one with the light-transmitting parts 5 and the light-transmitting parts 6. That is, the light-transmitting parts 5, the pixel units, and the light-transmitting parts 6 are arranged in a corresponding manner so that the projection beam can pass smoothly through the control layer 1, thereby effectively realizing the adjustment of the amount of light passing through each pixel unit of the control layer 1.

[0041] After the light source 200 is collimated by optical elements such as the Fresnel lens, when it is incident on the surface of the control layer 1, there is still a certain degree of oblique incident light. This part of the light, after exiting the control layer 1, will cause the display layer 2 to exhibit a certain brightness in the non-lit state, thus leading to a decrease in contrast during actual use. Furthermore, due to the light-blocking effect of the metal matrix and the black matrix, the collimated light cannot completely pass through the control layer 1, thereby reducing the utilization rate of the light source 200 and converting it into heat energy, causing the temperature of the control layer 1 to rise. Therefore, as... Figure 4 As shown, in this embodiment, a microlens array 7 is provided on the light-incident side of the control layer 1. The microlens array 7 includes multiple microlens units, each corresponding to a pixel unit of the control layer 1. Therefore, the projected beam can avoid the obstruction of the metal matrix and the black matrix, allowing the projected beam to directly illuminate the opening area of ​​the pixel unit. This concentrates the light propagation direction, improving the utilization rate of the light source 200 and achieving a brightness enhancement effect. Furthermore, the collimation of the projected beam further contributes to improved contrast. Therefore, this embodiment, by fully utilizing the LCD projection screen 100 formed by the control layer 1 and the display layer 2, not only improves contrast but also solves the problem of decreased brightness. Moreover, the microlens array 7 also improves light uniformity, further enhancing the light control consistency of the control layer 1 and further optimizing the projected image display effect.

[0042] In this embodiment, the microlens array 7 is attached to the light-incident side of the control layer 1. This structure ensures the stability of the microlens array 7 relative to the control layer 1, ensuring that the microlens units can accurately focus light onto the light-transmitting area of ​​the pixel unit, thereby reducing light loss, improving the utilization rate of the light source 200, and increasing the output brightness. In this embodiment, the microlens array 7 is made of resin material. The microlens units in the microlens array 7 protrude away from the control layer 1 to achieve a good light-focusing effect.

[0043] In this embodiment, the microlens array 7 is fabricated using nanoimprint lithography or photolithography. As a preferred embodiment, nanoimprint lithography is used. Nanoimprint lithography typically involves transferring a pattern onto a substrate using a template. The transfer medium is usually a polymer film, which is then hardened through methods such as hot pressing or irradiation to retain the transferred pattern. Nanoimprint lithography offers advantages such as ultra-high resolution, easy mass production, low cost, and high consistency. It ensures precise matching between microlens units and pixel units, thereby ensuring that the microlens units effectively focus light onto the light-transmitting area of ​​the pixel units, improving light output brightness.

[0044] In this embodiment, one pixel unit of the control layer 1 corresponds to one or more pixel units of the display layer 2. The resolution of the display layer 2 determines the resolution of the final projected image. Therefore, the resolution of the control layer 1 can be lower than the resolution of the display layer 2. The resolution of the control layer 1 is mainly to achieve pixel-level backlight partitioning. When the resolution is 1920*1080, it can achieve 2 million pixel-level backlight partitions. In this embodiment, the pixel units of the control layer 1 correspond one-to-one with the units of the display layer 2. Alternatively, one pixel unit of the control layer 1 can correspond to two pixel units of the display layer 2, meaning that two pixel units of the display layer 2 are located in the same backlight partition. In other words, this embodiment can, according to actual needs, make multiple pixel units of the display layer 2 correspond to one pixel unit of the control layer 1, meaning that multiple pixel units of the display layer 2 are located in the same backlight partition. It is known that the higher the resolution of the control layer 1, the more detailed the backlight partitioning, and the better the image effect that can be achieved. Figure 5 As shown, a corresponding scheme for pixel units in control layer 1 and pixel units in display layer 2 is illustrated.

[0045] In different technical solutions of this embodiment, the cooperation method between the control layer 1 and the display layer 2 is different; that is, the control layer 1 and the display layer 2 are bonded together, or there is a gap between the control layer 1 and the display layer 2. Both methods can meet specific usage requirements. Furthermore, in this embodiment, the size relationship between the control layer 1 and the display layer 2 can also be configured according to actual needs. When the size of the control layer 1 is greater than or equal to the size of the display layer 2, the size of the projected image corresponds to the size of the display layer 2. Therefore, when the size of the control layer 1 is greater than or equal to the size of the display layer 2, it can be ensured that the projection beam passing through the control layer 1 effectively covers the display layer 2. Figure 6 As shown, when the size of the control layer 1 is smaller than the size of the display layer 2, the projection beam passing through the control layer 1 cannot cover the display layer 2 well. Therefore, in order to ensure the integrity of the projected image, a beam expander 8 is provided between the control layer 1 and the display layer 2 to better meet the display requirements of the projected image.

[0046] Furthermore, the light-emitting side of the control layer 1 and the light-incident side of the display layer 2 share a single polarizer. For example... Figure 2 and Figure 3 As shown, polarizers are typically provided on both the light-incident and light-exit sides of a liquid crystal display (LCD). However, in this embodiment, three polarizers are sufficient to meet the requirements. Specifically, the LCD projection screen 100 further includes a first polarizer 9 on the light-exit side of the control layer 1, a second polarizer 10 shared between the control layer 1 and the display layer 2, and a third polarizer 11 on the light-exit side of the display layer 2. Therefore, in this embodiment, the control layer 1 includes both first polarizer 9 and second polarizer 10, and the display layer 2 includes second polarizer 10 and third polarizer 11. When the light source 200 emits a projection beam, it is modulated by the first polarizer 9 into the liquid crystal control unit of the control layer 1 in a first polarization state. The modulated light displays a black and white image with significant brightness on the control layer 1. Then, it is modulated by the second polarizer 10 and then by the liquid crystal control unit of the display layer 2, displaying a color image. After exiting through the third polarizer 11, a high-contrast color image combining the two is formed.

[0047] In this embodiment, the brightness information of each pixel of the image to be projected is first obtained. Then, based on the brightness difference of each pixel in the projected image, the brightness information of each pixel unit in the control layer 1 is calculated and determined. Next, the light modulation signal is transmitted to the control layer 1 and the image display RGB signal is transmitted to the display layer 2. Finally, the backlight-modulated projected image is displayed.

[0048] The above are merely preferred embodiments of this utility model. It should be noted that the above preferred embodiments should not be considered as limitations on this utility model, and the scope of protection of this utility model should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.

Claims

1. An LCD projection screen, characterized in that, It includes a control layer and a display layer, wherein the display layer is disposed on the light-emitting side of the control layer; the control layer is a non-color film liquid crystal screen used for modulation according to the brightness and darkness information of the displayed image, and the display layer is a color film liquid crystal layer used for modulation according to the color information of the displayed image.

2. An LCD projection screen as described in claim 1, characterized in that, A microlens array is provided on the light-incident side of the control layer. The microlens array includes a plurality of microlens units, and each microlens unit corresponds one-to-one with a pixel unit of the control layer.

3. An LCD projection screen as described in claim 2, characterized in that, The microlens array is attached to the light-incident side of the control layer.

4. An LCD projection screen as described in claim 2, characterized in that, The microlens array is made of resin material.

5. An LCD projection screen as described in claim 2, characterized in that, The microlens array is fabricated using nanoimprinting or photolithography.

6. An LCD projection screen as described in any one of claims 1 to 5, characterized in that, One pixel unit in the control layer corresponds to one or more pixel units in the display layer.

7. An LCD projection screen as described in any one of claims 1 to 5, characterized in that, The control layer and the display layer are bonded together, or there is a gap between the control layer and the display layer.

8. An LCD projection screen as described in any one of claims 1 to 5, characterized in that, The size of the control layer is greater than or equal to the size of the display layer; or the size of the control layer is less than the size of the display layer, and a beam expander is provided between the control layer and the display layer.

9. An LCD projection screen as described in any one of claims 1 to 5, characterized in that, The light-emitting side of the control layer and the light-incident side of the display layer share a single polarizer.

10. A projection device, characterized in that, include: The LCD projection screen as described in any one of claims 1 to 9; A light source emits a projection beam, which is guided to a control layer. After the control layer adjusts the light and dark intensity of its pixel units, the projection beam illuminates the display layer. And a lens, used to project the projection beam emitted from the display layer.

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