High transparent back projection screen

Abstract

The utility model discloses a high -transparency back projection curtain, which is equipped with: pyramid layer, be located close to the light of projector one side, low concentration titanium dioxide atomization layer, it is located pyramid layer far from the light of projector one side, high concentration titanium dioxide atomization layer, it is located low concentration titanium dioxide atomization layer far from pyramid layer one side, base material layer, it is located between low concentration titanium dioxide atomization layer and high concentration titanium dioxide atomization layer. The utility model discloses through setting pyramid layer, not only can collect greater angle range projector light, still can with the light of the light of the collection directional guide to the cone bottom, reduce light dispersion, improve light transmission efficiency. In addition, still can avoid ambient light and transmission light superposition and lead to picture contrast ratio to drop. Through setting two layers atomization layer, not only can avoid light spot gathering, still can control light exit angle, promote viewing contrast. The transmittance of the utility model is >75%, viewing visual angle is >120 DEG, picture uniformity is >90%.

Description

Technical Field

[0001] This utility model relates to the field of screen technology, specifically to a high-transparency rear projection screen. Background Technology

[0002] Projection screens are among the most commonly used peripherals for projectors. When properly paired with a projector, a projection screen can deliver excellent projection results. Functionally, projection screens are generally divided into front projection screens and rear projection screens. Rear projection screens do not require a light source and are typically used in spaces with sufficient room but uncontrollable ambient brightness. The working process of a rear projection screen involves efficiently transmitting projected light through the screen and creating a uniform image. However, existing rear projection screens suffer from low transmittance and significant ambient light interference, leading to washed-out or distorted images that severely impact the viewing experience. Therefore, providing a rear projection screen with high transmittance and the ability to isolate ambient light interference has become an objective requirement. Utility Model Content

[0003] This invention provides a high-transmittance rear projection screen to solve the problems of low transmittance, poor functionality, and significant ambient light interference of existing rear projection screens.

[0004] To achieve the purpose of this utility model, this utility model provides a high-transparency rear projection screen, which includes: The pyramidal layer, located on the side closest to the projector light source, is used to collect the projector light, direct the collected light to the base of the pyramid, and filter out stray light at large angles. A low-concentration titanium dioxide atomization layer is disposed on the side of the pyramidal layer away from the projector light, which is used to weakly scatter the light transmitted from the pyramidal layer and make the light uniformly distributed. A high-concentration titanium dioxide atomizing layer is disposed on the side of the low-concentration titanium dioxide atomizing layer away from the pyramidal layer. It is used to diffuse the light transmitted from the low-concentration titanium dioxide atomizing layer, so as to achieve uniform display of the image and improve the viewing contrast. A substrate layer is disposed between the low-concentration titanium dioxide atomization layer and the high-concentration titanium dioxide atomization layer, and is used to support the low-concentration titanium dioxide atomization layer and the high-concentration titanium dioxide atomization layer.

[0005] The pyramidal layer has an optical array formed by multiple pyramids on the side closest to the projector light source. Each pyramid has a height of 5 to 20 micrometers and a base side length of 10 to 30 micrometers.

[0006] Furthermore, the pyramid is one of a square pyramid, a hexagonal pyramid, or a cone.

[0007] The thickness of the pyramidal layer is 20-50 micrometers.

[0008] In the low-concentration titanium dioxide atomization layer, the titanium dioxide doping concentration is 0.5wt%~2wt% by weight, and the thickness of the low-concentration titanium dioxide atomization layer is 5~15 micrometers.

[0009] Furthermore, when the doping concentration of titanium dioxide in the low-concentration titanium dioxide atomization layer is 0.5 wt%, the thickness of the low-concentration titanium dioxide atomization layer is 12-15 micrometers; when the doping concentration of titanium dioxide in the low-concentration titanium dioxide atomization layer is 2 wt%, the thickness of the low-concentration titanium dioxide atomization layer is 5-8 micrometers.

[0010] In the high-concentration titanium dioxide atomization layer, the titanium dioxide doping concentration is 3wt%~8wt% by weight, and the thickness of the high-concentration titanium dioxide atomization layer is 8~20 micrometers.

[0011] Furthermore, when the doping concentration of titanium dioxide in the high-concentration titanium dioxide atomization layer is 3 wt%, the thickness of the high-concentration titanium dioxide atomization layer is 15-20 micrometers; when the doping concentration of titanium dioxide in the high-concentration titanium dioxide atomization layer is 8 wt%, the thickness of the high-concentration titanium dioxide atomization layer is 8-12 micrometers.

[0012] In the low-concentration titanium dioxide atomization layer, the particle size of the doped titanium dioxide particles is 100~500 nanometers; in the high-concentration titanium dioxide atomization layer, the particle size of the doped titanium dioxide particles is 100~500 nanometers.

[0013] The substrate layer is made of polyethylene terephthalate and has a thickness of 50-150 micrometers.

[0014] The beneficial effects of this utility model are as follows: 1) By placing a pyramidal layer on the side closest to the projector light source, not only can a wider range of projector light angles be collected, but the collected light can also be directed to the base of the cone, thereby reducing light scattering and improving light transmission efficiency. In addition, the cone wall can block some large-angle ambient light from entering the inner layer, preventing the superposition of ambient light and transmitted light from causing a decrease in image contrast.

[0015] 2) The light collected by the pyramidal layer is weakly scattered by a low-concentration titanium dioxide atomization layer, which improves the uniformity of light and avoids the accumulation of light spots. Then, the light is strongly scattered by a high-concentration titanium dioxide atomization layer, so as to achieve uniform display of the picture and control the light emission angle to improve the viewing contrast.

[0016] 3) By setting a substrate layer, it can provide structural support while ensuring high light penetration and avoiding light loss.

[0017] This utility model's high-transmittance rear projection screen can achieve a transmittance of >75%, which is 30-50% higher than that of traditional flat screens. It has a viewing angle of >120° and an image uniformity of >90%, making it suitable for scenarios such as home theaters and conference rooms where both brightness and image quality are required. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model.

[0019] Figure 2 This is a schematic diagram of a pyramidal layer structure according to the present invention.

[0020] Figure 3 yes Figure 2 Top view.

[0021] Figure 4 This is a top view of another pyramidal layer structure of this utility model.

[0022] Figure 5 This is a schematic diagram of the light transmission function of the square pyramid structure of this utility model.

[0023] In the figure, 10 is the pyramidal layer, 20 is the low-concentration titanium dioxide atomization layer, 30 is the high-concentration titanium dioxide atomization layer, and 40 is the substrate layer. Detailed Implementation

[0024] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0025] Please see Figure 1 This utility model provides a high-transparency rear projection screen comprising a pyramidal layer 10, a low-concentration titanium dioxide atomized layer 20, a high-concentration titanium dioxide atomized layer 30, and a substrate layer 40. This high-transparency rear projection screen features high light transmittance and excellent image display, making it suitable for various occasions requiring rear projection screens, especially home theaters, conference rooms, and other scenarios where both brightness and image quality are critical.

[0026] like Figure 1As shown, a pyramidal layer 10 is disposed near the projector light source. It collects the projector light, directs the collected light to the base of the pyramid, and filters out large-angle stray light. This pyramidal layer 10 is made of a light-transmitting material with a thickness of 20-50 micrometers. An optical array composed of multiple pyramids is located on the side near the projector light source. The height of each pyramid matches the incident angle of the projector light. In this embodiment, the height of each pyramid is 5-20 micrometers, and the side length of its base is 10-30 micrometers. Figure 2 , Figure 3 and Figure 4 As shown, a pyramid can be a square pyramid, a hexagonal pyramid, or other polygonal pyramids or cones.

[0027] This embodiment uses a square pyramid as an example to illustrate the light transmission function of the pyramid layer 10; the light transmission function of other pyramidal structures is similar. The transmission of projector light through the square pyramid is achieved through three stages: light collection, directional conduction, and loss suppression, thus solving the problem of oblique light loss in traditional flat screens. Specifically, because traditional flat screens can only efficiently receive light perpendicular to the screen surface, oblique light, especially oblique light from the projector edge, is easily lost due to reflection, resulting in a transmittance typically <60%. In this embodiment, as... Figure 1 , Figure 2 and Figure 5 As shown, because the cone opening of the four-sided pyramid structure is open, it can receive light covering the entire projection angle range of 30°-60° of the projector. When oblique light enters the cone opening, it undergoes 1-2 total internal reflections and is captured along the cone wall instead of being directly reflected and lost. This expands the light reception range by 40%-60% and increases the basic transmitted light amount by 15%-30%. On the other hand, the cone wall-base structure of the four-sided pyramid forms a directional light guiding channel: light entering the cone opening is constrained by the cone wall and can only be guided along the channel to the cone base, avoiding non-target scattering caused by random scattering within the layer, such as loss to the sides or back of the screen. Compared with a flat screen, the four-sided pyramid can increase the proportion of light from the cone opening to the cone base to over 90%, further reducing the loss of transmitted light. Furthermore, since large-angle ambient light, such as light from the ceiling at angles greater than 45° and strong light from outside windows, is easily reflected when it passes vertically through the pyramidal wall, the square pyramidal structure reduces the superposition interference between ambient light and effectively transmitted light. This prevents ambient light from "diluting" the brightness of the transmitted light, indirectly ensuring the visual contrast of the effectively transmitted light, making bright areas of the image brighter and dark areas darker. Therefore, the square pyramidal structure not only improves light transmittance but also directs light directionally, while simultaneously reducing the influence of ambient light and enhancing visual contrast.

[0028] like Figure 1As shown, a low-concentration titanium dioxide atomization layer 20 is provided on the side of the pyramidal layer away from the projector light source. This low-concentration titanium dioxide atomization layer 20 is used to weakly scatter the light transmitted from the pyramidal layer 10, making the light distribution uniform. Specifically, the low-concentration titanium dioxide atomization layer 20 is formed by doping titanium dioxide with a concentration of 0.5wt% to 2wt% into a transparent resin, and the thickness of the low-concentration titanium dioxide atomization layer 20 is 5 to 15 micrometers. Because the cones on the surface of the pyramidal layer 10 are distributed in an array, and each cone independently guides light, the light transmitted from the pyramidal layer 10 exhibits a unitized light intensity distribution, meaning that each cone base corresponds to a small light point. If this light is directly diffused into the high-concentration titanium dioxide atomization layer 30, uneven scattering can easily lead to grid-like dark lines on the image, causing image distortion. In this embodiment, the light transmitted from the pyramidal layer 10 is weakly scattered by the low-concentration titanium dioxide atomization layer 20. Since the titanium dioxide weight percentage in the low-concentration titanium dioxide atomization layer 20 is 0.5wt%~2wt%, its particle density is low, only slightly scattering the light spots without changing the directionality of the light. Therefore, the light still propagates along the light-guiding direction of the pyramid, while ensuring that the transmitted light loss is <5% and the light transmittance is >85%, providing uniform and directional incident light for the subsequent high-concentration titanium dioxide atomization layer 30. Furthermore, tests show that the thickness of the low-concentration titanium dioxide atomization layer 20 matches its internal titanium dioxide concentration. It also needs to match the projector parameters, screen size, viewing distance, etc. Choosing an appropriate thickness and titanium dioxide concentration not only avoids excessive light loss in this layer but also ensures uniform particle distribution. Specifically, when the doping concentration of titanium dioxide in the low-concentration titanium dioxide atomization layer 20 is close to 0.5 wt%, the thickness of the low-concentration titanium dioxide atomization layer 20 is 12-15 micrometers; when the doping concentration of titanium dioxide in the low-concentration titanium dioxide atomization layer 20 is close to 2 wt%, the thickness of the low-concentration titanium dioxide atomization layer 20 is 5-8 micrometers.

[0029] like Figure 1As shown, a high-concentration titanium dioxide atomization layer 30 is provided on the side of the low-concentration titanium dioxide atomization layer 20 away from the pyramidal layer 10. This high-concentration titanium dioxide atomization layer 30 is used to diffuse light, achieving uniform image display and improving viewing contrast. Specifically, the high-concentration titanium dioxide atomization layer 30 is formed by doping titanium dioxide with a concentration of 3wt% to 8wt% into a transparent resin, and its thickness is 8 to 20 micrometers. Although the light guided by the pyramidal layer 10 can be directed, the angle is narrow, only covering the projection angle of the projector. If emitted directly, it results in a small viewing angle, requiring the viewer to be in a specific position to see a clear image. Because the titanium dioxide weight concentration in the high-concentration titanium dioxide atomization layer 30 is 3wt%~8wt%, it can further diffuse the light transmitted by the low-density titanium dioxide atomization layer 20, allowing the light to cover the viewing angle range, typically 40°-120° horizontally and 10°-60° vertically, with a light transmittance >75%. This ensures a uniform image without blind spots and a contrast loss of <15%, ensuring that viewers in different positions can see a uniform image. In this embodiment, the high-concentration titanium dioxide atomization layer 30 only diffuses light in the viewing direction, without scattering in any other direction, thus avoiding light loss. On the other hand, the particle size of titanium dioxide also has a significant impact on the scattering effect. When the titanium dioxide particle size is too large, it can easily lead to a rough image. Experiments have shown that selecting titanium dioxide with a particle size of 100~500 nanometers can control the scattering intensity, prevent image blurring (such as blurred text edges), and ultimately ensure that the effective utilization rate of transmitted light is >40%, that is, the amount of light reaching the viewer's eyes accounts for >40% of the total light output of the projector. Furthermore, tests have shown that the thickness of the high-concentration titanium dioxide atomization layer 30 should match its internal titanium dioxide concentration. It also needs to be matched with projector parameters, screen size, viewing distance, etc. Choosing an appropriate thickness and titanium dioxide concentration ensures sufficient light scattering within the layer, preventing dark areas from appearing on the screen. Specifically, when the titanium dioxide doping concentration in the high-concentration titanium dioxide atomization layer 30 is close to 3wt%, the thickness of the high-concentration titanium dioxide atomization layer 30 is 15-20 micrometers; when the titanium dioxide doping concentration in the high-concentration titanium dioxide atomization layer 30 is close to 8wt%, the thickness of the high-concentration titanium dioxide atomization layer 30 is 8-12 micrometers.

[0030] like Figure 1As shown, a substrate layer 40 is provided between the low-concentration titanium dioxide atomized layer 20 and the high-concentration titanium dioxide atomized layer 30, which supports both layers. This substrate layer 40 is made of polyethylene terephthalate (PET), which has high light transmittance (>92%) and low light absorption (<3%), allowing transmitted light passing through the low-concentration titanium dioxide atomized layer 20 to enter the high-concentration titanium dioxide atomized layer 30 with almost no loss, ensuring that the overall light efficiency is not reduced. Furthermore, this substrate layer has strong physical stability, is temperature resistant, and shrinkage resistant. As an intermediate substrate, its smooth surface ensures the uniformity of the coating of the low-concentration titanium dioxide atomized layer 20 and the high-concentration titanium dioxide atomized layer 30, avoiding localized obstruction of transmitted light due to uneven substrate. Its thickness is 50-150 micrometers to ensure it can support the entire screen, is not prone to wrinkles, and has a moderate weight.

[0031] In summary, the high-transmittance rear projection screen of this invention, by setting a pyramidal layer 10 on the side near the projector light source, can not only collect projector light from a wider angle range, but also guide the collected light to the bottom of the cone, reducing light dispersion and increasing the basic transmitted light amount by 15%-30%, and increasing the proportion of light from the cone opening to the bottom of the cone to over 90%, thereby greatly improving transmission efficiency. Furthermore, the cone wall can block some large-angle ambient light from entering the inner layer, preventing the superposition of ambient light and transmitted light from causing a decrease in image contrast. On the other hand, by setting two atomization layers, the light is scattered twice. A low-concentration titanium dioxide atomization layer 20 weakly scatters the light collected by the pyramidal layer 10, improving light uniformity and preventing light spot aggregation. Then, a high-concentration titanium dioxide atomization layer 30 strongly scatters the light, achieving uniform image display and controlling the light emission angle to improve viewing contrast. The high-transmittance rear projection screen obtained by this invention can achieve a transmittance of >75%, which is 30-50% higher than that of traditional flat screens. It has a viewing angle of >120° and an image uniformity of >90%, making it suitable for scenarios such as home theaters and conference rooms where both brightness and image quality are required.

[0032] Although the present invention has been disclosed through the above embodiments, the scope of protection of the present invention is not limited thereto. Any modifications or substitutions made to the above components without departing from the concept of the present invention shall fall within the scope of the claims of the present invention.

Claims

1. A high-transparency rear projection screen, characterized in that, The rear projection screen features: The pyramidal layer, located on the side closest to the projector light source, is used to collect the projector light, direct the collected light to the base of the pyramid, and filter out stray light at large angles. A low-concentration titanium dioxide atomization layer is disposed on the side of the pyramidal layer away from the projector light, which is used to weakly scatter the light transmitted from the pyramidal layer and make the light uniformly distributed. A high-concentration titanium dioxide atomizing layer is disposed on the side of the low-concentration titanium dioxide atomizing layer away from the pyramidal layer. It is used to diffuse the light transmitted from the low-concentration titanium dioxide atomizing layer, so as to achieve uniform display of the image and improve the viewing contrast. A substrate layer is disposed between the low-concentration titanium dioxide atomization layer and the high-concentration titanium dioxide atomization layer, and is used to support the low-concentration titanium dioxide atomization layer and the high-concentration titanium dioxide atomization layer.

2. The high-transparency rear projection screen as described in claim 1, characterized in that, The pyramidal layer has an optical array formed by multiple pyramids on the side closest to the projector light source. Each pyramid has a height of 5 to 20 micrometers and a base side length of 10 to 30 micrometers.

3. The high-transparency rear projection screen as described in claim 2, characterized in that, The pyramid is one of the following: a square pyramid, a hexagonal pyramid, or a cone.

4. The high-transparency rear projection screen as described in claim 1, characterized in that, The thickness of the pyramidal layer is 20-50 micrometers.

5. The high-transparency rear projection screen as described in claim 1, characterized in that, The substrate layer is made of polyethylene terephthalate and has a thickness of 50-150 micrometers.

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