A projection screen and a projection system

Abstract

The present invention discloses a projection screen and a projection system. A microstructure layer for converging projection light is provided on the projection screen. The projection screen is divided into a plurality of imaging regions along the vertical direction. The microstructure layers within the range of each imaging region respectively converge the projection light to a convergence point. All the convergence points are on the same straight line perpendicular to the projection screen, and at least one convergence point of an imaging region does not coincide with the convergence points of other imaging regions. The projection screen and the projection system of the present invention effectively improve the viewing field range, effectively improve the viewing brightness and brightness uniformity in a large-area viewing field, reduce the limitation on the viewer's position, and enhance the viewing experience.

Description

Technical Field

[0001] The present invention relates to the technical field of projection display, and in particular to a projection screen and a projection system. Background Art

[0002] In a projection display system, a projector and a projection screen are required. The function of the projection screen is to image the image emitted by the projector and redistribute the projection light intensity. The redistribution of the projection light intensity by the projection screen relies on various microstructures on the screen to diffuse, converge the projection light, or control the light transmission direction as needed to meet the requirements of different viewing fields. One of the widespread problems of current projection screens is that at different viewing positions, the brightness difference of the screen display is very large. Unlike LCD or LED screens, the brightness does not vary greatly within a large viewing field. Therefore, one of the differences between projection screens and LCD or LED is that the brightness perceived by viewers under different viewing fields on the projection screen is uneven, which greatly affects the visual experience of viewers. In addition, in the currently popular short-focus projection applications, the viewing field of the projection screen perceived by viewers is smaller compared to LCD or LED.

[0003] The general design method of a projection system is to converge the projection light rays to the front of the geometric center of the projection screen through the microstructures on the projection screen. For example, the patent document with the publication number CN109917613A in China describes using the lens surface of a Fresnel lens to converge the projection light rays to a position 3 meters in front of the geometric center of the screen, as Figure 1 shown. The problem with this technical solution in practical applications is that only viewers located 3 meters in front of the geometric center of the screen can see the highest screen brightness. Viewers in other positions can receive very little light, and the screen brightness they see will be very low. Moreover, the screen brightness distribution is extremely uneven in other positions. The prior art can only see a brighter image when the viewer's eye line height is exactly at the height of the convergence point of the projection screen. For viewers with a higher or lower height, since the viewer's eye line deviates from the convergence point of the projection screen and cannot receive much light, the brightness of the image seen is very low, resulting in a very small viewing field of the projection system. Summary of the Invention

[0004] The technical problem to be solved and the technical task proposed by the present invention is to improve the prior art and provide a projection screen to solve the problems in the current technology that the viewing field of the traditional projection screen is small, the requirements for the viewer's position are high, there is only a small area of the best viewing range, and the viewing brightness is extremely low and the screen brightness is extremely uneven when deviating from the best viewing position.

[0005] To solve the above technical problems, the technical solution of the present invention is:

[0006] A projection screen is provided with a microstructure layer for converging projection light. The projection screen is divided into several imaging regions along the vertical direction. The microstructure layer within the range of each imaging region converges the projection light to a convergence point respectively, and all the convergence points are on the same straight line perpendicular to the projection screen, and at least one of the convergence points of an imaging region does not coincide with the convergence points of other imaging regions.

[0007] The projection screen of the present invention divides the projection screen into several imaging regions, and each imaging region has its corresponding projection light convergence point. In other words, the microstructure layer is also divided into several partitions along the vertical direction according to the division of the imaging regions, and each partition of the microstructure layer converges the projection light to a preset convergence point respectively. Compared with the prior art in which the entire projection screen converges the projection light to a single convergence point, the present invention effectively broadens the range of the area with a good viewing experience. Since each imaging region has a projection light convergence point respectively, viewers can always receive sufficient projection light within the viewing field of a large area, thus ensuring the viewing brightness. For example, when the viewer moves along the straight line where the convergence points are located and between the farthest convergence point and the nearest convergence point from the projection screen, there is always at least one imaging region whose projection light can be fully concentrated and converged to the position where the viewer is located, and a part of the projection light of other imaging regions will also be received by the viewer, thereby effectively improving the overall viewing brightness in a large viewing area. In the prior art, since the entire projection screen converges the projection light to a single convergence point, once the viewer deviates from the convergence point, the viewing brightness of the entire projection screen will suddenly decrease, affecting the viewing experience. Moreover, the present invention adopting a projection light convergence point for each imaging region also effectively improves the screen uniformity viewed in the viewing field of a large area. Usually, the central part of the image light projected by the projector has the highest brightness, that is, the light projected on the central region of the projection screen has the highest brightness. In the prior art, when the entire projection screen converges the projection light to a single convergence point, the entire picture viewed by the viewer at the best viewing position will be a picture with a brighter middle and darker edges on the four sides, and the brightness uniformity is poor. The present invention converges the projection light in different imaging regions to different points, which can avoid the excessive concentration of light and effectively improve the viewing brightness uniformity. The present invention greatly improves the effective viewing field range and enhances the viewing experience.

[0008] Further, the perpendicular distance from the convergence point of the imaging region in the middle in the vertical direction of the projection screen to the projection screen is greater than the perpendicular distances from the convergence points of the imaging regions near the top and near the bottom to the projection screen.

[0009] Alternatively, the vertical distance from the convergence point of the imaging area in the middle part to the projection screen is equal to the vertical distance from the convergence point of the imaging area near the top to the projection screen, and is greater than the vertical distance from the convergence point of the imaging area near the bottom to the projection screen.

[0010] In the present invention, the projection light of the middle imaging area is converged to a place farther from the projection screen, that is, the projection light of the middle imaging area is more diverged to the distance. This way can reduce the viewing brightness of the middle area of the projection screen when viewing at a relatively short distance, solve the problem that the middle of the projection screen is too bright and the edge is too dark, improve the viewing brightness uniformity, and because the projection light of the middle imaging area is converged to a place farther from the projection screen, it also enables a high-brightness image to be viewed when viewing from a distance, so that the overall brightness of the screen viewed at a short distance and a long distance will not vary too much, improve the consistency of the viewing experience at a short distance and a long distance, and increase the effective viewing field range. For the second method, when it is not necessary to view from a distance, the effective viewing field range can be appropriately reduced, which can increase the overall picture brightness when observing at a short distance.

[0011] Furthermore, the vertical distance from the convergence point of the imaging area near the top to the projection screen is greater than or equal to the vertical distance from the convergence point of the imaging area near the bottom to the projection screen. Generally, viewers are viewing at a medium distance. When using a short-focus projector to project image light onto the projection screen, the short-focus projector is usually set on the lower side of the projection screen. As a result, the top area of the projection screen is farther from the projector, and thus the brightness of the projection light received by the top area of the projection screen is lower. In order to improve the viewing brightness uniformity, the convergence point of the imaging area near the top is set at a medium distance, that is, the convergence point of the imaging area near the top is located between the convergence point of the middle imaging area and the convergence point of the imaging area near the bottom, so as to increase the projection light of the imaging area near the top received by the viewer and reduce the projection light of the middle imaging area and the imaging area near the bottom received by the viewer, thereby effectively improving the brightness uniformity.

[0012] Furthermore, the vertical distance from the convergence point of the middle imaging area to the projection screen is less than or equal to 12 times the height dimension of the projection screen. The vertical distance from the convergence point of the middle imaging area to the projection screen cannot be too large, which will cause a sudden change in the shape of the microstructure layer and is difficult to process and implement. Moreover, being too large will also cause the brightness of the central area of the projection screen to be too low, resulting in uneven viewing brightness instead.

[0013] Further, the vertical distance from the convergence point of the middle imaging area to the projection screen is greater than or equal to 6 meters, and the vertical distance from the convergence point of the imaging area near the bottom to the projection screen is greater than or equal to 2 meters and less than 6 meters. It is applicable to small-sized projection screens, such as projection screens within 100 inches, which can effectively increase the viewing field range and improve the screen brightness uniformity at any position within the viewing field range, facilitating the popularization of the projection screen.

[0014] Further, the imaging area can be equally or unequally divided along the vertical direction of the projection screen. The imaging area can be divided according to actual situations, enabling customization. Specific division can be carried out based on the viewing distance, projection screen size, viewer height, etc., which can maximize the viewing brightness and uniformity and improve the viewing experience.

[0015] Further, the projection screen is divided into three imaging areas: upper, middle, and lower along the vertical direction. Compared with a larger number of imaging areas, the amount of calculated data is relatively small, and the implementation is more convenient and simple, which is conducive to reducing the design difficulty.

[0016] Further, the straight line where the convergence point is located is lower than the geometric center height of the projection screen. During actual use, the height of the viewer's direct line of sight is lower than the geometric center height of the projection screen. In the prior art, the projection light is converged in front of the geometric center of the screen, so the observed brightness is lower than the designed value, and the viewing experience is poor. In the present invention, the convergence points of the projection light rays of each imaging area are set to be lower than the geometric center height of the projection screen, enabling the viewer to receive more projection light rays, thereby enabling the viewer to obtain a brighter image display effect and brightness uniformity effect from the projection screen.

[0017] Further, the straight line where the convergence point is located intersects with the straight line passing through the geometric center of the projection screen along the vertical direction, and the intersection point is outside the area of the projection screen. This makes the projection screen brightness symmetrical left and right, improves the brightness uniformity, and the viewer facing the geometric center of the projection screen can obtain the best viewing experience, with high viewing brightness and good brightness uniformity.

[0018] Further, the microstructure layer includes a number of unit lenses with serrated cross-sections arranged in a concentric circular ring shape in the plane direction of the projection screen. The microstructure layer is in the shape of an annular Fresnel lens, which can effectively converge the projection light rays. By designing the pitch, height, and lens surface inclination angle of the unit lenses, the convergence focus of each unit lens on the projection light rays can be controlled, thereby dividing the projection screen into several imaging areas. By designing and adjusting the parameters of the unit lenses in each imaging area, each imaging area can have an independent projection light ray convergence point, ultimately achieving the improvement of the viewing field range, viewing brightness, and brightness uniformity.

[0019] Further, the center of the concentric circles of the unit lens is located outside the area of the projection screen, that is, the microstructure layer is in the shape of an offset annular Fresnel lens. The center of the concentric circles of the unit lens is specifically located below the projection screen and on the straight line passing vertically through the geometric center of the projection screen. Since the center of the concentric circles is located outside the area of the projection screen, the unit lens on the projection screen area is a part of a perfect circle, that is, the unit lens is arc-shaped. In other words, the entire microstructure layer includes a number of arc-shaped unit lenses arranged radially along the center of the concentric circles.

[0020] A projection system includes the above-mentioned projection screen and a projector that projects image light onto the projection screen.

[0021] Further, when observed from the normal direction of the projection screen, the projector is located outside the area of the projection screen.

[0022] Compared with the prior art, the advantages of the present invention are as follows:

[0023] The projection screen and the projection system of the present invention effectively improve the viewing field range, effectively improve the viewing brightness and brightness uniformity in a large viewing field range, reduce the limitation on the viewer's position, and enhance the viewing experience. Description of the Drawings

[0024] Figure 1 is a schematic diagram of a projection system in the prior art;

[0025] Figure 2 is a schematic diagram of the projection system of the present invention;

[0026] Figure 3 is a schematic structural diagram of a microstructure layer of the present invention;

[0027] Figure 4 is another schematic structural diagram of a microstructure layer of the present invention;

[0028] Figure 5 is a third schematic structural diagram of a microstructure layer of the present invention;

[0029] Figure 6 is a fourth schematic structural diagram of a microstructure layer of the present invention;

[0030] Figure 7 is a schematic diagram of a projection system according to an embodiment of the present invention;

[0031] Figure 8 is a comparison diagram of the optical paths of a projection system of the present invention and a projection system in the prior art;

[0032] Figure 9 is a schematic structural diagram of a projection screen of the present invention;

[0033] Figure 10 It is a schematic cross-sectional structure diagram of an embodiment of a projection screen of the present invention;

[0034] Figure 11 It is a schematic cross-sectional view of an embodiment of a projection screen of the present invention;

[0035] Figure 12 It is a schematic cross-sectional view of an embodiment of a projection screen of the present invention.

[0036] In the figure:

[0037] 10 - Projection screen; 20 - Projection system; 101 - Substrate layer; 102 - Microstructure layer; 1021 - Unit lens; 103 - Reflective material layer; 104 - Diffusion layer; 105 - Coloring layer; 106 - First substrate layer; 1041 - Light diffusion material; 1051 - Light absorption material; Z - Straight line perpendicular to the projection screen; O1 - Center of concentric circles; O - Geometric center; F - Convergence point of projection light rays of the prior art projection screen; G - Viewer; Y - Projector. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than 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 efforts shall fall within the protection scope of the present invention.

[0039] A projection screen disclosed in an embodiment of the present invention can effectively improve the viewing field of view, reduce the limitation on the position of the viewer, ensure good viewing brightness and screen brightness uniformity within a relatively large viewing area range, and improve the movie-watching experience.

[0040] As Figures 2 to 6 shown, it is a schematic diagram of a projection system of the present invention. The projection system includes a projector Y and a projection screen 10. The projection screen 10 is used to image the projection light rays emitted by the projector Y. Viewed from the normal direction of the projection screen 10, the projector is located outside the area of the projection screen. Specifically, the projector Y is located below the front side of the projection screen 10. The projector Y is a short-focus projector, which transmits image light rays obliquely upward to the projection screen 10. The projection screen 10 is provided with a microstructure layer 102 for converging the projection light rays. The microstructure layer 102 is composed of a plurality of unit lenses 1021 arranged. Specifically, each unit lens 1021 is arranged in a curved shape along the plane direction of the projection screen 10, and adjacent unit lenses 1021 are arranged according to a certain preset direction and spacing, etc. As Figures 3 to 6As shown, the unit lens 1021 can specifically be in the shape of an arc line, a circular ring line, an elliptical line, a bow line, or other higher-order curves, etc. The wiring shape of the unit lens 1021 is specifically set according to the requirements for converging the projection light. In the cross-section in the thickness direction of the projection screen 10, the cross-sectional shape of the unit lens 1021 is serrated, or can also be described as a triangular convex structure. The unit lens 1021 has two surfaces forming an angle to reflect and converge the projection light;

[0041] As Figure 3 shown, the first schematic diagram of the microstructure layer 102, the unit lens 1021 is in the shape of an arc line, and the unit lenses 1021 in the microstructure layer 102 are arranged in concentric circles, that is, all the unit lenses 1021 have a common concentric circle center O1. The unit lenses 1021 are arranged at intervals along the radial direction, and the concentric circle center O1 of the unit lenses 1021 is located outside the area of the projection screen 10, that is, the microstructure layer is in the shape of an offset annular Fresnel lens. The concentric circle center O1 of the unit lenses 1021 is specifically located below the projection screen 10 and on the straight line passing vertically through the geometric center O of the projection screen 10. Since the concentric circle center is located outside the area of the projection screen, the unit lenses on the projection screen area are part of a perfect circle, that is, the unit lenses are in the shape of an arc line. In other words, the entire microstructure layer contains several arc-line-shaped unit lenses arranged along the radial direction of the concentric circle center; As Figure 4 shown, the second schematic diagram of the microstructure layer 102, the unit lens 1021 is in the shape of a circular ring line, and several of the unit lenses 1021 in the microstructure layer 102 are arranged in concentric circles, that is, all the unit lenses 1021 have a common concentric circle center O1. The unit lenses 1021 are arranged at intervals along the radial direction, and the concentric circle center O1 of the unit lenses 1021 coincides with the geometric center O of the projection screen 10; As Figure 5 shown, the third schematic diagram of the microstructure layer 102, the unit lens 1021 is in the shape of an elliptical line, and the centers of all the unit lenses 1021 coincide; As Figure 6 shown, the fourth schematic diagram of the microstructure layer 102, the unit lens 1021 is in the shape of a bow line, and the centers of all the unit lenses 1021 coincide.

[0042] The projection screen 10 is divided into a number of imaging regions along the vertical direction, at least three imaging regions, and may also be four, five or more imaging regions. The microstructure layers within the scope of each imaging region respectively converge the projection light to a convergence point. All the convergence points are on the same straight line perpendicular to the projection screen, and at least one convergence point of one imaging region does not coincide with the convergence points of other imaging regions. The more the number of imaging regions is divided, the more finely the convergence direction of the projection light incident on different positions of the projection screen can be controlled. However, the amount of data that needs to be calculated is relatively large, and the design difficulty is relatively high. Therefore, it is generally preferred to divide the projection screen into three upper, middle and lower imaging regions for design and calculation. Figure 2 In the figure, two virtual dotted lines divide the projection screen into three imaging regions. The upper imaging region converges all the projection light to the convergence point A (that is, all positions within this imaging region have only a single convergence point A for the projection light, and the following meaning is the same). The middle imaging region converges all the projection light to the convergence point B, and the lower imaging region converges all the projection light to the convergence point C. The three points A, B, and C are located on the same straight line Z perpendicular to the screen plane of the projection screen 10, and the three points A, B, and C do not coincide with each other. It is also possible that at least one of the three points A, B, and C does not coincide with the other points. For example, points A and C coincide as one point, and point B does not coincide with these two points. That is, the projection light in the upper and lower imaging regions converges to the same point, while the projection light in the middle imaging region converges to another different point.

[0043] Furthermore, the three imaging regions into which the projection screen 10 is divided along the vertical direction can be three equally divided imaging regions or three unequally divided imaging regions, which are specifically set according to the viewing distance, the size of the projection screen, the height of the viewer, etc.

[0044] Moreover, the above is to divide the projection screen 10 along the vertical direction of the projection screen. It is also possible to divide the projection screen along any divergent direction of the projection light emitted by the projector. Because the convergence of the projection screen to the projection light depends on the unit lens 1021, such as Figure 3 the microstructure layer 102 shown. The unit lens 1021 is a rotationally symmetric circular arc structure on the projection screen 10. Therefore, no matter which direction the projection screen 10 is divided, it can ultimately be equivalent to dividing the projection screen 10 along the vertical direction.

[0045] Further, the straight line Z perpendicular to the plane of the projection screen 10 intersects with the vertical center line of the projection screen, and the straight line Z is lower than the geometric center height of the projection screen. More preferably, the straight line Z is located outside the display area of the projection screen 10, that is, there is no intersection between the straight line Z and the projection screen 10. Because in actual viewing, the height of the viewer's direct line of sight is usually in the lower half area of the projection screen or below. To enable the viewer to see a brighter image on the projection screen, the projection screen needs to converge more projection light downward. Therefore, the straight line where the convergence point of the projection screen 10 is located also needs to deviate downward from the area range of the projection screen, so that the viewer can obtain a brighter image display effect and brightness uniformity effect from the projection screen.

[0046] As Figure 7 shown in the schematic diagram of the projection system, the vertical distance L2 between the convergence point B and the plane of the projection screen 10 is greater than the vertical distance L1 between the convergence point A and the plane of the projection screen 10, and also greater than the vertical distance L3 between the convergence point C and the plane of the projection screen 10. The projection screen designed in this way can diverge the projection light incident on the middle area as far as possible, which is beneficial to solving the problem of uneven brightness that the middle of the projection screen is too bright and the edge is dark, reducing the brightness felt by the viewer nearby. At the same time, it can also enable the viewer in the distance to view a brighter image, so that the brightness difference of the image felt by the viewer in the distance and nearby is not too large, thus effectively improving the viewing field of the projection screen.

[0047] Further, the vertical distance L2 between the convergence point B and the plane of the projection screen 10 can be the same as the vertical distance L1 between the convergence point A and the plane of the projection screen 10, and greater than the vertical distance L3 between the convergence point C and the plane of the projection screen 10. This is beneficial to increasing the image brightness of the projection screen for the viewer nearby, and is applicable to the situation where there is no viewer in the distance in the home scene.

[0048] Further, it can also be that the vertical distance L1 between the convergence point A and the plane of the projection screen 10 is greater than or equal to the vertical distance L3 between the convergence point C and the plane of the projection screen 10. Since the imaging area on the projection screen is relatively far from the projector itself, the image brightness of the upper imaging area itself is relatively low. Adopting this design method can make more projection light in the imaging area on the projection screen converge to the viewer at a medium distance, increasing the image brightness of the imaging area on the projection screen. And because the lower imaging area of the projection screen is close to the projector itself, the image brightness of the lower imaging area itself is very high. Reducing the convergence of the projection light in the lower imaging area to the viewer area can reduce the brightness of the lower area of the projection screen felt by the viewer, so that the overall brightness of the projection screen 10 felt by the viewer is more uniform. Therefore, such a design is beneficial to improving the display brightness uniformity of the projection screen.

[0049] Furthermore, the perpendicular distance L2 from the convergence point B to the plane of the projection screen 10 is greater than or equal to 6 meters. Because if the designed distance L2 is less than 6 meters, it will cause the brightness of the projection screen perceived by viewers in the home scenario to be extremely uneven and the viewing field of the projection screen to be extremely small, so it is not conducive to the popularization and application of the projection screen. Of course, the perpendicular distance L2 from the convergence point B to the plane of the projection screen 10 cannot be designed to be infinitely large to avoid causing a sudden change in the shape of the unit lens, resulting in the unit lens being difficult to process and manufacture. Generally, it is preferably that the perpendicular distance L2 from the convergence point B to the plane of the projection screen 10 is less than or equal to 12 times the height dimension of the projection screen.

[0050] Furthermore, the perpendicular distance L3 from the convergence point C to the plane of the projection screen is greater than or equal to 2 meters. Because if the designed distance L3 is less than 2 meters, too much light in the lower area of the projection screen is difficult for viewers to receive, which will cause the brightness of the lower area of the projection screen perceived by viewers to be too low, and instead will affect the brightness uniformity of the projection screen and is also not conducive to the actual use of the projection screen.

[0051] As a further explanation, as Figure 8 shown, it is a comparison diagram of the optical paths of the projection system of the present invention and the projection system of the prior art. The optical path of the projection system of the prior art is shown by a dashed line in Figure 8 and the solid line in Figure 8 represents the optical path designed by the projection system of the present invention. From Figure 8From the light path indicated by the dotted line, it can be seen that the design of the projection screen 10 in the prior art is to converge the light emitted by the projector to a position 3 meters in front of the geometric center O of the screen, that is, the focus F of the arc-shaped unit lens 1021 is 3 meters away from the screen at a vertical distance. In practice, the viewer G is usually at a position 3 meters or more than 3 meters in front of the screen, so the viewer at the focal position can just receive the most light, so it is believed that the viewer can see the brightest screen. However, this design does not take into account the height differences among viewers and the need for multiple viewers to watch side by side at the same time. When the height of the viewer deviates from the focal position (in most cases, when the viewer is sitting and watching, the line of sight of the eyes is lower than the geometric center of the screen. The projection screen of the prior art is designed and manufactured on the assumption that the viewer's line of sight is located at the convergence point F and its vicinity), the viewer can only receive very little light, so the brightness will be too low and the image on the screen will not be clear. In practice, it is difficult to find a viewer whose height just matches this design. Therefore, the design of the prior art is very unsuitable, has poor compatibility, and cannot solve the problem of uneven screen brightness. Moreover, when the light is all converged to the focal position (the convergence area is very small), when multiple viewers watch side by side, only the viewer at the focal position can receive the light, while other viewers can only receive very little light. Therefore, other viewers will also feel that the screen brightness is very low and uneven. Therefore, the design of the prior art is not applicable.

[0052] The technical solution of the present invention solves the above-mentioned problems of the prior art, such as Figure 8 The solid line in the middle indicates that when a general viewer G sits and watches the projection screen 10, the sight line of the eyes is lower than the geometric center O of the projection screen 10. New unit lenses are designed for different imaging areas on the projection screen 10. The unit lenses 1021 realize the function of converging the projection light. Figure 9As shown, the unit lens 1021 is curved. In this embodiment, the unit lens 1021 is in the shape of an arc line, and the cross-section of the unit lens 1021 in the thickness direction of the projection screen 10 is serrated. The unit lens 1021 has two surfaces with an included angle to reflect and converge the projection light. The specific ways to adjust the position of the convergence point of the projection light include: First, adjusting the included angle of the surface of the unit lens 1021 relative to the plane direction of the projection screen 10; second, adjusting the tooth height of the unit lens 1021 (the height of the unit lens 1021 in the thickness direction of the projection screen 10); third, adjusting the pitch of the unit lens 1021 (the width of the unit lens 1021 in the plane direction of the projection screen 10). By adopting one or a combination of the above methods, the position of the convergence point of the projection light for each unit lens 1021 is adjusted, and then the position of the convergence point of the projection light for different imaging regions is adjusted. The projection light is converged to multiple different positions that viewers can receive by a variety of unit lenses with different structures, improving the viewing field of the projection screen. The brightness and brightness uniformity of the viewed image can be guaranteed in a relatively large viewing field. That is, when the viewer is located 3 meters or farther in front of the screen, a large area can receive sufficient projection light. Therefore, regardless of whether the viewer is tall or short, there are many or few viewers, or the viewer is far or near, the brightness and brightness uniformity of the viewed image in this area are effectively improved. Therefore, the projection screen of the present invention improves the brightness, display brightness uniformity, and viewing field of the screen.

[0053] Further, as Figure 9 shown, a schematic structural diagram of a projection screen according to an embodiment of the present invention. From Figure 9 the left view, it can be seen that the projection screen includes a substrate layer 101 and a microstructure layer 102. The microstructure layer 102 is a concentric circle array structure composed of multiple arc-shaped unit lenses 1021 with a serrated cross-section. From Figure 5 the front view, it can be seen that the center O1 of the concentric circles of the concentric circle array is located outside the display area of the projection screen 10, preferably in the same direction as the position of the projector. The projection screen 10 is symmetric about the central axis passing through the center O1 of the concentric circles of the concentric circle array. In the actual production and manufacturing process and measurement process, it may not be completely symmetric left and right, and there may be a deviation of 1 mm to 2 mm.

[0054] Further, as Figure 10 shown, it is a schematic cross-sectional view of an embodiment of a projection screen. As Figure 10As shown in Figure a, a diffusion layer 104 and a coloring layer 105 are further included between the substrate layer 101 and the microstructure layer 102. The diffusion layer 104 and the coloring layer 105 are separated into two independent layers, and the arrangement positions of the two layers can be exchanged. The other side of the substrate layer 101 is set as a rough surface, which is formed by roughening the surface of the substrate. The way to form the rough surface here can be, after sandblasting or roughening the surface of the mold, transferring it with glue or spraying glue containing diffusion particles. The rough surface can further diffuse light, playing the roles of light homogenization, hardening protection, and imaging. The microstructure layer 102 includes multiple unit lenses 1021 with a zigzag cross-section. The unit lenses 1021 protrude towards the back side of the projection screen. A reflective material layer 103 is provided on the unit lenses 1021. The projection light emitted by the projector Y passes through the substrate layer 101 and the microstructure layer 102, and finally is reflected by the reflective material layer 103 on the microstructure layer, and then exits through the microstructure layer 102 and the substrate layer 101 into the viewing range; as Figure 10 As shown in Figure b, a diffusion layer 104 and a coloring layer 105 are further included between the substrate layer 101 and the microstructure layer 102. The diffusion layer 104 and the coloring layer 105 are fused into one layer. The other side of the substrate layer 101 is set as a rough surface. The microstructure layer 102 includes multiple zigzag unit lenses 1021. A reflective material layer 103 is provided on the unit lenses 1021.

[0055] Furthermore, the rough surface can also be made with microstructures, which are used to increase the diffusion angle of the projection screen, enabling the horizontal diffusion angle of the projection screen to be greater than the vertical diffusion angle of the projection screen. Or only increase the diffusion ability of some over-bright areas of the projection screen, so as to reduce the brightness of these over-bright areas and improve the brightness uniformity of the projection screen.

[0056] Furthermore, the other side of the substrate layer 101 can also be smooth, and an anti-reflection material is provided on this smooth surface, such as an anti-reflection film composed of high and low refractive index materials, which is used to reduce the reflection loss of obliquely incident projection light and enhance the display brightness of the projection screen.

[0057] As a further explanation, the substrate layer 101 can be composed of materials including but not limited to the following, such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, casein phosphopeptide, biaxial polypropylene, polycarbonate, polyethylene terephthalate, polyamide, polyurethane, polymethyl methacrylate, polycarbonate, thermoplastic polyurethane elastomer and other flexible plastic or rubber materials, or glass, acrylic, ceramic and other rigid transparent substrates.

[0058] As a further explanatory note, diffusion particles and a resin material are provided in the diffusion layer 104. These diffusion particles can evenly scatter the light passing through the inside of the diffusion layer 104, making the light intensity distribution more uniform. The diffusion particles include, but are not limited to, silica particles, aluminum oxide particles, titanium oxide particles, cerium oxide particles, zirconium oxide particles, tantalum oxide particles, zinc oxide particles, magnesium fluoride particles, etc. Their particle size is preferably 5 nm to 200 nm. It should be noted that when diffusion particles are provided in the diffusion layer 104, the diffusion particles can be evenly distributed in the diffusion layer 104 or unevenly distributed in the diffusion layer 104. For the best effect, it is preferred that the diffusion particles are evenly distributed in the diffusion layer 104.

[0059] Furthermore, the diffusion layer 104 can also be configured as a single-layer or multi-layer arc-shaped columnar microlens. The arc-shaped surface of the arc-shaped columnar microlens diffuses the light to increase the viewing field of the projection screen and improve the display brightness uniformity.

[0060] Furthermore, an absorbent material and a resin material are provided in the coloring layer 105. The absorbent material can absorb some unwanted light (such as ambient light) and selectively transmit the required light. The light absorption materials here include, but are not limited to, various pigments, dyes, or carbon black, black iron oxide, etc., which play a role in filtering light and adjusting color.

[0061] Furthermore, the reflective material layer 103 has a specular reflection function or a diffuse reflection function, that is, the reflective material layer 103 can be a specular reflection layer or a diffuse reflection layer. Both the specular reflection layer and the diffuse reflection layer can reflect light. The difference is that the surface of the specular reflection layer is as smooth as a mirror, and the reflected light and the incident light satisfy the optical reflection theorem, and a clear image can be formed. Generally, it can be made by electroplating; the surface of the diffuse reflection layer is slightly rough, and the reflected light is transmitted in all directions without rules and cannot form a clear image. Generally, it is made by printing or spraying.

[0062] As a further supplementary note, the reflective material layer 103 can be configured to have a certain light transmittance, so that the ambient light entering the projection screen can pass through the reflection layer, so that the ambient light is not reflected to the viewing area, which has a good effect on improving the contrast of the projection screen.

[0063] Furthermore, pigments / dyes that can reflect red, green, and blue light and absorb / transmit other visible light colors can also be added to the reflective material layer 103 to absorb more ambient light and improve the contrast of the projection screen.

[0064] Furthermore, the reflective material layer can also not be provided on the unit lens of the projection screen, so that the projection screen can be applied to the rear projection system scenario, with the projector and the viewer located on both sides of the projection screen.

[0065] Furthermore, the surface of the substrate layer can also be a smooth surface, enabling the acquisition of ultra-high-definition images. It can also be provided with microstructures having a horizontal diffusion angle greater than the vertical diffusion angle, so that the horizontal viewing angle of the projection screen is larger and a larger horizontal viewing field can be obtained. It can also be provided with microstructures having anisotropic diffusion angles, that is, the microstructures have different light diffusion capabilities in different directions. According to the different brightnesses at different positions on the projection screen, the diffusion angle of the microstructures is large at the positions with high brightness to reduce the brightness, and the diffusion angle of the microstructures is small at the positions with low brightness to ensure that the brightness is not reduced, making the display brightness of the projection screen more uniform and enabling a larger viewing field to be obtained.

[0066] As an alternative, as Figure 11 shown, it is a cross-sectional schematic diagram of a projection screen. As Figure 11 shown in Figure a in Figure 11 : On the other side of the substrate layer 101, a first substrate layer 106, a diffusion layer 104, and a coloring layer 105 are sequentially arranged. The diffusion layer 104 and the coloring layer 105 are separated into two independent layers, and the positions of the two layers can be interchanged. The outer surface of the first substrate layer 106 is set as a rough surface. The microstructure layer 102 includes multiple serrated unit lenses 1021, and a reflective material layer 103 is provided on the unit lenses 1021; as

[0067] As an alternative, as Figure 12 shown, it is a cross-sectional schematic diagram of a projection screen. A light diffusion material 1041 and a light absorption material 1051 are provided in the substrate layer 101. The light diffusion material 1041 contains diffusion particles. Providing a light diffusion material in the substrate layer 101 can further enhance the scattering angle of light inside the screen, making the screen brightness display more uniform; the light absorption material 1051 contains light-absorbing materials, which can play a role in filtering light and adjusting colors.

[0068] Furthermore, the materials of the unit lenses of the present invention include but are not limited to radiation-curing resins, thermosetting resins, and reactive-curing resins. The method of using the above raw materials to make unit lenses is to use a roller die made with unit lenses to transfer and coat the raw materials onto a substrate material.

[0069] Furthermore, the projection screen of the present invention further includes a black backplane, a decorative border, and a hanging member. The black backplane is disposed on the side of the reflective material layer away from the microstructure layer. The decorative border wraps around the periphery of the optical projection screen. The hanging member is disposed on the side of the black backplane away from the microstructure layer.

[0070] Furthermore, the black backplane can be closely attached to the reflective material layer by double-sided tape or EVA hot melt adhesive. A black coating can be provided on the surface of the black backplane to absorb unnecessary light incident on the black backplane, which can appropriately improve the contrast of the projection screen.

[0071] Furthermore, the decorative border is installed around the black backplane and surrounds the various layers of the projection screen in the thickness direction of the projection screen to fix and beautify the appearance of the projection screen and play a role in dividing and forming a projection display area. The fixing method between the decorative border and the black backplane can be pasted by double-sided tape or fixed by screws / bolts.

[0072] Furthermore, the hanging member is fixed at the corresponding position on the black backplane by double-sided tape pasting or screw fixing to facilitate the subsequent installation of the projection screen on the wall.

[0073] As a further supplementary explanation, the hanging member can also be replaced with a magnetic material to facilitate the installation of the projection screen on the wall by magnetic adsorption, ensuring the beauty of the wall.

[0074] The above are only the preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be construed as limiting the present invention. The protection scope of the present invention should be defined by the scope of the claims. For those of ordinary skill in the art in this technical field, without departing from the spirit and scope of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as within the protection scope of the present invention.

Claims

1. A projection screen, characterized in that, A microstructure layer for converging projection light is provided on the projection screen. The projection screen is vertically divided into several imaging regions. The microstructure layer within the range of each imaging region converges the projection light to a convergence point respectively. All the convergence points are on the same straight line perpendicular to the projection screen, and at least one convergence point of an imaging region does not coincide with the convergence points of other imaging regions. The perpendicular distance from the convergence point of the imaging region in the middle in the vertical direction of the projection screen to the projection screen is greater than the perpendicular distances from the convergence points of the imaging regions near the top and near the bottom to the projection screen. Alternatively, the perpendicular distance from the convergence point of the imaging region in the middle to the projection screen is equal to the perpendicular distance from the convergence point of the imaging region near the top to the projection screen, and greater than the perpendicular distance from the convergence point of the imaging region near the bottom to the projection screen.

2. The projection screen according to claim 1, characterized in that, The perpendicular distance from the convergence point of the imaging region near the top to the projection screen is greater than or equal to the perpendicular distance from the convergence point of the imaging region near the bottom to the projection screen.

3. The projection screen according to claim 1, wherein, The perpendicular distance from the convergence point of the middle imaging region to the projection screen is less than or equal to 12 times the height dimension of the projection screen.

4. The projection screen according to claim 1, wherein The perpendicular distance from the convergence point of the middle imaging region to the projection screen is greater than or equal to 6 m, and the perpendicular distance from the convergence point of the imaging region near the bottom to the projection screen is greater than or equal to 2 m and less than 6 m.

5. The projection screen according to any one of claims 1 to 4, characterized in that The imaging regions are equally or unequally divided along the vertical direction of the projection screen.

6. The projection screen according to any one of claims 1 to 4, characterized in that, The projection screen is vertically divided into upper, middle and lower three imaging regions.

7. The projection screen according to any one of claims 1 to 4, characterized in that, The straight line where the convergence points are located is lower than the geometric center height of the projection screen.

8. The projection screen according to claim 7, wherein The straight line where the convergence points are located intersects with the straight line passing through the geometric center of the projection screen vertically, and the intersection point is outside the region of the projection screen.

9. The projection screen according to any one of claims 1 to 4, characterized in that The microstructure layer includes a plurality of unit lenses with serrated cross-sections arranged in concentric circular rings in the plane direction of the projection screen.

10. The projection screen according to claim 9, characterized in that, The center of the concentric circles of the unit lenses is outside the region of the projection screen.

11. A projection system, characterized in that, It includes the projection screen according to any one of claims 1 to 10 and a projector for projecting image light onto the projection screen.

12. The projection system according to claim 11, wherein, Viewed from the normal direction of the projection screen, the projector is outside the region of the projection screen.

Images