A laser seamless splicing display system based on point cloud data

Abstract

The application discloses a laser seamless splicing display system based on point cloud data, which comprises at least two laser projectors for projecting a display image, a monitoring device and a data processing unit, each laser projector comprising at least three primary color laser light sources and a lens for imaging; the monitoring device comprises a projector monitoring unit for monitoring the working state of the projector and a point cloud data depth information acquisition unit for acquiring sampling points of the projected display image; the data processing unit outputs a projector lens adjustment signal according to the information from the projector monitoring unit and the information from the depth information acquisition unit so as to obtain a seamless splicing image of the projected display image. Since the point cloud data is introduced, the information acquired by the data processing unit is more abundant, and meanwhile, the color temperature correction is performed by using the color temperature information corresponding to each sampling point of the projected display image, so that an image picture with better color temperature uniformity can be obtained.

Description

Technical Field

[0001] This invention relates to the field of laser display. More specifically, it relates to a seamless laser splicing display system based on point cloud data. Background Technology

[0002] Currently, televisions and color monitors have become necessities of modern life, especially large-screen / ultra-large-screen displays, which have emerged in recent years and become highly sought-after products. Due to the huge market potential and profits of these products, countries are committed to developing high-definition and large / ultra-large-screen products to meet people's ever-evolving demands. Currently, large-screen displays are mainly achieved through two methods: flat-panel large-screen splicing displays and projector splicing.

[0003] For large-screen displays, LCD screens exceeding 85 inches are extremely expensive, making splicing undoubtedly the most cost-effective technology. However, regardless of whether it's a liquid crystal display (LCD), a plasma display panel (PDP), or a quantum dot light-emitting diode (QLED) display, large / ultra-large screen displays achieved through splicing all have visually visible mechanical seams that cannot be eliminated, affecting the viewing experience and making it difficult to truly achieve an immersive high-end visual experience. For large / ultra-large screen displays spliced ​​from multiple projectors, the mechanical seams can be eliminated. However, since current projectors mainly use lamps as the display light source, the splicing of multiple sub-screens will produce a "mosaic effect" due to different color temperatures. Because the color temperature of the light source is not adjustable, eliminating the "mosaic" is technically difficult. At the same time, current splicing of multiple projectors mainly relies on manual alignment adjustment, which is time-consuming. Even slight displacement of the projectors after alignment can cause "tearing" of the image, requiring readjustment.

[0004] Laser display, as a novel display technology, uses red, green, and blue primary color lasers as its light source. Due to the high brightness, narrow spectral width, and good directionality of lasers, laser displays can achieve ultra-high resolution and high-fidelity image reproduction across a wide color gamut. Furthermore, thanks to the projection technology upon which laser displays are based, large-size displays exceeding 100 inches are easily achieved. In addition, the light source for laser displays can consist of individual laser tubes or modules composed of multiple laser tubes. Its wavelength and output power can be adjusted in real time as needed. Therefore, when multiple screens are spliced, the intensity ratio and spatial distribution of the red, green, and blue primary color light sources can be precisely adjusted. This means that the color temperature and brightness of each sub-screen are controllable and adjustable, resulting in a white field with consistent color coordinates. Ultimately, this achieves truly seamless splicing and consistent color temperature in large / ultra-large screen displays, meeting the ultimate demands of the human eye for large-format, ultra-high-definition, and high-color-saturation display quality. Therefore, a seamless laser splicing display system is needed. Summary of the Invention

[0005] The purpose of this invention is to provide a laser seamless splicing display system based on point cloud data, so as to solve at least one of the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of this invention provides a laser seamless splicing display system based on point cloud data. The display system includes at least two laser projectors for projecting and displaying images, a monitoring device, and a data processing unit.

[0008] Each laser projector includes at least a three-primary-color laser light source and a lens for imaging;

[0009] The monitoring device includes a projector monitoring unit for monitoring the projector's working status and a point cloud data depth information acquisition unit for acquiring sampling points of the projected display image.

[0010] The data processing unit outputs a projector lens adjustment signal based on information from the projector monitoring unit and information from the depth information acquisition unit in order to obtain a seamless stitched image with aligned projected display images.

[0011] Preferably, the data processing unit outputs a lens adjustment signal to adjust the spatial position of the lens based on the position of the projector display area and the point cloud data of each sampling point.

[0012] Preferably, the depth information acquisition unit is further configured to acquire the color temperature data of each sampling point of the projected display image.

[0013] The data processing unit outputs a color temperature adjustment signal based on information from the projector monitoring unit and information from the depth information acquisition unit to obtain a seamless stitched image with consistent white field color temperature.

[0014] Preferably, the projector monitoring unit includes an image sensor for monitoring the projector display area and a temperature sensor for sensing the temperature of the laser light source.

[0015] Preferably, the depth information acquisition unit further acquires brightness data of each sampling point of the projected display image.

[0016] Preferably, the depth information acquisition unit includes a lidar, a binocular camera, and / or a depth camera.

[0017] Preferably, the data processing unit outputs a color temperature adjustment signal based on the laser source temperature and the color temperature data of each sampling point of the projected display image, which is used to control the intensity ratio, total intensity and intensity spatial distribution of the three primary colors of each laser projector.

[0018] Preferably, the display system further includes a projector controller corresponding to the laser projector, the projector controller adjusting the output power of each laser light source of the laser projector based on the color temperature adjustment signal.

[0019] Preferably, the projector controller obtains the laser source power adjustment signal based on the formula calculated using the following color coordinates.

[0020]

[0021] in, The tristimulus values ​​of red light are given. The tristimulus values ​​of green light are given. P represents the tristimulus value of blue light. R P G P B The light power of the R, G, and B primary color light sources are respectively (x W, y W ) represents the color coordinates of the target white point, Y W This represents the mixed white light stimulation value.

[0022] Preferably, the display system further includes a mechanical structure for adjusting the spatial position of the lens.

[0023] The beneficial effects of this invention are as follows:

[0024] The laser seamless splicing display system based on point cloud data provided by this invention can obtain richer information by the data processing unit due to the introduction of point cloud data. At the same time, by using the color temperature information corresponding to each sampling point of the projected display image for color temperature correction, an image with better color temperature uniformity can be obtained. Attached Figure Description

[0025] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0026] Figure 1 This diagram illustrates the structure of the laser seamless splicing display system based on point cloud data provided by the present invention.

[0027] Figure 2 This diagram illustrates the point cloud data collected by the depth information acquisition unit of the screen when the display area is not aligned, as described in Embodiment 1 of the present invention.

[0028] Figure 3 This diagram illustrates the point cloud data collected by the depth information acquisition unit when the display areas are basically aligned but have overlapping areas, as described in Embodiment 2 of the present invention.

[0029] Figure 4 This diagram illustrates the point cloud data collected by the depth information acquisition unit of the screen when the display area is aligned, as described in Embodiment 3 of the present invention. Detailed Implementation

[0030] To more clearly illustrate the present invention, the following description, in conjunction with embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0031] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0032] It should also be noted that in the description of this invention, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0033] Example 1

[0034] The first aspect of this invention provides a laser seamless splicing display system based on point cloud data. The display system includes at least two laser projectors for projecting and displaying images, a monitoring device, and a data processing unit.

[0035] Each laser projector includes at least a three-primary-color laser light source and a lens for imaging;

[0036] The monitoring device includes a projector monitoring unit for monitoring the projector's working status and a point cloud data depth information acquisition unit for acquiring sampling points of the projected display image.

[0037] The data processing unit outputs a projector lens adjustment signal based on information from the projector monitoring unit and information from the depth information acquisition unit in order to obtain a seamless stitched image with aligned projected display images.

[0038] like Figure 1 The diagram shows a schematic of the laser seamless splicing display system based on point cloud data provided by the present invention. The diagram includes a screen 1, a monitoring device 2, a laser projector 3, a laser projector 4, a projector controller 5, a projector controller 6, and a data processing unit 7.

[0039] Figure 1Laser projectors 3 and 4 use red, green, and blue primary color laser light sources as display light sources to project images onto their respective sub-screens. Each laser projector includes: a red laser module, a green laser module, and a blue laser module; collimation and shaping modules and decoherence converters sequentially arranged on the output optical paths of the red, green, and blue laser modules; optical valves and beam combining devices for combining the three laser beams, respectively, arranged sequentially on the subsequent optical paths of the red, green, and blue laser modules; or beam combining devices and optical valves sequentially arranged afterward for combining the three beams from the red, green, and blue laser modules; and an imaging lens for image formation.

[0040] The red laser module is a red semiconductor laser, the green laser module is a green semiconductor laser, and the blue laser module is a blue semiconductor laser. The red laser module includes at least one red semiconductor laser unit, each laser unit having a different center wavelength, and their combination covers the wavelength range output by the red laser module. The green laser module includes at least one green laser unit, each green laser unit having a different center wavelength, and their combination covers the wavelength range output by the green laser module. The blue laser module includes at least one blue laser unit, each blue laser unit having a different center wavelength, and their combination covers the wavelength range output by the blue laser module.

[0041] The imaging lens is an ultra-short throw projection lens with a throw ratio of less than 0.25.

[0042] The imaging lens is fixed by a frame with two-axis motorized slide rails. The projector controller 5 and projector controller 6 control the movement of their respective imaging lenses in the horizontal and vertical directions to adjust the display area.

[0043] The beam combining device is specifically an X-prism, a TIR prism, or a spatial-temporal beam combining device.

[0044] The three laser beams, after being processed by the decoherentizer, are first combined and then enter the same light valve to display an image, or the three laser beams, after being processed by the decoherentizer, sequentially pass through the reflective film, the light guide plate, and the liquid crystal panel to display an image.

[0045] Collimation and shaping module, such as an aspherical lens, cylindrical lens, or spherical lens;

[0046] Decoherence devices, such as micro-optical devices, vibrating mirrors, rotating waveplates, multimode fibers, or beam scanners, are used to construct the aforementioned laser projectors using optical valves. At least two laser projectors are then used to display the white field, and each segment's white field undergoes color temperature control via a monitoring-feedback device, resulting in a seamless, spliced ​​large screen with a consistent color temperature.

[0047] Preferably, the data processing unit outputs a lens adjustment signal to adjust the spatial position of the lens based on the position of the projector display area and the point cloud data of each sampling point.

[0048] Figure 1 The data processing unit 7, based on the position of the projector display area and the point cloud data of each sampling point, calculates the lens position adjustment signal through projection transformation. The projector controller 5 and the projector controller 6 control their respective lenses to move horizontally or vertically based on the lens position adjustment signal to align the edges of the image.

[0049] Preferably, the depth information acquisition unit is further configured to acquire the color temperature data of each sampling point of the projected display image.

[0050] The data processing unit outputs a color temperature adjustment signal based on information from the projector monitoring unit and information from the depth information acquisition unit to obtain a seamless stitched image with consistent white field color temperature.

[0051] Figure 1 The projector monitoring unit in the monitoring device 2 described above is used to monitor the light source temperature and display area of ​​the laser projectors 3 and 4. The depth information acquisition unit is used to sample the displayed image on the projection screen to obtain point cloud data. The depth information acquisition unit further includes a color temperature acquisition device, which acquires the point cloud data of each sub-screen and the white field color temperature data at each sampling point on the sub-screen in real time. The point cloud data acquired by the depth information acquisition unit is as follows: Figure 2 As shown.

[0052] Figure 2 This diagram illustrates point cloud data collected by the depth information acquisition unit of the screen when the display area is not aligned, as described in Embodiment 1 of the present invention. The projection area 1 is... Figure 1 The image projected by the laser projector 3, with projection area 2 being... Figure 1 The image projected by the laser projector 4 is shown in the image. Black dots represent sampling points on the screen, and gray dots represent sampling points outside the screen. In this embodiment, the collected data is stored as a 76800*4 matrix. Each row represents the position and color temperature information of a sampling point. Columns 1-3 store the coordinates of the point, and column 4 stores the white field color temperature data of the point.

[0053] like Figure 2As shown, the display system not only needs to adjust the position of the imaging lens to obtain a seamless spliced ​​image with the projected display images aligned, but also needs to use the data processing unit 7 to adjust the color temperature of the laser projector 3 and the laser projector 4, while reducing the local output power of the overlapping area per unit time to reduce the brightness, so as to form a seamless spliced ​​large screen with consistent color temperature.

[0054] The display system samples the projection screen to obtain point cloud data and combines it with the color temperature and brightness information corresponding to each sampling point on the screen, as well as the light source temperature and display area of ​​laser projectors 3 and 4. Then, the above signals are fed back to the data processing unit 7 for processing. According to the data processing results, the projector controller 5 is used to adjust the lens position of laser projector 3 and the power ratio of the three primary color light sources, and the projector controller 6 is used to adjust the lens position of laser projector 4 and the power ratio of the three primary color light sources, so that the display images of laser projectors 3 and 4 are aligned and have the same white field color temperature, thereby realizing the splicing and fusion on the laser screen and projecting a seamless spliced ​​complete image without visual differences.

[0055] Preferably, the projector monitoring unit includes an image sensor for monitoring the projector display area and a temperature sensor for sensing the temperature of the laser light source.

[0056] Preferably, the depth information acquisition unit further acquires brightness data of each sampling point of the projected display image.

[0057] The depth information acquisition unit includes an illuminance meter for acquiring brightness information of each sampling point of the projected display image.

[0058] Preferably, the depth information acquisition unit includes a lidar, a binocular camera, and / or a depth camera.

[0059] The depth camera of the depth information acquisition unit includes an RGB-D camera.

[0060] Preferably, the data processing unit outputs a color temperature adjustment signal based on the laser source temperature and the color temperature data of each sampling point of the projected display image, which is used to control the intensity ratio, total intensity and intensity spatial distribution of the three primary colors of each laser projector.

[0061] The display system adjusts the mechanical structure on the inner lens frame of laser projectors 3 and 4 according to the display area, thereby adjusting the spatial position of the lens. At the same time, it combines the color temperature, brightness information and light source temperature of point cloud data to control the intensity ratio, total intensity and intensity spatial distribution of the three primary color lasers. Finally, it completes the multi-screen splicing with consistent white field and no visible mechanical seams, realizing the display of large / ultra-large screen images without "mosaic" by two or more laser light source projectors.

[0062] Preferably, the display system further includes a projector controller corresponding to the laser projector, the projector controller adjusting the output power of each laser light source of the laser projector based on the color temperature adjustment signal.

[0063] The display system sends color temperature adjustment signals from each sub-screen to laser projector controller 5 and laser projector controller 6, respectively adjusting the power ratio of the three primary color laser light sources of laser projector 3 and laser projector 4. The introduction of point cloud data helps to improve the uniformity of color temperature of the spliced ​​screen, thereby enabling two or more laser light source projectors to have consistent white field color temperature and seamless splicing of large / ultra-large screen image display.

[0064] Preferably, the projector controller obtains the laser source power adjustment signal based on the formula calculated using the following color coordinates.

[0065] In the CIE 1931 XYZ colorimetric system, the X, Y, and Z tristimulus values ​​of a given light source can be obtained by integrating the intensity of the light source with the spectral tristimulus values ​​over the entire spectrum, i.e.:

[0066]

[0067] in, These are the spectral tristimulus values ​​for the CIE 1931 XYZ colorimetric system. Let be the color stimulus function, and k be the proportionality constant.

[0068] The relationship between the tristimulus values ​​of mixed white light and the tristimulus values ​​of the R, G, and B primary colors is as follows:

[0069]

[0070] Color coordinates of mixed white light:

[0071]

[0072] By combining the above equations, we can obtain the color coordinates (x, y) of the target's white point. W, y W The optical power P of the R, G, B three-primary-color light source R P G P B The relationship is as follows:

[0073]

[0074] in, The tristimulus values ​​of red light are given. The tristimulus values ​​of green light are given. The spectral tristimulus values ​​are for blue light.

[0075] Preferably, the display system further includes a mechanical structure for adjusting the spatial position of the lens.

[0076] The display system adjusts the mechanical structure on the lens frame of laser projector 3 and laser projector 4 according to the display area, thereby adjusting the spatial position of the lens.

[0077] The laser seamless splicing display system based on point cloud data provided by this invention can improve the uniformity of color temperature of the spliced ​​screen by introducing point cloud data. Its technical solution can increase the total display resolution and display area by at least 100%, obtain high-resolution, high-quality, and large-size images. At the same time, it has a simple structure, saves space, is low in cost, and is easy to implement. It can truly realize laser seamless splicing of large / ultra-large screens, better reduce the perception of splicing overlap areas when watching movies, and greatly improve the viewing comfort.

[0078] Example 2

[0079] In this embodiment, the structure of the laser seamless splicing display system based on point cloud data is consistent with that in Embodiment 1. The projection area in this embodiment is as follows: Figure 3 As shown. At this time, there is no need to adjust the position of the imaging lens. It is only necessary to use the data processing unit 7 to adjust the color temperature of the laser projector 3 and the laser projector 4, and at the same time reduce the local output power of the overlapping area per unit time to reduce the brightness, so as to form a seamless splicing large screen with consistent color temperature.

[0080] Example 3

[0081] In this embodiment, the structure of the laser seamless splicing display system based on point cloud data is consistent with that in Embodiment 1. The projection area in this embodiment is as follows: Figure 4 As shown. At this point, there is no need to adjust the position of the imaging lens, and there is no overlapping area. It is only necessary to use the data processing unit 7 to adjust the color temperature of the laser projector 3 and the laser projector 4 to form a seamless splicing large screen with consistent color temperature.

[0082] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A laser seamless splicing display system based on point cloud data, characterized in that, The display system includes at least two laser projectors for projecting and displaying images, a monitoring device, and a data processing unit. Each laser projector includes at least a three-primary-color laser light source and a lens for imaging; The monitoring device includes a projector monitoring unit for monitoring the projector's working status and a point cloud data depth information acquisition unit for acquiring sampling points of the projected display image. The data processing unit outputs a projector lens adjustment signal based on information from the projector monitoring unit and information from the depth information acquisition unit in order to obtain a seamless spliced ​​image with aligned projected display images. The depth information acquisition unit is further used to acquire the depth information acquisition unit for obtaining the color temperature data of each sampling point of the projected display image; The data processing unit outputs a color temperature adjustment signal based on information from the projector monitoring unit and information from the depth information acquisition unit in order to obtain a seamless stitched image with consistent white field color temperature. The projector monitoring unit includes an image sensor for monitoring the projector display area and a temperature sensor for sensing the temperature of the laser light source. The data processing unit outputs a color temperature adjustment signal based on the laser source temperature and the color temperature data of each sampling point of the projected display image, which is used to control the intensity ratio of the three primary colors of the laser projector, the total intensity, and the spatial distribution of the intensity. The display system further includes a projector controller corresponding to the laser projector, which adjusts the output power of each laser source of the laser projector based on the color temperature adjustment signal; The projector controller obtains the laser source power adjustment signal based on the following formula calculated using color coordinates. in, 、 、 The tristimulus values ​​of red light are given. , , The tristimulus values ​​of green light are given. , , The tristimulus values ​​of blue light are given. , , They are respectively R , G , B The optical power of a three-primary-color light source Let the target white point have the color coordinates. This represents the mixed white light stimulation value.

2. The laser seamless splicing display system based on point cloud data according to claim 1, characterized in that, The data processing unit outputs a lens adjustment signal to adjust the spatial position of the lens based on the position of the projector display area and the point cloud data of each sampling point.

3. The laser seamless splicing display system based on point cloud data according to claim 1, characterized in that, The depth information acquisition unit further acquires the brightness data of each sampling point of the projected display image.

4. The laser seamless splicing display system based on point cloud data according to claim 1, characterized in that, The depth information acquisition unit includes a lidar, a binocular camera, and / or a depth camera.

5. The laser seamless splicing display system based on point cloud data according to claim 1, characterized in that, The display system further includes a mechanical structure for adjusting the spatial position of the lens.

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