Abstract:
A display system includes a laser projector that projects light onto a the back of a screen, a sensor that detects light reflected from the back of the screen, a processor in communication with the sensor, the processor controlling light projected from the laser projector based on data regarding the light detected from the sensor. The laser projector, sensor, and processor are all contained within a single housing.

Description:
CROSS REFERENCE TO RELATED APPLICATION(S) 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/210,533 filed Mar. 20, 2009, which is incorporated by reference as if fully set forth. 
     
    
     FIELD OF INVENTION 
       [0002]    The field of the invention relates to videowalls and modular display systems that make use of a projector contained within a housing. 
       BACKGROUND 
       [0003]    Videowall and modular display systems are currently used in control room and entertainment applications. Videowall systems with open frames using CRT projectors are manufactured by Philips. Videowall systems composed of solid frames are manufactured by Electrosonic, Toshiba, Gunderman, Pioneer, and Mitsubishi. These products traditionally use straight and folded optical systems, the difference between the two being the need for a mirror and the increased importance of rigidity in the design of the videowall module. 
         [0004]    Projections cubes may use CRT, LCD, or DLP imaging systems. These systems have an innate video format that depends on the imager. Most imagers have had a 4:3 ratio and so the construction of the frame often provides for this format. More recently 16:9 ratio imagers have been used in videowall systems. 
         [0005]    In this disclosure, the words “cube” and “projection cube” refer to the box like shape of standard modular projection displays. These terms are considered generic and could be used to describe a module from any system where a display is contained in a stackable housing. 
         [0006]    In the videowall or projection cube setting, the fixed format of the imager has a direct impact on the lamp requirements in the LCD and DLP based systems. In most cases, both light and processing power are wasted because the entire imager is not used. 
       SUMMARY 
       [0007]    A display system includes a laser projector that projects light onto a the back of a screen, a sensor that detects light reflected from the back of the screen, a processor in communication with the sensor, the processor controlling light projected from the laser projector based on data regarding the light detected from the sensor. The laser projector, sensor, and processor are all contained within a single housing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0008]      FIG. 1  is an illustration of a parts of a typical projection cube. 
           [0009]      FIG. 2  is an illustration of an embodiment of the present disclosure. 
           [0010]      FIG. 3  is an illustration of a system comprising projection modules. 
           [0011]      FIG. 4  is an array of hexagons according to an embodiment. 
           [0012]      FIG. 5  shows a pattern printed on the back of a screen for projector alignment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0013]    The embodiments described herein may comprise a scanning laser-based video projection modular display system that includes a color or multicolor scanning laser video projector, a diffusion screen surface with a reflective pattern defining the outside edges of the screen, a sensor to detect reflections and ensure that the correct data is displayed on the screen while also calibrating the white point and color spectrum of the laser. The embodiments may also include a processor to map the incoming video data onto the screen. The laser projector may additionally be used to communicate with other panels during configuration and trouble-shooting. 
         [0014]      FIG. 1  shows a projection cube  10  herein is a frame  1  that incorporates a screen  2  and a projector  3 . The frame  1  can be open or closed. Expanding on the general cube,  FIG. 2  shows a cube  10  that includes all or some of the following: a housing or frame  11  containing a screen  12  and a projector  13 . The projector  13  is a scanning projector such as a Microvision Pico projector or a Light Blue Optics Pico projector. The projector  13  is programmed to scan across a luminance and chrominance meter  15  in order to maintain calibration. And a sensor such as a CMOS or CCD  16  can be used to detect reflections  17  off the back  18   a  of the screen  18 , which is visible to a viewer by looking at the screen  18 &#39;s front  18   b.  A sensor controls the location of video imagery would most likely include a small CCD or CMOS device in addition to a dedicated sensor to adjust white balance (such as the Avago APDS 9008). 
         [0015]    As shown in  FIG. 5 , a reflective pattern  50  can be printed on the back of the screen  18  can also be used to align the laser projector&#39;s scanning head and the active projection area. The pattern  50  can be printed or embossed or otherwise incorporated into the screen material in such a way that light generated by the laser projector  13  can be used by the sensor  16  to generate data that the processor  22  can use to determine the absolute position of the scanning laser on the screen  12 . The pattern  50  may include reference points for different screen resolutions. In this illustration the lines on the right  51  are ⅓ marks and the lines on the left  52  are ¼ screen marks. 
         [0016]    A GPU or other processor can be included on the main board within each cube  10 . 
         [0017]      FIG. 3  shows a system comprising multiple projection cubes  21  that include a primary processor or processors  22  connected to the projection cubes  21  wirelessly or by wires  23 . Such a system could include a camera  24  to automate configuration and alignment. 
         [0018]    Data communication between the sensor  24  and processor  22  and cubes  21  can be based on DisplayPort or any other standard that incorporates video and data information in a single stream. Such a system would allow the controller and any external inputs such as cameras to communicate with the internal GPU in order to remap the video and tune the scanning laser system. 
         [0019]    In the multi-cube, multi-display arrangement of  FIG. 3 , the projector (inside each cube) directs the light source onto X, Y (and even Z) coordinates on a screen (labeled  18  in  FIG. 2 ) in accordance with an incoming portion of a video signal from the processor  22 . A control unit (not shown) maps the incoming video signal onto the screen based on data from the sensor  24 . 
         [0020]    What is described in the embodiments shown in  FIGS. 1-3 , is a closed loop feedback system wherein the sensor  16 , 24  feeds optical measurements made from detecting the light projected onto the back of the screen  18  into the processor  19 . The processor, which is shown as separate from the projector  13  but may be part of it, employs a mapping software to then map what it is projecting onto the screen  18  based on the feedback from the sensor  16 . The display mapping can be adjusted by a user to achieve different effects including contrast enhancement, high speed playback, lower power consumption, polarized playback for 3D applications, and bandwidth management. 
         [0021]    Hexagonal modules  31  are one embodiment of the present disclosure, as shown in  FIG. 4 , and could be used in place of the cubes  21 . The projection system may use a unique mechanical orientation between the pico projection cubes/hexagons relative to one another in the form of tessellations. This greatly differs from previous video wall systems that create video imagery in a single 2-dimensional plane. By the use of mechanical attachment or hinge points between the various pico cube tessellations, the formation of uniquely articulated 3-dimensional shapes becomes possible. 
         [0022]    An enhancement of the Modular Pico Projection Wall could be to include pico laser projectors singularly or in pairs for each projection module to create stereoscopic 3D images. The light from each projector, or pair of projectors, could be polarized using linear or circular polarization. The stereoscopic system employed could use either a time sequential (active) or a time parallel (passive) stereoscopic technique. The result could be viewed with passive or active (synchronized) 3D glasses. 
         [0023]    One of the advantages of the scanning laser projector is that all of the photonic energy generated by the laser lands on the active areas of the screen and no energy-wasting over-scanning required. Furthermore, custom shapes can be created with relative ease since the closed loop feedback system allows the laser to illuminate just the active projection areas. It is therefore possible to create a square, a triangle, an oval, a hexagon or just about any other shape without wasting large amounts of light and energy required in traditional displays. 
         [0024]    The laser projector used herein may vary the pixel pitch of the screen. The pixel pitch of traditional display systems employing LED, plasma, LCD, LCOS, and DLP technology subsystems, is fixed by the imaging device. The laser projector may also use part of an imager and duplicate content across pixels to reduce the resolution (which might be desirable in a modular display where the display resolution can exceed the source resolution in even small displays). 
         [0025]    In a laser projection wall using a scanning laser it would be possible to vary the pixel pitch of the screen either as a whole or fractionally using configuration software to setup the wall and using a video server to deliver the appropriate content to the right section of the screen. This means a small section of the screen could have a 1 mm pixel pitch but the larger area of the screen could have a 4 mm pixel pitch. This also means that the screen could be configured to accurately reflect the native resolution of the source material no matter how large the display. This accurate pixel for pixel display of the content usually leads to the highest quality image. 
         [0026]    The ability to vary the pixel pitch and to configure the screen for different applications increases the flexibility of the product and takes full advantage of the convergence of data and video networks. Such a system could run off Display Port or Ethernet or a Fiber-Channel Over Ethernet backbone. The low power requirements of the lasers will also allow the combination of the data and power connections further reducing parts. 
         [0027]    Another proposed enhancement in this video projection modular display system could involve an infrared sensor that could sense whether a viewer&#39;s body was in front of the screen. The sensor could relate this information to the processor/GPU which could then pull higher resolution data off the data bus for the effective local image area. The image displayed could then be higher resolution to serve that viewer; the closer the viewer, the sharper the image, the farther the viewer moves from the screen, the less bandwidth/video data is allocated to that part of the screen. This could allow for the most effective use of limited video data bandwidth resources. 
         [0028]    The ability to vary the duty cycle of the laser is also an advantage. The sensors in the unit could adjust screen brightness to suit the ambient light levels. 
         [0029]    A user may also be able to choose between higher pixel fill levels (lower point brightness) and lower pixel fill levels (higher point brightness). This may be advantageous in a display that could be used in different viewing environments. The higher point brightness may allow a user to present a higher contrast display under the right conditions. A lower point brightness with higher fill level may be more desirable in a near field viewing environment. 
         [0030]    While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.