Patent Publication Number: US-2010128229-A1

Title: Weather-tight Video Projector with Unattended Operation

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of Provisional Patent Application 61/117,601 filed Nov. 25, 2008. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     This invention relates to an image projector; in particular, a weather-tight video projector capable of unattended operation in inclement weather. 
     Image projectors, by their nature, require high intensity light sources which generate high levels of thermal radiation. Conventional image projectors require vented enclosures and electric ventilation fans in order to keep internal temperatures from rising to unacceptable levels, thus making them unsuitable for outdoor use in inclement weather. Furthermore, conventional image projectors require operator input to display content by either interacting with a connected personal computer or video source or directly interacting with control buttons and/or menu selections on the projector itself.
     Relevant prior art includes:   U.S. Pat. No. 7,357,520 April, 2008 Vitantonio et al.   U.S. Pat. No. 7,296,898 November, 2007 Wu   U.S. Pat. No. 6,712,476 March, 2004 Ito et al.   

     BRIEF SUMMARY OF THE INVENTION 
     The primary object of the present invention is to provide a weather-tight video projector that can be used outdoors in inclement weather. Another object of the invention is to provide a video projector that operates unattended without user interaction or connection to an external image source. Other advantages will become apparent from a consideration of the drawings and ensuing description of this application. 
     Advantages: 
     One advantage of the invention is that it may be used outdoors in inclement weather. 
     Another advantage of the invention is that it operates unattended without user interaction or connection to an external image source. 
     Another advantage of the invention is that one or several video images may be pre-loaded for continuous projection without intervention. 
     Another advantage of the invention is that the projection lens assembly can be easily interchanged to modify the throw distance/magnification. 
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     Drawings—Figures: 
       FIG. 1  shows exemplary uses of the invention. 
       FIG. 2  is a perspective view of an exemplary embodiment of the invention. 
       FIG. 3  is a block diagram showing the unattended operation provided by the projector&#39;s custom firmware. 
    
    
     DRAWINGS—REFERENCE NUMERALS 
     
         
           4 . Large Heat Sink 
           5 . High Power Light Emitting Diode (LED)/LEDs 
           6 . Current Limiting Resistor 
           7 . Weather-tight DC Power Socket 
           8 . Reflector/Collimating Optic 
           9 . LCD Controller/Video Player Module with on-board Memory/USB Interface 
           10 . Weather-tight USB Socket 
           11 . Transmissive, Color Liquid Crystal Display (LCD) Panel 
           12 . LCD/Lens Mount 
           13 . Condensing Lens 
           14 . Projection Lens 
           15 . Threaded, Interchangeable Lens Mount 
           16 . Weather-Tight Case 
           17 . Mounting/Tripod Socket 
           18 . LCD Ribbon Cable 
           19 . Weather-tight Audio Output Socket 
           20 . Clear Insulating Lens 
       
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows exemplary uses of this invention not suitable for existing video projectors including, but not limited to:
         Projecting repeating holiday themed video images onto exterior surfaces of homes or businesses for extended periods of time, through varying weather conditions.   Projecting repeating video images of advertising or public information onto exterior surfaces of buildings and public areas such as walls and sidewalks for extended periods of time, through varying weather conditions.   Projecting repeating real estate marketing information for potential buyers onto an exterior surface of a house or building for extended periods of time, through varying weather conditions.       
       FIG. 2  shows the video projector with a weather-tight case  16  cut away to show internal components. A high power LED or multiple high power LEDs  5  are mounted to a large heat sink  4  using thermally conducting method. The large surface area of the heat sink  4  as well as its placement with fins in contact with the outside air eliminates the need for a cooling fan and/or air vents. A constant current is fed to the LED/LEDs  5  via a current limiting resistor  6  from a weather-tight DC power socket  7 . The power socket  7  also feeds power to an LCD controller/video player module  9  which includes on-board memory and USB connectivity. The LCD controller/video player module hardware utilized in the present invention to transfer, store, process and display video images onto the LCD are known in the art (as used in common personal media players “PMPs”) and will not be discussed herein. The LCD controller/video player module  9  is also connected to a weather-tight USB socket  10  for transferring video files from a host computer. The LCD controller/video player module  9  may be further connected to a weather-tight audio output socket  19  for connecting external loud speakers. The LCD controller/video player module  9  is further connected to a transmissive, color liquid crystal display (LCD) panel  11  via a flat ribbon cable  18 . A reflector/collimating optic  8  is mounted so that light output from the LED/LEDs  5  is concentrated on the LCD panel  11 . The LCD panel  11  is secured by an LCD/lens mount  12 . A condensing lens  13  is mounted adjacent to the LCD panel  11  thereby condensing its transmitted light towards a projection lens  14 . Spherical lenses of the piano-convex or biconvex type, which are common and inexpensive, work well as both condensing and projection lenses. To minimize image distortion due to aberrations, more expensive aspheric lenses and/or compound lens sets may be used. The projection lens  14  is mounted to a threaded, interchangeable lens mount  15  which is attached to the case  16  via corresponding threads of the opposite gender. Although  FIG. 2  shows the lens mount  15  having female threads (accepting the male threads of the case  16 ), the arrangement may be inverse—lens mount  15  having male threads being accepted by corresponding female threads on case  16 . Manual focus is accomplished by rotating lens mount  15  causing it to move axially towards or away from condensing lens  13 . Lens mount  15  and corresponding lens  14  can be easily interchanged with others of varying tubular length and focal length to allow for varying throw distance/magnification. A clear insulating lens  20  may be included to insulate the LCD controller/video player module  9  and LCD panel  11  from excessive heat generated by high-power LED/LEDs  5 . 
       FIG. 3  is a block diagram showing the unattended operation provided by the projector&#39;s custom firmware. 
     Alternative Embodiments 
     A constant current producing circuit may be used instead of the current limiting resistor  6  to improve power efficiency. 
     A wired or wireless communications module using standard technologies such as (but not limited to) Ethernet, 802.11, Bluetooth or cellular may be included to allow for adding or removing video files via networked or wireless connection to a host computer. 
     An internal loud speaker may be included instead of or in addition to the audio output socket.