The present disclosure relates to a projector. More specifically, the present disclosure relates to a presentation projector that dynamically masks out one or more objects positioned between the projector and a screen.
During a typical office presentation, a digital data file such as a slideshow may be loaded onto a computing device and displayed on a screen via a projector. FIG. 1 illustrates an exemplary projector 100 projecting a presentation onto a screen 102. The projector 100 receives a video-in signal 104. The video-in signal 104 is processed by a liquid crystal display (LCD) panel controller 106. In a typical LCD projector, three LCD panels 108 are used, one each for projecting the colors red, blue and green. By opening or closing each pixel on the LCD panels 108, a variety of colors may be projected for each pixel by combining the outputs of the various LCD panels 108. Based upon the video-in signal 104, the LCD panel controller 106 determines the state of each pixel (i.e., opened or closed) for every pixel in the LCD panels 108. The LCD panel controller 106 transmits a control signal to the LCD panels 108 indicating the state (i.e., open or closed) for each pixel in the panel. A lamp 110 projects a strong beam of light through each of the LCD panels 108. The lamp 110 may be a high intensity lamp such as a metal halide lamp or other similar lamp. After the light emitted by the lamp 110 passes through the LCD panels 108, the light passes through one or more lenses 112, and the projected light 114 is directed by the lenses toward the screen 102.
The projector 100 may be a portable device placed on a desk or table at a low enough level that the light emitted from the projector may be projected at eye level of a person 116 walking in front of the projector. The person 116 walking in front of the projector may experience discomfort due to bright light shining in their eyes. Audience members may be distracted by the images projected onto the person 116 walking in front of the projector, as well as the shadow 117 cast by the person on the screen 102.