Ключевые слова: audiovisual, background, beam, black, blue, board, business, cable, ceiling, classroom, college, computer, conference, corporate, digital, education, equipment, gray, grey, hang, home, indoors, lcd, led, lens, light, meeting, modern, mounted, movie, multimedia, office, overhead, photographic, presentation, projection, projector, roof, room, screen, slide, study, teach, technology, video, viewer, visual, white, working,