method and apparatus for projecting infrared or near infrared or low intensity visible light from a pen , pointer or other guiding object in the form of a coded pattern image , detectable by a camera and recognition system but invisible , or hardly visible to the user and audience , thus controlling and interacting with a computer during a presentation , computer supported work and / or other interactive use of a computer , including pointing , selecting , drawing and writing , both distantly and closely to the front or rear projection screen or possible other type of display screen , without any distracting visual patterns or spots , while the possible visual feedback to the user and audience can be generated by the computer and display system onto the display screen in a controlled and context - sensitive way . the projected complex images from the positioning device when operating remotely and when operating closely to the screen , are created by optical alignment of one or several diffractive optical elements , collimating lens and / or mirrors , and one or more light sources . the light sources can preferably be laser diodes or light emitting diodes . in a preferred embodiment , the light sources are emitting visible , infrared or near - infrared light .