A novel notion "retro-transmissive" material as an optical element for head mounted display is introduced and discussed. Using this, so called "false image projector" is proposed. This projector does not need any screen such as the retro-reflective screen that was generally used for head mounted projection system. The fundamental operating principle of the optics is discussed both in macro-view and micro-view. The simple early prototype is developped and the result of experiments indicated the optical system works as proposed operating principle.