PURPOSE: To attain enlargement regardless of relative positions of an observer and image enlarging devices by projecting the same two image which are reproduced by two image reproducing device upon the left and right eyes of the observer independently at a mutually small angle of convergence.

CONSTITUTION: The 1st image reproducing device 12 and the 2nd image reproducing device 14 such as cathode-ray tubes are arranged having image surfaces nearly at right angles to each other. In this case, the 1st polarizing plate 16 is at right angles to the 4th polarizing plate 26, so the 1st image 30 of the 1st image reproducing device 12 is not formed on the left eye 22 of the observer 22, and only the 2nd image 32 of the 2nd image reproducing device 14 is formed on the left eye 22 of the observer 8. Similarly, only the 1st image 30 of the 1st image reproducing device 12 is formed on the right eye 24 of the observer 8. Thus, the enlargement is attained regardless of relative positions of the observer and image reproducing devices.