Stereoscopic image display apparatus

A stereoscopic image display apparatus has a display section 110 and a visual point position detecting mechanism for detecting positional information of an observer. The display apparatus uses an optical barrier having a mask pattern formed therein, and makes a patterned beam pass through an optical system to illuminate a display having a discrete pixel structure and displaying a synthetic parallax image by use of scanning lines. The observer stereoscopically observes the image information displayed on the display. The synthetic parallax image is comprised of m parallax images where m is an integer not less than 3. The contents of the synthetic parallax image are changed according to visual point position information outputted from the visual point position detecting mechanism according to positions of visual points of the observer.