1. A display apparatus comprising: a display section; and a light-beam control section configured to control a light beam coming from said display section or a light beam propagating to said display section; said display apparatus having a first display mode for displaying a plurality of observing-point images on said display section wherein said observing-point images include two or more first observing-point images, and one or a plurality of second observing-point images, and the number of pixels included in each of said second observing-point images is smaller than the number of pixels included in each of said first observing-point images each of said first observing-point images is displayed by making use of a first pixel group including a plurality of pixels; each of said second observing-point images is displayed by making use of a second pixel group including pixels; the number of pixels included in said second pixel group is smaller than the number of pixels included in said first pixel group; and two or more said first pixel groups used for displaying said two or more first observing-point images and one or a plurality of said second pixel groups used for displaying said one or a plurality of second observing-point images form a basic pixel set; in said basic pixel set, an interpolated pixel group pertaining to said second pixel group is interpolated between said first pixel groups; each pixel of said interpolated pixel group is a pixel of an observing-point image for an intermediate observing point between observing points for said first observing-point images displayed by said first pixel groups interpolating said interpolated pixel group in said basic pixel set; and said two or more first observing-point images and one or a plurality of said second pixel groups used for displaying said one or a plurality of second observing-point images form a basic pixel set.