Temporally multiplexed display with landscape and portrait operation modes

An autostereoscopic display apparatus, comprising:

• a display device comprising an array of pixels arranged in an aperture with a shape having two perpendicular axes of mirror symmetry, the display device being controllable to direct an image displayed on all of the pixels into a selectable one of a plurality of viewing windows having different positions and extending at an angle in a range from 25 to 65 degrees relative to one of said axes of the shape of the aperture;
• a sensor system arranged to detect the position of an observer in two dimensions across the display device and the orientation of the view of the observer;
• and
• a control system arranged to control the display device to display temporally multiplexed left and right images and synchronously to direct the displayed images into viewing windows in positions corresponding to the left and right eyes of the observer, in dependence on the detected position of the observer and on the detected orientation of the view.