The new high-density directional (HDD) display using the time-multiplexing technique is proposed to reduce the
complexity of the multi-projection system used for the HDD display. The HDD display is a natural three-dimensional
display which has been developed to solve the visual fatigue problem caused by the accommodation-vergence conflict.
The proposed HDD display consists of multiple time-multiplexing display modules. Each module consists of an LED
array, a DMD, lenses, and an aperture array. A number of directional images are displayed by the DMD at a high frame
rate and the LED's emit light one after another in synchronization with the DMD. The apertures are arranged twodimensionally,
and their horizontal positions are different. The LED's are arranged in a same way. All directional images
displayed by the DMD pass through different apertures. Multiple modules are arranged two-dimensionally with the
different horizontal positions and all images are combined by a common lens. A vertical diffuser is used as a display
screen to cancel the difference of the vertical display directions. All directional images are superimposed on the vertical
diffuser, and are given the different horizontal display directions. Each module generates 15 directional images at a
frame rate of 60 Hz. Four modules are combined to display 60 directional images in the different horizontal directions
with the angle pitch of 0.31°.