Display arrangement having pin diode switching elements

Abstract

For satisfactory operation of a display arrangement having an electro-optical display medium and picture elements arranged between row and column electrodes and connected in series with an anti-parallel arrangement of PIN diodes, the diodes should have a small reverse current notwithstanding any ambient radiation present. In a display arrangement according to the invention, a small photo-current in the reverse direction is obtained due to the fact that the i-region and the p- or n-type region do not adjoin each other directly in the proximity of the edge of the mesa-shaped PIN diode. The region within which the aforementionhed regions adjoin each other is preferably located at a distance from the edge of the mesa-shaped PIN diode amounting to at least once the penetration depth of the ambient radiation plus the diffusion length of charge carriers in the i-region. Due to such a construction of the PIN diode, the electrical field becomes substantially zero with reverse voltage in the proximity of the edge of the diode and hence ther sensitivity of a display arrangement according to the invention to ambient radiation, especially to the ambient radiation laterally incident on the diode, becomes considerably lower.