House post box with content indicator

摘要

House post box may be of an individual type (single), or as a compact, multicompartment installation. Inside each individual box is a letter indicator, signaling the presence of the box contents, together with an associated switch and display. On a base plate are located a phototransmitter and a photoreceiver, whose mutual angular position is adjustable and fixable in vertical and horizontal direction. On the box side, opposite to the transmitter and receiver, is fitted with a deflecting foil.