The seven-segment LED display is ubiquitous. But how old do you think the fundamental idea behind it is? You nixie tube fans will be thinking of the vacuum-tube era, but a reader sent us this ...

seven-segment display (Image courtesy of LXD, Inc.) In their natural state, liquid crystals line up with the orientation "rubbed" into the front and rear glass panels. The rubbings are microscopic ...

Seven-segment displays have been around for a long ... drive followers that flip the red segments in and out of view. The display can cycle through all ten states in a single rotation of the ...