This is how big display boards used to be made. A projector was pointed at a large bank of photomultiplier tubes (electron tube equivalent of the CdS photoresistors in the article) and the tubes translated whatever light level fell on them to a corresponding pixel, aka lightbulb.
This is how big display boards used to be made. A projector was pointed at a large bank of photomultiplier tubes (electron tube equivalent of the CdS photoresistors in the article) and the tubes translated whatever light level fell on them to a corresponding pixel, aka lightbulb.
(post is archived)