Wikipedia
OCR-A
OCR-A is a font that arose in the early days of computer optical character recognition when there was a need for a font that could be recognized not only by the computers of that day, but also by humans. OCR-A uses simple, thick strokes to form recognizable characters. The font is monospaced (fixed-width), with the printer required to place glyphs cm ( inch) apart, and the reader required to accept any spacing between cm ( inch) and cm ( inch).