Ribbon identification

Every printer uses different methods to check, if there is enough ribbon left. The ribbons need to have a special shutdown-part, so the printer can recognise the end of the ribbon.

The printer uses the rotation of the unused ribbon to check the winding. As soon as this ribbon stops, the printer stops too. No shut-down part if the ribbon is needed for this method.

Another method tries to shine light through the ribbon. If the light beam can get through the invisible shutdown-part, the printer stops at once.
The reflection-method stops the printer as soon as light is reflected from the metallised shutdown-part.