Portable thermal sheet printer with integral battery

摘要

A thermal line printer (10) has an upper cover (14) and a lower housing (16) containing a nickel-cadmium battery. Sheet input (P) is via a slot (20) (exiting at 22). An on-off switch (26) activates the printer with an indicator lamp (30). The printer has multiple heater elements arranged in two groups, driven independently in time. The number of activated heads is minimised by control process and is varied according to remaining battery life.