Thermal Printer Diagnostic Function
Original Publication Date: 1981-Jun-01
Included in the Prior Art Database: 2005-Feb-11
Diagnosis of faults existing in a thermal printer having a print head with multiple chips each having multiple dots is accomplished by selectively energizing the print elements so as to produce recognizable patterns from each of the more commonly occurring faults. The print patterns which result from these faults are shown in Fig. 1. The existence of a dot which is continuously energized is shown at 1. A missing or unenergized chip results in the absence of any printing, such as 2. A missing dot or unenergized dot on a chip shows up as 3. A substantial difference between the ends of a segment appear as 4, with one end having substantially greater density than the other. A single line across the page would indicate that the page has not moved.