| 摘要 |
A hand-held labeller employing a thermographic recording apparatus utilizes compensating circuitry (40,70,42) for adjusting the energy applied to the print head (66) to assure uniform printing over various operating conditions. The compensating circuit includes circuitry that adjusts the length of time that each printing element of the print head (66) is energized as a function of battery voltage, ambient temperature, element resistance and the elapsed time since the element was previously energized. In addition, the monitoring of resistance and voltage permit detection of open or shorted printing elements and discharged or faulty battery cells. A D.C. motor (50) that is driven by a variable pulse width circuit (48) drives a web of labels past the print head. <IMAGE> |
