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  • Tip : About the Dymo LabelWriter 450 Turbo printhead

Tip : About the Dymo LabelWriter 450 Turbo printhead

This is some very technical information, but it is quite interesting. The Dymo LabelWriter 450 Turbo print head prints the image onto the label by heating a row of resistive elements; this blackens the thermally sensitive label material. These 672 resistive elements are .085 mm square and are spaced at 300 per inch on the print head. To print a line, the control electronics load the desired data into a serial shift register. This shift register has one register for each print element. A "1" in a register causes the corresponding dot to be printed; a "0" leaves the dot blank.

The darkness or density of the image depends upon the amount of heat applied to the label material. The heat depends upon both the temperature of the print head and the amount of energy applied to the resistive elements. The energy applied to the resistive elements depends upon the voltage applied and the length of time that the voltage is applied. In order to maintain a constant density, the control electronics measure the print voltage and the head temperature before each print cycle, and then calculate the required print strobe time.

The power supply is designed to handle printing an average of 37% of the total dots per line at full speed. If the voltage drops below 19.3 volts at the print head, printing is suspended until the power supply recovers to 21 volts.

In order to protect the print head from excessive heat, the control electronics halt printing if the print head temperature exceeds 70° C. Printing resumes when the print head cools to 56° C.