The History of Thermal Printers

ATMs often print receipts using thermal printers.

Thermal printers use heat rather than toner or ink to print, graph or otherwise produce output. They are often used in point-of-sale systems that print a receipt and in bar code-labeling systems for retail or inventory systems, but they also have other uses, such as rendering fetal ultrasound scan images.

Direct Thermal Printers

Thermal printers of old employed direct thermal printing, whereby images are produced by heating thermal paper that is impregnated with a chemical that changes color where heated. This technology works well in applications with a short shelf life, such as shipping labels and receipts. Thermal paper is sensitive to heat and light and has limited long-term durability. Direct thermal printers are quiet, fast and inexpensive, but the paper is relatively costly. Some older faxes used this method of printing but are mainly obsolete now.

Thermal transfer printers

Newer thermal transfer technology uses an inked ribbon that transfers the ink onto the media surface, where it cools and becomes anchored. The print is thus put on top of the media rather than the media itself containing the color. This technology produces far more durable labels and bar codes. These printers are also quiet and fast, but you need to change out the ribbons periodically.

Uses

Both types of printers remain in use today. Direct thermal receipt printers are commonly used in gas stations for credit card receipts. Such receipts become marred when they are scratched and fade over time. In applications where durability is required, the print produced by thermal transfer printers excels at longevity and is impervious to environmental conditions.

References

• Zebra: Direct Thermal and Thermal Transfer Printing
• Bar Coding: Comparison of Barcode Printers

Resources

• Zebra: Direct Thermal and Thermal Transfer Printing