Receipt Printer Technologies: Impact, Thermal and Inkjet

Impact:

Impact printing is done by several tiny pins, aligned in a column, striking an ink ribbon positioned between the pins and the paper, creating dots on the paper. Characters are composed of patterns of these dots by moving the printhead laterally across the page in very small increments.

The pins, contained in the printhead, are driven by several hammers (actuating plate) which force each pin into contact with the ink ribbon (and paper) at a certain time. The force on these hammers comes from the magnetic pull of small wire coils (solenoids/drive coil) which are energized at a particular time, depending on the character to be printed. Timing of the signals sent to the solenoids is programmed into the printer for each character, and translated from information sent by the host about which characters to print.

Benefits:

• Price – generally cheaper than other printing methods
• No special paper media
• Highly reliable and durable in harsh hospitality environments such as kitchens
• Impact receipts can be used with multi-part paper. This is ideal for credit card receipts and journaling

Drawbacks:

• Noisy – fine for a kitchen but not an upscale boutique
• Slower than other printing methods
• Ribbons that need replacing – ink on your hands

Thermal:

Thermal printing is done by a thermal print head that applies head directly to special thermal paper. When a specific temperature is applied the dyes and developers in the thermal paper chemically react and turn the paper the specific color of the dye.

Two color thermal printing is done similarly as well. Two-color thermal paper has two types (colors) of dyes and developers. At one specific temperature the first color (generally red, but can be other) is formed. At a higher temperature black is formed.

Benefits:

• Fast printing – Ideal for high volume retailers
• Quiet printing – when noise is unacceptable
• No ribbons to replace
• Two color printing on specific models

Drawbacks:

• Special thermal paper media
• More expensive than impact

Inkjet:

In thermal inkjet printing, the ink in a nozzle is heated with a small electrical element. As the ink heats to 300º Centigrade, it expands and boils to form a bubble. As the bubble grows, the ink is pushed out of the ink cartridge nozzle. When the bubble bursts, the droplet is expelled onto the paper. This technology is called thermal inkjet.

Benefits:

• Fast printing – Ideal for high volume retailers
• Quiet printing – when noise is unacceptable
• No ribbons to replace
• No special paper media
• Two/Multi color printing on specific models
• Receipts last a long time

Drawbacks:

• Price of purchasing spare replacement cartridges
• More expensive than impact
• Ink can smear