Non-linear power control of a thermal print head in a plastic card printer
AssigneeEntrust Corporation
InventorWade Kragtorp
Life of this patent
Estimating the term…
Abstract
Printing multi-color images on non-vinyl plastic identification documents in identification document printing systems. A non-linear pixel density adjustment curve is used to adjust the pixel density data of a multi-color image to be printed which adjusts the power applied to the thermal print head. The use of a non-linear pixel density adjustment curve to adjust the pixel density data improves the quality of the resulting multi-color printed image, reduces mass transfer of the dye donor layer, and reduces breaking of the carrier film of the print ribbon.
Claims14
A method of printing a multi-color image on an identification document made of polyethylene terephthalate glycol or polycarbonate in a print station of an identification document printing system, comprising:
- inputting print data corresponding to the multi-color image to be printed into a printer controller that controls operation of a thermal print head of the print station that includes a multicolor print ribbon, the print data including pixel density data;
- processing the print data to adjust the pixel density data using a non-linear pixel density adjustment curve to create modified pixel density data;
- and
- using the modified pixel density data to control the thermal print head of the print station to print the multi-color image on the polyethylene terephthalate glycol or polycarbonate identification document using the multicolor print ribbon.
A method of printing a multi-color portrait image of a person on a polyethylene terephthalate glycol plastic card in a print station of plastic card printing system, comprising:
- inputting print data corresponding to the multi-color portrait image to be printed into a printer controller that controls operation of a thermal print head of the print station that includes a multicolor print ribbon, the print data including pixel density data;
- processing the print data to adjust the pixel density data using a non-linear pixel density adjustment curve to create modified pixel density data;
- and
- using the modified pixel density data to control the thermal print head of the print station to print the multi-color portrait image onto the polyethylene terephthalate glycol plastic card using the multicolor print ribbon.
A plastic card printing system, comprising:
- a card input configured to input a polyethylene terephthalate glycol or polycarbonate plastic card;
- a print station having at least one print ribbon and at least one thermal print head;
- a card transport mechanism for transporting the polyethylene terephthalate glycol or polycarbonate plastic card from the card input to the print station;
- a printer controller connected to and controlling operation of the thermal print head, the printer controller is programmed to include a non-linear pixel density adjustment curve to adjust pixel density data of a multi-color image to be printed.
Dependencies are inferred from the claim text.