Transfer printer and method

A transfer printer configured to transfer ink from a printer ribbon to a substrate which is transported along a predetermined substrate path adjacent to the printer comprising:

• a tape drive for transporting ribbon between first and second ribbon spools along a ribbon path;
• a printhead being displaceable towards and away from the predetermined substrate path and being arranged to, during printing, contact one side of the ribbon to press an opposite side of the ribbon into contact with a substrate on the predetermined substrate path, and a printing surface;
• an image capture system configured to capture images of the ribbon at an imaging location;
• and
• a controller arranged to:
• determine a first characteristic of the image capture system, the first characteristic comprising a spatial distribution of radiation intensity with a first part and a second part corresponding to respective first and second regions of an imaging location of the image capture system, wherein the ribbon is not positioned in the first and second regions when determining the first characteristic;
• obtain a second characteristic of the image capture system, the second characteristic comprising a modified spatial distribution of radiation intensity with a first part and second a part corresponding to the respective first and second regions of the imaging location, wherein the ribbon is positioned in the first region when obtaining the second characteristics;
• and
• adjust the second part of the second characteristic based upon the second part of the first characteristic, and a relationship between the first part of the second characteristic and the first part of the first characteristic.

A computer program comprising computer readable instructions arranged to:

• determine a first characteristic of an image capture system of a transfer printer, the first characteristic comprising a spatial distribution of radiation intensity with a first part and a second part corresponding to respective first and second regions of an imaging location of the image capture system, wherein the ribbon is not positioned in the first and second regions when determining the first characteristic;
• obtain a second characteristic of the image capture system, the second characteristic comprising a modified spatial distribution of radiation intensity with a first part and a second part corresponding to the respective first and second regions of the imaging location, wherein the ribbon is positioned in the first region when obtaining the second characteristics;
• and;
• adjust the second part of the second characteristic based upon the second part of the first characteristic, and a relationship between the first part of the second characteristic and the first part of the first characteristic.