Patent ID: 6686944
Filing Date: 2004-02-03
Classification: B41J

Abstract:
A method for recognizing a color of a printing ribbon used in a printer, the method comprising:providing a printing ribbon comprising colored dye disposed in regions arranged in a repeated sequence wherein light colors of dye and undyed ribbon cause a photosensor output to be a high level above a threshold and dark colors of dye cause the photosensor output to be a low level below the threshold; the repeated sequence of colored dye being a short dark region, a first long light region, a first long dark region, a short light region, a second long dark region, and second long light region; the ribbon capable of being moved relative to a print head so that the print head is capable of inducing the ribbon to transfer dye of a specific color onto a print medium; illuminating a sensing area of the ribbon, the sensing area being adjacent to the photosensor and being a predetermined distance from the print head; moving the ribbon relative to the sensing area; measuring output of the photosensor over time as the ribbon moves; correlating output of the photosensor to the repeated sequence as the ribbon moves to determine the color of the ribbon under the print head; and setting operational parameters of the printer and print head according to the color of the ribbon under the print head.