Binary printer with halftone printing temperature correction
AssigneeLexmark International, Inc.
InventorsRobert Wilson Cornell, Scott Michael Heydinger, James H. Powers
Life of this patent
Estimating the term…
Abstract
A binary printer for printing halftone color images on a substrate so that the determination of whether to print a dot or to not print a dot of each color ink at each pixel location is based at least in part upon an estimated temperature of the print head. The temperature of the print head may be estimated based upon direct measurement of the ambient temperature and/or direct measurement of temperature of some portion of the print head. Alternatively, the temperature of the print head may be estimated by counting the number of dots fired by the print head.
Claims24
An image processing apparatus for use in a binary printer, the apparatus comprising:
- a. a temperature estimation unit adapted to estimate an effective temperature of a print head based upon a number of print dots within a predetermined portion of a printable image;
- and
- b. a color correction unit adapted to receive the estimated temperature from the temperature estimation unit, adapted to receive color image data corresponding to a number of dots to be printed per unit area, and adapted to generate corrected color image data based upon the estimated temperature and the received color image data so as to modify the number of dots to be printed per unit area.
An image processing apparatus for use in a binary printer, the apparatus comprising:
- a. a temperature estimation unit for estimating an effective temperature of a print head based upon a number of print dots within a predetermined portion of a printable image;
- and
- b. a color correction unit for receiving the estimated temperature, for receiving image data in the form of nominal halftone color values corresponding to at least two colors, and for determining binary halftone color values based on the estimated print head temperature and the nominal halftone color values.
A method of processing image data for printing by a binary printer, the method comprising the steps of:
- a. estimating an effective print head temperature;
- b. providing image data in the form of nominal halftone color values corresponding to at least two colors, the nominal halftone color values representing probabilities that dots will be printed within a predetermined area of the image;
- c. correcting the nominal halftone color values based upon the estimated temperature so as to adjust the probabilities that dots will be printed within the predetermined area of the image and thereby adjust the number of dots to be printed within the area;
- and
- d. determining binary halftone color values based on the corrected nominal halftone color values, the binary halftone color values indicating whether or not to print dots at locations in the image.
An image processing apparatus for use in a binary printer, the apparatus comprising:
- a. a temperature estimation unit adapted to estimate an effective temperature of a print head;
- b. a color correction unit adapted to receive the estimated temperature from the temperature estimation unit, adapted to receive color image data, and adapted to generate corrected color image data based upon the estimated temperature and the received color image data;
- wherein the temperature estimation unit estimates the temperature based upon the corrected color image data generated by the color correction unit for some predetermined portion of the image.
An image processing apparatus for use in a binary printer, the apparatus comprising:
- a. a temperature estimation unit for estimating an effective temperature of a print head;
- and
- b. a color correction unit for receiving the estimated temperature, for receiving image data in the form of nominal halftone color values corresponding to at least two colors, and for determining binary halftone color values based on the estimated print head temperature and the nominal halftone color values;
- wherein the temperature estimation unit estimates the temperature based upon the binary halftone color values for some predetermined portion of the image.
A method of producing a color halftone image, the method comprising the steps of:
- a. estimating a print head temperature;
- b. providing binary halftone image data corresponding to at least two colors, the binary halftone image data representing a number of dots to be printed within a predetermined area of the image;
- c. adjusting the binary halftone image data based upon the estimated temperature in order to modify the number of dots to be printed within the predetermined area of the image;
- and
- d. driving a printhead to selectively deposit dots at various locations according to the adjusted binary halftone image data, so as to produce a binary halftone image.
Dependencies are inferred from the claim text.