Method and apparatus for the calibration of a multichannel printer

摘要

A method and apparatus are disclosed for the calibration of a multichannel printer. The printer comprises a plurality of diode lasers which are modulated in accordance with an information signal. Radiation from the diode lasers is imaged onto a receiving medium such as a thermal print medium. The thermal print medium is supported on a drum which is rotatable about an axis. In order to balance the output from the diode lasers, test patterns are formed on the receiving medium with each of the lasers using known power inputs. The density of each of the test patterns is measured, and the density values obtained are correlated with the input power levels for each of the lasers. The measurement of densities produced by a single laser is facilitated by slowing the print head down by a factor of the number of lines normally printed and writing with one line source at a time.