Abstract: An encoder and related methods for use in a printing device indexing system are provided. In some embodiments, the system comprises a feedroller or other component configured to index media through a printing device, and an encoder disk is coupled to the feedroller. In these embodiments, the system includes a reflective optical detector having a transmitter and a receiver provided adjacent a first surface of the encoder disk, the reflective optical detector being configured to detect the passage of the home position mark as the encoder disk rotates by the reflection of radiation off of the first surface. Also provided in some embodiments are methods for setting a counter to correspond with the home position of a rotatable element by utilizing threshold signal levels.

Abstract: An apparatus and method is provided for compensating for the effects of thermally induced droplet size variations in ink-jet printers. The apparatus includes a temperature determination unit for determining the temperature of the print head, and a halftone adjustment unit configured to receive the print head temperature from the temperature determination unit and to receive image data in the form of nominal halftone values. The adjustment unit can increase or decrease the number of dots to be printed, and thereby compensate for droplet size variations, either by adjusting the nominal halftone values based upon the temperature or by adjusting a threshold array based upon the temperature. The temperature determination unit can predict the print head temperature by counting the number of dots to be printed by counting the binary halftone values fed to the swath memory.