Multiple ink jet print cartridge alignment method

Abstract

Abstract An improved image registration system for a multi-color inkjet printer/plotter (10) is disclosed. The inventive system comprises a carriage assembly (100) for retaining multiple inkjet cartridges (102, 104, 106, 108). Each cartridge (102, 104, 106, 108) has a plurality of nozzles (502, 504, 506, 508) adapted to eject ink in response to the application of an electrical signal thereto. A first mechanism (112) is provided for moving the carriage assembly (100) in a first axis. A second mechanism (152) is provided for moving print media (30) in a second axis transverse to the first axis. A first position encoder (110) senses the position of the carriage assembly (100) in the first axis and a second position encoder (156) senses the position of the carriage assembly (100) in the second axis. A control circuit (300) provides electrical signals which cause the nozzles (502, 504, 506, 508) in the inkjet cartridges (102, 104, 106, 108) to eject ink onto the media (30) and create an image thereon in response to timing signals. The inventive system includes a sensor module (200) which optically senses the image and provides a set of sensed signals in response thereto. The sensed signals are processed to provide collected timing signals. In a particular embodiment, a test patters (40) is generated and illuminated by a light source (232) in the sensor module (200). The light source (232) has spectral energy in the color bands of interest. The test pattern (40) includes a plurality of images which when scanned by the sensor module (200) allows the module (200) to generate an output signal of a given frequency. The output signal is sampled and processed to provide corrected timing signals for activation of the nozzles. By detecting the position of the pattern, the misalignment of a particular pen may be corrected.

Inventors

• 👤 Keith E. Cobbs
• 👤 Robert W. Beauchamp
• 👤 Paul R. Sorenson

Bibliographic Details