Patent ID: 7328996
Filing Date: 2008-02-12
Classification: B41J

Abstract:
1. A sensor and ink-jet print-head assembly comprised in a housing for a hand-held and hand-operated printing device controlled by a processor, comprising: two position sensors, at least a first sensor being related to a first coordinate system, having one axis in a relation to a print-head array, arranged in a fixed position relative to said sensors, and one axis in a direction through both sensors; at least one input control on said housing and connected to said processor to input control commands; a coordinate determining routine associated with the processor to determine reference coordinates in a second coordinate system provided in relation to a print medium, said reference coordinates being established by a control command input through said input control and based on a sensor signal; a position calculating routine associated with the processor to track the assembly's position related to said reference coordinates in said second coordinate system by integrating displacement of at least one sensor position in the first coordinate system; and a transform routine associated with the processor to transform the sensor coordinates to position coordinates in the second coordinate system, whereby the assembly's position on the print medium is determined in relation to the reference coordinates, said transform routine being operable to derive said transformation of the sensor coordinates, through the position of the first sensor related to the first coordinate system and an angle of the print-head array in relation to the second coordinate system, and to derive the angle of the print-head array in relation to the second coordinate system as the difference of the sensor movement in the y-direction of the first coordinate system multiplied with a constant which is determined in relation to the distance between the two sensors.