Patent ID: 9085136
Filing Date: 2015-07-21
Classification: B41J

Abstract:
1. A liquid ejecting apparatus, comprising: a liquid ejecting head for ejecting a liquid toward a medium; a light reflection optical sensor which is provided to a carriage that moves reciprocatingly in a movement direction that intersects a conveyance direction of the medium, which has a light-emitting unit and a light-receiving unit, and which outputs an output value corresponding to an amount of light received by the light-receiving unit; a dark output value acquisition unit for acquiring a dark output value corresponding to the amount of light received by the light-receiving unit when at a position where the optical sensor targets for detection a dark region provided so that the amount of light received by the light-receiving unit receiving reflected light of light irradiated by the light-emitting unit is less than that of the medium; an approximation function acquisition unit for acquiring a plurality of coordinate points indicated by the position and the output value of a portion where the output value increases or decreases with respect to the change in position when the optical sensor, which moves in the movement direction, is within a range of positions where an edge of the medium is targeted for detection, in a state where the medium has been conveyed to a position where detection by the optical sensor is possible, and for computing an approximation function on the basis of the plurality of coordinate points; and an edge position detection unit for detecting the edge position of the medium on the basis of the approximation function and the dark output value, the dark output value acquisition unit and the approximation function acquisition unit sequentially acquires the dark output value and the plurality of coordinate points, respectively, while the carriage progressively moving only in a single direction along the movement direction.