Patent ID: 8851612

Claim:
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 able to move in a movement direction that intersects with a conveyance direction for 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 support unit having a plurality of protrusions for supporting the medium; a first detection unit for detecting an edge of the medium by comparing a threshold value at which the medium can be detected and the protrusions cannot be detected and an output value of the optical sensor moving the movement direction in a state where the medium has been conveyed to a position at which detection by the optical sensor is possible; and a second detection unit for detecting a position of the edge by using the output value of the optical sensor and a comparison value when the edge of the medium is detected by the first detection unit.