Patent ID: 7598973

Claim:
A line head, comprising: a substrate; a plurality of first light emitters, operable to emit light so as to form an image and arrayed on the substrate along a first line extending in a first direction so as to form a light emitter array, each of the first light emitters having a first dimension in the first direction; a first driver, operable to drive the first light emitters; and a plurality of second light emitters, operable to emit light so as to form a test pattern that is different from the image formed by the plurality of first light emitters and that is used for detecting a tilt of the line head, and arrayed on the substrate along a second line extending in the first direction, each of the second light emitters having a second dimension in the first direction which is larger than the first dimension and a third dimension smaller than the first dimension in a second direction perpendicular to the first direction.