Imaging device

A method of projecting individually controllable laser beams onto an imaging surface that is movable relative to an imaging device, the method comprising:

• providing an imaging device for projecting individually controllable laser beams onto an imaging surface, the imaging device and imaging surface being movable relative to each other in a reference X-direction, the imaging device comprising:
• a plurality of semiconductor chips each of which comprises a plurality of individually controllable laser beam emitting elements arranged in a two dimensional main array of M rows and N columns, the emitting elements in each row having a uniform spacing Ar and the emitting elements in each column having a uniform spacing ac;
• the chips are mounted on a support such that the main arrays of each pair of chips that are adjacent one another in a reference Y-direction, transverse to the X-direction, are offset from one another in the X-direction;
• wherein were all the emitting elements to be activated continuously and were the chips and the imaging surface to be relatively moved in the X-direction, the emitted laser beams of the two chips of the pair would trace on the imaging surface 2·M·N parallel lines that extend in the X-direction and are uniformly spaced from one another in the Y-direction, by a nominal distance Ar/M, whereby the laser beams of each chip trace a set of M·N lines without overlapping the set of lines of the other chip;
• each chip further comprises at least one additional column in addition to the N columns of elements of the main array, the additional column being disposed on one side of the main array along the Y-direction, and containing at least one selectively operable laser emitting element capable of tracing at least one additional line that lies between the respective sets of M·N lines of each chip and that is spaced from two adjacent lines, each from a respective one of the sets, by a distance smaller than the uniform element spacing in each row Ar;
• and,
• individually projecting the laser beams onto the imaging surface.