1. A method of adjusting an exposure device suited for an electrophotographic printer, said exposure device comprising a plurality of light-emitting elements, said method comprising the steps of: energizing selected light-emitting elements according to a selection scheme; using a pre-determined energy level for energizing each selected light-emitting element and obtaining a corresponding exposure intensity distribution from the exposure device; predicting a toner area coverage distribution, based on the obtained exposure intensity distribution and on a pre-established transfer function; and obtaining an attribute of the predicted toner area coverage distribution and determining setting values for the energy levels for energizing each selected light-emitting element such that the obtained attribute becomes a target attribute.