Patent ID: 7405807

Claim:
A method of forming an optical image in a radiation-sensitive layer, the method comprising the steps of: providing a radiation source ( 17 ); providing a radiation-sensitive layer ( 5 ); positioning a plurality of individually controlled light valves ( 21 - 25 ) between the radiation source ( 17 ) and the radiation-sensitive layer ( 5 ); positioning an optical element ( 40 ) comprising a plurality of radiation-converging elements ( 43 ) between said light valves ( 21 - 25 ) and the radiation-sensitive layer ( 5 ), such that each converging element ( 43 ) corresponds to a different one of the light valves ( 21 - 25 ) and serves to converge radiation from the corresponding light valve in a spot area in the radiation-sensitive layer ( 5 ); simultaneously writing image portions in radiation-sensitive layer areas by scanning said layer ( 5 ), on the one hand, and the associated light valve/converging element pairs, on the other hand, relative to each other and switching each light valve ( 21 - 25 ) between an on and an off state in dependence upon the image portion to be written by the light valve ( 21 - 25 ); the method being characterized by the steps of measuring said written image portions and comparing a scale thereof to a corresponding image scale of the image portions required to be written by the light valves ( 21 - 25 ) to determine whether or not there is a difference therebetween; and if so, adjusting said image scale so as to correspond with said measured scale; wherein said adjusting step comprises physically altering a distance between one or more adjacent radiation-converging elements ( 43 ) relative to each other.