Method of forming optical images, a control circuit for use with this method, apparatus for carrying out said method and process for manufacturing a device using said method

Apparatus for forming an optical image in a radiation-sensitive layer (5), the apparatus comprising:

• a radiation source (17);
• positioning means for positioning a radiation-sensitive layer (5) relative to the radiation source (17);
• a plurality of individually controllable light valves (21-25) arranged between the source (17) and the location of the radiation-sensitive layer (5);
• an imaging element (40) comprising a plurality of radiation-converging elements (43) arranged between the plurality of light valves (21-25) and the location of 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 (21-25) in a spot area in the radiation-sensitive layer (5);
• writing means for simultaneously writing image portions in radiation-sensitive layer areas by scanning the 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),
• wherein at least some spot areas in the radiation-sensitive layer (5) are scanned by a plurality of spots created by respective light valve/converging element pairs:
• control means for selectively reducing the intensity of, or switching off, one or more of said plurality of individually controlled light valves (21-25) scanning the same spot area in said radiation-sensitive layer (5) so as to adjust the position in said radiation-sensitive layer (5) of an edge position of a feature of said optical image.