Exposure control device

An exposure control device, comprising:

• an illumination optical system comprising means for generating a coherent pulsed light beam, and adapted for irradiating a second object with said pulsed light beam through a first object having a pattern thereon, thereby transforming said pattern onto said second object;
• means, provided in said illumination optical system, for displacing a speckle pattern, formed on said first and second objects with a specific periodicity by means of said pulsed beam, over a predetermined range and in predetermined directions on said first and second objects;
• means for storing, in advance, a number of pulses of said light beam required for substantially smoothing the integrated exposure amount over the entire area of said second object when plural pulses of said light beam are generated during the displacement of said speckle pattern over said predetermined range;
• and
• means for determining the number of pulses of said light beam required for giving a predetermined exposure to said second object, the intensity of each pulse of said light beam given by said illumination optical system, and the number of pulses per cycle of the displacement of said speckle pattern, said determining being based on said stored number of pulses.