Taper hole forming apparatus, taper hole forming method, light modulation means, and modulation mask

摘要

PROBLEM TO BE SOLVED: To provide a tapered bore forming device capable of simultaneously forming a plurality of tapered bores having an approximately the same taper angle.SOLUTION: The tapered bore forming device 10 includes a light modulation means 15 for modulating light from a mask lighting system 11 and emitting the light having nearly circular isointensity lines to a workpiece 18. The light modulating means 15 has a plurality of unit modulating means each having distribution of modulation quantity corresponding to the tapered bores 20 and the light beams modulated and emitted to the workpiece 18 by the respective unit modulation means become unit gradation light beams 50 having distribution of the light intensity corresponding to the tapered bores 20 respectively. Further, the width w of an inclined portion 52 in one unit gradation light beam 50 out of the respective unit gradation light beams 50 is different from the width of the inclined portion 52 in at least one unit gradation light 50 out of the other unit gradation light beams 50.