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AssigneeKabushiki Kaisha Toshiba
InventorsHideki Ide, Masahiro Uekita, Eijiro Koike
Estimating the term…
A diffraction optical element is provided to reduce harmful lights and also suppress deterioration in the optical characteristics of the element. The diffraction optical element 22 is formed with a plurality of diffraction gratings 17′, 18′, 19′ and 20′. From these diffraction gratings, there are selected the diffraction gratings 18′, 19′ and 20′ whose groove apex angles are less than a predetermined angle. The diffraction gratings 18′, 19′ and 20′ has chamfer surfaces 18c′, 19c′ and 20c′ formed on the lower side of respective slanted surfaces 18a′, 19a′ and 20a′. The chamfer surfaces 18c′, 19c′ and 20c′ are slanted to the slanted surfaces 18a′, 19a′ and 20a′, respectively.
A diffraction optical element comprising:
A molding die for molding a diffraction optical element having a plurality of diffraction gratings formed to have a blazed profile in section, the molding die comprising:
A method of manufacturing a molding die for molding a diffraction optical element having a plurality of diffraction gratings formed to have a blazed profile in section, the molding die having a plurality of grooves formed to correspond to the diffraction gratings of the diffraction optical element and also have a blazed profile in section, the method comprising the steps of:
Dependencies are inferred from the claim text.