Statement of Invention or “Hunting Expedition”?: Written Description for Claimed Ranges

“A written description . . . requires a statement of an invention, not an invitation to go on a hunting expedition to patch together after the fact a synthetic definition of an invention.” For claims reciting ranges, satisfying the written description requires an applicant to explicitly describe the claimed ranges or the end values of the ranges as of the filing date.  Written description cannot solely rely on cobbling together the numbers of the range after the fact. Id. at 1329. A failure to meet the written description requirement due to the lack of such a statement cannot be cured by disclosing representative working examples within the claimed range.