Patent ID: 7862689

Claim:
A water content estimation apparatus, comprising: a first detection unit for detecting a first information regarding a water content of a sheet material at a position in contact with or adjacent to the sheet material; a second detection unit for detecting a second information regarding at least one of factors that change the water content of the sheet material from conveyance of the sheet material detected by the first detection unit until a performance of image formation processing, results of the image formation processing being affected by the water content of the sheet material, wherein the second information includes at least one of: (1) temperature including: air temperature and member temperature; (2) humidity including: relative humidity and absolute humidity; and (3) heat source including: quantity of light and radiation heat; and an estimation computation unit for computing, based on the detection results obtained by the first detection unit and the second detection unit, an estimation of the sheet material water content changed from after conveyance of the sheet material until a performance of the image formation processing.