Patent ID: 7837191

Claim:
A sheet carrying state determining device comprising: a detection information acquiring unit configured to acquire information about sheet detection timing by two sensors that are arranged at positions different from each other in a sheet carrying direction and arranged at positions different from each other in a direction orthogonal to the sheet carrying direction; a control unit configured to determine a skew of a carried sheet in addition to performing sheet detection in accordance with the information acquired by the detection information acquiring unit; and a third sensor arranged at a position that is connected with at least one of the two sensors by a straight line having a different inclination angle from a straight line connecting the two sensors with respect to the sheet carrying direction, the detection information acquiring unit being further configured to acquire information about sheet detection timing by the third sensor, and in accordance with a sheet movement time in a first section between the two sensors in the sheet carrying direction and in a second section between one of the two sensors and the third sensor, the control unit being further configured to combine results of determination of the sheet movement time in the two sections and thereby determine a skew of the sheet separately from another factor than a skew that influences the sheet carrying state.