Sheet feeding state determination method, sheet feeding device, and image forming apparatus

A sheet feeding state determination method for determining a state of a sheet feeding device;

• the sheet feeding device comprising:
• a feeding mechanism including a feeding rotating body configured to contact an upper surface of a topmost sheet of a stack of sheets, a feed-out rotating body that is spaced apart from the feeding rotating body, and a separating member that is positioned below the feed-out rotating body and biased toward the feed-out rotating body, the feeding mechanism rotating the feeding rotating body and the feed-out rotating body to execute a feeding process of feeding sheets from the stack of sheets to a conveying path, and separating accompanying sheets that are fed out accompanying each sheet from each sheet by the separating member;
• a sheet detecting device configured to detect each sheet at a detection position on a downstream side of the feed-out rotating body and the separating member in a sheet feeding direction;
• and
• a timing device configured to measure an elapsed time from a time when the feeding process for each sheet is started to a time when each sheet is detected by the sheet detecting device;
• the sheet feeding state determination method, comprising:
• a processing device deriving a positional deviation amount representing a deviation amount of a position of a target sheet relative to an initial reference position at a time when the feeding process for the target sheet is started, based on a target measurement time measured by the timing device for the target sheet fed by the feeding process and a preset reference feeding time;
• the processing device counting a separation failure count that is the number of times the positional deviation amount exceeds a separation failure determination value corresponding to a path length from the initial reference position to the separating member;
• and
• the processing device determining a deterioration state of the feeding mechanism based on the separation failure count.