Conveyance device and image forming apparatus

A conveyance device comprising:

• a conveyance roller which conveys a recording medium;
• a registration roller which stops a conveying of the recording medium conveyed by the conveyance roller and then starts the conveying of the recording medium again;
• a sensor which detects the recording medium conveyed by the conveyance roller;
• a mode setting part which sets a mode corresponding to a type of the recording medium;
• a storage which stores threshold information corresponding to the mode set in the mode setting part;
• a conveyance state determination part which determines a conveyance state of the recording medium based on a detection result of the sensor and the threshold information;
• and
• a drive control part which controls a driving of the conveyance roller and the registration roller based on a determination result of the conveyance state determination part, wherein
• the mode setting part sets the mode to either a plain paper mode or a tab paper mode,
• the storage stores plain paper mode threshold information showing a threshold used in the plain paper mode and tab paper mode threshold information showing a threshold used in the tab paper mode,
• the conveyance state determination part determines, when the plain paper mode is set, whether the conveyance state of the recording medium is a skew conveyance state or a tab paper conveyance state, based on the detection result of the sensor and the plain paper mode threshold information, and
• the conveyance state determination part determines, when the tab paper mode is set, whether the conveyance state of the recording medium is the skew conveyance state or the tab paper conveyance state, based on the detection result of the sensor and the tab paper mode threshold information.