A sheet characteristic detection device includes: a detector that is disposed on a sheet ejection path through which a sheet is ejected and that detects an electrical resistance value of the sheet; and a charge neutralizer that is disposed on a downstream side of the detector on the sheet ejection path and that neutralizes electric charge on the sheet.

An image forming apparatus includes an image forming unit to form an image on a sheet based on a mode selected from a plurality of modes having different image forming speeds, a memory to store first data for a first mode included in the plurality of modes, the first data indicating a correspondence for the first mode between a type of the sheet and the image forming speed, and second data for a second mode included in the plurality of modes, the second data indicating a correspondence for the second mode between a type of the sheet and the image forming speed, and a display. A controller determines a first image forming speed for the first mode from the first data based on the type of the sheet, and determines a second image forming speed for the second mode from the second data.

An information processing apparatus controls an image forming apparatus to form an image, with an image forming speed of the image forming apparatus being controlled. The information processing apparatus includes an interface to acquire sheet information related to a sheet on which the image is to be formed by the image forming apparatus, and a controller to receive user instruction information for adjusting an image forming speed for a certain mode included in a plurality of modes and to control the image forming speed for the certain mode based on the user instruction information and the sheet information.