Temperature control system for a fuser

摘要

An improved fuser system especially effective for a large document type of copier is provided. The fusing system is of the heat and pressure type wherein a fuser roll is internally heated by a lamp so that the fuser surface is at a required fusing temperature. When the full width of the roll is used in a particular fusing operation, e.g. 36'' wide documents are being copied, the lamp is heated to a maximum temperature. When the document copy is less than 36'' and for a center registered system, the ends of the fuser roll would tend to overheat, since the copy media is absorbing heat only in the center portion. According to one aspect of the invention, a control circuit is provided to recognize that the shorter widths of the copy media are being used and to lower the lamp temperature in response thereto to prevent the fuser roll ends from overheating. A further concept is to recognize the type of media being used and to lower the lamp temperature in response to selection of copy media of different fusing characteristics.