Sheet moisture replacement system using water jet technology

A system for fixing a toner image to a copy sheet in an electrophotographic system so as to avoid the formation of a wave along the edge of the copy sheet and a curl in the body of the sheet, comprising:

• first and second fusing rollers defining a nip therebetween, at least one of said fusing rollers being heated, and wherein the fusing rollers serve to fix a toner image on a copy sheet through the application of heat and pressure to the copy sheet;
• a device to transport a copy sheet from said fusing rollers to a sheet conditioning system, comprising;
• at least one water jet positioned on opposite sides of the copy sheet with each of said at least one water jet being connected to a quantity of liquid;
• a pair of generally cylindrical rolls, each having an outer cylindrical surface, said rolls being aligned with respect to one another along their axes so as to define a nip between said outer cylindrical surfaces;
• and
• a control device for determining the location and density of toned images on the copy sheet and providing signals indicative thereof to actuate said water jets in accordance with said signals.

A device for replenishing the moisture that a copy sheet loses as it is heated in an electrophotographic machine of the type having a thermal fuser, comprising:

• a water jet on both sides of the copy sheet;
• a source of liquid connected to each of said water jets;
• a pair of transfer rolls arranged to form a nip therebetween through which the copy sheet is conveyed;
• a controller for determining toner density on the copy sheet and generating toner density signals to actuate said water jets to apply liquid to each of said transfer rolls in accordance with said toner density signals.

A method for replenishing the moisture that a copy sheet loses as it is heated in an electrophotographic machine of the type having a thermal fuser, comprising the steps of:

• providing a water jet on both sides of the copy sheet;
• providing a controller for determining toner density on the copy sheet and generating density signals to actuate said water jets in accordance with said signals;
• supplying water from said water jets to each one of a pair of rolls that are arranged so as to form a nip therebetween;
• transporting the copy sheet from the fuser through the nip of the rolls;
• transferring water from each of said pair of rolls to said copy sheet.

A method for adding moisture to a copy sheet, comprising the steps:

• providing a pair of water jets including a quantity of liquid for each water jet;
• supplying a pair of generally cylindrical rolls, each having an outer cylindrical surface, said rolls being aligned with respect to one another along their axes so as to define a nip between said outer cylindrical surfaces, and wherein one each of said pair of water jets is positioned to apply liquid to a both sides of a sheet prior to the sheet entering said nip;
• using a controller to provide signals indicative of imaged areas of the sheet;
• and
• actuating said pair of water jets in accordance with said signals and controlling the flow of fluid to the sheet from said water jets in accordance with said signals.

A device for adding controlled amounts of moisture to a copy sheet, comprising:

• a water jet;
• a reservoir for storing a quantity of liquid and connected to said water jet;
• a pair of generally cylindrical, pressure rolls, each having an outer cylindrical surface, said rolls being aligned with respect to one another along their axes so as to define a nip between said outer cylindrical surfaces;
• and
• a controller for controlling application of liquid from said water jet to selected portions of each sheet passing thereunder before each sheet enters said nip formed between said outer cylindrical surfaces.

A system for fixing a toner image to a copy sheet in an electrophotographic system so as to avoid the formation of copy sheet curl, comprising:

• first and second fusing rollers defining a nip therebetween, at least one of said fusing rollers being heated, wherein the fusing rollers serve to fix a toner image on a copy sheet through the application of heat and pressure to the copy sheet;
• and
• A sheet conditioning system that receives a sheet after it exits said fusing rollers, said sheet conditioning system comprising;
• a water jet, a pair of generally cylindrical, pressure rolls, each having an outer cylindrical surface, said rolls being aligned with respect to one another along their axes so as to define a nip between said outer cylindrical surfaces, and control means for actuating said water jet to apply water to selected portions of one of said rolls before the sheet enters said nip.