Sheet moisture replacement system using porous rolls
AssigneeXerox Corporation
InventorBarry P. Mandel
Life of this patent
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Abstract
A system for adding moisture to a copy sheet is disclosed. The toner fixation step of electrostatographic reproduction desiccates paper, which may lead to the formation a wave along the sheet edge. The invention uses a pair of porous rolls defining a nip to transfer additional moisture to the copy sheet as it is passed through the nip. The added moisture prevents edge wave formation.
Claims24
A device for adding moisture to a copy sheet, comprising:
- a reservoir for storing 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 at least one of said rolls
- i) having a hollow shaft for support thereon and rotation therewith, said shaft further having channels therein for accommodating the passage of liquid to the roll and further including bearing means for rotation thereabout;
- and
- ii) being constructed of a material having a microporous structure enabling liquid to flow from the center of the roll to its periphery;
- conduit means for conducting fluid from the reservoir to at least one of said rolls;
- flow control means intermediate the rolls and the reservoir for controlling the flow of fluid along said conduit means from the reservoir to at least one of said rolls;
- and
- means for rotating at least one of said rolls about its central cylindrical axis,
- wherein liquid is conducted along the conduit means from the reservoir to the hollow shaft of at least one roll, and from thence through the micropores of the roll to its outer cylindrical surface for transfer to a copy sheet as it passes through the nip.
A system for fixing a toner image to a copy sheet in an electrostatographic system so as to avoid the formation of a wave along the edge of the copy sheet, 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;
- means for conveying the copy sheet from the fusing rollers to a moisture replenishing station, said moisture replenishing station including
- i) a reservoir for storing a quantity of liquid;
- ii) a pair of generally cylindrical porous rolls arranged so as to define a nip therebetween;
- and
- iii) means for conveying liquid from the reservoir to the porous rolls at a measured rate,
- wherein the copy sheet is supplied with liquid from the porous rolls as it passes through the nip defined by the porous rolls.
A method for replenishing the moisture that a copy sheet loses as it is heated in an electrostatographic machine of the type having a thermal fuser, comprising the steps of:
- transporting liquid from a reservoir to a pair of rolls made of a microporous material that are arranged so as to form a nip therebetween;
- transporting the copy sheet from the fuser through the nip of the rolls;
- and
- transferring liquid from the rolls to said copy sheet.
Dependencies are inferred from the claim text.