Fusers and intermediate transfer members

Abstract

Drum intermediate transfer member or fuser apparatus, for use in a printer or copier, comprising: a drum having a drum surface and including a liquid-containing region in the interior of the drum thermally connected to the drum surface, such that the liquid is capable of heating and cooling the drum surface; and a liquid transfer system including a hot liquid reservoir, a cold liquid reservoir, at least one pump, pipes and optionally at least one valve arranged to selectively pump liquid between the liquid-containing region and the hot liquid reservoir, and between the liquid-containing region and the cold liquid reservoir.

1 . Drum intermediate transfer member or fuser apparatus, for use in a printer or copier, comprising: 
 a drum having a drum surface and including a liquid-containing region in the interior of the drum thermally connected to the drum surface, such that the liquid is capable of heating and cooling the drum surface;    a liquid transfer system including a hot liquid reservoir, a cold liquid reservoir, at least one pump, pipes and optionally at least one valve arranged to selectively pump liquid between the liquid-containing region and the hot liquid reservoir, and between the liquid-containing region and the cold liquid reservoir; and    including one or both of: 
 an accumulator in the hot liquid reservoir which allows the volume of liquid in the hot liquid reservoir to change substantially without a commensurate change in liquid pressure: and  
 an accumulator in the cold liquid reservoir which allows the volume of liquid in the cold liquid reservoir to change substantially without a commensurate change in liquid pressure.  
   
     
     
         2 . Apparatus according to  claim 1  wherein the liquid-containing region and the liquid transfer system are sealed from the outside, and are substantially free of gas.  
     
     
         3 . Apparatus according to  claim 1  wherein the liquid-containing region does not rotate when the drum rotates.  
     
     
         4 . Apparatus according to  claim 1  and comprising at least one rotating seal used to transfer liquid into and out of the liquid-containing region.  
     
     
         5 . Apparatus according to  claim 1  wherein the optional at least one valve comprises a three-way valve and including an outlet pipe connecting the liquid-containing region directly or indirectly to the three-way valve, controllable to direct liquid leaving the liquid-containing region into either the hot liquid reservoir or the cold liquid reservoir.  
     
     
         6 . Apparatus according to  claim 1  wherein the optional valve comprises a three-way valve and including an input pipe connecting the liquid-containing region directly or indirectly to a three-way valve, controllable to direct liquid from either the hot liquid reservoir or the cold liquid reservoir into the liquid-containing region.  
     
     
         7 . Apparatus according to  claim 1  and including a heating element in the hot liquid reservoir.  
     
     
         8 . (Cancelled)  
     
     
         9 . Apparatus according to  claim 7  and including a temperature sensor in the hot liquid reservoir.  
     
     
         10 . Apparatus according to  claim 9  wherein the temperature in the hot liquid reservoir is maintained in a certain range by using feedback from the temperature sensor to control the heating element.  
     
     
         11 . Apparatus according to any of the preceding claims  claim 1  and including a refrigerating element in the cold liquid reservoir.  
     
     
         12 . (Cancelled)  
     
     
         13 . Apparatus according to  claim 11  and including a temperature sensor in the cold liquid reservoir.  
     
     
         14 . Apparatus according to  claim 13  wherein the temperature in the cold liquid reservoir is maintained in a given range by using feedback from the temperature sensor to control the refrigerating element.  
     
     
         15 . Apparatus according to  claim 1  and including an accumulator in the hot liquid reservoir which allows the volume of liquid in the hot liquid reservoir to change substantially without a commensurate change in liquid pressure.  
     
     
         16 . Apparatus according to  claim 1  and including an accumulator in the cold liquid reservoir which allows the volume of liquid in the cold liquid reservoir to change substantially without a commensurate change in liquid pressure.  
     
     
         17 . Apparatus according to  claim 15  and including an accumulator in the cold liquid reservoir which allows the volume of liquid in the cold liquid reservoir to change substantially without a commensurate change in liquid pressure.  
     
     
         18 . Apparatus according to  claim 17  wherein the accumulator in the hot liquid reservoir is linked to the accumulator in the cold liquid reservoir, so that when one reservoir increases in volume, the other reservoir decreases in volume by the same amount.  
     
     
         19 . Apparatus according to  claim 18  wherein the accumulators comprise a movable sealed barrier between the hot liquid reservoir and the cold liquid reservoir.  
     
     
         20 . Apparatus according to  claim 1  and including an accumulator in the liquid-containing region which allows the volume of liquid in the liquid-containing region to change substantially without a commensurate change in liquid pressure.  
     
     
         21 . (Cancelled)  
     
     
         22 . Apparatus according to  claim 1  wherein the liquid-filled region is largely drained of liquid of one temperature, before it is filled with liquid of a different temperature.  
     
     
         23 . Apparatus according to  claim 1  wherein the liquid-containing region heats and cools the surface of the drum indirectly through a separate thin region which also contains liquid.  
     
     
         24 . Apparatus according to  claim 56  wherein the liquid in the thin region is volatile and increases the gas pressure in the thin region when the liquid therein is heated.  
     
     
         25 . Apparatus according to  claim 56  wherein different liquids are used in the liquid-containing region and in the thin region.  
     
     
         26 . Apparatus according to  claim 1  wherein the liquid in the liquid-containing region has low volatility in the operating range of temperature.  
     
     
         27 . (Cancelled)  
     
     
         28 . Apparatus according to  claim 56  wherein the liquid in the thin region is volatile and increases the gas pressure in the thin region when the liquid therein is heated.  
     
     
         29 - 31 . (Cancelled)  
     
     
         32 . Apparatus according to  claim 56  and including a pressure sensor in the thin region.  
     
     
         33 . (Cancelled)  
     
     
         34 . Apparatus according to  claim 1  and including a pressure sensor in the liquid-containing region or in the liquid transfer system, and including a controller that controls one or more of said at least one pump and at least one valve, wherein the controller causes hot liquid to flow out of the liquid-containing region and/or causes cold liquid to flow into the liquid-containing region, if the pressure in the liquid-containing region or in the liquid transfer system rises higher than a given value.  
     
     
         35 . Apparatus according to  claim 56  and including an overflow valve in the liquid-containing region or in the liquid transfer system, wherein the valve opens and relieves the pressure in the liquid-containing region or in the thin region, if the pressure rises higher than a given value.  
     
     
         36 . Apparatus according to  claim 1 , and including an overflow valve in the liquid transfer system or the liquid-containing region that allows excess liquid to leave the liquid transfer system or the liquid-containing region.  
     
     
         37 . Apparatus according to  claim 57  wherein the overflow valve is forced open mechanically when the liquid pressure rises higher than a given value.  
     
     
         38 . Apparatus according to  claim 1 , and including a pressure sensor in the liquid-containing region or in the liquid transfer system.  
     
     
         39 . (Cancelled)  
     
     
         40 . Apparatus according to  claim 57 , and including an overflow reservoir, wherein excess liquid that flows through the overflow valve enters the overflow reservoir, and liquid can flow from the overflow reservoir into the liquid transfer system or the liquid-containing region when the pressure falls below a given value.  
     
     
         41 - 42 . (Cancelled)  
     
     
         43 . Apparatus according to  claim 56 , wherein at least part of the boundary between the liquid-containing region and the thin region is flexible, so that an increase in pressure in the thin region will lead to an increase in pressure in the liquid-containing region.  
     
     
         44 - 46 . (Cancelled)  
     
     
         47 . Apparatus according to  claim 36  wherein the overflow valve is forced open mechanically when the liquid pressure rises higher than a given value.  
     
     
         48 - 49 . (Cancelled)  
     
     
         50 . Apparatus according to  claim 34 , wherein the controller receives data from the pressure sensor and opens the overflow valve when the pressure rises higher than a given value.  
     
     
         51 . Apparatus according to  claim 34 , and including an overflow reservoir, wherein excess liquid that flows through the overflow valve enters the overflow reservoir, and liquid can flow from the overflow reservoir into the liquid transfer system or the liquid-containing region when the pressure falls below a given value.  
     
     
         52 . Apparatus according to  claim 1 , and including a controller that controls one or more of said at least one pump and said at least one valve, thereby to control selective pumping.  
     
     
         53 . Apparatus according to  claim 1 , and including a bleed valve for removing unwanted gas from the apparatus.  
     
     
         54 . Apparatus according to  claim 1 , and including a shut-off valve closable to prevent liquid from flowing into the liquid-containing region.  
     
     
         55 . Drum intermediate transfer member or fuser apparatus, for use in a printer or copier, comprising: 
 a drum having a drum surface and including a liquid-containing region in the interior of the drum thermally connected to the drum surface, such that the liquid is capable of heating and cooling the drum surface; and    a liquid transfer system including a hot liquid reservoir, a cold liquid reservoir, at least one pump, pipes and optionally at least one valve arranged to selectively pump liquid between the liquid-containing region and the hot liquid reservoir, and between the liquid-containing region and the cold liquid reservoir,    wherein the liquid-filled region is largely drained of liquid of one temperature, before it is filled with liquid of a different temperature.    
     
     
         56 . Drum intermediate transfer member or fuser apparatus, for use in a printer or copier, comprising: 
 a drum having a drum surface and including a liquid-containing region in the interior of the drum thermally connected to the drum surface, such that the liquid is capable of heating and cooling the drum surface; and    a liquid transfer system including a hot liquid reservoir, a cold liquid reservoir, at least one pump, pipes and optionally at least one valve arranged to selectively pump liquid between the liquid-containing region and the hot liquid reservoir, and between the liquid-containing region and the cold liquid reservoir;    wherein the liquid-containing region heats and cools the surface of the drum indirectly through a separate thin region which also contains liquid.    
     
     
         57 . Drum intermediate transfer member or fuser apparatus, for use in a printer or copier, comprising: 
 a drum having a drum surface and including a liquid-containing region in the interior of the drum thermally connected to the drum surface, such that the liquid is capable of heating and cooling the drum surface;    a liquid transfer system including a hot liquid reservoir, a cold liquid reservoir, at least one pump, pipes and optionally at least one valve arranged to selectively pump liquid between the liquid-containing region and the hot liquid reservoir, and between the liquid-containing region and the cold liquid reservoir; and    an overflow valve in the liquid-containing region or in the liquid transfer system, wherein the valve opens and relieves the pressure in the liquid-containing region, transferring excess liquid outside the liquid containing region and the liquid transfer system.    
     
     
         58 . Drum intermediate transfer member or fuser apparatus, for use in a printer or copier, comprising: 
 a drum having a drum surface and including a liquid-containing region in the interior of the drum thermally connected to the drum surface, such that the liquid is capable of heating and cooling the drum surface;    a liquid transfer system including a hot liquid reservoir, a cold liquid reservoir, at least one pump, pipes and optionally at least one valve arranged to selectively pump liquid between the liquid-containing region and the hot liquid reservoir, and between the liquid-containing region and the cold liquid reservoir;    a pressure sensor in the liquid-containing region or in the liquid transfer system; and    a controller that controls said at least one pump, wherein the controller causes hot liquid to flow out of the liquid-containing region and/or causes cold liquid to flow into the liquid-containing region, if the pressure in the liquid-containing region or in the liquid transfer system, measured by the pressure sensor, rises higher than a given value.