Paper feeder and image forming system

Abstract

A paper feeder sucking and feeding a paper sheet from a stack of paper sheets loaded on a paper table, the paper feeder includes: a pair of blowing ports that are disposed across a stack of paper sheets and blow air toward a side surface of the stack of paper sheets to float a paper sheet; and a hardware processor that performs blowing control of blowing air to float a paper sheet in a first operation mode in which a height of one blowing ports is different from a height of another blowing ports.

What is claimed is: 
     
         1 . A paper feeder sucking and feeding a paper sheet from a stack of paper sheets loaded on a paper table, the paper feeder comprising:
 a pair of blowing ports that are disposed across a stack of paper sheets and blow air toward a side surface of the stack of paper sheets to float a paper sheet; and   a hardware processor that performs blowing control of blowing air to float a paper sheet in a first operation mode in which a height of one blowing ports is different from a height of another blowing ports.   
     
     
         2 . A paper feeder sucking and feeding a paper sheet from a stack of paper sheets loaded on a paper table, the paper feeder comprising:
 a pair of blowing ports that are disposed across a stack of paper sheets and blow air toward a side surface of the stack of paper sheets to float a paper sheet;   a sheet holder that abuts on a floated paper sheet from above to regulate a floating height of the paper sheet; and   a hardware processor that performs blowing control of blowing air to float a paper sheet in a second operation mode in which a height of the at least one sheet holder corresponding to one side surface of a stack of paper sheets is different from a height of the at least one sheet holder corresponding to another side surface of the stack of paper sheets.   
     
     
         3 . A paper feeder sucking and feeding a paper sheet from a stack of paper sheets loaded on a paper table, the paper feeder comprising:
 a pair of blowing ports that are disposed across a stack of paper sheets and blow air toward a side surface of the stack of paper sheets to float a paper sheet; and   a hardware processor that performs blowing control of blowing air to float a paper sheet in a third operation mode in which an amount of air blown from one blowing port is different from an amount of air blown from another blowing port.   
     
     
         4 . The paper feeder according to  claim 1 , further comprising
 a sheet holder that abuts on a floated paper sheet from above to regulate a floating height of the paper sheet,   wherein the hardware processor performs the blowing control in a second operation mode in which a height of the at least one sheet holder corresponding to one side surface of a stack of paper sheets is different from a height of the at least one sheet holder corresponding to another side surface of the stack of paper sheets, in addition to the first operation mode.   
     
     
         5 . The paper feeder according to  claim 1 , wherein
 the hardware processor performs the blowing control in a third operation mode in which an amount of air blown from the one blowing port is different from an amount of air blown from the other blowing port, in addition to the first operation mode.   
     
     
         6 . The paper feeder according to  claim 2 , wherein
 the hardware processor performs the blowing control in a third operation mode in which an amount of air blown from the one blowing port is different from an amount of air blown from the other blowing ports, in addition to the second operation mode.   
     
     
         7 . The paper feeder according to  claim 1 , further comprising
 a sheet holder that abuts on a floated paper sheet from above to regulate a floating height of the paper sheet,   wherein the hardware processor performs the blowing control in a second operation mode in which a height of the at least one sheet holder corresponding to one side surface of a stack of paper sheets is different from a height of the at least one sheet holder corresponding to another side surface of the stack of paper sheets and a third operation mode in which an amount of air blown from one of the blowing ports is different from an amount of air blown from the other of the blowing ports, in addition to the first operation mode.   
     
     
         8 . The paper feeder according to  claim 1 , further comprising
 a duct that is connected to each of the blowing ports to guide air blown from a blower to the blowing port,   wherein the duct is movable in a vertical direction to adjust the height of the blowing port.   
     
     
         9 . The paper feeder according to  claim 8 , wherein
 the duct is movable in a vertical direction by a pressure of air.   
     
     
         10 . The paper feeder according to  claim 9 , further comprising
 a lock mechanism that regulates the movement of the duct to adjust the height of the blowing port.   
     
     
         11 . The paper feeder according to  claim 2 , wherein
 the at least one sheet holder is provided above the blowing ports.   
     
     
         12 . The paper feeder according to  claim 11 , further comprising
 a movable mechanism that adjusts the height of the at least one sheet holder.   
     
     
         13 . The paper feeder according to  claim 1 , wherein
 the hardware processor   further includes, as an operation mode in the blowing control, a normal operation mode in which the height of the one blowing port and the height of the other blowing port are aligned, and   switches, based on one or both of information on a paper sheet and a floating state of a paper sheet, between the normal operation mode and the first operation mode.   
     
     
         14 . The paper feeder according to  claim 13 , wherein
 in the first operation mode, the height of the one of the blowing ports or the height of the other of the blowing port is lower than that in the normal operation mode.   
     
     
         15 . The paper feeder according to  claim 2 , wherein
 the hardware processor   further includes, as an operation mode in the blowing control, a normal operation mode in which the height of the sheet holder corresponding to one side surface of a stack of paper sheets and the height of the sheet holder corresponding to another side surface of the stack of paper sheets are aligned, and   switches, based on one or both of information on a paper sheet and a floating state of a paper sheet, between the normal operation mode and the second operation mode.   
     
     
         16 . The paper feeder according to  claim 3 , wherein
 the hardware processor   further includes, as an operation mode in the blowing control, a normal operation mode in which the amount of air blown from the one blowing port is equal to the amount of air blown from the other blowing port, and   switches, based on one or both of information on a paper sheet and a floating state of a paper sheet, between the normal operation mode and the third operation mode.   
     
     
         17 . The paper feeder according to  claim 13 , wherein
 the hardware processor switches the operation modes on the basis of a time from floating of a paper sheet to suction of the paper sheet by a sheet suction portion positioned above a stack of paper sheets.   
     
     
         18 . The paper feeder according to  claim 5 , wherein
 when the amount of air blown from the one blowing port is different from the amount of air blown from the other blowing port, the hardware processor sets a height of the blowing port blowing a larger amount of air lower than a height of the blowing port blowing a smaller amount of air.   
     
     
         19 . The paper feeder according to  claim 6 , wherein
 when the amount of air blown from the one blowing port is different from the amount of air blown from the other blowing port, the hardware processor sets a height of the sheet holder blowing a smaller amount of air lower than a height of the sheet holder blowing a larger amount of air.   
     
     
         20 . An image forming system comprising:
 the paper feeder according to  claim 1 ; and   an image forming apparatus that forms an image on a paper sheet fed from the paper feeder.   
     
     
         21 . An image forming system comprising:
 a paper feeder that sucks and feeds a paper sheet from a stack of paper sheets loaded on a paper table;   an image forming apparatus that forms an image on a paper sheet fed from the paper feeder; and   a hardware processor that controls the paper feeder and the image forming apparatus;   wherein the paper feeder includes   a pair of blowing ports that are disposed across a stack of paper sheets and blow air toward a side surface of the stack of paper sheets to float a paper sheet, and   the hardware processor   performs blowing control of blowing air to float a paper sheet in a first operation mode in which a height of one blowing port is different from a height of another blowing port.   
     
     
         22 . An image forming system comprising:
 a paper feeder that sucks and feeds a paper sheet from a stack of paper sheets loaded on a paper table;   an image forming apparatus that forms an image on a paper sheet fed from the paper feeder; and   a hardware processor that controls the paper feeder and the image forming apparatus;   wherein the paper feeder includes:   a pair of blowing ports that are disposed across a stack of paper sheets and blow air toward a side surface of the stack of paper sheets to float a paper sheet, and;   a sheet holder that abuts on a floated paper sheet from above to regulate a floating height of the paper sheet, and   the hardware processor   performs blowing control of blowing air to float a paper sheet in a second operation mode in which a height of the at least one sheet holder corresponding to one side surface of a stack of paper sheets is different from a height of the at least one sheet holder corresponding to another side surface of the stack of paper sheets.   
     
     
         23 . An image forming system comprising:
 a paper feeder that sucks and feeds a paper sheet from a stack of paper sheets loaded on a paper table;   an image forming apparatus that forms an image on a paper sheet fed from the paper feeder; and   a hardware processor that controls the paper feeder and the image forming apparatus;   wherein the paper feeder includes   a pair of blowing ports that are disposed across a stack of paper sheets and blow air toward a side surface of the stack of paper sheets to float a paper sheet, and   the hardware processor   performs blowing control of blowing air to float a paper sheet in a third operation mode in which an amount of air blown from one blowing port is different from an amount of air blown from another blowing port.   
     
     
         24 . An image forming system comprising:
 the paper feeder according to  claim 2 ; and   an image forming apparatus that forms an image on a paper sheet fed from the paper feeder.   
     
     
         25 . An image forming system comprising:
 the paper feeder according to  claim 3 ; and   an image forming apparatus that forms an image on a paper sheet fed from the paper feeder.