Medium feeding device and image forming apparatus

Abstract

A medium feeding device includes: multiple transporters each including a stacking unit on which a medium is stackable in a vertical direction, a feeder that feeds air to multiple media, each of which is the medium, stacked on the stacking unit to cause the multiple media to float and separate, a delivery unit that successively delivers the media floated and separated by the feeder, and a detector that detects a state of the medium floated and separated by the feeder; and at least one processor configured to: upon detection of a state of possibility of jam or multi feeding of the medium by the detector of one of the multiple transporters during transport, switch to another transporter at a predetermined timing to feed the medium; and upon detection of the state of possibility of jam or multi feeding of the medium by the detector, change an amount of air feed by the feeder of the one transporter before being switched.

What is claimed is: 
     
         1 . A medium feeding device comprising:
 a plurality of transporters each including a stacking unit on which a medium is stackable in a vertical direction, a feeder that feeds air to a plurality of media, each of which is the medium, stacked on the stacking unit to cause the plurality of media to float and separate, a delivery unit that successively delivers the media floated and separated by the feeder, and a detector that detects a state of the medium floated and separated by the feeder; and   at least one processor configured to:   upon detection of a state of possibility of jam or multi feeding of the medium by the detector of one of the plurality of transporters during transport, switch to another transporter at a predetermined timing to feed the medium; and   upon detection of the state of possibility of jam or multi feeding of the medium by the detector, change an amount of air feed by the feeder of the one transporter before being switched.   
     
     
         2 . The medium feeding device according to  claim 1 ,
 wherein the processor is configured to:   when there is another one of the plurality of transporters by which the medium is feedable, switch to the another transporter.   
     
     
         3 . The medium feeding device according to  claim 2 ,
 wherein the processor is configured to:   when there is no other transporter by which the medium is feedable, make preparations to enable another one of the plurality of transporters to feed the medium, and when the timing allows, switch to the another transporter after the preparations are completed; and   when the timing does not allow, continue to feed the medium from the original one transporter without switching to the another transporter.   
     
     
         4 . The medium feeding device according to  claim 2 ,
 wherein the processor is configured to:   when there is no other transporter by which the medium is feedable, make preparations to enable another one of the plurality of transporters to feed the medium, stop feeding of the medium from the one transporter before being switched until the preparations are completed, and start feeding of the medium from the another transporter to which the one transporter has been switched after the preparations are completed.   
     
     
         5 . The medium feeding device according to  claim 2 ,
 wherein the timing is:   after detection of a state of possibility of jam or multi feeding of the medium by the detector, through change of an amount of air feed by the feeder of the one transporter before being switched; and   after detection of a state of possibility of jam or multi feeding of the medium for a second time by the detector in the one transporter before being switched.   
     
     
         6 . The medium feeding device according to  claim 5 ,
 wherein the processor is configured to:   when a state of possibility of jam or multi feeding of the medium is not detected for a second time by the detector in the one transporter before being switched, feed the medium from the original one transporter without switching to the another transporter.   
     
     
         7 . The medium feeding device according to  claim 5 ,
 wherein the processor is configured to:   when a state of possibility of jam or multi feeding of the medium is detected for a second time by the detector in the one transporter before being switched, output information on possibility of jam or multi feeding of the medium to a notifier that notifies a user.   
     
     
         8 . The medium feeding device according to  claim 2 ,
 wherein the processor is configured to:   after switching to the another transporter to feed the medium,   continue air feed by the feeder in the original one transporter, and when a state of possibility of jam or multi feeding of the medium is not detected for a second time by the detector in the original one transporter, switch to the original one transporter to feed the medium.   
     
     
         9 . The medium feeding device according to  claim 1 ,
 wherein the detector includes an image capture unit that captures a floated and separated state of an end of the medium.   
     
     
         10 . The medium feeding device according to  claim 1 ,
 wherein the detector includes a photoelectronic sensor that detects a floated and separated state of an end of the medium with a light receiving unit that receives light from a projector.   
     
     
         11 . The medium feeding device according to  claim 1 ,
 wherein a condition to detect a state of possibility of jam or multi feeding of the medium by the detector is that a predetermined number or less of the plurality of media are floated.   
     
     
         12 . The medium feeding device according to  claim 1 ,
 wherein a condition to detect a state of possibility of jam or multi feeding of the medium by the detector is that a predetermined number or more of the plurality of media are not separated, and in a bundle state.   
     
     
         13 . An image forming apparatus comprising:
 the medium feeding device according to  claim 1 ; and   an image former that forms an image on the medium fed by the medium feeding device.   
     
     
         14 . An image forming apparatus comprising:
 the medium feeding device according to  claim 2 ; and   an image former that forms an image on the medium fed by the medium feeding device.   
     
     
         15 . An image forming apparatus comprising:
 the medium feeding device according to  claim 3 ; and   an image former that forms an image on the medium fed by the medium feeding device.   
     
     
         16 . An image forming apparatus comprising:
 the medium feeding device according to  claim 4 ; and   an image former that forms an image on the medium fed by the medium feeding device.   
     
     
         17 . An image forming apparatus comprising:
 the medium feeding device according to  claim 5 ; and   an image former that forms an image on the medium fed by the medium feeding device.   
     
     
         18 . An image forming apparatus comprising:
 the medium feeding device according to  claim 6 ; and   an image former that forms an image on the medium fed by the medium feeding device.   
     
     
         19 . An image forming apparatus comprising:
 the medium feeding device according to  claim 7 ; and   an image former that forms an image on the medium fed by the medium feeding device.   
     
     
         20 . An image forming apparatus comprising:
 the medium feeding device according to  claim 8 ; and   an image former that forms an image on the medium fed by the medium feeding device.