Image forming apparatus and method for conveying recording material

Abstract

The present invention provides an image forming apparatus including an image forming unit configured to form an image on a sheet, a conveying path along which the sheet is conveyed to the image forming unit, a sensor configured to detect the width of the sheet in a direction perpendicular to a conveying direction, and a control unit configured to determine a conveying state of the sheet in the direction perpendicular to the conveying direction according to an output of the sensor, and configured to control a conveyance interval of the sheet according to the determination result. The control unit sets the conveyance interval according to the width of the specified sheet and the width detectable by the sensor, regardless of the determination result.

1 . An image forming apparatus comprising:
 an image forming unit configured to form an image on a recording material;   a conveying path along which the recording material is conveyed to the image forming unit;   a sensor provided in the conveying path, the sensor being configured to detect the width of the recording material in a direction perpendicular to a conveying direction; and   a control unit configured to determine a conveying state of the recording material in the direction perpendicular to the conveying direction according to an output of the sensor, and configured to control a conveyance interval of the recording material according to the determination result,   wherein the control unit sets the conveyance interval regardless of the determination result, according to the width of the specified recording material and the width detectable by the sensor.   
     
     
         2 . The image forming apparatus according to  claim 1 ,
 wherein the control unit sets the conveyance interval if the difference between the width of the specified recording material and the width detectable by the sensor is equal to or smaller than a predetermined value, regardless of the determination result.   
     
     
         3 . The image forming apparatus according to  claim 2 ,
 wherein the control unit sets the conveyance interval to a first conveyance interval if the sensor detects the recording material and if the width of the specified recording material is larger than a predetermined width.   
     
     
         4 . The image forming apparatus according to  claim 3 ,
 wherein the control unit sets the conveyance interval to a second conveyance interval that is larger than the first conveyance interval when the sensor does not detect the recording material and when the width of the specified recording material is smaller than a predetermined width.   
     
     
         5 . The image forming apparatus according to  claim 2 ,
 wherein the control unit sets the conveyance interval to a third conveyance interval that is larger than the second conveyance interval if the sensor detects the recording material and if the width of the specified recording material is smaller than a predetermined width.   
     
     
         6 . The image forming apparatus according to  claim 1 ,
 wherein the sensor is provided at a predetermined distance away from the center of the width serving as a reference.   
     
     
         7 . The image forming apparatus according to  claim 1 , further comprising a plurality of the sensors,
 wherein the control unit sets the conveyance interval to a predetermined conveyance interval according to the width of the specified recording material and the width detectable by the plurality of sensors, regardless of the determination result.   
     
     
         8 . The image forming apparatus according to  claim 7 ,
 wherein the control unit sets the conveyance interval to the predetermined conveyance interval if the difference between the width of the specified recording material and the width detectable by the plurality of sensors is equal to or smaller than a predetermined value, regardless of the determination result.   
     
     
         9 . The image forming apparatus according to  claim 1 , further comprising a measuring unit configured to measure the length of the recording material in the conveying direction,
 wherein the control unit selects whether or not the conveyance interval is set using the determination result, according to the length of the recording material in the conveying direction measured by the measuring unit.   
     
     
         10 . A method for conveying a recording material in an image forming apparatus, the method comprising:
 determining a conveying state of a recording material by detecting the width of the recording material in a direction perpendicular to a conveying direction with a sensor;   setting a conveyance interval of the recording material according to the determined conveying state of the recording material; and   setting the conveyance interval according to the width of the specified recording material and the width detectable by the sensor, regardless of the determination.   
     
     
         11 . The method according to  claim 10 ,
 wherein the conveyance interval is set regardless of the determination, if the difference between the width of the specified recording material and the width detectable by the sensor is equal to or smaller than a predetermined value.   
     
     
         12 . The method according to  claim 11 ,
 wherein the conveyance interval is set to a first conveyance interval if the sensor detects the recording material and if the width of the specified recording material is larger than a predetermined width.   
     
     
         13 . The method according to  claim 12 ,
 wherein the conveyance interval is set to a second conveyance interval that is larger than the first conveyance interval when the sensor does not detect the recording material and when the width of the specified recording material is smaller than a predetermined width.   
     
     
         14 . The method according to  claim 12 ,
 wherein the conveyance interval is set to a third conveyance interval that is larger than the second conveyance interval, if the sensor detects the recording material and if the width of the specified recording material is smaller than a predetermined width.   
     
     
         15 . The method according to  claim 10 ,
 wherein whether or not the conveyance interval is set using the determination result is selected according to the length of the recording material in the conveying direction measured by a measuring unit.