Sheet conveying device capable of acquiring conveying amount of uppermost sheet in stack of sheets by conveying member, image forming apparatus, and acquisition method

Abstract

A sheet conveying device includes a sheet supply portion, a first acquisition processing portion, a measurement processing portion, and a second acquisition processing portion. The sheet supply portion includes a conveying member which rotates while being in contact with an upper surface of a stack of sheets lifted by a lift portion, and supplies a sheet in contact with the conveying member. The first acquisition processing portion acquires speed information regarding a conveying speed of the sheet. The measurement processing portion measures an elapsed time from a start of supply of the sheet by the sheet supply portion to when the sheet is detected by a detection portion after the conveying member is rotated by a reference amount. The second acquisition processing portion acquires a conveying amount of the sheet when the conveying member is rotated by the reference amount based on the acquired speed information and the elapsed time.

1 . A sheet conveying device, comprising:
 a lift portion which lifts a stack of sheets;   a sheet supply portion which includes a conveying member which rotates while being in contact with an upper surface of the stack of sheets lifted by the lift portion, and supplies a sheet that comes into contact with the conveying member to a conveying path;   a detection portion which detects the sheet supplied by the sheet supply portion on the conveying path;   a first determination processing portion which determines, when the stack of sheets is lifted by the lift portion, whether or not an execution condition of measurement processing is satisfied, the measurement processing being processing of measuring an elapsed time from a start of supply of the sheet by the sheet supply portion to a time when the sheet is detected by the detection portion after the conveying member is rotated by a predetermined reference amount;   a first acquisition processing portion which acquires, when it is determined by the first determination processing portion that the execution condition is not satisfied, speed information related to a conveying speed of the sheet by the sheet supply portion using the detection portion;   a measurement processing portion which executes the measurement processing when it is determined by the first determination processing portion that the execution condition is satisfied; and   a second acquisition processing portion which acquires a conveying amount of the sheet when the conveying member is rotated by the reference amount based on an acquisition result obtained by the first acquisition processing portion and a measurement result obtained by the measurement processing.   
     
     
         2 . The sheet conveying device according to  claim 1 , comprising:
 a sheet storing portion which is detachably provided in a housing of the sheet conveying device and stores the stack of sheets, wherein   the lift portion is provided in the sheet storing portion, and   the first determination processing portion determines whether or not the execution condition is satisfied when the lift of the stack of sheets by the lift portion is a first lift after the sheet storing portion is attached to the housing.   
     
     
         3 . The sheet conveying device according to  claim 1 , wherein
 the first acquisition processing portion acquires the speed information at a time when the sheet is supplied for a first time after the stack of sheets is lifted by the lift portion, and   the measurement processing portion executes the measurement processing at the time when the sheet is supplied for the first time after the stack of sheets is lifted by the lift portion.   
     
     
         4 . The sheet conveying device according to  claim 1 , comprising:
 a bias portion which biases the conveying member toward the stack of sheets; and   an adjustment processing portion which adjusts a bias force of the bias portion based on an acquisition result obtained by the second acquisition processing portion.   
     
     
         5 . The sheet conveying device according to  claim 1 , comprising:
 a second determination processing portion which determines whether or not a maintenance timing for the conveying member has arrived based on an acquisition result obtained by the second acquisition processing portion.   
     
     
         6 . The sheet conveying device according to  claim 5 , wherein
 the first determination processing portion determines whether or not the execution condition is satisfied every time the stack of sheets is lifted by the lift portion,   the sheet conveying device comprises:   a setting processing portion which sets an initial conveying amount based on the acquisition result obtained by the second acquisition processing portion, and   the second determination processing portion determines whether or not the maintenance timing has arrived based on the conveying amount of the sheet when the conveying member is rotated by the reference amount, that is acquired after setting the initial conveying amount, and the initial conveying amount.   
     
     
         7 . The sheet conveying device according to  claim 6 , comprising:
 a change processing portion which changes the execution condition such that a frequency at which the execution condition is satisfied increases as a difference between the initial conveying amount and the conveying amount of the sheet acquired by the second acquisition processing portion increases.   
     
     
         8 . The sheet conveying device according to  claim 6 , comprising:
 a change processing portion which changes the execution condition such that a frequency at which the execution condition is satisfied increases as a cumulative number of the sheets supplied by the sheet supply portion increases.   
     
     
         9 . The sheet conveying device according to  claim 5 , comprising:
 a notification processing portion which, when it is determined by the second determination processing portion that the maintenance timing has arrived, notifies to that effect.   
     
     
         10 . The sheet conveying device according to  claim 1 , wherein
 the first determination processing portion determines whether or not the execution condition is satisfied every time the stack of sheets is lifted by the lift portion, and   the sheet conveying device comprises:   a setting processing portion which sets an initial elapsed time based on the measurement result obtained by the measurement processing;   a second determination processing portion which determines whether or not a maintenance timing for the conveying member has arrived based on the elapsed time measured after setting the initial elapsed time and the initial elapsed time; and   a notification processing portion which, when it is determined by the second determination processing portion that the maintenance timing has arrived, notifies to that effect.   
     
     
         11 . An image forming apparatus, comprising:
 the sheet conveying device according to  claim 1 ; and   an image forming portion which forms an image on the sheet conveyed by the sheet conveying device.   
     
     
         12 . An acquisition method executed in a sheet conveying device including a lift portion which lifts a stack of sheets, a sheet supply portion which includes a conveying member which rotates while being in contact with an upper surface of the stack of sheets lifted by the lift portion, and supplies a sheet that comes into contact with the conveying member to a conveying path, and a detection portion which detects the sheet supplied by the sheet supply portion on the conveying path, the acquisition method comprising:
 a first determination step of determining, when the stack of sheets is lifted by the lift portion, whether or not an execution condition of measurement processing is satisfied, the measurement processing being processing of measuring an elapsed time from a start of supply of the sheet by the sheet supply portion to a time when the sheet is detected by the detection portion after the conveying member is rotated by a predetermined reference amount;   a first acquisition step of acquiring, when it is determined in the first determination step that the execution condition is not satisfied, speed information related to a conveying speed of the sheet by the sheet supply portion using the detection portion;   a measurement step of executing the measurement processing when it is determined in the first determination step that the execution condition is satisfied; and   a second acquisition step of acquiring a conveying amount of the sheet when the conveying member is rotated by the reference amount based on an acquisition result obtained in the first acquisition step and a measurement result obtained by the measurement processing.