Image forming apparatus and feeding apparatus

Abstract

A feeding apparatus includes a feeding member to feed a recording material stacked on a stacking portion, a first conveyance member, a separation member to form a nip portion with the first conveyance member and separate a plurality of recording materials at the nip portion, a second conveyance member, a detection unit, and a control unit. The control unit controls to feed a stacked first recording material and, after a first recording material rear end passes through the feeding member, the control unit controls to feed a stacked second recording material while partially overlapped with the first recording material and thereby the first recording material rear end passes through the nip portion after a second recording material leading end passes through the nip portion. The control unit controls so that the second recording material is stopped before the second recording material leading end reaches the second conveyance member.

What is claimed is: 
     
         1 . A feeding apparatus comprising:
 a feeding member configured to feed a recording material stacked on a stacking portion;   a first conveyance member configured to convey the recording material fed by the feeding member;   a separation member configured to form a nip portion with the first conveyance member and separate a plurality of recording materials at the nip portion;   a second conveyance member configured to convey the recording material conveyed by the first conveyance member;   a detection unit configured to be disposed between the first conveyance member and the second conveyance member and to detect the recording material; and   a control unit configured to control the feeding member and the first conveyance member so that a first recording material that is stacked on the stacking portion is fed by the feeding member and, after a rear end of the first recording material passes through the feeding member, a second recording material that is stacked on the stacking portion is fed by the feeding member while being partially overlapped with the first recording material and thereby the rear end of the first recording material passes through the nip portion after a leading end of the second recording material passes through the nip portion, and control the feeding member and the first conveyance member so that the second recording material is stopped before the leading end of the second recording material reaches the second conveyance member,   wherein, after the first recording material is conveyed by the second conveyance member and the first recording material and the second recording material that are partially overlapped are separated from each other, the control unit changes a feeding condition for the feeding member and the first conveyance member to feed the stopped second recording material in accordance with a detection result of the second recording material by the detection unit.   
     
     
         2 . The feeding apparatus according to  claim 1 , wherein a timing at which feeding of the second recording material is started is the feeding condition and the control unit changes the timing at which feeding of the second recording material is started. 
     
     
         3 . The feeding apparatus according to  claim 2 , wherein the control unit starts the feeding of the second recording material at a predetermined timing in a case where the detection unit detects the second recording material, and starts the feeding of the second recording material at a timing earlier than the predetermined timing in a case where the detection unit does not detect the second recording material. 
     
     
         4 . The feeding apparatus according to  claim 1 , wherein a feeding speed of the second recording material is the feeding condition and the control unit changes the feeding speed of the second recording material. 
     
     
         5 . The feeding apparatus according to  claim 4 , wherein the control unit feeds the second recording material at a predetermined speed in a case where the detection unit detects the second recording material, and feeds the second recording material at a speed faster than the predetermined speed in a case where the detection unit does not detect the second recording material. 
     
     
         6 . The feeding apparatus according to  claim 1 , further comprising:
 a motor configured to drive the feeding member, the first conveyance member, and the second conveyance member; and   an electromagnetic clutch configured to transmit or intercept driving force from the motor with respect to the feeding member and the first conveyance member.   
     
     
         7 . The feeding apparatus according to  claim 1 , further comprising:
 a first motor configured to drive the feeding member and the first conveyance member; and   a second motor configured to drive the second conveyance member.   
     
     
         8 . The feeding apparatus according to  claim 1 ,
 wherein the detection unit includes a sensor arm configured to rotate by being in contact with a recording material that is conveyed and includes an encoder configured to detect a rotation angle of the sensor arm, and   wherein the control unit obtains a position of the leading end of the stopped second recording material from the rotation angle of the sensor arm, which is detected by the encoder, and changes the feeding condition in accordance with the position of the leading end of the second recording material.   
     
     
         9 . The feeding apparatus according to  claim 1 ,
 wherein the detection unit includes a transmission unit configured to transmit an ultrasonic wave and includes a reception unit configured to receive the ultrasonic wave that is transmitted by the transmission unit and passes through plural recording materials,   wherein the detection unit is configured to detect, based on the ultrasonic wave received by the reception unit, a timing at which the leading end of the second recording material that is conveyed while being partially overlapped with the first recording material passes through the detection unit, and   wherein the control unit is configured to obtain a position of the leading end of the second recording material from the timing at which the leading end of the second recording material passes through the detection unit, and to change the feeding condition in accordance with the position of the leading end of the second recording material.   
     
     
         10 . The feeding apparatus according to  claim 1 ,
 wherein, in a case where the first recording material is fed to the nip portion by the feeding member, the separation member rotates in a predetermined direction to feed the first recording material,   wherein, in a case where the second recording material is fed to the nip portion by the feeding member while the first recording material is held by the nip portion, the separation member rotates in the predetermined direction to feed the second recording material, and   wherein, in a case where a third recording material that is stacked on the stacking portion is fed while the first recording material and the second recording material are held by the nip portion, the separation member stops rotating or rotates in a direction opposite to the predetermined direction to prevent the third recording material from being fed.   
     
     
         11 . The feeding apparatus according to  claim 1 , wherein, in a case where the first recording material is fed, the control unit stops drive of the feeding member before the rear end of the first recording material passes through the feeding member after a leading end of the first recording material reaches the second conveyance member and, after the rear end of the first recording material that is conveyed by the second conveyance member passes through the feeding member, drives the feeding member again to feed the second recording material by the feeding member while being partially overlapped with the first recording member. 
     
     
         12 . The feeding apparatus according to  claim 1 , wherein, in a case where the first recording material is fed, the control unit continuously drives the feeding member without stopping the drive of the feeding member before the rear end of the first recording material passes through the feeding member after a leading end of the first recording material reaches the second conveyance member, and feeds the second recording material by the feeding member while being partially overlapped with the first recording material, after the rear end of the first recording material passes through the feeding member. 
     
     
         13 . An image forming apparatus comprising:
 a feeding member configured to feed a recording material stacked on a stacking portion,   a first conveyance member configured to convey the recording material fed by the feeding member,   a separation member configured to form a nip portion with the first conveyance member and separate a plurality of recording materials at the nip portion,   a second conveyance member configured to convey the recording material conveyed by the first conveyance member,   an image forming unit configured to form an image on the recording material conveyed by the second conveyance member,   a detection unit configured to be disposed between the first conveyance member and the second conveyance member and to detect the recording material, and   a control unit configured to control the feeding member and the first conveyance member so that a first recording material that is stacked on the stacking portion is fed by the feeding member and, after a rear end of the first recording material passes through the feeding member, a second recording material that is stacked on the stacking portion is fed by the feeding member while being partially overlapped with the first recording material and thereby the rear end of the first recording material passes through the nip portion after a leading end of the second recording material passes through the nip portion, and control the feeding member and the first conveyance member so that the second recording material is stopped before the leading end of the second recording material reaches the second conveyance member,   wherein, after the first recording material is conveyed by the second conveyance member and the first recording material and the second recording material that are partially overlapped are separated from each other, the control unit changes a feeding condition for the feeding member and the first conveyance member to feed the stopped second recording material in accordance with a detection result of the second recording material by the detection unit.   
     
     
         14 . A method for a feeding apparatus having a feeding member configured to feed a recording material stacked on a stacking portion, a first conveyance member configured to convey the recording material fed by the feeding member, a separation member configured to form a nip portion with the first conveyance member and separate a plurality of recording materials at the nip portion, a second conveyance member configured to convey the recording material conveyed by the first conveyance member, and a detection unit configured to be disposed between the first conveyance member and the second conveyance member and to detect the recording material, the method comprising:
 controlling the feeding member and the first conveyance member so that a first recording material that is stacked on the stacking portion is fed by the feeding member;   feeding, by the feeding member, while being partially overlapped with the first recording material and after a rear end of the first recording material passes through the feeding member, a second recording material that is stacked on the stacking portion to be fed such that the rear end of the first recording material passes through the nip portion after a leading end of the second recording material passes through the nip portion;   controlling the feeding member and the first conveyance member so that the second recording material is stopped before the leading end of the second recording material reaches the second conveyance member; and   changing, after the first recording material is conveyed by the second conveyance member and the first recording material and the second recording material that are partially overlapped are separated from each other, a feeding condition for the feeding member and the first conveyance member to feed the stopped second recording material in accordance with a detection result of the second recording material by the detection unit.   
     
     
         15 . A non-transitory computer-readable storage medium storing a program causing a feeding apparatus to perform the method according to  claim 14 .