Medium conveyance device, control method, and control program

Abstract

A medium conveying apparatus includes a loading tray to place media, a feed roller to separate and sequentially feed the media placed on the loading tray, a motor to drive the feed roller, a sensor located on a downstream side of the feed roller in a medium conveying direction to detect a medium, and a processor to control the motor. In a separation period from a start of medium feeding by the feed roller to detection of a front edge of the first medium by the sensor, when feeding a first medium of a plurality of media placed on the loading tray, the processor controls the motor to rotate the feed roller at a constant speed, and when feeding a second or subsequent medium, the processor controls the motor to rotate the feed roller at a first speed and then at a second speed higher than the first speed.

What is claimed is: 
     
         1 . A medium conveying apparatus comprising:
 a loading tray on which one or more media are to be placed;   a feed roller to separate and sequentially feed the one or more media placed on the loading tray;   a motor to drive the feed roller;   a sensor located downstream of the feed roller in a medium conveying direction to detect a medium; and   a processor to
 when feeding a first medium of one or more media placed on the loading tray, control the motor to rotate the feed roller at a first speed after the start of medium feeding by the feed roller and before the detection of a front edge of the first medium by the sensor, and rotate the feed roller at a second speed higher than the first speed after the detection of the front edge of the first medium by the sensor, and 
 when feeding a second or subsequent medium, control the motor to rotate the feed roller at a third speed higher than the first speed and lower than the second speed after the start of medium feeding by the feed roller and before the detection of the front edge of the second or subsequent medium by the sensor, and rotate the feed roller at the second speed after the detection of the front edge of the second or subsequent medium by the sensor. 
   
     
     
         2 . The medium conveying apparatus according to  claim 1 , wherein the second speed is set to different speed according to a conveyance mode set for the medium conveying apparatus. 
     
     
         3 . The medium conveying apparatus according to  claim 1 , wherein the first speed is set to the same speed regardless of a conveyance mode set for the medium conveying apparatus. 
     
     
         4 . The medium conveying apparatus according to  claim 1 , further comprising a separation roller located to face the feed roller, wherein
 a speed of the separation roller is set to the same speed regardless of a conveyance mode set for the medium conveying apparatus.   
     
     
         5 . The medium conveying apparatus according to  claim 4 , wherein
 the second speed when the conveyance mode is set to a first mode is higher than the second speed when the conveyance mode is set to a second mode, and wherein   a rotation speed of the separation roller when the conveyance mode is set to the first mode is higher than a rotation speed of the separation roller when the conveyance mode is set to the second mode.   
     
     
         6 . The medium conveying apparatus according to  claim 1 , wherein the processor controls the motor to rotate the feed roller at a fourth speed higher than the third speed and lower than the second speed before rotating the feed roller at the second speed when feeding the second or subsequent medium. 
     
     
         7 . The medium conveying apparatus according to  claim 1 , wherein
 the processor acquires a size of a medium, and wherein   the processor, when feeding the second or subsequent medium, controls the motor to rotate the feed roller at a fourth speed higher than the third speed and lower than the second speed before rotating the feed roller at the second speed when the size of a preceding medium is less than or equal to a size threshold value.   
     
     
         8 . The medium conveying apparatus according to  claim 7 , wherein the processor, when feeding the second or subsequent medium, controls the motor to rotate the feed roller at a fifth speed higher than the fourth speed and lower than the second speed before rotating the feed roller at the second speed when the size of the preceding medium is greater than the size threshold value. 
     
     
         9 . The medium conveying apparatus according to  claim 1 , further comprising an ejection roller to eject the media, wherein
 the processor acquires a size of a medium, and wherein   the processor sets a rotation speed of the ejection roller when the size of the medium is greater than a first size threshold value to a speed lower than the rotation speed of the ejection roller when the size of the medium is less than or equal to the first size threshold value.   
     
     
         10 . The medium conveying apparatus according to  claim 1 , further comprising an ejection roller to eject the media, wherein
 the processor acquires a size of a medium, and wherein   the processor sets a rotation speed of the ejection roller when the size of the medium is less than a second size threshold value to a speed lower than the rotation speed of the ejection roller when the size of the medium is less than or equal to the second size threshold value.   
     
     
         11 . The medium conveying apparatus according to  claim 1 , wherein
 the processor acquires a size of a medium, and wherein   the processor delays a timing of increasing a rotation speed of the feed roller when the size of a preceding medium is greater than a first size threshold value relative to a timing of increasing the rotation speed of the feed roller when the size of the preceding medium is less than or equal to the first size threshold value.   
     
     
         12 . The medium conveying apparatus according to  claim 1 , further comprising a conveyance roller to convey the media fed by the feed roller, wherein
 the processor acquires a size of a medium, wherein   the processor stops the feed roller when a front edge of the medium passes the conveyance roller and resumes feeding by the feed roller after a rear edge of the medium passes a predetermined position, and wherein   the processor delays a resumption timing of feeding by the feed roller when the size of a medium of which a rear edge has passed the predetermined position or a medium preceding said medium is greater than a first size threshold value relative to a resumption timing of feeding by the feed roller when the size of the medium of which the rear edge has passed the predetermined position or the medium preceding said medium is less than or equal to the first size threshold value.   
     
     
         13 . The medium conveying apparatus according to  claim 1 , wherein the processor controls the motor to rotate the feed roller again after stopping the feed roller during conveying a medium. 
     
     
         14 . A method for feeding a medium, the method comprising:
 separating and sequentially feeding one or more media placed on a loading tray by a feed roller;   driving the feed roller by a motor;   detecting a medium by a sensor located downstream of the feed roller in a medium conveying direction; and   controlling the motor, wherein   when feeding a first medium of one or more media placed on the loading tray, controlling the motor to rotate the feed roller at a first speed after the start of medium feeding by the feed roller and before the detection of a front edge of the first medium by the sensor, and rotate the feed roller at a second speed higher than the first speed after the detection of the front edge of the first medium by the sensor, and wherein   when feeding a second or subsequent medium, controlling the motor to rotate the feed roller at a third speed higher than the first speed and lower than the second speed after the start of medium feeding by the feed roller and before the detection of the front edge of the second or subsequent medium by the sensor, and rotate the feed roller at the second speed after the detection of the front edge of the second or subsequent medium by the sensor.   
     
     
         15 . The method according to  claim 14 , wherein the second speed is set to different speed according to a conveyance mode set for the medium conveying apparatus. 
     
     
         16 . The method according to  claim 14 , wherein the first speed is set to the same speed regardless of a conveyance mode set for the medium conveying apparatus. 
     
     
         17 . The method according to  claim 14 , wherein a speed of a separation roller located to face the feed roller is set to the same speed regardless of a conveyance mode set for the medium conveying apparatus. 
     
     
         18 . A computer-readable, non-transitory medium storing executable instructions for feeding a medium, the executable instructions comprising:
 controlling a motor to drive a feed roller to separate and sequentially feed one or more media placed on a loading tray, wherein   when feeding a first medium of one or more media placed on the loading tray, controlling the motor to rotate the feed roller at a first speed after the start of medium feeding by the feed roller and before the detection of a front edge of the first medium by a sensor located downstream of the feed roller in a medium conveying direction, and rotate the feed roller at a second speed higher than the first speed after the detection of the front edge of the first medium by the sensor, and wherein   when feeding a second or subsequent medium, controlling the motor to rotate the feed roller at a third speed higher than the first speed and lower than the second speed after the start of medium feeding by the feed roller and before the detection of the front edge of the second or subsequent medium by the sensor, and rotate the feed roller at the second speed after the detection of the front edge of the second or subsequent medium by the sensor.   
     
     
         19 . The computer-readable, non-transitory medium according to  claim 18 , wherein the second speed is set to different speed according to a conveyance mode set for the medium conveying apparatus. 
     
     
         20 . The computer-readable, non-transitory medium according to  claim 18 , wherein the first speed is set to the same speed regardless of a conveyance mode set for the medium conveying apparatus.