Image forming apparatus and conveyance control method
An image forming apparatus includes: a transfer section that transfers an image onto a sheet; a sheet conveying member that conveys the sheet, the sheet conveying member being provided upstream of the transfer section in a sheet conveyance direction; and a hardware processor that controls displacement of the sheet conveying member so that the sheet is displaced along a width direction of the sheet. The hardware processor sets a displacement speed of the sheet conveying member for the sheet during transfer of the image by the transfer section to be lower than the displacement speed of the sheet conveying member for the sheet before the transfer of the image by the transfer section.
1. An image forming apparatus comprising:
a transferrer that transfers an image onto a sheet;
a sheet conveyer that conveys the sheet, the sheet conveyer being provided upstream of the transferrer in a sheet conveyance direction; and
a hardware processor that controls displacement of the sheet conveyer so that the sheet is displaced along a width direction of the sheet,
wherein the hardware processor sets a displacement speed of the sheet conveyer for the sheet during transfer of the image by the transferrer to be lower than the displacement speed of the sheet conveyer for the sheet before the transfer of the image by the transferrer, the sheet conveyor moving along the width direction of the sheet at the displacement speed during the transfer of the image by the transferrer.
2. The image forming apparatus according to claim 1 , wherein the hardware processor sets the displacement speed of the sheet conveyer to be lower than a sheet conveyance speed in the transferrer.
3. The image forming apparatus according to claim 2 , wherein the hardware processor sets the displacement speed of the sheet conveyer to be higher than a speed of deviation of the sheet in the width direction.
4. The image forming apparatus according to claim 1 , wherein the hardware processor causes a drive source that transmits a drive force for the displacement to the sheet conveyer to operate at a self-excitation frequency.
5. The image forming apparatus according to claim 1 , wherein the hardware processor sets a speed of return operation to return the sheet conveyer to an initial position to be higher than the displacement speed during the transfer of the image.
6. The image forming apparatus according to claim 1 , wherein where the sheet conveyer is displaced a plurality of times for the sheet, the hardware processor sets the displacement speed during the transfer of the image for each displacement.
7. The image forming apparatus according to claim 6 , wherein the hardware processor sets different displacement speeds for each of the plurality of times the sheet conveyor is displaced.
8. The image forming apparatus according to claim 7 , wherein the hardware processor sets the displacement speed to be lower on a more downstream side in the conveyance direction of the sheet.
9. The image forming apparatus according to claim 1 , wherein the hardware processor controls the displacement of the sheet conveyer, using a table in which a value of the displacement speed is registered.
10. The image forming apparatus according to claim 9 , wherein the table is provided corresponding to a type of sheet.
11. The image forming apparatus according to claim 9 , wherein the table is provided corresponding to a temperature and humidity around the image forming apparatus.
12. The image forming apparatus according to claim 9 , wherein the table is provided for each of a front side and a back side of the sheet.
13. The image forming apparatus according to claim 9 , wherein the table is provided corresponding to a sheet feed tray.
14. The image forming apparatus according to claim 1 , wherein the hardware processor changes the displacement speed according to a displacement amount of the sheet conveyer.
15. The image forming apparatus according to claim 1 , comprising a user setter that allows setting the displacement speed during the transfer of the image.
16. The image forming apparatus according to claim 1 , wherein the hardware processor changes the displacement speed during the transfer of the image for a next sheet, according to a result of reading the image on the sheet.
17. The image forming apparatus according to claim 1 , wherein the hardware processor changes the displacement speed during the transfer of the image, according to a result of detection by a loop detector that detects an amount of a loop of the sheet in a loop forming space between the transferrer and the sheet conveyer.
18. The image forming apparatus according to claim 1 , wherein the hardware processor controls the displacement of the sheet conveyer so as to eliminate deviation from a target position, and performs one displacement operation of the sheet conveyer for the sheet during the transfer of the image by the transferrer with a displacement amount that is equal to or below a predetermined displacement amount threshold value so as to prevent transfer deviation of the image.
19. The image forming apparatus according to claim 18 , wherein the hardware processor causes the sheet conveyer to be displaced a plurality of times for the sheet, and if a cumulative value of displacement amount exceeds the threshold value, stops the displacement of the sheet conveyer for the sheet.
20. A conveyance control method for an image forming apparatus including a transferrer that transfers an image onto a sheet and a sheet conveyer that conveys the sheet, the sheet conveyer being provided upstream of the transferrer in a sheet conveyance direction, the sheet conveyer being displaced so that the sheet is displaced along a width direction of the sheet, the method comprising:
setting a displacement speed of the sheet conveyer for the sheet during transfer of the image by the transferrer to be lower than the displacement speed of the sheet conveyer for the sheet before the transfer of the image by the transferrer, the sheet conveyor moving along the width direction of the sheet at the displacement speed during the transfer of the image by the transferrer.