Patent ID: 9448521
Filing Date: 2016-09-20
CPC Classification: G03G

Claim Text:
1. An image forming apparatus in which a sheet conveyance speed is changeable, comprising: a development section configured to perform development with a developer; a replenishment section having a conveyance member and configured to replenish the development section with the developer contained in a container using the conveyance member; and a control section configured to control the replenishment section to control an amount of the developer that is replenished into the development section in response to a change of the sheet conveyance speed, wherein the development section includes a sensor configured to detect an amount of the developer contained in the development section, the control section has a first replenishment threshold and a second replenishment threshold, in a predetermined period of time immediately after a reduction of the sheet conveyance speed, the control section causes the replenishment section to replenish the development section with the developer when the amount of the developer detected by the sensor is equal to or smaller than the first replenishment threshold, in a subsequent period after a lapse of the predetermined period of time, the control section causes the replenishment section to replenish the development section with the developer when the amount of the developer detected by the sensor is equal to or smaller than the second replenishment threshold, the first replenishment threshold that is used in the predetermined period of time is set to a smaller value than the second replenishment threshold that is used in the subsequent period, so that the first replenishment threshold is harder to satisfy for determining that replenishment with the developer is to be performed than the second replenishment threshold, and a magnitude of the sheet conveyance speed in the predetermined period of time and a magnitude of the sheet conveyance speed in the subsequent period are the same.