Patent ID: 8287088
Filing Date: 2012-10-16
Classification: B41J

Abstract:
1. An image forming apparatus comprising: a recording unit configured to eject ink drops; a conveyance mechanism that conveys the recording unit in a main scanning direction by a driving force of an internal motor; a position detecting unit that detects the position of the recording unit in a conveyance path; an image forming control unit that controls the recording unit to eject ink drops during conveyance of the recording unit thereby to form an image onto a sheet passing an ejection position of the ink drops in a sub-scanning direction; and a conveyance control unit that drives the motor to control conveyance of the recording unit, wherein the conveyance control unit is configured to: define a constant speed moving area, which is an area in the conveyance path in which the conveyance control unit moves the recording unit at a constant speed, to be a smaller area than an image forming area which is the area in the conveyance path in which image forming operation by the image forming control unit is performed, define the control changeover point to be one of an end point downstream in the conveyance direction of the image forming area and a point downstream in the conveyance direction from the end point, and, set the target speed such that, in an acceleration zone starting from a start point upstream in the conveyance direction of the image forming area to where the recording unit is shifted to a constant speed state and in a deceleration zone starting from the deceleration start point to where the recording unit reaches the end point downstream in the conveyance direction of the image forming area, a speed curve of the recording unit is symmetrical with respect to an axis of a speed direction passing a midpoint between an end point of the acceleration zone and the deceleration start point which is a start point of the deceleration zone, in a two-dimensional coordinate system having position and speed as dimensions.