Image forming apparatus with means for correcting image density unevenness

An image forming apparatus comprising:

• recording means scanningly movable in a raster scan direction for recording an image on a recording medium in each raster scan;
• relative movement means for causing relative movement between said recording means and the recording medium at a relative speed in a sub-scan direction substantially perpendicular to the raster scan direction;
• and
• control means for controlling said recording means in accordance with any change in the relative speed of movement between said recording means and the recording medium in the sub-scan direction, wherein said control means includes memory means for storing data concerning a deviation of a recording position of said recording means relative to a relative position of the recording medium, and reads out, during the relative movement, the stored data from said memory means in accordance with the relative movement between the recording medium and said recording means to control said recording means in accordance with the stored data.

An image forming apparatus including recording means for recording dot images on a recording medium in accordance with image signals, said apparatus comprising:

• relative movement means for causing relative movement between said recording means and the recording medium in a sub-scan direction which is different from a main scan direction of said recording means;
• memory means for storing at a concerning a variation in a speed of said relative movement means;
• and
• control means for effecting a correction of recording density unevenness caused by the variation in the speed of said relative movement means, by reading out, during the relative movement, the stored data from said memory means in accordance with the relative movement between the recording medium and said recording means to control a number of print dots per area recorded by said recording means in accordance with the stored data.

An image forming apparatus including recording means for recording images on a recording medium in accordance with image signals, said apparatus comprising:

• relative movement means for causing, after recording in a main scan direction by said recording means, relative movement between said recording means and the recording medium in a sub-scan direction which is different from the main scan direction;
• memory means for storing data concerning a variation in a speed of said relative movement means;
• and
• control means for effecting correction of recording density unevenness caused by the variation in the speed of said relative movement means, by reading out, during the relative movement, the stored data from said memory mean in accordance with the relative movement of the recording medium and said recording means to control a driving frequency of said recording means in accordance with the stored data.

An image forming apparatus including recording means for recording dot images on a recording medium in accordance with image signals, said apparatus comprising:

• relative movement means for causing, after recording in a main scan direction by said recording means, relative movement between said recording means and the recording medium in a sub-scan direction which is different from the main scan direction;
• memory means for storing data concerning a variation in a speed of said relative movement means;
• and
• control means for effecting a correction of recording density unevenness caused by the variation in the speed of said relative movement means, by reading out, during the relative movement, the stored data from said memory means in accordance with the relative position of the recording medium to control a diameter of the recording dot recorded by said recording means in accordance with the stored data.