Patent ID: 6934498
Filing Date: 2005-08-23
Classification: G03G

Abstract:
1. A color image forming apparatus comprising: an electrostatic charger; an image carrier that is charged by the electrostatic charger; an exposing unit that irradiates a light to the image carrier to form a latent image on the image carrier; a developing unit that develops the latent image with toner of a specific color to form a toner image of the specific color; a transfer belt that moves at a specific moving speed to feed the recording medium to the developing unit so that the toner image is transferred to the recording medium; a pattern forming unit that forms a mark pattern including a first mark and a second mark on the transfer belt using toner; a sensor that detects the first mark and the second mark while the transfer belt is moving; an acquiring unit that acquires a current interval between the first mark and the second mark and calculates an interval difference between the current interval and a predetermined reference interval; a speed detector that detects a first moving speed that is a moving speed of the transfer belt during a period of time from formation of the mark pattern to detection of the mark pattern, and a second moving speed that is a moving speed of the transfer belt while transferring the toner image to the recording medium; a calculating unit that calculates a speed difference between the first moving speed and the second moving speed; and a control unit that controls image formation based on the interval difference and the speed difference.