Rotor driving control device and image forming apparatus

#The present invention relates to a rotor driving control device suitable for reducing a rotation period fluctuation of a rotor when rotating and driving the rotor by a motor and the like, and an image forming apparatus having the rotor driving control device.

#FIG. 6 explains an image forming apparatus. FIG. 6 shows a color image forming apparatus such as a four colors tandem type color printer. At first, the structure of FIG. 6 is explained. A controller 5 controls the entire image forming apparatus. Reference numerals 1a to 1d denote photoconductor drums, respectively. The photoconductor drums 1a to 1d are formed with latent images of black, cyan, magenta, and yellow, respectively. Desired latent images are formed on the photoconductor drums 1a to 1d by photolithography machines 2a to 2d. Motors 6a to 6d rotate the photoconductor drums 1a to 1d, respectively. A belt 3 is driven by a driving motor 4, and feeds a transfer paper 7.

#Next, the operations of the image forming apparatus shown in FIG. 6 will be explained. When the image formation is started, the transfer paper 7 is fed from a paper feeding unit (not shown) to the belt 3. The transfer paper 7 is transferred by the belt 3, and sequentially fed to the photoconductor drum of each color. At this time, the latent images are formed on the photoconductor drums 1a to 1d from the above by the photolithography machines 2a to 2d. Toner is attached to these portions, and then the toner is transferred onto the transfer paper 7 disposed just below the photoconductor drum while the transfer paper 7 being passed. In the image forming apparatus shown in FIG. 6, the photoconductor drums 1a to 1d of respective colors are driven by DC brushless motors and the like, respectively. However, a displacement of the sub-scanning direction generates in the formed image by the following (i) (ii).

#FIG. 1A is a drawing explaining that detected portions used to detect a rotation period fluctuation of the present invention is structured by slits.

#FIG. 1B is a drawing explaining that detected portions used to detect a rotation period fluctuation of the present invention is structured by slits.

#FIG. 2A is a drawing explaining that detected portions used to detect a rotation period fluctuation of the present invention is structured by edges.

#Hereinafter, embodiments of the present invention will be described with reference to the drawings.

#Structure of DC Motor Driving System

#One embodiment of the present invention will be explained by an image forming apparatus having the structure shown in FIG. 7. FIG. 7 is a structured diagram of a single driving control device in a driving control mechanism of photoconductor drum shown in FIG. 6.