1. An image forming apparatus, comprising: a latent image carrier having a moving surface on which a latent image is formed; a drive control mechanism to control a drive of the latent image carrier so as to match a rotation angular speed of the latent image carrier with a target rotation angular speed thereof; a surface moving member having a moving surface on which an adjustment pattern for use in controlling the drive of the latent image carrier is formed; an image forming mechanism to develop the latent image with toner and transfer a resultant toner image on the moving surface of the surface moving member so as to form the adjustment pattern along a surface moving direction thereof; a pattern sensor to detect the adjustment pattern; and a correction mechanism to correct the target rotation angular speed of the latent image carrier based on an amplitude and a phase of a variable component in a pattern interval of the adjustment pattern detected with the pattern sensor.