To provide an image recording apparatus or a pixel clock generator, which can maintain good image quality by hardly exerting an influence on the image quality, even if the accuracy of each output pulse of a rotary encoder is insufficient.

This apparatus for drawing an image on an image medium on a rotor by using a pixel clock signal is characterized by comprising a means for generating a signal indicating a rotational state, a means for measuring a rotational signal, a means for computing correction data on the rotational signal from measurement results, and a means for generating the pixel clock signal by using the correction data.