A pixel clock generating device includes a time interval detection unit detecting a time interval between a first signal and a second signal in each of cyclically repeating N (‰§ 2) time periods; a comparing unit cyclically selecting a target value from N target values corresponding to the N time periods and outputting an error indicating a difference between the detected time interval and the selected target value for each of the N time periods; a frequency calculation unit correcting a frequency of the pixel clock signal based on the error and cyclically generating a frequency specification signal indicating the corrected frequency for each of the N time periods; a high-frequency clock generating unit generating a high-frequency clock signal; and a pixel clock generating unit generating a pixel clock signal based on the frequency specification signal and the high-frequency clock signal.