a laser recording apparatus for printing multi - tone image data by driving a laser diode according to levels of an analog signal containing the image data thereby to modulate a laser beam output by the laser diode , and causing the modulated laser beam to scan a recording medium in transverse directions . the output of the laser diode is stopped or reduced in level for a certain time in each of periods at predetermined intervals , each period corresponding to each pixel in the printed image . this eliminates mode hopping noise and optical feedback induced intensity noise , and hardly gives rise to the problem of electromagnetic wave disturbance . by elongating or shortening the time for stopping or reducing the emission by the laser diode , the image density may be adjusted without impairing the above advantage .