Method and apparatus for scanning a receiving medium.

摘要

A method and apparatus are disclosed for scanning a receiving medium. The present invention can be used in scanner apparatus in which a diode laser is modulated by a drive current which is controlled in accordance with a digital information signal. Radiation from the diode laser is imaged onto a receiving medium such as a thermal print medium. In order to overcome the problem of artifacts in images produced by such apparatus, random noise is used in the apparatus to mask the image artifacts. In one embodiment of the present invention, an error signal, provided by a random noise generator, is injected into the drive current for the diode laser. In a second embodiment, states of bits in the digital information signal are randomly changed in order to randomly change the laser drive current. <IMAGE>