A method for generating a screened reproduction of an image includes the steps of providing a representation of an original, defining a desired screen dot arrangement for the image, and writing screen dots in a line by line fashion. The representation of an original has input density values representing the grey levels of various locations of the original for a given color separation. Each screen dot is made up of a plurality of line segments whose length and location determines the dot configuration and whose length and location is determined by employing the input density values of the original and the desired screen dot arrangement. The method is characterized in that at least some of the plurality of line segments are shifted from an otherwise generally straight line configuration so as to cause them to conform to a desired overall dot shape.
A light beam modulated with image information has its optical axis moved in a given direction by a light beam moving unit, and reflected successively by a plurality of rotating reflecting mirrors of a spinner to a photosensitive medium. The movement of the light beam which is caused by the light beam moving unit is controlled depending on the speed at which the reflecting mirrors move and the direction in which the reflecting mirrors move, so that the light beam reflected by each of the reflecting mirrors can scan the photosensitive medium. An image represented by the image information can efficiently be recorded on the photosensitive medium.
