Abstract: Disclosed are apparatus and methods for implementing polar halftone techniques that substantially reduce or eliminate interference patterns while printing on rotating circular media with a radial print system. In one embodiment, Cartesian image pixels are selected such that screen pixels or “dots” are arranged fan-shaped along radii (or “spokes”) and in annular ring segments (or “arcs”). Halftone sampling frequency may be varied along spokes and arcs or along a polynomial curve relative to the center of spinning media, in order to reduce distortion and artifacts.

Abstract: Method and apparatus for printing onto a rotating media is described. According to one embodiment, the printing system includes a print head that is laterally displaced from a radial printing radius, a rotating mechanism to rotate the media, and a controller to print onto an annular print area. The annular print area is defined by an inner hub circumference, two lines substantially parallel to the radial printing radius and tangential to the inner hub circumference, and an outer edge of the media. The print head moves about the annular print area by one or more motion mechanism and prints images onto the media.

Abstract: Methods and apparatus for determining angular position information and the printing of individual ink objects at target print sectors disbursed around an annular surface on a circular spinning media such as on a CD, dynamically during the radial printing process, are described. Mechanisms for computing the instantaneous angular position and apparatus for collocating encoder devices in close proximity to the CD rotation motor are disclosed.

Abstract: Disclosed are apparatus and methods for implementing a radial sled printer device that substantially simplifies the complexity and reduces system costs and size for radial printing devices, both for devices that print and those that also record and print a label on circular media. In an embodiment, a print head is radially mounted in a substantially fixed position over a platter such that said platter moves as a sled under the print head for dispensing ink object along a radius or a line parallel to a radius as the media spins, effecting labeling of the media. In an alternate embodiment, a print head is radially mounted in a fixed position over an optical recording drive such that said drive moves as a sled under the print head for dispensing ink object along a radius as the media spins, affecting recording and labeling the media in a single insertion of the media.

Abstract: Methods and apparatus for curing or drying of individual ink objects, dynamically during the radial printing process, at the ink object's point of incidence are described. Mechanisms for curing or drying ink objects, dynamically during the radial printing process, at the ink object's point of incidence, reducing ink object migration while the ink is wet, caused from inherent centrifugal forces and secondary air turbulence during the radial printing process, reducing image distortion, resulting in a more clearly printed image, such as on a spinning CD, are disclosed.