Wilson Morgan Routt

Optical design and optimization of a high-performance laser printhead

The fundamental considerations involved in the design of a print engine, or of a printer component such as a laser printhead, arise from visual acuity characteristics of the human visual system and from the physics of interaction of light with scattering/absorbing media. For production of gray-scale images, the visual system imposes strict limitations on unintended luminance variations, both in contrast magnitude and in spatial distribution. Unintended variations in size, spacing, and lightness of the picture elements composing the image are a major source of image degradation. Further, the scattering of light in a medium such as paper leads to the Yule-Nielsen Effect in which the surface luminance of paper between picture elements is altered in a non-linear way as pixel-to-pixel spacing or pixel size changes.