Advances utilizing the Ogon, a Lens Free Optical Scanner (LFOS)

Abstract

The demand for high-speed, high-accuracy optical scanners has already pushed Galvanometer Scanner (GS) and Polygon Mirror (PM) scanners' development limits. Both GS and PM families suffer from a change of the optical path length, change in the incidence angle to the work surface, and change in beam diameter at the work area. Additionally, the PM not only introduces much worse nonlinearity in positioning and speed than the GS, but also produces an asymmetric scan around the optical axis. In practice, the PM is also more challenging to implement, as its physical structure introduces production and tolerance errors such as balance, jitter, speed stability, and perpendicularity. The &Oslash;gon, Lens Free Optical Scanner (LFOS), (patented by Tecnica, Inc., <strong></strong>New York, New York USA) on the other hand, provides a simple scanning method, linear transfer functions, fixed optical path length, incident beam always normal to the work surface, and a constant beam diameter. This paper describes the optics of the &Oslash;gon and compares it with the GS and PM. The analysis shows the &Oslash;gon delivering a linear transfer function, where the surface speed, surface beam location, and beam diameter are constant at all times, while the PM and GS fail to keep any of these values stable. More importantly, the &Oslash;gon optical performance is defined within the optics and linearly mapped onto the surface by having the light source optical axis, the optical axis of the first reflector, its rotational axis, and the curve path on the work surface rotational axis on the same line. This property alone ensures that the &Oslash;gon requires minimal alignment, thus enabling an easy implementation with no calibration. Applications of this novel scanning system are provided to validate the theory and to conclude the study.