Abstract: A system for creating the perception of visual depth in two dimensional single image displays. A polarizing projection filter 1c provides means to control the plane of polarization of projected imagery. The plane of polarization is changed by changing the orientation of the polarizing projection filter. An observer wears special viewing glasses 2 with polarizing filters when viewing imagery polarized by the polarizing projection filter. The plane of polarization of the polarizing viewing filter for the right eye 3 is oriented 30 degrees clockwise from horizontal. The plane of polarization of the polarizing viewing filter for the left eye 4 is oriented 30 degrees counterclockwise from horizontal. When the polarizing projection filter has an angular offset of approximately 45 degrees clockwise from horizontal the projected imagery appears approximately 20 times brighter to an observer's right eye than to the observer's left eye.

Abstract: A bicycle drive chain (1) guide to prevent the drive chain (10) from derailing off the inside of the inner chain wheel. The chain guide is a simple one piece device which can be easily attached to the bicycle frame during manufacturing.