The present invention relates to an illumination system comprising a light guide having an entrance face, an exit face and an aperture in which a light source can be arranged, and a display system comprising such an illumination system. A driving force of the drive unit is transmitted to the first and second clamp arms through knuckle joints, which are connected to first and second piston rods, power-boost levers, and link arms. Light scattering patterns 3P are provided on a plane 3d formed by cutting. The invention also provides a method for the preparation of the grease composition and a method for lubrication of bearings, gears, surfaces and other lubricated components comprising use of the grease composition of the present invention.