Abstract: Disclosed is an apparatus for scanning a surface with electromagnetic radiation. The apparatus comprises a base plate for supporting a medium said medium having a scanning surface to be scanned, an optical head unit adapted to scan the scanning surface with electromagnetic radiation propagating along an optical axis, a fluid film generation unit connected to the optical head unit and adapted to generate a fluid film between the scanning surface and a gliding surface of the fluid film generation unit for maintaining a predetermined distance between the gliding surface and the scanning surface during scanning operation of the optical head unit across the scanning surface, and control means for controlling the position of the fluid film relative to the optical axis.

Abstract: The invention relates to a method for enabling transmission of substantially equal amounts of energy from at least one light source (LS) comprising intensity variations in time to at least two light sensitive points (LSP), said transmission being controlled by means of at least one illumination arrangement (1), and said method comprising establishment of a correlation between said intensity variations and at least one feature of said illumination arrangement. The invention furthermore relates to an illumination arrangement (1) for controlling transmission of energy to at least two light sensitive points (LSP), wherein said controlling transmission enables transmission of substantially equal amounts of energy to each of said at least two light sensitive points (LSP).

Abstract: The invention relates to a method for establishing a light beam (CLB) with substantially constant luminous intensity comprising the steps of establishing a light beam (LB) by means of a light source (SAL) and controlling an attenuation of said light beam (LB) on the basis of occurrences of luminous intensity peaks (IP) in said light beam (LB).

Abstract: A method of illuminating at least two illumination points by means of at least one spatial light modulator, said at least one spatial light modulator comprising a plurality of light modulators, whereby a predefined amount of energy transmitted to said points is at least partly controlled by varying the number of said light modulators illuminating said point.