Abstract: A lithography apparatus comprising variable lenses is described. These variable lenses are included in a microlens array. At least some of the lenses have two or more immiscible liquids whose optical properties can be varied, for example, by an application of a voltage.

Abstract: For the detection of an amplitude transient in a field of elements having a multivalent amplitude distribution by comparison of amplitude values of neighbouring elements, the amplitude transient is further localised by calculating an interpolation point as a function of amplitude values around the detected amplitude transient, said interpolation point being indicative of the location of the amplitude.

Abstract: The code is scanned along at least four non-coincident parallel lines in a bar code reading device. The actual processing is started when a margin of sufficient width is detected. The width of the bar is counted and the width found is used to address a table memory. This results in a width indication for a valid bar and a reset signal for an invalid bar. There is provided an bar counter which counts the bars and which addresses a bar memory in order to store the bar identification therein. When the reset signal is received, the series of bar identification received thus far for the relevant line is invalidated, unless all bars of a complete code have already been received. During validation a check is performed as regards correct contents and possibly correspondence between two potentially correct bar codes found.