a waveform of an input voltage or performs slidable relative motion, thereby enabling the driving device to reciprocally move the lens.
However, in this conventional device, the driving rods are fixed so that a length of barrel cannot be changed. This accordingly is an impediment to reduction in size. Also, a driving signal of the device is an asymmetrical wave signal, not a sine wave signal, thereby complicating a driving circuit.
Therefore, there is a need for a lens driving device which can be mounted in a small volume, controlled precisely due to high driving resolution, while operating with a small driving power and achieving a sufficient driving distance.

1. Field of the Invention
The invention relates to a method of controlling a printing system that is arranged to process a sequence of media sheets and is operable with a finite number of different settings, the method comprising a step of calculating a time to finish that will be needed for processing the sequence.
2. Background of the Invention
A printing system typically comprises a number of functional components, e.g. one or more print stations and a media management system for timely supplying media sheets, which may be of different types and have different properties, to the print station and for discharging the printed sheets. Some of these components may be capable of operating in different modes which are determined by corresponding setting parameters. For example, the media management system may be set to operate in either a simplex mode or a duplex mode, and/or different colour modes may be available for printing in black only, in a multicolour mode or a full colour mode. When a fuse station is used for fixing an image on the media sheets, different modes of operation may also be distinguished by different operation temperatures to which the fuse station has been set. Depending on settings, different conveying speeds of the media sheets may need to be selected.
US 2002135792 A1 describes a printing system which is capable of calculating and di