An image generating device for an optical, in particular medical tracking system, for determining the position of a recorded image point, includes a light scattering effect generating device, in particular a star andor cross effect generating device. A method and apparatus for increasing transmission capacity are needed, which can transmit a large-capacity high-speed signal in order to transmit a signal through a united OTN by adapting signals from various tributary signal networks which have been independently operated for voice, image, or data transmission. One embodiment of the invention may be used to measure misalignment between two conductive layers. The bladder houses an insert die, the shape of which is identical with an internal shape of the bladder, and a hydraulic oil path is formed in the insert die. The system includes a helical compressor unit, a motor unit dedicated to the helical compressor unit for driving the helical compressor unit, and a control unit for adjusting a rotational speed of the motor unit and to generate a predefined discharge rate of compressed air from the helical compressor unit, independently of a drive assembly of the vehicle.