Abstract: A transmitter in which a complex low IF digitised signal is applied in quadrature to a complex phase comparator together with a digitised frequency down-converted version of an analogue signal produced by a transmitter VCO. The low IF digitised signal serves as a reference against which the digitised frequency down-converted version of the transmitter VCO is compared. The output of the complex phase comparator is converted to an analogue signal which is applied as a control signal to the transmitter VCO. An analogue embodiment of the transmitter which uses zero-IF signals is also disclosed.

Abstract: The invention relates to a method of controlling several radiation-emitting elements. The invention consists in the compensation of differences in the emission power of the individual elements due to variations in the efficiency of the elements or to differing operating conditions by operating each radiation-emitting element with an individual pulse length determining the overall emission time. In this way, the energy emitted by all elements triggered is substantially identical.

Abstract: In a device for electronic recording of images with an optical, radiation-emitting exposure device and a detector system for detecting the image information received, a sequentially triggered system of radiation-emitting elements is provided for exposure, and the image to be recorded is optically scanned by the sequentially triggered radiation-emitting elements.

Abstract: The invention relates to an optical system comprising a semiconductor laser and an optical instrument collimating the laser light. In accordance with the invention, the semiconductor laser and the optical instrument are accommodated in separate holders which are adjusted relative to one another in such a way that a criterion relating to the laser light is optimally fulfilled. After completion of the adjustment, the two holders, both forming the external housing of the entire system, are joined to one another.

Abstract: A circuit arrangement for actuating semiconductor lasers with the transmitted optical power being controlled with the aid of a photodiode optically coupled to the laser radiation, whose amplified photoelectric current controls the current of the laser in such a way that its radiation capacity remains constant, is to be improved, in particular, such that the circuitry expenditure is low, the band width large and the operating point of the laser easy to set, and, furthermore, such that a digital or HF signal for modulation of the laser radiation can be coupled without difficulty.

Abstract: A photoelectric current amplifier comprises several partial amplifiers whose outputs lead to a common summing output.