A synthesized signal (30) by the electromagnetic wave signal (10) from a detector and the complementary signal (20) from the complementary signal emitting device is a signal at a uniform level.

A differential amplifier (114) converts the binary precoded data signal and the complementary binary precoded data signal to a four-level data signal and to a complementary four-level data signal.

A complementary Schmitt circuit is connected to the rectifier stage and produces a second intermediate signal in response to the voltage of the second complementary signal.

A data signal (DS) is modulated with an additional signal (ZSB, ZSG) by amplitude modulation.

A circuit for detecting a predefined reoccurring phase point in the wave form of periodic electrical signal has an input stage which rectifies the signal into first and second complementary signals.

The third comparator inverts a synchronizing clock signal to generate a complementary synchronizing clock signal.

The level of the complementary signal generated by the complementary generating section (11) is shifted by a level shift section (14).

The registered address signal provides at least a true and a complement signal, with the true and complement signal set to approximately the same logical value upon assertion of the reset signal.

Said additional signal is not transmitted in the non-transparent functional units (FE).

The gate is also coupled to receive a logic input signal (IN1), and a logic complement input signal (IN1b).

The transitions of the logic complement input signal are delayed by a pre-determined amount relative to transitions of the logic input signal.

The asynchronous timing circuit (14) comprises a time- continuous feedback loop (22, 26) with a combinatorial logic circuit (22) with inputs for a feedback signal and a further signal provided by a further logic circuit.

The AND logic gate combines logically the second output signal from the first comparator with the complementary synchronizing clock signal to produce the modified synchronizing signal.

A second lead (13) interconnects the emitter circuit to the receiving circuit for transmission of a complementary signal.

In a photoreceptor using a differential signal method, influence of the imbalance between a positive signal and a complementary signal cannot be corrected, and the reception property is deteriorated.