Patent ID: 7254345

Claim:
An optical receiver operable in response to a light signal and comprising: a clock and data recovery circuit (CDR) for recovering a sequence of clocks and a sequence of data signals in response to an intermediate data signal obtained from the light signal, with reference to a threshold control signal used for recovering the data signal sequence; a controller, responsive to the intermediate data signal and the threshold control signal, for detecting an eye pattern of the intermediate data signal that includes an eye aperture to control an eye aperture size; and a waveform equalizer, responsive to an electric signal converted from the light signal and an internal control signal, for reshaping a waveform of the electric signal into a waveform-shaped signal in accordance with the internal control signal to supply the waveform-shaped signal to the clock and data recovery circuit as the intermediate data input signal, wherein said waveform equalizer comprises: a single bit delay circuit that delays the electric signal by one bit; a variable gain amplifier that controls an amplitude of the delayed electric signal in response to the internal control signal from the controller; and a subtracter that subtracts the amplitude controlled and delayed electric signal, which is received from the variable gain amplifier, from the electric signal converted from the light signal.