Abstract: A pixel modulation circuit outputs a pulse signal having a pulse width corresponding to pixel data representing a gradation level of each pixel. The pixel modulation circuit comprises a first triangular pulse generating circuit for generating a periodic triangular pulse signal, a complement and antilog output circuit capable of outputting a level signal corresponding to both antilog and complement values of pixel data, and a comparison circuit for comparing the triangular pulse signal with the level signal.

Abstract: A triangular wave generator circuit having a triangular wave generator unit for generating a triangular wave signal, and a comparator for comparing the generated triangular wave signal with a predetermined level. The triangular wave generator unit controls the generated triangular wave signal in accordance with the comparison result by the comparator.

Abstract: In a parallel to serial converter, data is inputted in parallel to a set of latches in a cycle of an inputted first clock signal. A second clock signal having a 50% duty cycle is generated according to the inputted first clock signal. The second clock signal is delayed to output a third clock signal and a switching unit selects and outputs the latched data in response to the second and third clock signals.

Abstract: A triangular wave generator circuit having a triangular wave generator unit for generating a triangular wave signal, and a comparator for comparing the generated triangular wave signal with a predetermined level. The triangular wave generator unit controls the generated triangular wave signal in accordance with the comparison result by the comparator.

Abstract: A phase-locked signal generator which performs phase-locked control of the output of a triangular-wave VCO when a trigger signal is not inputted, and which performs, when the trigger signal is inputted, short interval suspension of oscillation of the triangular-wave VCO, and detection of a phase difference between the trigger signal and the reference clock signal by a successive phase measuring portion after the short interval by using the triangular-wave signal, thereby obtaining phase data. The measured phase data is held until the next trigger signal, and the phase of the triangular-wave VCO is controlled in accordance with the phase data so that the triangular-wave signal has a fixed phase with respect to the reference clock signal. A square-wave signal outputted from the triangular-wave VCO is used as the phase-locked clock signal.