PURPOSE: To apply the processor to a high speed system with comparatively simple configuration by providing a means for generating two specific patterns and a means for generating a binary signal to the processor, thereby eliminating broken or interrupted character or line and improving the resolution and reproducibility while keeping the gradation reproducibility of an intermediate tone image area.
CONSTITUTION: Two triangle wave having a period twice the picture element period with high gradation reproducibility generated by pattern generating circuits 103, 104 are used for pattern signals to generate a binarizing signal with pulse width modulation. An edge direction detection circuit 107 detects the presence and direction of an edge based on the absolute value of a difference between two photoelectric conversion element with an attentional picture element inbetween and on the relation of quantity. If the signal is an edge, a proper triangle wave in the two triangle waves is selected depending on the direction, and the selected triangle wave and analog signal obtained by convering a digital picture signal are compared to select a generated binary signal with a time width. Thus, a picture having high quality is obtained.
SUZUKI YUZURU
HIBI YOSHIHARU
TERADA YOSHIHIRO
SEKINE HIROSHI
TAKAYA KAZUYASU
Next Patent: connection equipment