| 摘要 |
PURPOSE:To increase resolving power in one dot lateral line, and to improve the quality of a picture by zigzag arranging P type regions in an LED array light source in which the P type regions are disposed to an N type indirect transition type crystal. CONSTITUTION:With an LED for an LED array light source for a beam writing head in a non-impact printer using an electrophotograph system, P type regions 18 are formed on the surface layer of an N type indirect transition type crystal 17, and electrodes 19 for conduction are arranged alternately on both sides of rows. The P type regions 18 are disposed zigzag in a row. The directions of displacement of the P type regions 18 are directed in the directions in which there are the electrodes 19 for adjacent P type regions 18, the luminance peaks of light emissions of each P type region 18 are arranged to an approximately rectilinear shape, and the mutual effect of the peaks of light emission is reduced. The quantity of displacement optimizing a spot diameter in the direction of a by-scan is determined by the size of the P type region 18, the characteristics of an image forming element such as a SELFOC lens and the distribution of the illuminance of an image surface in the direction of the by-scan. |
