| 摘要 |
<p>PURPOSE:To form a half-tone picture through simple circuit constitution by modulating the luminance of a light emitting element and giving respective picture elements gradations. CONSTITUTION:When a base line CS is activated by a decoder and a switching element S is switched, switching elements SA and SB on a data line side are turned on corresponding to 2-bit picture element data DMSB and DLSB. Then, the values of current limiting resistances RA and RB are predetermined so that the current IFA flowing through the resistance RA is smaller than the current IFB flowing through the resistance RB, imposing quad luminance modulation upon an LED. Therefore, the density of each dot on a photosensitive body is modulated by said luminance modulation.</p> |
