| 摘要 |
PURPOSE:To obtain a picture output with high quality by constitution that a line drawing such as character is recorded and displayed in a multi-value output. CONSTITUTION:A couple of picture density signals S1, S2 are applied to input terminals 31, 32. A semiconductor laser 11 is driven in response to the signal S1 by transistors (TRs) 33, 34 constituting a differential switch, and TRs 36, 37 drives a laser 11 in response to the signal S2. When both the signals S1, S2 are logical H, the optical output of the laser 11 is brought into LO, when the signal S1 is logical L and the signal S2 is logical H, the optical output is brought into an intermediate output LM, and when both the signals S1, S2 are logical L, the optical output is brought into the maximum output LH. An output of ternary state, white, gray and black states, is obtained by the optical outputs LO, LM and LH, and a stepwise print of a skwe line part of a character or the like is smoothed to attain easy to see picture. |
