| 摘要 |
PURPOSE:To obtain a scanned optical image with high-precision and high-picture quality by modulating a light source while controlling the transmission of a picture signal in accordance with a detection signal of a code signal on a medium to be scanned. CONSTITUTION:A luminous flux L emitted from a light source 1 is scanned in the subscanning direction of an arrow D1 by a deflector 3 and is scanned in the main scanning direction of an arrow D2 by a deflector 5, and a two-dimensional scanning line A is obtained on a medium 7 to be scanned. During this time, a code signal 8 on the medium is read by a code signal generating optical system 9, and output pulses are counted by a means 20 and are inputted to a comparing circuit 21. The difference between this pulse number and the pulse number obtained by counting reference clocks 22 by a means 23 is operated in the circuit 21, and a signal corresponding to this difference is sent to a clock oscillating circuit 25 through a signal generating circuit 24 at intervals of a certain time. The circuit 25 generates pulses in accordance with this signal to control a picture signal generating circuit 26, and the light source 1 is modulated by the picture signal from the circuit 26. The deflected luminous flux is detected by a position detector 30, and the output is inputted to a sweeping circuit 32 and the circuit 24 through a beam position signal generating circuit 31, and the deflector 3 is controlled by the circuit 32. |
