| 摘要 |
PURPOSE: To realize the control of polarization without being affected by environmental change and to apply it to a printer so as to obtain a very accurate printed image by adding output from a reference polarization signal generating means to a polarization control means thereby obtaining a polarized light beam for a reference polarization signal, detecting the deviation of the polarized light beam from a specified polarization state by a polarization state detecting means and correcting it. CONSTITUTION: A polarizing means 103 is arranged between a semiconductor laser light source 101 and a rotary polygon mirror 105 and set in an initial state so as to change the polarization direction of a laser beam being the nearly linearly polarized light beam. Namely, the polarized light beam 111 is generated under the control of a polarization and light quantity control circuit 110. By arranging a half mirror 601 used as a spectrally splitting means and then polarization films 602 and 603 arranged mutually in optical cross Nicol before two photoreceptor drums 108 and 109, one photoreceptor drum is irradiated only with unidirectional polarized light beams 112 and 113. A line synchronizing signal receiving part 115 takes write start timing for every surface of the polygon mirror 105. |
