| 摘要 |
<p>In an electro-optic line printer of the type having a bit addressable linear modulator for modulating a sheet-like beam of light in response to pixel bits to expose the printer recording medium in line-by-line fashion, interference between the beam upper and lower sidebands is suppressed by selective polarisation. In one form, the beam is vertically polarized and a halfwave plate, disposed so that the axis thereof is at 45° to the Fourier transform plane, is inserted into the path of one of the sidebands to change the polarization of the one sideband from vertical to non- interferring horizontal. In a second embodiment, a halfwave plate is inserted into the path of each sideband, the axes of the plates being such as to form a 45° angle therebetween whereby the sidebands are polarized at an angle of 90° to one another avoiding interference therebetween.</p> |
