this diagonal line is indicated as the number 2 line in the patterns shown in fig3 and 4 next the beam sweeps across mirror 42 resulting in the diagonal line number 3 mirror 43 is angularly situated such that the light reflected from it to mirror 55 is projected as a horizontal line numbered 4 in fig3 and 4 mirror 44 has a slightly different angular orientation from mirror 43 so that when the beam from the mirror 32 sweeps across it the resulting horizontal line 5 is displaced from line 4 reflected from mirror 43 actually with mirrors 43 and 44 oriented as shown perfect horizontal lines will not be generated at the scanner window rather two nearly horizontal lines will be generated whose angular difference causes them to be displaced from each other if exact horizontal lines are desired mirrors 43 and 44 should be parallel with each other with one slightly displaced towards the rotating mirror 32 the beam from mirror 32 then sweeps successively mirrors 45 46 and 47 which are reflected from mirror 56 and eventually form lines 6 7 and 8 in the scan pattern at this point the light impinging upon the rotating reflector encounters a new face each of the faces of the rotating.