Abstract: A facsimile document scanner 10 is illustrated which includes an optical system 23 having a folded optical path 40 and an adjustable focusing lens 42. A test pattern 60 in the form of a plurality of alternate light and dark stripes 64, 66 is printed upon a strip 62 secured to the inner wall of the cabinet 12. When the scanner is at rest, the test pattern 60 is focused upon a linear photodiode array 50 mounted in an integrated circuit pack 51. The number of light and dark stripes 64, 66 is equal to the number of photodiodes in the linear photodiode array 50 across the document width. For adjustment purposes, an oscilloscope 70 is connected to a serial output from the integrated circuit pack 50 and the optical system 23 is adjusted to obtain a uniform signal display 80.

Abstract: An apparatus for mounting a mirror 20 is described which includes a flat mounting plate 10 having a rectangular mirror opening 12. Positioned about the mirror opening 12 are spaced rectangularly shaped holes 18. Placed against the bottom wall 26 of a "U" shaped channel 22 is a sheet of foam material 34 upon which the back of a front surface mirror 20 is placed. The edges of the walls 28, 30 of the "U" shaped channel have tabs 32 which are placed into the holes 18. The tabs 32 are bent over or deformed to secure the channel 22 and mirror 20 to the mounting plate 10.

Abstract: An apparatus for damping the acoustical impact noise traveling along a length of paper as it passes through a printer including resilient urethane foam rollers in engagement with a large proportion of the width of the paper with a pressure damping roller depressing portions of the paper deeply into engagement with the resilient roller to enable the resilient roller to damp acoustical energy traveling along the length of the paper.