Original Publication Date: 1983-May-01
Included in the Prior Art Database: 2005-Feb-07
Stanich, MJ: AUTHOR [+2]
U.S. Patent 3,835,249 describes a laser printhead which produces xerographic images for hard-copy reproduction. In this device, one laser beam sweeps a photoconductor drum, while a second beam functions in a beam-position detecting system.
U.S. Patent 3,835,249 describes a laser printhead which produces xerographic images for hard-copy reproduction. In this device, one laser beam sweeps a photoconductor drum, while a second beam functions in a beam- position detecting system.
In Fig. 1, laser 10 provides a continuous beam 11 which is reflected off mirror
12. Reflected beam 13 is directed to beam splitter 14. As a result of the operation of beam splitter 14, two slightly spaced beams 17 and l8 are formed. These two beams pass through beam-- diameter compression optics, where the beam diameters are reduced to a size compatible with an acousto-optic modulator (not shown).
Beam l8 is the beam which will "write" on the photoconductor drum (not shown), whereas beam 17 is the beam with functions in a beamposition detecting system (not shown), in order to track the position of beam 18 as it sweeps the drum.
Fig. 2 shows beam splitter 14 enlarged.
Incoming ray 13 strikes the front surface of the splitter. The
area which the incoming ray strikes can either be coated to produce a desired splitting percentage, or glass substrate 20 may be chosen such that its uncoated surface produces the desired splitting efficiency. The beam is split at this point into the two required beams. Detector beam 17 comprises about 10% of the energy of beam 13. The remainder of the beam, 21, passes into the glass and forms writing beam 18.
Beam 21 hits back surface 22 of the splitter. Surface 22 is coated with a diele...