Browse Prior Art Database

Laser Raster Scanner

IP.com Disclosure Number: IPCOM000074706D
Original Publication Date: 1971-May-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Latta, MR: AUTHOR

Abstract

Described is an optical device for raster scanning of images (including alphanumeric data as a special case). It utilizes a laser/ rotating mirror scheme and includes image scanning without disturbing an existing printing function.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 55% of the total text.

Page 1 of 2

Laser Raster Scanner

Described is an optical device for raster scanning of images (including alphanumeric data as a special case). It utilizes a laser/ rotating mirror scheme and includes image scanning without disturbing an existing printing function.

Drawing A shows a top view of the system. The optics path passing straight through the beam splitter BS1, and on through beam expander BE1, modulator M, beam compressor BC, to the rotating mirror RM, through Lens L1 to the print line indicated by line start detector LS1, is that of the laser printer. At BS1 a small fraction of the incident laser power is split off and follows an alternate path. This path sends the beam through a beam expander BE2, and passes through a beam splitter BS2 before striking the rotating mirror on another face, The optical element L2 immediately following the reflection of the beam from the rotating mirror may be identical to the type used for L1.

Scanning across one horizontal line on a page is performed by the reflected beam from the rotating mirror as in the printer. However, now this scanning beam is only used for illumination of the document. The spot which scans across the document produces a retroreflected beam which passes back through the system retracing the path through L2. When it returns to BS2, 50% of the energy changes direction and passes through another lens which focuses the optical signal onto a pinhole/PMT combination. Due to the reversibility of optical path the retro...