Browse Prior Art Database

Spot Size Modulation in Electrophotographic Printer

IP.com Disclosure Number: IPCOM000034177D
Original Publication Date: 1989-Jan-01
Included in the Prior Art Database: 2005-Jan-26
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Prakash, R: AUTHOR

Abstract

Disclosed is an apparatus for varying the size of the spot generated by a scanning light beam by diffracting the beam into one or more output beams displaced in a direction transverse to the scanning direction. The input light beam is diffracted into one or more output beams by passing the input beam through an acousto-optic modulator which is driven by an acoustic wave having one or more frequencies. As shown in Figs. 1 and 2, in an electrophotographic printer, an input light beam is diffracted into one or more output light beams by an acousto-optic modulator. The output light beams are scanned across a photosensor P in a line direction indicated by arrow A. During line scanning, the input light beam is modulated on and off to produce a series of spots on photosensor P.

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 72% of the total text.

Page 1 of 2

Spot Size Modulation in Electrophotographic Printer

Disclosed is an apparatus for varying the size of the spot generated by a scanning light beam by diffracting the beam into one or more output beams displaced in a direction transverse to the scanning direction. The input light beam is diffracted into one or more output beams by passing the input beam through an acousto-optic modulator which is driven by an acoustic wave having one or more frequencies. As shown in Figs. 1 and 2, in an electrophotographic printer, an input light beam is diffracted into one or more output light beams by an acousto-optic modulator. The output light beams are scanned across a photosensor P in a line direction indicated by arrow A. During line scanning, the input light beam is modulated on and off to produce a series of spots on photosensor P. The length L of each spot (in the line scan direction) is determined by the time T during which the input light beam is on. The height H of each spot (in a direction transverse to the line scan direction) is determined by the number of output beams produced by the acousto-optic modulator during the time T. Instead of driving the acousto-optic modulator to produce multiple output light beams to determine the spot height H, one can drive the acoustooptic modulator with a high frequency "chirp" to deflect a single output light beam in a direction transverse to the line scan direction. Concurrently, the output light beam is scanned across photosenso...