Browse Prior Art Database

Blocking Infrared Light From Fluorescent Lamps With Filters

IP.com Disclosure Number: IPCOM000099353D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 2 page(s) / 74K

Publishing Venue

IBM

Related People

Bobo, KN: AUTHOR [+2]

Abstract

Disclosed is a method of preventing infrared light generated by fluorescent lamp heaters from discharging an infrared sensitive photoconductor used in electrophotographic (EP) printers.

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This is the abbreviated version, containing approximately 58% of the total text.

Blocking Infrared Light From Fluorescent Lamps With Filters

       Disclosed is a method of preventing infrared light
generated by fluorescent lamp heaters from discharging an infrared
sensitive photoconductor used in electrophotographic (EP) printers.

      Many electrophotographic printers use an infrared light source
to discharge images on an infrared sensitive photoconductor.  A
typical infrared sensitive photoconductor light response curve is
shown in the figure, curve A.  Light from 400 nm to 900 nm will
discharge the dark charge on the photoconductor, and a later EP
process step will develop an image.  Fluorescent lamps have long been
used in EP engines as an inexpensive method of discharging large
areas of photoconductor prior to several EP process steps which can
include pretransfer, transfer and preclean.  To extend the lamp life
and to reduce the turn on rate of fluorescent lamps, a small voltage
is applied to lamp filaments to keep them warm in the off state.  An
unwanted byproduct of this practice is the generation of infrared
light energy:  a typical plot of infrared light energy is shown as
curve B in the figure.  The overlapping of the infrared light energy
curve on the photoconductor curve allows the lamp heaters to
discharge the photoconductor and causes two undesirable print quality
problems.  First, when the printer is in the idle state, the
fluorescent lamps are off with the heaters on.  The infrared light
energy generated by the heat...