12
USER GUIDE
White x1
IR850 x1
VSC
®
80: Reflected light sources: White/IR
Flood lighting (Reflectance contrast)
Software control
Side lighting (Oblique lighting)
Software control
Software control
x2 IR980
x2 IR940
x2 IR850
x2 IR780
x2 White
VSC
®
80: Light sources
Light emitting diodes
Vapour discharge tubes
Ultraviolet (UV)
Visible
Infrared (IR)
▲
▲
▲
▲
200
400
700
1000
Wavelength (nm)
A variety of light sources are available to provide illumination in the UV, Visible and IR parts of the
spectrum. Each of the main light sources is suitable for maximising the visual contrast of a specific type
of feature in a document: Technical Notes (Document examination) (p. 41-1). The VSC
®
80 main unit is
controlled by the PC system and VSC
®
software. Refer to the relevant User Manual for full details. See
also: Quick Start Guide (Replacing the lamps) (p. 03-1).
Light emitting diodes (LED)
LED
Colour
Nominal wavelength (nm)
Bandwidth (10%)
Peak
IR980
880
– 1030
980
IR940
880
– 980
940
IR850
800
– 880
850
IR780
740
– 800
780
UV365
350
– 390
365
White
400
– 700
Light emitting diodes can be manufactured to produce narrow bandwidth light within an ever-expanding
part of the UV, visible and IR region of the electromagnetic spectrum. The bandwidth of the radiation is
generally much greater than that produced by vapour discharge tubes.
White light emitting diodes are normally manufactured by incorporating a phosphor into a blue LED. The
resulting white light therefore has a generally bluer appearance than that from incandescent lamps
Illumination modes: Reflected light sources
x1 White
x1 IR850
VSC
®
80: L
IGHT SOURCES
IR980 x2
IR940 x2
IR850 x2
IR780 x2
White x2