Toshiba e-STUDIO2330C Service Manual page 136

[ 1 ] Principle of original size detection
Reflection type photosensors are placed on the base frame of the scanner unit as shown in the figure
below. Each sensor consists of an infrared Light Emitting Diode (LED) on the light emitting side, and a
phototransistor on the light receiving side.
When there is an original on the original glass, light beams from the LEDs are reflected by the original
and led to the phototransistors. This means that the presence of the original is detected by the
presence of reflection (when scanning black image).
[ A4 Series ] [ LT Series ]
Original Original glass Original Original glass
APS-R
APS-R
APS-3
APS-3
APS-2
APS-1
APS-C
APS-C
APS-2
Fig. 7-13
e-STUDIO2330C/2820C/2830C/3520C/3530C/4520C © 2008, 2009 TOSHIBA TEC CORPORATION All rights reserved
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