Drucker Diagnostics Paralens Advance - Manual (Page 20)

3.1.5 Optics (continued)
The red light source is a 610 nm LED and is used
primarily for scanning the red cell layers in the
blood tube and for detecting tube characteristics,
i.e., closure type, tube type, fill volume, float length,
etc. A slit mask controls the area of illumination of
the tube.
The blue light source is a miniature tungsten lamp
for fluorescence scanning of the buffy coat. An
interference filter is used for blocking all light of
a wavelength of 490 nm or longer. An aspheric
condensing lens, having a focal length of 8.5 mm,
concentrates the light energy onto the tube.
In order to maintain a constant relative position with
respect to the photodetector, the blue light source
is mechanically attached to the analyzer frame.
The tube, which moves along its longitudinal axis,
remains vertically perpendicular to the light source
during the scanning process. The light source is
movable for adjustment purposes only. A position
layout of the optics chamber is shown in Figure
3-10.
3.1.6 Electronics
The electronics of the analyzer (Figure 3-11)
consists of a single chip microcomputer, allocated
by function to the following four circuit boards:
• Main PC board, mounted in base of lower
housing.
• Memory PC board, located in removable
cartridge, with up to 512K bytes of UV-erasable
program (EPROM).
• Display PC board.
• Optics PC board, photodetector pre-amplifier,
and circuitry within shielded enclosure behind
filter wheel housing.
The main PC board provides all of the instrument
control functions, including the filter wheel and
transport motor controls, illumination control,
printer outputs, timekeeping, data storage, signal
conditioning, and digitizing.
3-5
Figure 3-10.
Position Layout of Analyzer Optics
Figure 3-11.
Simplified Interconnection Diagram
LOAD PLATFORM
MEASURE DEVICE
TUBE SUPPORT
& CLAMP
LOAD POSITION
MEASURE POSITION
INDEX POSITION
TUBE SENSOR
FILTER WHEEL
OPTICAL SLIT
LENS
COLLET & CAM
SILICON DETECTOR LENS
490 CUTOFF FILTER
FLUORO. SOURCE LAMP (BLUE)
INDEXING PINS
OPTICAL SLIT
END OF TRAVEL DETECTOR
RED L.E.D.
TRANSMITTANCE SOURCE
POWER PACK
DISPLAY MULTIPLE D.C.
PC OUTPUT
BOARD
OPTICS
LAMP
PHOTO
DETECTOR
PC
BOARD EPROM
CART-
RIDGE
FILTER
DOOR MOTOR
SWITCH
MAIN PC BOARD
MOTOR
MEMBRANE CARRIAGE
KEYPAD