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SIGMA Manual Number 41019
Revision AA
Display
Spectrum uses a highly reflective thin film transistor (HRTFT) liquid crystal display containing:
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240 X 320 pixels (240 x270 are active)
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Color HRTFT - 16 out of a palette of 262,144 possible colors
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0.2235 mm X 0.2235 mm dot pitch
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Illumination by side mounted LEDs and diffuser.
The display employs front lighting using six white LEDs. Brightness of the LED front light is con-
trolled by a constant current source implemented on the 60091 I/O Board. The display can be easily
viewed while mounted to an IV pole, with viewing distances up to 15 feet and a minimum viewing
angle of ±30 degrees from a line perpendicular to the display plane. The display has two flex circuit
connections: The first 50-conductor flex circuit carries digital display and control data as well as
power for the display. The second 5-conductor display flex circuit carries power for the back light.
Both of these flex circuits connect to 0.5 mm flex circuit connectors on the I/O Board.
I/O Board
This 10-layer, 100% surface-mount component circuit board distributes input and output (I/O) from
all sensors (except the ultrasonic air detector) through flex circuit connections that will be discussed
in detail below. The I/O board also receives the keypad, motor and display flex circuit signals. The I/
O board hosts A/D converters and discrete I/O to interface to the Spectrum sensors.
Processor Board
This 10-layer, 100% surface mount component circuit board distributes input and output (I/O) from
the ultrasonic air detector through a 40-pin flex circuit connection (detailed below). Additionally, the
processor board hosts the Sharp processor, which controls the HRTFT display, and performs most of
the primary computations for Spectrum. The processor board also hosts the real-time clock (RTC)
chip and lithium back-up battery for the RTC, Flash and static RAM memory.
Flex Circuits
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Ultrasonic Flex
— This flex circuit provides connections to two pairs of ultrasonic piezoelec-
tric crystals (receive and transmit) as well as the secondary tube temperature thermistor. The
Ultrasonic Flex is connected to the processor board (60087) through a 0.5 mm pitch, 40-
conductor, right angle flex connector.
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Upper Aux Flex
— This flex circuit provides connections to the upper door latch and link
discrete signals, once per revolution hall effect sensor, and slide clamp sensor signals. The
upper aux flex is connected to the I/O board (60091) through a 0.5 mm pitch, 30-conductor,
vertical flex connector.
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Lower Aux Flex
— This flex circuit provides connections to the lower door latch and link
discrete signals. The lower aux flex is connected to the I/O board (60091) through a 0.5 mm
pitch, 10-conductor, vertical flex connector.
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Force Sensor Flex
— This flex circuit provides connections to the distal force sensor and the
primary tube temperature thermistor. The force sensor flex is connected to the I/O board
(60091) through a 0.5 mm pitch, 10-conductor, vertical flex connector.
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Backflex
— This flex is connected to the I/O board (60091) through a 0.5 mm pitch, 30-
conductor, vertical flex connector. The backflex provides the following functions: