KaVo ORTHOPANTOMOGAPH OP 2D, Service Manual

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20 ORTHOPANTOMOGAPH OP 2D
2. Unit Description
Position control
The position of the rotating unit (R-movement) is moni-
tored by optosensors on L2100 (Rotation Position Sen-
sor Circuit). The optosensors indicate in which sector
the rotating unit is. The optosensors ensure that the
rotating unit is in the correct position, start or PIO (Pa-
tient In/Out), for an exposure.
The statuses of the optosensors are monitored continu-
ally by the unit software.
The upper and lower limits of the vertical carriage (Z-
movement) are monitored by microswitches.
Overview of the Imaging Chain
This description assumes that the unit is ready to take
an exposure.
Image acquisition is controlled by the image capturing
driver which is installed as part of the driver software in
the PC connected to the unit.
When an exposure is taken L1200 (the CPU) then
sends a PPOWER and CCDENA signal. CCDENA sig-
nal activates voltages for the CCD sensor.
The CPU's control software continuously monitors the
status of the connection with the image capturing driver.
The CPU enables the IMAGE signal to activate pixel
clocking. The CPU then produces the TDI clock signal,
which clocks the pixels from the CCD sensor. Derivation
of several CCD clock signals from the TDI clock is done
by the CCD sensor board. The CPU also controls the
generator board supplying power to the tubehead.