Image Control
Circuit/Mechanical Descriptions
CCD Camera
The CCD Camera used with the system has a macro-focusing lens and video circuits that pick up images from the output face of
the image intensifier tube. The camera sends those images to the Video Controller PCB in the Workstation for processing and
storage, along with display on the workstation monitors and possible storage on videotape.
In operation, switch closures on the C-Arm control panel are sent to the Control Panel processor and then routed via RS232
communication to the Fluoro Function PCB. The Fluoro Function PCB microprocessor directs the camera to respond to the key
operation; camera Iris control and camera rotation. The camera reports its status back to the PCB and the system by the
readings from various positioning pots.
The Fluoro Functions PCB provides control to the CCD Camera motors and also to the Collimator motors (refer to the Collimator
chapter of this manual for more details). Control of the camera gain and mode is accomplished with a manchester (digital) RS-
422 signal. In addition, the PCB also supplies control voltages to the Image Intensifier (refer to the Image Intensifier section of
this chapter for more details) to control field size and transfers data and other signals between the workstation and the Control
Panel Processor PCB.
The manchester encoded data sent from the Fluoro Functions PCB to the camera is used to control camera gain, integration of
multiple frames by the camera and camera mode (50/60 hZ).
Camera gain is used in the ABS control loop to achieve the desired brightness with the lowest technique. It is an output from the
.abs tables stored on the C-arm.
The integration bit is used during pulsed shots at 4 pulses per second and less where the pulse length is greater than the frame
time. The camera must be told to integrate across multiple frames to acquire all the photons.
The mode is used to command either 50 or 60 hZ operation since the 9800 camera is capable of operating at either frame rate
(40 ms frame time at 25 frames per second or 33.3 ms frame time at 30 frames per second).
If the manchester data is not being sent and received properly you should expect to see faulty ABS behavior and dark images in
pulsed fluoro shots at 4 pulses per second and less.
2
Service
Periodic Maintenance
Contents
Schematics
Illustrated Parts
Installation
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