9600 Service Manual - gmecorp-usa.com

2 Video Control
IMAGE PROCESSOR PCB
The Image Processor PCB is the image data processor that contains a Graphic System
Processor (GSP) which is driven by a 50 MHz clock. All Workstation image processing
functions are controlled by the Image Processor. The GSP provides control signals to
the Video Switching PCB, and Scan Converter PCB. Because the Image Processor
PCB is multi layer and uses surface mount circuits, repair of this board outside of the
factory is not recommended. Functionality of the Image Processor PCB is determined
by the use of system based diagnostic test programs.
A/D CONVERTER
The video signal enters the Image Processor PCB via connector P4 pin 5. The video
signal can be monitored at TP3 on the Image Processor PCB. The video signal is sent
to A/D converter U17 where it is converted to an 8 bit digital number. The digital video
data is then sent to the scan converter section of the Image Processor PCB.
SCAN CONVERTER
The Scan Converter section consists of a two video frame memory that receives the
digital video data from the A/D converter U17. The video data is written into one frame
of memory at a time. When the first frame of memory is full, video data is written into the
second frame of memory. The first frame of video data is read out to the Image
Processor circuitry while the second frame of video data is read in. By changing the
way the video data is read out of the frame memory, the scan converter is able to
provide horizontal and vertical image reversal control for the images displayed on the
monitors and peripherals. This scan converter function is provided because the CCD
camera does not offer horizontal and vertical image reversal control.
D/A CONVERTERS
After the video data has been processed by the Image Processor circuitry, left and right
video data is sent to the D/A converters U2 (LVID) and U16 (RVID). The D/A converters
convert the processed digital video data into an analog video signal. The left video
signal is used by the internal VCR, Hard Copy Camera and Thermal Printer. The left
video signal exits the Image Processor PCB via P4 pin 9 where it goes back to the
Video Switching PCB. The right video signal exits the Image Processor PCB via P4 pin
1 which also goes back to the Video Switching PCB. The right video signal is not being
used.