M
[email protected]
- Jan 1, 1970
- 0
I'm working on a low light still camera project using low cost Sony
ICX429AL interlaced CCD sensors.
Project architecture is : a PIC 16F877A (@20Mhz) for timing signals
generation, double correlated sampling, 16 bits ADC, data download to a
PC via USB.
In software I generate an acquisition sequence as follows :
1. Sensor reset ( via a single PhiSUB pulse )
2. Delay ( exposure )
3. Odd field start sequence ( from ICX429 datasheet )
4. Odd field download ( a loop of vert.shift and horiz.reg. read )
5. Even field start sequence
6. Even field download ( a loop of vert.shift and horiz.reg. read )
Camera works fine, but I have an important difference in ADU levels for
odd and even fields. That generate a very annoying pattern of
horizontal stripes ( sometimes called "Venetian blind" )
Even though a small amount of "venetian blind" seems to be normal for
interlaced sensors, the amount i have is not normal. Gap between even
and odd fields could be as high as 5000 ADU (in a 0-32767 scale).
I checked hardware and software sequences many times, and everything
seems correct. So, I guess, I'm missing something very basic that I may
give as granted, but that must be wrong.
Anyone with more experience could please give an advice ?
Don't be afraid to ask, if you need more details ( I'd like to get rid
of this....!!! )
Regards,
Marco Paolilli
Italy
ICX429AL interlaced CCD sensors.
Project architecture is : a PIC 16F877A (@20Mhz) for timing signals
generation, double correlated sampling, 16 bits ADC, data download to a
PC via USB.
In software I generate an acquisition sequence as follows :
1. Sensor reset ( via a single PhiSUB pulse )
2. Delay ( exposure )
3. Odd field start sequence ( from ICX429 datasheet )
4. Odd field download ( a loop of vert.shift and horiz.reg. read )
5. Even field start sequence
6. Even field download ( a loop of vert.shift and horiz.reg. read )
Camera works fine, but I have an important difference in ADU levels for
odd and even fields. That generate a very annoying pattern of
horizontal stripes ( sometimes called "Venetian blind" )
Even though a small amount of "venetian blind" seems to be normal for
interlaced sensors, the amount i have is not normal. Gap between even
and odd fields could be as high as 5000 ADU (in a 0-32767 scale).
I checked hardware and software sequences many times, and everything
seems correct. So, I guess, I'm missing something very basic that I may
give as granted, but that must be wrong.
Anyone with more experience could please give an advice ?
Don't be afraid to ask, if you need more details ( I'd like to get rid
of this....!!! )
Regards,
Marco Paolilli
Italy