ACS-1024-LG Photon Vision Systems, Inc., ACS-1024-LG Datasheet - Page 6

• Manufacturer Part Number: ACS-1024-LG
• Description: Image Sensor, CMOS|CCD, 1026x1026 Pixels, 132pin LCC
• Manufacturer: Photon Vision Systems, Inc.

undisturbed for further reading allowing noise elimination or continued signal accumulation for optimal image contrast. The
“sensing” of the pixel signal is a key advantage over CCD’s.
Snapshot shutter allows video to be temporarily stored on the Hold capacitor. The sequence starts with the Hold FET and the
Reset FET turned “on” to bias both the Hold capacitor and the pixel to the same level. The Reset FET and the Hold FET are
turned “off”. The pixel is allowed to integrate. The Hold FET is selected, the video on the pixel is sampled, and the Hold FET
is turned “off” or deselected. When the row is selected for reading, the Row FET is selected and the stored video is read.
Then, the Rest FET and Hold FET are selected, re-biasing the pixel to the reset value and both are turned off. The rest value is
sampled and subtracted for pattern noise free video.
The “Adaptive Exposure Control” method describes Non Destructive Read Out (NDRO) for ACS sensors. The pixels are
biased to the reset value by selecting and deselecting the Hold FET and Reset FET as previously described. The pixels are
allowed to integrate. The Hold FET is selected and deselected for sampling the pixel value. The value is read for optimal
signal levels. If more integration is desired, the pixels are allowed to integrate longer and pixel value is re-sampled by
selecting and deselecting the Hold FET. When the desired signal level has been achieved, a row is selected for reading by
selecting the Select FET and sampling the video by selecting and deselecting the Hold FET. The Hold and Bias FETs are then
Selected and deselected to re-bias the pixels the reset value and the background.
These are the standard methods allowed and controlled internally by the ACS sensors series. If the imager is operated in the
slave mode, greater operator control allows more flexibility, to minimize the number of operations performed per frame of
Video and potentially reduce the associated noise generated.
Photon Vision Systems, Inc.
Product DATASHEET ACS PDS0003 Subject to change without notice. Page 6 of 26
Copyright© 2002 Rev A