th7899m Datasheet, PDF (3/24 Pages) ATMEL Corporation – Full Field CCDImage Sensor 2048 x 20Pixels48

TH7899M
Figure 3. Cross Sectional View (AA') of a Photoelement and Potential Profile During
Integration
Image Area
Full Field Modes (No
Mechanical Shield On
Package)
The image area consists of an array of 2048 x 2048 useful photoelements for imaging.
The matrix also includes:
• 7 columns of dark reference and 5 isolation columns (half covered) on the right and
left sides. The isolation columns are to ensure the 2048 active columns and are
100% photosensitive,
• 8 supplementary lines in each zone A B C and D; these lines are useful when using
an optical shield in case of frame transfer architecture with memory zone to correct
smearing (digital correction).
Among these 8 lines in zones A and D, 3 lines at the top and at the bottom of the full
image area are masked with aluminium, all the other supplementary lines are
photosensitive.
The image area is divided into 4 parts of 520 lines each (electrically but not optically).
These 4 parts can be driven independently allowing different operating modes as
described hereunder.
In such cases a mechanical shutter is needed to shield the array from incident illumina-
tion during the readout period to avoid parasitic signal (smearing) particularly at low data
rates. Such a shutter is not necessary if no light is coming onto the photosensitive area
during the readout time (e.g. in case of pulsed light source).
There are mainly three different modes which can square with different optical formats,
with readout optimized in speed or with simplified operating conditions.
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