Andor Technology iXon Ultra 897 User Manual page 42

the frame (or 'image area') of the CCD-chip.
2 Charge in the frame is shifted vertically by one row, so that the bottom row of
charge moves down into the shift register.
3 Charge in the frame is shifted vertically by a further row, so that the next row of
charge moves down into the shift register, which now contains charge from two
rows - i.e. the charge is vertically binned.
Charge in the shift register is moved horizontally by one pixel, so that charge on
4
the endmost pixel of the shift register is moved into the Gain Register, and then
into the output node of the amplifier.
5 The charge in the output node of the amplifier is passed to the analog-to-digital
converter and is read out.
Steps 4 and 5 are repeated until the shift register is empty. The process is
6
repeated from Step 2 until the whole frame is read out.
Shifting the charge horizontally from several pixels at a time into the output node is
known as horizontal binning.
Horizontal binning in combination with vertical binning allows you to define so-
called superpixels that in Image Display Mode (see SECTION 4.7 DISPLAYING
DATA) represent as a single picture element charge that has been binned from a
group of pixels. For example, charge that is binned vertically from two rows and
horizontally from two pixels before being read out is displayed as a superpixel of
dimensions 2 x 2 pixels. You can define these superpixels from the Imaging Dialog
Box, which is accessible from the Setup Acquisition Dialog Box (see SECTION 4.5
SETTING THE ACQUISITION).
On the one hand, superpixels (by comparison with single pixels) result in a more
coarsely defined; on the other hand, superpixels offer the advantages of summing
data on-chip prior to readout.
ELECTRON MULTIPLYING CCDS
Horizontal Binning
Section 3 . 1
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