User`s guide

ACQUISITION MODES
SDK SECTION 4
Page 43
Frame Transfer
Frame transfer is a mode of operation of the chip that is only available if your system contains a Frame
Transfer CCD (FT CCD). It can be switched on for any acquisition mode.
A FT CCD differs from a standard CCD in 2 ways:
• Firstly, a FT CCD contains 2 areas, of approximately equal size (see figure 7 below).
1. The first area is the Image area, this area is at the top and farthest from the readout
register. It is in this area that the CCD is sensitive to light.
2. The second area is the Storage area and sits between the Image area and the readout
register. This area is covered by an opaque mask, usually a metal film, and hence is not
sensitive to light.
• The second way in which a FT CCD differs from a standard CCD is that the Image and the Storage
areas can be shifted independently of each other.
These differences allow a FT CCD to be operated in a unique mode where one image can be read out while
the next image is being acquired. It also allows a FT CCD to be used in imaging mode without a shutter.
Figure 7: Frame Transfer CCD