Full Frame And Frame Transfer / Interline Ccds; Camera Hardware Architecture - Santa Barbara Instrument Group STL-1001E Operating Manual

transports the charge packets in a serial manner to an on-chip amplifier. The
final operating step, charge detection, is when individual charge packets are
converted to an output voltage. The voltage for each pixel can be amplified off-
chip and digitally encoded and stored in a computer to be reconstructed and
displayed on a television monitor."
Output

2.2.1. Full Frame and Frame Transfer / Interline CCDs

In the STL-1301E, STL-1001E and STL-6303E, the CCD is read out electronically by shifting each
row of pixels into a readout register at the Y=0 position of the CCD (shown in Figure 2.1), and
then shifting the row out through an amplifier at the X=0 position. The entire array shifts up
one row when a row is shifted into the readout register, and a blank row is inserted at the
bottom. The electromechanical shutter built into the camera covers the CCD during the readout
to prevent streaking of the image. Without a shutter the image would be streaked due to the
fact that the pixels continue to collect light as they are being shifted out towards the readout
register. CCDs with a single active area are called Full Frame CCDs.
For reference, the TC-237 guiding CCD uses a different type of CCD, which is known as
a Frame Transfer CCD. In these devices all active pixels are shifted very quickly into a pixel
array screened from the light by a metal layer, and then read out. This makes it possible to take
virtually streak-free images without a shutter. This feature is typically called an electronic
shutter. The interline CCD used in the STL-4020M and STL-11000M is similar to a frame
transfer except that the protected pixels are interlaced with the active pixels.
2.3.

Camera Hardware Architecture

This section describes the STL-4020M, STL-1301E, STL-1001E, STL-11000M and STL-6303E CCD
cameras from a systems standpoint. It describes the elements that comprise a CCD camera and
the functions they provide. Please refer to Figure 2.2 below as you read through this section.
1
"History and Advancements of Large Area Array Scientific CCD Imagers", James Janesick, Tom
Elliott. Jet Propulsion Laboratory, California Institute of Technology, CCD Advanced Development
Group.
Section 2 - Introduction to CCD Cameras
1
Y=1
Amplifier
Y=N
X=1
Figure 2.1 - CCD Structure
Page 26
Readout Register
X=M