Specifications

Section 2 - Introduction to CCD Cameras
Page 28
Table 2.1 below lists some interesting aspects of the CCDs used in the Research models
of SBIG cameras.
Camera CCD
Array
Dimensions
Number of
Pixels Array Pixel Sizes
STL-4020M KAI-4020M 15.2 x 15.2 mm 4.2 million 2048 x 2048 7.4 x 7.4 µ
STL-1301E KAF-1301E 20.5 x 16.4 mm 1.3 million 1280 x 1024 16 x 16 µ
STL-1001E KAF-1001E 24.6 x 24.6 mm 1.0 million 1024 x 1024 24 x 24 µ
STL-6303E KAF-6303E 27.6 x 18.4 mm 6.3 million 3072 x 2048 9 x 9 µ
STL-11000M KAI-11000M 36.1 x 24.7 mm 11 million 4008 x 2745 9 x 9 µ
TC237 Tracking CCD TC-237H 4.9 x 3.7 mm 325 thousand 657 x 495 7.4 x 7.4 µ
Table 2.1 - Camera CCD Configurations
The CCD is cooled with a solid-state two-stage thermoelectric (TE) cooler. The TE cooler
pumps heat out of the CCD and dissipates it into a heat sink, which forms part of the optical
head's mechanical housing. In the Research Series cameras this waste heat is dumped into the
air using a heat exchanger and a small fan. The heat exchanger is also capable of water
circulation for additional efficiency if needed in hot climates. An inlet and outlet are provided
on the bottom of the camera head for passing water through the heat exchanger. Only a very
small flow is required and an ordinary aquarium pump is sufficient if it will pull the flow up
the length of tubing you might require at your installation. An optional 110VAC pump and
tubing are also available from SBIG.
Since the CCD is cooled below 0°C, some provision must be made to prevent frost from
forming on the CCD. The Research Series cameras have the CCD/TE Cooler mounted in a
windowed hermetic chamber sealed with an O-Ring. The hermetic chamber does not need to
be evacuated, another "ease of use" feature we employ in the design of our cameras. Using a
rechargeable desiccant in the chamber keeps the humidity low, forcing the dew point below the
cold stage temperature.
Other elements in the self contained Research Series cameras include the preamplifier
and an electromechanical shutter. The shutter makes taking dark frames a simple matter of
pushing a button on the computer and provides streak-free readout. Timing of exposures in
Research Series cameras is controlled by this shutter.
The Clock Drivers and Analog to Digital Converter interface to the CCD. The Clock
Drivers convert the logic-level signals from the micro controller to the voltage levels and
sequences required by the CCD. Clocking the CCD transfers charge in the array and is used to
clear the array or read it out. The Analog to Digital Converter (A/D) digitizes the data in the
CCD for storage in the Host Computer.
The micro controller is used to regulate the CCD's temperature by varying the drive to
the TE cooler. The external Power Supply provides +5V and ±12V to the cameras. Finally, the
cameras contain a TTL level telescope interface port to control the telescope and the internal
motorized filter wheel.
Although not part of the CCD Camera itself, the Host Computer and Software are an
integral part of the system. SBIG provides software for the Research Series cameras for the IBM
PC and Compatible computers running Windows 95/98/2000/Me/NT/XP. The software
allows image acquisition, image processing, and auto guiding with ease of use and professional