Polaroid ST-8E, ST-9E, ST-7E manual CCD System Block Diagram

Section 2 - Introduction to CCD Cameras

TE Cooler Tracking CCD

	Micro-	Clock
	controller		Drivers
PC
Interface
		16 Bit	Preamp
		A/D
Telescope
				Shutter	Imaging CCD
Interface

Desktop

Power

Supply

Host Computer

Parallel Interface

Figure 2.2 - CCD System Block Diagram

As you can see from Figure 2.2, the ST-7E, ST-8E and ST-9E are completely self contained. Unlike our previous products, the ST-7E, ST-8E and ST-9E contain all the electronics in the optical head. There is no external CPU like the ST-5C, ST-237, ST-6 and STV.

At the "front end" of any CCD camera is the CCD sensor itself. As we have already learned, CCDs are a solid state image sensor organized in a rectangular array of regularly spaced rows and columns. The ST-7E, ST-8E and ST-9E use two CCDs, one for imaging (Kodak KAF series) and one for tracking (TI TC211, like the ST-4/4X). Table 2.1 below lists some interesting aspects of the CCDs used in the various SBIG cameras.

		Array	Number of
Camera	CCD	Dimensions	Pixels	Pixel Sizes
Tracking CCD	TC211	2.6 x 2.6 mm	192 x 164	13.75 x 16 µ
ST-5C	TC255	3.2 x 2.4 mm	320 x 240	10 x 10 µ
ST-237	TC237	4.7 x 3.6 mm	640 x 480	7.4 x 7.4 µ
STV	TC237	4.7 x 3.0 mm	320 x 200	14.8 x 14.8 µ
ST-6	TC241	8.6 x 6.5 mm	375 x 242	23 x 27 µ
ST-7E	KAF0401E	6.9 x 4.6 mm	765 x 510	9 x 9 µ
ST-8E	KAF1602E	13.8 x 9.2 mm	1530 x 1020	9 x 9 µ
ST-9E	KAF0261E	10.2 x 10.2 mm	512 x 512	20 x 20 µ
	Table 2.1 - Camera CCD Configurations

The CCD is cooled with a solid-state a 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 ST-7E and ST-8E cameras this waste heat is dumped into the air

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