How does the CCD work?
In a CCD, the electrical field at different parts of the surface is controlled by an array or matrix of electrodes; these electrodes are called the gates. (CCD arrays can be either one-dimensional or two-dimensional, but here we will consider the one-dimensional array in detail, and then apply that information to understand the two-dimensional array.) This array of electrodes biases each small part of the surface differently, which allows any flow of charge on the CCD to be controlled. 1,2 The surface of the CCD is further broken down into smaller regions called pixels, or picture elements.8 This name is appropriate because they represent a single “grain” of the imaged object (just like you can see that your TV images appear to be made up of tiny “grains”). The array of electrodes apply a positive potential, (+Vg, a positive electric field) to two-thirds of each pixel, thus forward-biasing that portion of the pixel. Let’s represent the first third of the pixel by (1, the second third b
