I have a project in which I have to show the link between differential equations and the CCD camera of the eyewriter

For a school project, I decided to talk about the Eyewriter which uses CCD cameras. I found that these cameras work with capacitors. We learned that the charge and discharge of capacitors can be modelised with differential equations. The question is : how do differential equations allow the Eyewriter to work properly? I have tried to search for information but everything is too complicated and I end up not understanding much. Does anyone have a simple explanation of how CCD cameras work and how I can incorporate differential equations in my project please?