AQA A-Level Physics/Charge Coupled Devices (CCD)
Charge Coupled Device
[edit | edit source]- A CCD is a silicon chip divided into picture elements (pixels)
- Incident photons cause electrons to be released
- The number of electrons liberated is proportional to the intensity of light
- These electrons are trapped in 'potential well' in the CCD
- An electron pattern is built up which is identical to the image formed on the CCD
- When exposure is complete, the charge is processed to give an image
- Quantum efficiency of a pixel is greater than 70%