1. Photodiode: The CCD sensor consists of an array of tiny, light-sensitive photodiodes. Each photodiode is capable of converting light into an electrical charge.
2. Light Capture: When light hits the photodiode, it creates an electrical charge proportional to the intensity of the light. The more light that hits the photodiode, the greater the charge.
3. Charge Transfer: Once the charges are created, they need to be moved out of the photodiodes and into a storage area for further processing. This is where the "Charge-Coupled" part of the CCD comes into play.
- Each photodiode is connected to its neighboring photodiodes through a series of electrodes.
- By applying the appropriate electrical signals to these electrodes, the charges can be shifted from one photodiode to the next.
- This shifting or transferring continues until the charges reach the end of the CCD sensor.
4. Readout: At the end of the CCD sensor, there is an output register. The charges are transferred from the CCD array into the output register, where each charge is measured.
5. Analog-to-Digital Conversion: The analog charges are then converted into digital values through a process called analog-to-digital conversion (ADC).
6. Digital Image: The resulting digital values represent the brightness or intensity of each pixel in the image. These values are stored and processed to create the final digital image.
In summary, a CCD sensor converts incoming light into electrical charges, transfers these charges through the device using a series of electrodes, measures the charges, converts them to digital values, and assembles these values into a complete digital image.