How does the sensor CCD work...

The sensor CCD has turned into one of our inseparable technological partners. It is possible that many you do not even know what is, not why it works, but almost with entire safety you use it or have used it in some electronic device. Do not you imagine where? Without going further in your mobile phones with camera or in a digital camera. Any electronic device that receives photo or video uses almost with entire safety a sensor CCD. Now then: how does a sensor CCD work?
The basic functioning is not too complicated to understand and it is based on the photoelectric effect. This effect was described of theoretical form by Einstein in the year 1905 (receiving later the Nobel Prize in 1921) and it comes to us to say that when a photon (light) affects on a surface, if it has enough energy, it is going to manage to start some electrons of the material. With this it is possible to generate a usable electric current for what it is needed.

Knowing this, we can already begin treating the sensor. As we said already in the previous paragraph, the sensor CCD works basically for the photoelectric effect. Therefore, after the light makes affect on him there are started electrons that finish in a condenser. To major intensity of the light more electrons are started and therefore major is the stored load. Depending on this load it goes to have a different voltage that will be what determines finally the color. This happens for every cell of the sensor, or what is known generally as a pixel. If we join quite these cells or pixels it is when we have the captured image, which then we will be able to see in the computer or in any other device.
When it is said that a digital camera has a number of pixels it means that the sensor CCD has this number of cells and therefore, major resolution is going to have the image to major number of cells. The cells of the sensor CCD are ready in rectangular form, hence the digital photos have this form.
To finish, I want to propose a small exercise to you. It is sure that you have listened more than once that a digital camera has 5 Mpx (5 million pixels), or even more. Now then: have you ever stopped to calculate the number of pixels (resolution) that has your screen of the computer? You can do it very easily multiplying the pixels breadth by the high place, that is to say: 1280x800, 1440x900, or the resolution that you have. The result is surprising: truth?
Greetings ;)
Source of the images: Wikipedia (1) and (2)