Pixel, photodiode and capacitor

In summary, a pixel is the smallest element in an image, while a photodiode is a device that converts light into electrical current and a capacitor is a device that stores charge. In a digital camera, the photodiode captures light and stores the charge in a capacitor, which represents a pixel in the image. The CCD sensor behind the lens contains an array of pixels, each with a photodiode and capacitor, which work together to capture and store the image.
  • #1
bonefish
3
0
Hi!

I'm having trouble figuring out the difference between a pixel and a photodiode as well as a capacitor- they all seem like the same property to me! :confused:

Can someone please help me?:confused:

Thanx
 
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  • #2
A photo diode is a physical device that creates charge when photons strike it. A capacitor is a device that holds charge. A pixel is the smallest piece of information in an image.

So in a digital camera's charge coupled device (the "film" of the digital camera), a photodiode collects light and stores the charge in a capacitor until it is needed. That is a pixel in the image. Of course there are many pixels in a typical image (maybe millions). These are shifted out when needed.
 
  • #3
  • #4
In digital camera, there is a sensor array behind the lens that capture the digital image. The sensor is called CCD which is charge coupled device. It composed of an array of small sensor, each one is one pixel. It is arranged in rows and column. Each contain a photo diode sensor that capture the color and brightness and translate to a charge and store in the cap inside each pixel cell. After capture the image and store in each of the cap inside each pixel, the circuit in camera then transfer the charge of each pixel into memory. This can then be display on the screen or put it on picture. So:

1) Pixel is the smallest element of the image sensor.
2) Each pixel contain a color photo sensor that put charge into the cap of each pixel.
3) Each pixel have a cap inside to be charge by the photo sensor and store the amount of charge proportion to the color and intensity.
4) circuit in camera then shift the charge amount out of the CCD device and store in memory that form the picture.
 
Last edited:
  • #5
thanx guys:wink:
 

What is a pixel?

A pixel, short for picture element, is the smallest unit of a digital image or display. It is a small square or dot that contains a single color and combines with other pixels to create an image.

What is a photodiode?

A photodiode is a semiconductor device that converts light into an electrical current. It is commonly used in cameras and image sensors to detect and measure light.

What is a capacitor?

A capacitor is an electronic component that stores electrical energy. It is made up of two conductive plates separated by an insulating material and is commonly used in electronic circuits to regulate and filter electrical signals.

How are pixels, photodiodes, and capacitors related?

Pixels, photodiodes, and capacitors are often found together in electronic devices such as digital cameras and image sensors. Photodiodes are used to capture light and convert it into an electrical signal, which is then stored in the capacitor. The capacitor then transfers the signal to the pixel, which displays the corresponding color on the screen.

Why are pixels, photodiodes, and capacitors important in digital imaging?

Pixels, photodiodes, and capacitors are essential components in digital imaging as they work together to capture, store, and display images. Without these components, digital cameras and image sensors would not be able to function and produce high-quality images.

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