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### Course: Electrical engineering>Unit 9

Lesson 4: Digital camera

# What is inside a digital camera? (1 of 2)

In this video we go inside the digital camera to discover what is inside and how it works. Created by Karl Wendt.

## Want to join the conversation?

• Why is the CPU under that blob? What is the blob made of?
• The blob is made of epoxy. The epoxy protects the connections to the CPU from impact and moisture.
• What is a diode?
• He talks more about it in 'what is in a tap light?' I hope that answers your question.
• How does the image that comes in through the lens and hits the plastic turn into 1's and 0's?
• Different formats (like jpg and png) handle this differently, but the camera is able to take the information on a pixel-by-pixel basis (sometimes this isn't the case on cheaper models) and convert it to a simple binary code based on the amount of red, green, and blue detected (I'm pretty sure it's in that order most of the time, too).

The image itself is all those pixel codes put together in order. That order depends on the format. If I recall correctly, png does it line by line, while jpg does it in clusters.
• How does a diode work exactly?
• It is made from semiconductor material like silicone that has been treated to contain a surplus (negative) electrical charge on one side and a lack (positive) on the other.
Where the two materials meet, the negative and positive charges switch places in order to balance things out, but when that has happened, the current stops flowing through the diode so well.
In order to allow the current to flow, you need to apply positive charge to the positive side, negative to the negative side (think of how batteries have + and - ends). The build up of same charge on each side increases the pressure on the meeting point between the two layers of the diode and allows the barrier of exchanged electric charge to be overwhelmed, so the diode begins to conduct well again.
If positive charge is applied to the negative side (and negative to the positive, i.e. if you were to attach a battery the other way round, it would only reinforce the barrier that has formed where the two layers of the diode meet.
• are quartz in all digital cameras?
• quartz are in all digital stuff, it's more than "counting time", it's used to synchronize different parts of the ICs
• Dr. Wendt, do you put this stuff back together when you're done?
• How does a Liquid Crystal display work?
• an LCD is technically different from a TFT (which is on the back of the camera) but here's the principle of operation

The LCD works by polarizing molecules and obscuring parts of the glass they are under. so LCDs are not directly visible if there is no ambient light (think old digital watches - if you're in a dark room, unless you shine a light on the display, you can;t see it)

The TFT matrix is always illuminated from the back usually by CCLs. The TFT matrix consists of lots and lots of thin light filters that only let certain ligth pass through them. The LCD matrix is placed under those light filter and it either obscures or lets the light through. This way a color image is created.

• What is a l e d