How Do Touch Screens...Touch?

Summary

The video explains how touchscreens work, contrasting the technology used in phones versus kiosks. It breaks down the layers of a phone's touchscreen - strong Gorilla glass on top, then a grid that stores electric charge, detecting disruption when touched. It notes how gloves and wet fingers interfere with this system. Finally, it explains how screens display color via pixels containing red, green and blue light emitters, which combine to form millions of colors across the high resolution display.

Takeaways

• 😲 Touch screens work by detecting changes in electric charge distribution caused by touch
• 👨‍🔬 Gorilla glass makes touch screens durable
• 😀 McDonald's kiosks use pressure-sensitive touch screens with less precision
• 📱 Smartphones use capacitive touch screens that detect finer changes
• 🔋 The capacitive grid holds electric charge like a capacitor
• 🧠 The processor detects changes in charge distribution when touched
• 💡 Fingers conduct electricity to alter charge while gloves insulate
• 🌊 Wet fingers confuse the screen by activating multiple points
• 🎨 Pixels use RGB colors to create images on the display
• 💰 It costs one subscribe for this smartphone lesson!

Q & A

What are the two main types of touch screens explained in the video?

The two main types are resistive touch screens, like those used in McDonald's kiosks, and capacitive touch screens, which are used in most personal devices like phones and laptops.

What is gorilla glass and why is it important for touch screens?

Gorilla glass is a type of very strong, durable glass that is used for the top layer of capacitive touch screens. It provides protection for the sensitive layers below.

How does a resistive touch screen work?

A resistive touch screen has two plastic layers coated in a conductive material. When pressed, the layers connect to detect the touch. However, it requires more pressure than a capacitive screen.

What are the main layers in a capacitive touch screen?

The main layers are 1) the top gorilla glass layer, 2) a grid that holds a negative charge, 3) a grid that stores a positive charge when the first grid is near, and 4) a processor that detects changes in charge.

How does a capacitive touch screen detect touch location?

The positively charged grid has a precise diamond pattern. When a finger touches the screen, it changes the charge at specific diamonds. The processor matches these locations to the display.

Why don't gloves work on capacitive screens?

Gloves act as an insulator that blocks the electrical interaction between the screen and your finger needed for capacitive sensing.

Why do water drops sometimes cause issues with capacitive screens?

Water is conductive so it can activate multiple points on the grid at the same time, confusing the processor.

How does a screen display color?

Each pixel contains red, green and blue subpixels. By controlling the brightness of each one, any color can be produced.

Where does the glass for touch screens come from?

It starts as high purity silica sand which is melted and molded into glass sheets.

What enables touch sensing in a resistive screen?

The two plastic layers are coated in a conductive material that allows electricity to pass between them when pressed.