How Touchscreen Works In Simple Words

Summary

This video explores the fascinating evolution of touchscreen technology, from its humble beginnings in the 1960s to the advanced displays we use today. It highlights the differences between resistive and capacitive touchscreens, explaining how each works and where they're commonly found. The video also introduces other types of touchscreens, such as infrared, surface acoustic wave, and near field imaging, used in specialized fields like the military. Viewers will learn why their phone doesn't respond when wearing gloves, and how touchscreens have become integral to daily life across various industries.

Takeaways

• 📅 Touchscreens originated in the 1960s, with E.A. Johnson developing the first finger-driven screen in 1965.
• 👆 The first touchscreen could only process one touch at a time, but it was used in British air traffic control until the 1990s.
• 🧪 The resistive touchscreen was accidentally invented in the 1970s by a team led by Dr. G. Samuel Hurst while conducting atomic physics research.
• 🔄 The first multi-touch display was invented in the 1980s by scientists at the University of Toronto.
• 💵 Resistive touchscreens are commonly found in devices like ATMs and point-of-sale systems, where they register touch by detecting pressure.
• 📱 Capacitive screens, used in modern smartphones, respond to the electrical charge in human skin rather than pressure, allowing multi-touch functionality.
• 🧤 Capacitive touchscreens do not work when users wear gloves (unless the gloves are conductive) or when fingers are wet, due to interference with electrical charge.
• 🔊 Surface acoustic wave touchscreens use ultrasonic sound waves to detect touches, absorbing energy when touched.
• 💡 Infrared touchscreens use invisible light beams that are interrupted when the screen is touched, similar to security systems in movies.
• 🛡️ Near field imaging touchscreens are highly durable and used in military applications, working even with gloves or styluses.

Q & A

When was the first finger-driven touchscreen created?

The first finger-driven touchscreen was created in 1965 by E.A. Johnson. It could only process one touch at a time and was used by British air traffic controllers until the late 1990s.

What was the major innovation introduced by Dr. G. Samuel Hurst and his team in the 1970s?

Dr. G. Samuel Hurst and his team accidentally invented the resistive touchscreen in the 1970s while studying atomic physics. This allowed researchers to complete tasks in hours instead of days.

What is the difference between resistive and capacitive touchscreens?

Resistive touchscreens require physical pressure to register a touch and consist of two layers that bend when pressed. Capacitive touchscreens, on the other hand, detect changes in electrical current when they come into contact with anything conductive, such as human skin.

Why do resistive touchscreens perform poorly in bright light?

Resistive touchscreens are hard to read in bright light because they have multiple layers that reduce clarity and make it difficult to see the display in direct sunlight.

What are the two main types of capacitive touchscreens?

The two main types of capacitive touchscreens are projective and surface. Projective displays use a grid of sensor chips, while surface displays use sensors in the corners and a thin film over the screen to detect touch.

Why don't capacitive screens work when you're wearing gloves?

Capacitive screens don't work with regular gloves because gloves do not conduct electricity. Special gloves with conductive threads are needed to interact with these screens.

What causes issues when using a capacitive touchscreen with wet fingers?

Wet fingers can cause problems with capacitive touchscreens because water conducts electricity, making it difficult for the screen to determine where your finger is touching.

How does an infrared touchscreen work?

Infrared touchscreens use a grid of invisible infrared light rays in front of the screen. When a user touches the screen, the rays are interrupted, and a microchip analyzes the interruptions to determine the location of the touch.

What makes surface acoustic wave touchscreens unique?

Surface acoustic wave touchscreens use ultrasonic sound waves that travel across the screen. When the screen is touched, these sound waves are disturbed, and a microchip analyzes the disruption to detect the touch.

What is near field imaging, and where is it commonly used?

Near field imaging detects changes in the electric field of the screen when a finger or other object comes close to it. This technology is durable and often used in military applications because it works even with gloves or a stylus.