What are E Ink displays?

About E Ink displays: 

• These are a special type of screen technology often used in e-readers like the Amazon Kindle.
• The technology was originally developed in the 1990s at MIT and is now owned by E Ink Corporation.
• Working:

o The screens work using tiny microcapsules filled with positively charged white particles and negatively charged black ones suspended in fluid inside the display.

o By applying positive or negative electrical charges to different areas of the screen, the white or black particles can be made to rise to the surface, creating the text and images on the display.

o Unlike LCD and LED displays that use a backlight, E Ink displays reflect light – just like paper. This makes them easier on the eyes for long reading sessions.

o They also require very little power since they don’t need a backlight and only use energy when the image changes.

o The lack of backlighting also means that they are easier to read under brighter lighting conditions, which isn’t the case with LCD/LED displays at all – legibility actually takes a hit under bright sunlight.

• Advantages

o They consume very little power compared to LCD and OLED displays. An E Ink display only draws power when the image is changed, meaning it can display a static image for weeks or months without needing a charge.

o They cause less eye strain for the user. 

• Disadvantages

o It has a slow refresh rate compared to LCD and OLED displays, making them unsuitable for video or animation.

o It has limitations on colour and resolution compared to other display technologies.

o The niche nature of E Ink manufacturing means the displays remain expensive, especially in larger sizes.

• Other applications: It is used in bus stop displays and walking direction signs and restaurants menu boards etc. 

Q1:What is a liquid-crystal display (LCD)?

It is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directly but instead use a backlight or reflector to produce images in color or monochrome.

Source:Unlocking the science of E Ink displays: Why we believe they must catch on