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LCD writing tablet functional principal

Created: 2024-05-19 | Modified: 2024-11-02

Cholesteric liquid-crystal drawing tablet

Tablet screen filled

Prelude

I recently stumbled across drawing tablets seemingly works by the means of magic, the search term is: LCD writing tablet I have a thing for daylight viewable screens, so the allure was irresistible for me.

After one quick trip to the local hardware store, and subsequently the local hacker space, i was able to examine the technology first hand, and for low monetary cost too, i might add.

Properties

The properties are as follows:

Daylight viewable
Passive working principle (only requires power to clear the display)
Pressure amount sensitivity (light pressure = thin line, hard pressure = thick line)

Layers

The tablet consists of a sandwich of 3 layers:

A dark background
A layer of cholesteric liquid-crystals
A piece of translucent plastic

Functional principal

The means of function of this device, is merely a property of how the cholesteric liquid-crystal work:

"crystals flow at different rates, depending on the direction of pressure being applied"

"anisotropic flow causes the molecules to order themselves to reflect light in those places where a stylus touches the plastic sheet."