Why LCD Writing Tablet is more and more popular and how it works?
If you’ve stepped foot into a large bookstore chain, craft store or one of those places that sell educational types of toys, chances are you’ve seen something similar to the pearl. This thin device is a pressure-sensitive LCD writing tablet designed to replace standard slate chalkboards, whiteboards, memo pads…
At first glance, it’s very thin, lightweight and has a decent sized bezel for holding. Running the included stylus across the sleek surface will reveal the true nature of the device. The pressure sensitivity and width of the stylus tip gave us the impression of writing with a thick colored pencil. There is a fair range of stroke width depending on how hard you press on the screen.
The erase function for the tablet is powered by a button cell battery that claims to erase up to 10,000 times. The writing and drawing function doesn’t actually require any power because of the nature of the pressure-sensitive LCD. Similar to e-paper screens, there is no energy required to keep draw or keep the image displayed, only to reset the screen. Still, 10,000 cycles ought to be enough to last for one year.
The device’s single button functions as a screen clear. There is a lock switch to prevent the button from erasing the screen when it’s accidentally pressed, but chances are you’re not going to be knocking out some great piece of artwork or jotting down a super-important note on the tablet, anyway.
How it works
The LCD Writing Tablet works on the principle of anisotropic flow, a unique feature of cholesteric liquid crystals, in which crystals flow at different rates, depending on the direction of pressure being applied. When a thin film of cholesteric liquid crystal is sandwiched between two sheets of specialized plastic, anisotropic flow causes the molecules to order themselves to reflect light in those places where a stylus touches the plastic sheet.
The liquid crystals are surrounded by polymer pillars, which control flow, resulting in excellent line sharpness. The written image is retained until electrically erased with the push of a button. In electronic erase, the flash of an electric field rearranges the molecules so that they are less reflective.