Physics 2000 Einstein's Legacy Laptop Screens

Calculator Displays

I'm still trying to make sure I have all this light-dark, on-off stuff straight. Signal on means dark...so the numbers in a calculator display must be places where the electric field is turned on.

That's right. Take a look at this next applet; it's a model of a calculator display. Selecting "outside" shows you the display itself; select "inside" to see the electrodes and liquid crystal molecules underneath.

As you play around with this applet, think about how it relates to the other pictures and applets you've seen: which way is the light going through? Which way do the electric fields go? Note that you're seeing many layers of the twisted cells at once; that's why the molecules are pointing in so different directions.

That's really cool. It looks like the "pixels" in this display are much bigger than the ones in a computer screen--each one of those seven big chunks in the shape of the number 8 is like one pixel, right?

Right--that's one reason most calculators are so limited in what they can display. Elaborate graphics require smaller pixels, as well as color and shading capabilities. And now I think we're ready to return to laptop screens, and see how the ideas we've discussed here can be applied to displaying such fancy graphics...



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