Smartphones

The angles from which you can view an LCD screen vary according to which manufacturer made it, how much was paid for it, and generally sheer luck.

Clearly, until a laptop screen is opened to at least 90' from the keyboard, there is little need to be able to view the screen because you would have to bend down and squint through the gap between the screen and the keyboard.

The main cause is the process by which LCD TFT laptop screens are constructed. Check these out:

http://displaytech-us.com/pdf/ol_lcd/LCDConstruction.PDF

http://www.mmselectronics.co.uk/01607.htm

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