Counterclockwise: the touchscreen evolution
The human-computer interface has been a problem since the dawn of computers. As far as smartphones are concerned, the clear winner is the touchscreen. But how did we get here?
The proto-touchscreen was the light pen, which was first developed in the 50s and 60s and was available to consumers as an accessory for 8-bit computers in the 80s. The light pen is a simple but clever solution that works only with CRT monitors – it senses the electron beam as it scans across the phosphor drawing the image line by line, pixel by pixel. When the beam is sensed by the pen, the computer just makes a note of which pixel was being drawn at the time, that’s how it knows where the pen is on the screen.
An honorable mention goes to the Sony Xperia Projector. It runs Android and not only projects the screen, but uses IR sensors to turn the image into an actual touchscreen. This is the holy grail of mobile tech – you can have a screen tens of inches in size (user adjustable) while keeping physical dimensions of the device small.
Image copyright Pippa Park Image caption Pippa Park was in less celebratory mood when a …