What is the efficiency of a laser device like nowadays?

I went to a 3D TV IEEE demo back in the 1970's where the device looked
like a TV but had "depth". Kind of like those kids puppet theatres! The
big thing I remember at the time was the huge power consumption
(1000-2000W?) needed to produce even a moderately lit picture. It was
said at the time that the appliance would probably never be marketed as
a 3DTV in every house would flatten the electricity supply system every
time a football/crickrt match was on!

I cant quite remember the physics or name behind the 3D technique. Some
kind of inteference pattern generation maybe. The name escapes me...

Cheers Bob VK2YQA

Spike wrote:


Powered as it is by AAA cells, it seems to have
a greater power, and a greater reserve of power, than
those laserpointers powered by watch batteries.

The shortest Google search would have turned up the information needed
to avoid him making such an obvious statement. A CR2032 battery has a
capacity of 220 mAh at a current drain of 0.2 m/A.A modern AAA battery
far exceeds that - I've left it as an exercise for the OP to search
for that info..