It's my lighting design task last year.
I designed a series of lamps which do not have the switch. And for some of these concepts have already been existed (one even been produced ) , I choose this one for further designing.
As you see it doesn't have a switch. To turn it on, just rotate it 90 degrees.
I found it hard to turn the concept into reality !!! :(
Yep! Make "impossible" possible is the attraction of product design :D
Finally i spent 3 days making a simple plastic prototype before the deadline.
It looks simple and poor.....but it works.
Here is a demo video of the prototype.
And there are some pic of the making process.
You can see the LEDs were taking from a flashlight :>