If I am understanding the brief correctly, I think I may have some experience in the area of your business. A couple of years ago I worked on the digital signage information, advertising and queue processes at my local zoo.
#14 and #15 I've used the sun dial to show an ancient way of measuring time that is as natural and predictable as the human behavior your product manages. I've incorporated the screen as an obvious illustration of the digital media space you offer. I've put up #13 and #15 to show how it can be simplified for single colour stationery/invoice printing. #11 is in case the sun dial just doesn't work for you. :)
Thanks Robin. We really like the element of a screen, because we use them and thats our core business. We would prefer it simpler and with a more modern like the flat tv we have now. We appreciate the abstraction so dont worry about rendering o drawing an exact TV.