Perhaps I'm not reading your question correctly or I'm not through enough in my answer so if you are asking where is' TSA's written word on the projector-
Well the TSA website doesn't cover that
http://www.tsa.gov/travelers/airtrav...rial_1248.shtm
is the closest, though technically a video projector isn't photographic equipment or film.

But if one digs around on their list here: http://www.tsa.gov/travelers/airtrav...rial_1169.shtm
not of those choices cover a video projector either.

So I won't fault the original poster for asking here, on the frequent flyers forum in the hopes that someone else has gone before, done this and is willing to share their experience.

There have been quite a few instances where different travelers through the checkpoint experience different treatments on the same item, regardless of TSA's published information, on their website. Some are waved through without a blink with their possession a few have to part with the same item. And the clause of 'at the TSO's discretion' seems to just be at their whim.

There were travelers whom presented a printout of the website stating a certain item was approved to carry on but told by the TSO 'the website is outdated.' There were quotes of another instances where the TSO, probably not the same person as the first previous example, who said 'not today it isn't [approved]' regarding a different item.

This thread is one example. That woman could not bring her breast milk through, but other women have been able to.
http://www.flyertalk.com/forum/trave...reastmilk.html
citing
http://www.anktangle.com/2011/01/tsa...reastmilk.html

(I don't think I'm using the search function in the most efficient manner, I can't find the thread/post of the other incidents and the second quote, my search comes up with multiple partial results but not the ones I'm looking for. But I know I've read it on here, this forum.)

I, myself, have encounter something as simple as the issue of the Checkpoint Friendly Laptop Bag. I had one, but when I got to the checkpoint, the TSO scolded me for not taking out the laptop of the bag. Regardless it was approved. But on my return trip, with the same bag, I was allowed to leave the laptop computer in the bag as it went through the x-ray machine. Other people have gone through just fine with the same bag. This is just my personal example of how 'our mileage may vary with the TSO.'