Meditation blackouts?, experiences of a questionable nature Options

Lately, when in meditation, I have been experiencing something quite odd: when deep in meditation, I tend to have moments where I "blackout" or loose complete awareness of my environment. I am not thinking anything, but the experience is very 'bright' and positive; it isn't scary in the least. But when it does happen, it catches me by surprise, and that surprise jolts me out of the state. I have lost fair amounts of time in this state, but it feels like seconds. This has happened in zazen, Manjushri, and Kuan Yin meditation, for the sake of detail.

So, my real questions are, what could this state be? Do others experience it? If so, will you share some knowledge about it or thoughts on what it might be?

Any input is appreciated!

I got that when I made myself pass out once. I'm sure that statement sounds very unhelpful, but I'll go into detail.

In that state, I was alone - but there was no concept of alone. Everything was black - but I had no eyes to see with, to differentiate black from anything else, so it wasn't really black at all. I couldn't feel, see, taste, smell or touch anything. The only thing that existed in the universe at all was myself.

Quite an enjoyable experience for me... is that anything like what you were experiencing?