Help!!! Problem with screen - dead pixels?...Sony TXN15P

Hi,
I have my Sony TXN15P for about a year and was rather happy with it however today a strange thing happened to the screen - please see attached photo.
Those blotches are best visible on bright screen and almost not visible on black. No apparent damage was done to the laptop, it seems those blotches just appeared by themselves...
Do you have any idea of what this could be?..Are those look like dead pixels?
Could this be fixed somehow?
Any help will be greatly appreciated.
Thank you in advance!

 

the attached picture is pure white.

 

Thank you for the reply!
It's really strange because in overnight time one of blotches disappeared and I saw myself that on screen photo there are only two blotches left.
Now it seems it was something (liquid?) between (could it be?!) screen and some kid of covering lid?...
Please sorry for this confusion, I was not able to remove any of blotches with a cloth and now one of them just disapeared by itself in 6-7 hours...

 

Now that I look closer there are still three of the blotches, just one of them became less visible.
Please find attached two photos I made with the camera, hope now you will see what's going on.
Nothing related to this could be seen on surface of the screen though...
I have those imprints of the keyboard almost from the first several days I owned my laptop (this problem was discussed on forum, I believe) and so I always put microfiber cloth between screen and keyboard while closing laptop but it didn't prevent from those blotches!