TV wall mount portrait orientation storage
I'm looking for an articulating, rotating TV wall mount for a particular use.
I have a 12' square room with windows in the center of the back (viewing) wall.
To the left side of the windows, there is a 26" space between the edge of the window and the corner of the room.
I believe there's a stud about halfway between window and corner.
I would like to fit a flat screen TV so that it stores in the 26" space, but comes out as far as possible to the right side (toward the center of the windows, which have curtains).
My concept is a roughly 40" TV that stores in portrait mode in the corner space. For use, the screen comes out toward the center of the back wall as far as possible (ideally, 6', but I'm a reasonable man). The screen rotates to landscape orientation. To put it away, I rotate the screen back to portrait, and fold TV and arm back into my 26" space. The arm, then, should fold and store vertically, but should fold out horizontally when in use.
I've seen lots of articulating arms that fold horizontally. If my stud is in the middle of my space, that gives me about a foot on either side, meaning the longest one arm segment could be is one foot. Most arms have two segments, which limits total extension to two feet, placing the center of the TV at only 3 feet from the corner.
Anyone have good ideas, or can you recommend a long articulating arm that stores vertically, but extends horizontally (or with a locking ball joint at the base)?
I've attached an image that attempts to illustrate this.