Another patent filed by Sony Ericsson called as ‘Orientation Based Multiple Mode Mechanically Vibrated Touchscreen Display’. From my reading, this patent has something related with Sony Playstation Portable (PSP) and perhaps a game phone. Below the quote that mention about it.

[0029]FIG. 3 is set out to mimic the look and feel of the popular Sony.TM. Playstation Portable (PSP.TM.) gaming device. The area designated by reference number 300 is reserved for game action. It is essentially the display within the display.

The dashed box referred to by reference number 305 represents the buttons that appear on the right hand side of the PSP.TM.. The dashed box referred to by reference number 310 represents the buttons that appear on the bottom of the PSP.TM.. Lastly, the dashed box referred to by reference number 315 represents the buttons that appear on the left hand side of the PSP.TM.

The buttons represented by reference numbers 305, 310, and 315 are graphical renditions on the mechanically vibrated touchscreen display 150 of the portable mobile communications device 100. The mechanically vibrated touchscreen display is configurable and re-configurable to suit the mode or application desired by the user.

In this example, when the user presses an area of the mechanically vibrated touchscreen display that corresponds to one of the buttons that is associated with the PSP.TM. interface, a tactile sensation is returned to the user that indicates a button was pressed.

The exact type of tactile sensation emitted by the mechanically vibrated touchscreen display and experienced by the user can vary according to parameters set out in the display configuration associated with that mode. Thus, some buttons may have different feels than other buttons.

You can read the full patent article here.