Sony is working on a new kind of PlayStation controller, according to patent filings.

The documentation shows a controller that looks like the existing DualShock controller but includes extra buttons in places they have not been seen before on any PlayStation controller.

It is not clear whether the new controller is intended for the current generation of PlayStation consoles or if Sony is working on it for the PlayStation 5, which is coming later this year, though it might be aimed at both.

It is also not certain that it will actually arrive, since the designs were revealed as part of a patent application granted on 26 December and discovered by gaming website Polygon. Companies often file for patents for devices that never actually arrive in market, or do so in a different form.

The new controller appears to be largely similar to the existing DualShock controller for the PlayStation 4.

But it has buttons on its back. They are placed behind where the analog sticks currently sit, though Polygon noted that the patent makes reference to the fact they could move – it is not explicit about whether that means the buttons could be adjustable on the controller, or simply that they might be put in a difference place when the controller actually arrives with players.

Earlier this month, Sony revealed two buttons that stick to the back of the existing controller to add what appears to be largely similar functionality. The “Back Button Attachment” includes an extra screen and slips onto the back of any normal DualShock controller.

By doing so it caught up with companies like Microsoft, which has offered the Xbox Elite controller for some time – though as a separate purchase, rather than an attachment. A number of third-party companies make both attachments and redesigned controllers that include triggers on the back.

Like the new Back Button Attachment, the unreleased PlayStation controller appears to allow users to programme the buttons on the back. That means that as well as being used as entirely new buttons, they could also be swapped for existing ones, which should be easier to reach since they sit where the fingers normally lie on the back of the controller anyway.

While it does not make any reference to which console the new controller is being considered for, the patent does include a micro-USB port for charging. 

Rumours suggest that the upcoming PlayStation 5 will switch to a USB-C port instead, which could suggest that it is at least being considered for the current generation PlayStation 4.