As reported by VGC, Sony has patented “Operation Device” for mobile devices. Specifically, the patent is titled:
OPERATION SYSTEM, INFORMATION PROCESSING SYSTEM, OPERATION INFORMATION GENERATION METHOD, AND OPERATION INFORMATION GENERATION PROGRAM
A section labeled Background Technology summarizes the patent.
The controller (operation device) described in Patent Document 1 has a left side grip portion and a right side grip portion gripped by the left and right hands of the user, and a direction button and an operation button arranged on the front surface of the controller.
The controller is similar to the DualShock 4 and clearly houses a mobile device, much in the same way as other controllers do, including the Razer Kishi, Razer Junglecat, GameSir X2, and the Backbone One.
Sony developing a mobile controller supports their investment into the mobile market. Most relevant to cloud gaming, the controller hopefully indicates that Sony will be launching PS Now compatibility on mobile devices. Currently, PS Now streaming is available only on PlayStation consoles and PC.