Sony filed a patent application in Japan (2013-61476) for a full frame 35mm f/1.8 mirrorless lens designed for curved sensors. The patent contains also calculations for 35mm f/2.8, 35mm f/2.2 and 30mm f/2.0 lenses, all designed for a curved sensor. Sony, Nikon, Konica Minolta and others have also filed various patents for curved sensors in the past. The purpose of a curved sensor is to improve the sharpness in the corners of the image and reduce aberration.
