Compared to traditional flat sensors, the new curved CMOS sensor is 1.4 times more sensitive to light in its center and an impressive 2 times more sensitive at the edges, according to a report at the Symposium on VLSI Technology in Hawaii, delivered by Kazuichiro Itonaga, a device manager for Sony R&D Platform in Atsugi-shi, Japan.
The pure geometry of a curved sensor allows it to be used with a flatter lens, with a higher aperture, a key factor in allowing more light to pass to the sensor. The most obvious advantage of the curvature, however, is that light can now hit photodiodes more directly rather than obliquely. In addition, the curved form results in reductions to the noise from current flowing through a pixel even when its not receiving any external light (the so called “dark current”).
Sony uses a sophisticated process with a custom “bending machine” to flex the sensor and achieve a human retina-grade curvature. Itonaga specified that the machine first bends the sensor, but it’s also fortified with a ceramic coating after the bending for stability.
Sony's new curved CMOS sensor could improve camera light sensitivity up to 2 times
Being a new sensor that requires a new system of lenses, it is a great fit for devices like smartphones with a fixed-focus (prime) lens, and no interchangeable lens support. Sony already showed one of a few if not the only compatible lens (a prime lens), at the presentation, and it also demonstrated an image shot with the new system.
Best of all, all of this innovation is not just in patent imagination land - Sony has already manufactured around 100 full-size sensors with their custom bending machine.