Rambus Inc is developing an image sensor with a new structure that allows to drastically reduce the cost and size of digital camera unit by eliminating an optical lens, which accounts for a large part of the cost and size.

In principle, the new structure enables to realize the main functions of a camera only with a CMOS sensor and signal processor. Some lens functions are realized by adding optical properties to the CMOS sensor. The CMOS sensor having those lens functions measures 0.8 x 0.8mm, Rambus said. When an analog-digital converter and signal processing part are added to the CMOS sensor, it functions as a digital camera.

The details of the new technology will be announced by David G. Stork, distinguished research scientist, research director, Rambus, who is developing the technology, at Trillion Sensors Summit Japan 2014, which will take place Feb 20 and 21, 2014, in Tokyo.

Because a "digital camera" can be realized with a low cost and small size, it becomes possible to disperse cameras everywhere. And they can be disposable.

Unlike the case where a lens is used, it is necessary to add a circuit to signal-process data collected by the CMOS sensor. Especially, to process video in real time, a high processing capability is required.

Still, Rambus considers that there are some applications with which the advantage of eliminating optical components outweighs the disadvantage. It is because the annual increase rate of the cost performance of signal processing capability is 150%, which is higher than that of optical components (5%), according to the company's estimates. It can be said that it is becoming necessary to add new design parameters at the time of developing optical component products.