Startups increase light in telephone cameras

Regarding smartphone cameras, bigger, it's better. Image sensors and larger lenses have more light with whom to work, so that they can solve more details. This is particularly important, because filters that create color images also block around 70% of incoming light.

These colored filters – deposited like a grid of red, green and blue on the pixels of the image sensor – have existed for decades. But new approaches promise to use light physics to create color images without blocking so many photons. Three of these paths towards clearer images were presented at 2023 IEEE International Electronic Electronic Reunion (IEDM). Now these methods are starting to emerge from the laboratory stage.

Samsung, for example, will provide Xiaomi-based the new China-based new phone from the new Xiaomi-Prisc technology in Samsung to improve low light performance. Technology does not replace color filters; It uses diffraction to collect more light in each pixel specific to color. This improves light sensitivity by 25%According to the company.

Meanwhile, two new startups have developed ways to capture color -free color images. A spin-off Imec called Eye This month announced that it had raised 15 million euros in seed funding. And PXE holographic imaging Technology presented which combines depth detection and color imagery, in January to This year's consumer electronics show (THESE).

PXE and Eyeo are compatible with CMOS sensors, the most common digital image sensor used in cameras today. “The CMOS sensor is a very mature and strong platform on which you build there. You have it in each device today, ”explains the founder and CEO of PX Yoav Berlatzky. But “everyone wants more photons reaching their CMOS sensors”.

Eyeo filter -free color camera

Eyeo aims to market the research presented by IMEC at the IEDM in 2023 for applications in consumer electronics, security, etc. By removing the color filter, the start -up image sensor is made three times as sensitive as traditional CMOS sensors. “It is as if we finally opened the eyes of an image sensor,” explains the CEO of Eyeo Jereon Hoet.

Color separators in the image of the Eyeo image sensor guide from different wavelengths with appropriate pixels.Eye

It works by sending light through vertical waves guides which divide the light as a function of the wavelength, then direct the photons to the appropriate pixel. The wave guides act as a funnel, so these pixels can be reduced to less than 0.5 micrometer wide, about half the size of a typical smartphone pixel. The technology also corresponds better to the sensitivity of the color of the human eye than the imaging based on today's filters, according to IMEC research.

Color fractionation technology is designed to be made with existing tools and processes already used in CMOS foundries. The challenge occurs on the software side. Eyeo is now working to ensure that the sensor is compatible with its potential customer systems, according to HOET.

In terms of applications, Hoet claims that the advantage of the smaller and more sensitive image sensors of Eyeo is particularly clear for smartphones. However, it expects technology to be adopted first for other uses, such as safety systems for low -light conditions or augmented reality devices that require ultra -compact sensors.

Pxe brings 3D to CMOS

The basic idea behind Px's approach is similar. The two companies aim to imitate color filters without losing photons and “get the colors in the right place on the right pixel” by folding light waves, Bertlatzky sums up.

In this version of the photo above, the red lines indicate that an object is closer, while the blue lines mean that it is more distant. Pxeal

PXE technology uses a layer of diffractive material which he calls a “holocoder” to not only create color images but also to act as a depth sensor (hence the “holographic” part of the company name). When the white light passes through the Holocoder, it creates an interference pattern recorded by the sensor. PXE algorithms then use this model to rebuild a virtual 3D image – a hologram. The interference pattern also code information on the wavelength of light, so that color (and infrared) images can be rebuilt simultaneously.

Berlatzky says that PXE equipment is “less exotic” than colored separators and other approaches that use specially designed metasurfacces. Much of its power comes from the software. “The base of the algorithm is the physics of light,” explains Berlatzky. “You can think of this as if we do so in the opposite, from the CMOS sensor to the world, and rebuild what the camera really see, in terms of depth and image.”

Like Eyeo, the PXE image sensor could be used in a range of applications, especially in those who already have separate depth and image sensors, such as cars and smartphones.