Smartphone Filter-free CMOS sensor enhances color images

When it comes to smartphone cameras, it is better. Large image is more light to work with sensors and lenses, so they can solve more details. This is particularly important, as the filters that make color images also block about 70 percent of the coming lights.

These colors filter- The pixel of the image sensor remains out as red, green and blue grids – have been around for decades. But new approaches promise to take advantage of the physics of light to create color images without blocking so many photons. Three such ways to speed up images Was presented in 2023 IEEE International Electron Device Meeting (IEDM). Now, these methods are emerging from the laboratory phase.

For example, Samsung, Will provide The front camera for the new phone of Xiaomi-based Xiaomi, which uses Samsung’s nano-purpose technology to improve low-light performance. The technique does not replace the color filter; It uses diffraction to collect more light in each color-specific pixel. It increases light sensitivity 25 percentAccording to the company.

Meanwhile, two new startups have developed ways to catch color images without filters. An IMEC is called spinoff Eye This month announced that it has collected € 15 million (US $ 17 million) in seed funding. And PXE Hallographic Imaging Deepening technology This year’s consumer electronics show (CES) in January.

Both PXE and IO are compatible with CMOS sensors, which are the most common digital image sensors used in cameras today. PXE founder and CEO says, “CMOS is a very mature and strong platform to build sensors. Today you have every device.” Yoav berlatzkyBut “Everyone wants more photons to reach their CMOS sensors.”

IO’s filter-free color camera

The IO aims to commercialize research presented by IEDM in 2023 for applications in consumer electronics, safety, and more. By removing the color filter, the image sensor of the startup is made three times sensitive as a traditional CMOS sensor. “It is as if we are opening the eyes of an image sensor in the end,” says IO’s CEO Jeroen Hot,

Color splitors in IO’s image sensors guide light for pixels suitable for various wavelengths.Eye

It works by sending light through vertical wavegides that divide the light on the basis of wavelength, then moves the photons to the appropriate pixel. Wavegides act like a funnel, so those pixels can be reduced in a width of less than 0.5 micrometers, about half the size of a specific smartphone pixel. Technology also matches the color sensitivity of human eye than today’s filter-based images. IMEC research,

The collapse technology is designed with existing devices and procedures that have already been used in the CMOS foundry. The challenge comes on the software side. According to Hot, Neyo is now working to ensure that the sensor is compatible with its potential customers’ systems.

In terms of applications, Hoet says that the benefit of small, more sensitive image sensors of IO is particularly clear for smartphones. However, he hopes that the technique will be first adopted for other uses, such as a security system for low-light conditions or ultracampact sensors for a promoted reality devices.

PXE brings 3D to CMOS

The original idea behind PXE’s approach is the same. The purpose of both companies is to mimic the color filter without losing the photons and “somehow achieve color in the right place on the right pixel” bending light waves, Baralatzki summoned.

In this version of the picture above, the red lines indicate that an object is close, while the blue lines means that it is away. PXE

The technique of PXE uses a layer of tectonic materials, which is called a “holkodar”, not only to create color images but also to act as a depth sensor (hence the company name’s “Hallographic” part). When white light passes through Holkodar, it creates an intervention pattern that is recorded by the sensor. The algorithm of PXE then a virtual 3D image- use that pattern to recreate a hologram. The intervention pattern also encodes information about the wavelength of light, so color (and infrared) images can be rebuilt together.

Berlatzky says that PXE’s hardware is “less foreigner” than color splitors and other approaches that exclusively use engineer Metasurfaces. Most of its power comes from software. “The base of the algorithm is the physics of light,” Baralatzki explains. “You can think about it as if we are running it in reverse, the CMOS comes out from the sensor to the world, and the camera really looking at the depth and image is re -organizing it.”

Like the IO, the image sensor of PXE can be used in a series of applications – especially in those who have already different depth and image sensors, such as cars and smartphones.