Panasonic promises high sensitivity sensors using 'Micro Color Splitters'
Panasonic has devised a method to increase the sensitivity of image sensors, by replacing the near-universal colour filter array with prism-like 'Micro Color Splitters' to generate colour information. The key advantage is that all of the incoming light is directed to the sensor, instead of half or more being absorbed by the colour filter dyes. This promises to deliver images with less noise in low light. The development is published in the journal Nature Photonics, and outlined in a press release on Panasonic's website.
According to Panasonic, the dyes used in conventional colour filter arrays absorb at least half of the incoming light before it reaches the sensor's photosites. In contrast, the company's 'Micro Color Splitter' technology passes all of the incoming light to the sensor. In practical terms, this corresponds to a sensitivity increase of a whole stop, which should in turn result in a stop improvement in noise performance. In other words, a 'Micro Color Splitter'-based sensor should give similar noise at ISO 3200 as a conventional Bayer sensor does at ISO 1600, for example.
Perhaps the most interesting aspect of this development is that it may be the first serious alternative to colour filter array-based sensors since the Foveon X3 appeared over 10 years ago. Like any new technology there'll be plenty of development to do before it appears in a real product, but the prospect of a stop better high ISO performance is certainly a tantalising one.
Panasonic Develops Technology for Highly Sensitive Image Sensors Using Micro Color Splitters
|Constitution and features compared with the conventional method|
Osaka, Japan - Panasonic Corporation has developed unique "micro color splitters", which separate the light that falls on image sensors by exploiting light's wavelike properties. Applying them to actual image sensors allows bright color images to be achieved even under low-light conditions. This development makes color filters unnecessary by using the micro color splitters that control the diffraction of light at a microscopic level. Panasonic has achieved approximately double the color sensitivity in comparison with conventional sensors that use color filters.
Image sensors are used in devices like smartphones, digital still cameras and video cameras, as well in security, vehicle parking, office, and healthcare applications - anywhere, in fact, that digital imaging is needed. Conventional color image sensors use a Bayer array, in which a red, green, or blue light-transmitting filter is placed above each sensor. These filters block 50 - 70% of the incoming light before it even reaches the sensor. Progress is being made in increasing the resolution of image sensors used in mobile and other devices by reducing pixel size, but demand for higher-sensitivity cameras is also increasing. Panasonic has developed a new technology that can be applied to existing or future sensors to enable them to capture uniquely vivid color images.
The developed technology has the following features.
- Using color alignment, which can use light more efficiently, instead of color filters, vivid color photographs can be taken at half the light levels needed by conventional sensors.
- Micro color splitters can simply replace the color filters in conventional image sensors, and are not dependent on the type of image sensor (CCD or CMOS) underneath.
- Micro color splitters can be fabricated using inorganic materials and existing semiconductor fabrication processes.
This development is based on the following new technology.
- A unique method of analysis and design based on wave optics that permits fast and precise computation of wave-optics phenomena.
- Device optimization technologies for creating micro color splitters that control the phase of the light passing through a transparent and highly-refractive plate-like structure to separate colors at a microscopic scale using diffraction.
- Layout technologies and unique algorithms that allow highly sensitive and precise color reproduction by combining the light that falls on detectors separated by the micro color splitters and processing the detected signals.
Panasonic holds 21 Japanese patents and 16 overseas patents, including pending applications, for this development.
This development is described in general terms in the Advance Online Publication version of Nature Photonics issued on February 3, 2013.
More on the Technology
|Conventional method using a color filter||Developed method using a micro color splitter|
1. Unique method of analysis and design based on wave optics permitting fast and precise computation of wave-optics phenomena
FDTD is widely used to analyze light in wave form, but its heavy computation workload has up to now made it impractical for designing micro color splitters. On the other hand, BPM is an effective method of fast computation, but it has lower precision than FDTD and cannot accurately simulate color splitting. This prompted Panasonic to develop a practical and original design method that permits fast and precise computation of wave-optics phenomena. This technology allows the precise modeling of optical phenomena such as reflection, refraction, and diffraction by modeling spaces in regions with different optical constants and applying BPM to the spaces. This method can be applied not only to the design of micro color splitters, but can be extended to the design of other nano-scale optical processing systems.
2. Device optimization technologies leading to the creation of micro color splitters that control the phase of the light passing through a transparent and highly-refractive plate-like structure and use diffraction to separate colors on a microscopic scale
Color separation of light in micro color splitters is caused by a difference in refractive index between a) the plate-like high refractive material that is thinner than the wavelength of the light and b) the surrounding material. Controlling the phase of traveling light by optimizing the shape parameters causes diffraction phenomena that are seen only on a microscopic scale and which cause color separation. Micro color splitters are fabricated using a conventional semiconductor manufacturing process. Fine-tuning their shapes causes the efficient separation of certain colors and their complementary colors, or the splitting of white light into blue, green, and red like a prism, with almost no loss of light.
3. Layout technologies and unique algorithms that enable highly sensitive and precise color reproduction by overlapping diffracted light on detectors separated by micro color splitters and processing the detected signals
Since light separated by micro color splitters falls on the detectors in an overlapping manner, a new pixel layout and design algorithm are needed. The layout scheme is combined and optimized using an arithmetic processing technique designed specifically for mixed color signals. The result is highly sensitive and precise color reproduction. For example, if the structure separates light into a certain color and its complementary color, color pixels of white + red, white - red, white + blue, and white - blue are obtained and, using the arithmetic processing technique, are translated into normal color images without any loss of resolution.
- 1. Diffraction
- Behavior of light as a wave on the wavelength (nanometer) scale. Various phenomena occur when a wave encounters an obstacle.
- 2. Bayer array
- The arrangement of color filters used in most single-chip digital imaging sensors used in digital cameras, camcorders, and scanners to create a color image. The filter pattern is 50% green, 25% red and 25% blue.
- 3. Charge Coupled Device Image Sensor (CCD sensor)
- A type of solid-state image sensing device for digital imaging, used in digital video cameras of all types. It has higher sensitivity and lower noise than other sensing devices.
- 4. Complementary Metal Oxide Semiconductor Image Sensor (CMOS sensor)
- A solid-state image sensing device for digital imaging using CMOS.
- 5. Finite-Difference Time-Domain method (FDTD)
- FDTD is a versatile modeling technique used to solve Maxwell's equations by spatial and temporal discretization.
- 6. Beam Propagation Method (BPM)
- A numerical analysis technique in electromagnetics for solving the Helmholtz equation under conditions of a time-harmonic wave.
Jan 20, 2016
Jan 5, 2016
Jan 5, 2016
Jan 5, 2016
|Hook Head Lighthouse by kroker|
from Best Photo of the Week
|Green turtle in the shallows by gcachon|
Canon went and put an APS-C sensor in a G series compact. The result is a mighty tempting camera for travel.
Google Photos is adding a few pet-friendly features that will make it easier to find photos of your favorite pooch. Now, you can organize your pet photos by facial recognition, and you can even search your library by breed.
Colorful tripod maker MeFOTO has launched a new tripod... and a whole new brand name. Meet the GlobeTrotter travel video tripod, the first product to be released under the MeVIDEO brand.
If you own a Moto Z, you'll soon be able to attach a Polaroid instant printer to it. Check out the unreleased Moto Mod, which was leaked earlier today.
DJI has developed a technology called AeroScope that allows law enforcement to identify and track airborne drones that are breaking UAV regulations, while simultaneously addressing privacy concerns.
The Nikon D850 is a 45.7MP full-frame DSLR with an autofocus system lifted wholesale from the pro-sports focused D5. 4K capture, continuous shooting at 7 or 9 frames per second make it sound like the ultimate all rounder. Is it all that these specs suggest?
The Mate 10's Kirin 970 chipset with integrated AI processing allows for object recognition, motion detection and automatic scene selection in the camera app.
DxO has announced version 3.0 of the iOS app for its 'One' connected camera. It adds support for multi-camera Facebook Live broadcasting and both time-lapse still and video capture. Android users will be pleased to hear that a One for their platform is on the way, as well. Several new accessories are available, including a battery pack.
Canon has introduced the PowerShot G1 X Mark III, which borrows the 24MP APS-C sensor and Dual Pixel AF system from the company's recent mirrorless and DSLR cameras, adds a 24-72mm equiv., F2.8-5.6 lens and puts them into a lightweight body – but it'll cost you quite a bit.
It's not often that we see a genuinely interesting compact camera, and the Canon PowerShot G1 X Mark III is one such beast. We've pulled out the top features of the camera and tell you why they matter – and put the Mark III up against the competition.
Apple's HDR effect in the iPhone 8 Plus is on by default and more aggressive than in previous generations. It's also good enough to convince DPR contributor Jeff Carlson to leave it on all the time.
Canon's 28mm F2.8 IS USM may be small in size, but it's big on fun. We wrote about our experience using it as our only lens in Big Sur, California, but in case you missed out on our full gallery, take a look to see what this little lens can do.
Travel photographer Elia Locardi tells the story behind this gorgeous (and rare) panorama of the Dubai cityscape draped in fog.
Bison, drift cars, horseback riders, antelope – from the beach to the race track, the Sony 100-400mm G Master is one versatile piece of kit.
"Wildlife photography in Yellowstone National Park is an incredible opportunity, yet some bad photographers are giving all photographers a bad name by not following the rules."
Casio's bionic-looking new action camera, the GZE-1, is built with extreme sports in mind. The little camera is drop-proof, freeze-proof, dust-proof, and waterproof to 50 meters.
Yashica recently released the digiFilm Y35: a camera that tries to simulate the "experience" of shooting film... and it's just the worst.
Western Digital has revealed some interesting new technology that, it claims, will allow them to develop 40TB hard drives by the year 2025.
Photographer Micael Widell wanted to see just how affordable it could possibly be to get into digital photography—so he bought a full DSLR kit with battery grip and 50mm lens on eBay for just $80.
Confused about DxOMark's scoring system? This straightforward video by Marques Brownlee breaks down how DxO gets its scores, and why you should always look beyond that "overall" number.
It's not exactly a revolutionary device, but the iPhone 8 Plus does promise some evolutionary updates in the camera department. DPR contributor Jeff Carlson has been putting the 8 Plus to the test in some everyday shooting situations – take a look at how it fared.
This week in Hollywood, DJI introduced its new Zenmuse X7 camera, a Super 35 format cinema camera of its own design that can also capture 24MP still images in APS-C format. Is it time to start thinking of DJI as a camera company?
Landscape and astrophotographer Asif Islam shot a series of timelapses starting in Los Angeles and getting farther and farther away, showing how the Milky Way emerges as the light pollution fades.
Ultraviolet photography is something that relatively few photographers explore, but it’s a fascinating realm to explore with less of an investment in equipment than most people think.
After almost fifteen years of nearly buying one, Barney recently found a working Canon PowerShot G5 in his local thrift shop. It must be Throwback Thursday.
DJI has launched the Zenmuse X7, a Raw video capable Super 35 camera module. The camera/gimbal system which mounts to the company's drones features a new, proprietary lens mount.
Windowed is a free app that lets you upload photos to Instagram straight from your Mac or PC—no tablet, smartphone, or complicated workaround required.
Nikon has published a list lenses that it deems worthy of its newest DSLR: the 45.7MP Nikon D850.
The Nikon D850 isn't the first camera to hit triple digits on DxOMark; in fact, the Pentax 645Z was listed at 101 all the way back in 2015. So why was the full review never published? DxOMark explained earlier today.
Due to 'slower-than-expected development of the VR market,' Nokia has decided to pull the plug on its $25K Ozo VR camera while it restructures the company and sheds as many as 310 jobs.