Aug 17

Ricoh Patents Dynamically Adjustable Multimode Lightfield Imaging System

Ricoh Patents Dynamically Adjustable Multimode Lightfield Imaging System (Fig. modified from Shroff & Berkner 2014) Ricoh researchers Sapna A. Shroff and Kathrin Berkner have lodged a patent application that describes a new way to dynamically adjust the recording parameters of a light field camera. The US Patent and Trademark Office has recently published patent application US20140192255, entitled “Dynamic Adjustment of Multimode Lightfield Imaging System Using Exposure Condition and Filter Position”, in which the authors use a non-homogeneous filter module at the pupil plane of a multimode imaging system, which can be moved and thus used to modify the imaging system’s exposure conditions. Continue reading

Aug 12

Light Field Powered: First Smartphones with Holographic Displays Could Arrive within Two Years

Ostendo's Quantum Photonic Imager Chips produce real 3D images with depth (top: resulting image with diffuser, bottom: actual QPI array; Youtube Screenshot via InsightMediaTV1) Just a few years ago, mobile displays took a leap forward with increased pixel densities that ensure crisp images on realtively small screens. Today, most smartphones feature displays with up to 538 pixels per inch (ppi) – a resolution that is much higher than what the human eye can see. So what’s the next display innovation we can look forward to?
In her recent article on IEEE Spectrum, Sarah Lewin introduced two companies that are working on making what she calls “holographic” light field displays (i.e. glasses-free 3D displays) a reality.

Ostendo Technologies recently presented the results of nine years’ work at the Display Week conference: An array of 4×2 Quantum Photonic Imager chips (each consisting of LEDs, image processors and embedded rendering software) plus microlens array form a 1 megapixel (1024x768px, XGA resolution) prototype display which sends out light not into every direction – like conventional displays do – but rather into very narrow, collimated angles of light. This enables the prototype to emit different images into different directions, producing about 2,500 different perspective views, so the image and motion displayed appear consistent regardless of the viewer’s position. Continue reading

Aug 05

Samsung Patents Modified Light Field Sensor with Monochrome Sub-Images

Fig. 6 from Samsung's patent application shows three exemplary colour-filtered light rays passing through microlenses to create monochrome sub-images (Fig. modified from Lee et al., 2014). In order to record colour images, camera sensors typically use a colour filter array consisting of red, green, and blue filters on top of the light-intensity sensing sub-pixels. After recording each sub-pixel’s light intensity, the so-called “demosaic” process combines four monochrome sub-pixels (2x red, 2x green, 1x blue) into a single pixel containing RGB colour information.
In microlens-based light field cameras, this “demosaic” job may result in a blur effect around the boundaries of objects in the final image.
Image Sensors World found a patent application by Samsung which can solve this blur-problem: In the patent application entitled “Photographing device and photographing method for taking picture by using a plurality of microlenses”, authors Tae-Hee Lee et al. propose moving the colour filter in front of the microlenses (instead of having them behind the microlenses), creating single-colour sub-images. Continue reading

Jul 15

Visera Patents Integrated Light Field Sensor Manufacturing Process

Fig. 3 from the patent application shows a schematic of a light field camera including the proposed single-piece light field sensor (picture modified from Wang et al., 2014) Light field technology is making its way into the mainstream, but the production and assembly of some of its components has not quite reached an efficient scale of mass production.
A typical light field sensor consists of an ordinary image sensor and a microlens array (MLA) or printed mask.
In the assembly of light field sensors, one of the most vital processes is the precise adjustment of the MLA‘s position on the sensor. This adjustment is required for every individual sensor and can thus take up a long time. Since the MLA is usually positioned using screws or springs, physical impact on the light field camera may displace the light field sensor’s layers.

With patent application US 20140183334 A1 “Image sensor for light field device and manufacturing method thereof“, recently discovered by Image Sensors World, Visera Technologies is aiming for an integrated manufacturing method for light field sensors: Authors Wei-Ko Wang and colleagues propose a system where two layers of microlenses (and an intermediate space layer) are formed directly on the image sensor using semiconductor processes. Continue reading

Jul 06

Pinlight Display: Light Field Glasses for Augmented-Reality Applications

Nvidia Pinlight Display: Light Field Glasses for Augmented-Reality Applications (picture: Siggraph 2014 website) Earlier this year at Augmented World Expo, Nvidia researcher Douglas Lanman gave a talk about Near-Eye Light Field displays, i.e. electronic glasses which allow users to experience both 3D and depth. When asked about Augmented Reality (AR) applications during the discussion, Lanman noted that creating a set of transparent glasses that would also include microlenses (or something equivalent) but still allow “normal” see-through vision, was a real challenge. He very briefly teased “pinlight displays”, which were to be presented at the same conference, but no further information could be found online.

In the Emerging Technologies section of the Siggraph 2014 conference (10-14 August 2014), Adam Maimone and colleagues from the University of North Carolina at Chapel Hill and Nvidia will be presenting their new invention in a talk entitled “Pinlight Displays: Wide-Field-of-View Augmented-Reality Eyeglasses Using Defocused Point-Light Sources”. Continue reading