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Tuesday, April 29, 2014
The power of IFTTT on Android
Better LED Than Dead
You don't have to be a Buddhist to reserve your spot at the Ruriden mausoleum in Tokyo.
All it takes is about $7400, plus $88 per month until you need the space, and your bones can rest in perpetuity in a charnel house festooned with LED-lit glass statues, with state-of-the-art lighting controls.
A recent story on JapanTimes.co.jp describes the mausoleum at the Kokoku Temple. One wall contains 2,046 small statues made of "ruriki" glass, each illuminated by an individually addressable, color-controllable LED. They are described as "Buddhist" statues, which may or may not mean statues of the Buddha; that's how I picture them.
There are no photos of the space on the web, which strikes me as odd, because it sounds impossibly photogenic in a somewhat macabre way. Picture a wall of small Buddhas, all glowing golden in a dark space. (It might be blue for a memorial service.) You approach a computer terminal and type in the name of your revered ancestor. One ruriki Buddha glows in a different color to mark the resting place being sought.
Family members are given an IC security card so that they can enter the facility off-hours.
Most of those who visit live in the neighborhood in central Tokyo, and aren't able to afford to buy a traditional burial plot in what must be some of the most expensive real estate in the world. Some of these people have relocated their loved ones' remains from the countryside to the mausoleum for convenience in visiting.
The chief priest at the temple, Taijun Yajima, is quoted: "We believe Buddhist ceremonies should change with the times and environment... as long as we can maintain a balance."
The article doesn't give any technical details about the LEDs used, of course. It does sound like the color is fully controllable, as well as the light level. Philips Color Kinetics would do the trick for such a relatively large-scale installation. Philips Hue would not be suitable because its ZigBee-based controller can run at most a few hundred lamps. It's possible the temple uses a local product that is not exported to the US. Japan has, after all, the highest penetration of LED-based lighting of any country in the world.
— Keith Dawson 
How to Read a Patent: Guidelines for Non-Lawyers
Those who have suffered through enough technical journal articles to gain fluency in the language of scientific discourse will have no trouble learning how to read patents.
Written by lawyers, not scientists, patents frequently are far more syntactically and grammatically sound than the average technical paper. Furthermore, anyone who possesses the dedication and self-discipline to learn how to understand a phrase like "amorphous silicon (a-Si) has two important advantages compared with bulk crystalline silicon: the luminescence efficiency in bulk a-Si is higher than that in crystalline silicon due to its structural disorder" should, with enough practice, be able to read a phrase like "the indirect-bandgap-semiconductor, light-emitting diode (401) of Claim 1, wherein said indirect-bandgap semiconductor is selected from the group consisting of silicon, germanium and a silicon-germanium alloy" with equal ease. It's English, not rocket science.
Now that you have been duly encouraged to persevere, let's move on to the technical details.
There are four main parts of a patent: the title, the abstract, the claims, and the description. This installment provides a general overview of these four parts, with editorial commentary.
Title
This provides a high-level description of the invention. People who are accustomed to scientific journal articles are usually disappointed by patent titles' overall lack of specificity, as they generally provide only a vague sketch of the subject matter. Often, the title will allow the reader to determine if the patent is at least tangentially related to the reader's interest; however, maddeningly broad titles like "Laser devices" are also common.
Abstract
According to the USPTO, a patent's abstract should be:
...a summary of the disclosure as contained in the description, the claims, and any drawings; the summary shall indicate the technical field to which the invention pertains and shall be drafted in a way which allows the clear understanding of the technical problem, the gist of the solution of that problem through the invention, and the principal use or uses of the invention.
Patent abstracts are generally quite informative and usually suffice as a comprehensive overview of the patented invention. It is nevertheless important to read them mindfully: In some cases, patent abstracts intentionally obfuscate the elements of the patent that are most relevant to the company's targeted products. (This is more common when an invention could reasonably be used in a number of different ways, for a number of different applications.) A trained scientist or engineer will recognize the cross-applicability of the invention, however, and can easily check the claims and description for additional information -- if she or he is paying attention.
A simple, visual explanation of dependent and independent claims. The independent claim describes the substance of the invention, and the dependent claims describe enhancements or uses of the invention. The dependent claims necessarily depend on the independently claimed invention and do not stand on their own as separate inventions. Click here for a larger version.
Claims
If a patent is the "deed" to an intellectual property, the patent's claims are the property's street address. No matter what its abstract says, and regardless of the extraneous information provided in its description, a patent's claims define the nature of the protected invention.
There are two types of patent claims: independent claims, which stand alone as unique descriptors of an invention; and dependent claims, which elaborate on various embodiments of the invention. It is very easy to tell them apart, as a dependent claim will invariably begin with a phrase like, "The invention as described in claim 1, where..." An independent claim, by definition, does not reference (i.e., does not depend on) any other claims.
Description
This section defines the invention described by the patent's claims. For example, if the patent claims, "A white shirt," the description might specify that the shirt could be made out of cotton, linen, or any other natural fiber. Similarly, the description might mention that the shirt has a collar, or that the material can be treated with a stain-resistant finish. A patent's description therefore provides both boundaries and speculation. It is often designed to push the boundaries of the imagination, to incorporate all possible embodiments and uses of the patented inventions.
The most important thing to remember, when reading a patent's description, is that the patent's assignee owns only the intellectual property that is described by the patent's claims. Furthermore, the patent's claims are only valid to the extent that they are supported by the patent's description. The claims define the ownership rights, and the description defines the claims.
Disclaimer
The author is a scientist, not an attorney, and this information should not be construed as legal advice. It is the author's opinion that, as patents are intended to be understood by those who are "skilled in the art" -- i.e., by scientists and engineers, who do not necessarily have a legal background -- factual interpretation does not require the assistance of a legal professional. Technically adept non-lawyers are fully capable of discerning whether or not two patents contain similar information; however, bar-certified counsel is certainly recommended for those who have questions regarding legal issues, such as infringement or patentability.
Monday, April 28, 2014
Researchers Develop Tiny, Efficient LEDs
From computer monitors and digital display boards to smartphones and wearable technologies, many modern electronics utilize LEDs. As these devices get smaller and faster, there is more demand for LEDs that are smaller, stronger, and more energy efficient. To accommodate this trend, University of Washington (UW) scientists have built the thinnest known LED that can be used as a source of light energy in electronics. The LED is based off of flexible two-dimensional semiconductors, making it possible to stack or use in more diverse applications than current technology allows.
Light-scattering nanoparticles help LEDs mimic sunlight
Lighting has come a long way in the past few years, but even with all the technological advances that have been made, we still haven’t managed to mimic real daylight with much accuracy. We can cheat and use special lights to help plants grow, and we’ve got all sorts of lights that can change their color temperature to suit our moods, but no matter how we tweak it, artificial light still just doesn’t feel quite the the same as real, natural light. Thanks to a recent breakthrough, however, this might not be the case in the future. Soon, you’ll be able to call up natural-looking daylight with the flip of a switch, thanks to a newly-developed lighting panel that uses nanoparticles to create something similar to actual daylight. In the future, this might make it possible to produce something close to natural light in even the most dank, windowless interiors.
Are Your LEDs Electrically Overstressed? Part 1
[Yankun Fu, a process development engineer at Cree, has written an article characterizing LED failures that occur due to electrical overstress. Part 1 is now up on our sister site EDN. -- Ed.]
Like any semiconductor component, all LEDs are susceptible to electrical overstress (EOS). Although EOS is by far the leading cause of LED failures regardless of the manufacturer, to date there has been no data to characterize EOS failures or determine the specific conditions that cause EOS failures. We tested more than a dozen commercially available LEDs from multiple manufacturers to identify the conditions that cause EOS failure in mid-power, high-power and chip-on-board (COB) LEDs. This article identifies the transient conditions that are benign to LED components and those that can induce EOS and catastrophic failure and suggests some ways to minimize the potential for EOS.
What is EOS?
EOS is the exposure of an LED to current or voltage beyond its maximum specifications. EOS failures result from excessive localized heat generated by the current or voltage transient that accompanies the EOS event. Like all semiconductor devices, LEDs have a limited ability to survive overstress, which we refer to as the maximum withstand power.
EOS differs from electrostatic discharge (ESD), the rapid transfer of static charge between a non-operating part and an object at a different electrical potential. EOS events have a duration that ranges from milliseconds to seconds, which is longer than ESD events that typically range from picoseconds to nanoseconds.
EOS can be a single event or an ongoing periodic or non-periodic event. Following are some typical causes of EOS:
- A driver that produces a current spike
- Constantly driving the LED over its maximum rated current
- A power surge from the main AC power input, such as a lightning strike
- Hot-plugging an LED into an energized power supply
Read the rest of the story at EDN.
— Keith Dawson
Monday Roundup: Skin So Soft
This week: $5 million for African lamps, the new World Trade Center's light show, and GaAs grown on graphene.
LEDs from nanowires grown on graphene
Researchers from the Norwegian University of Science and Technology, Trondheim, have developed a process for growing gallium arsenide wires on graphene by molecular beam epitaxy (MBE). Here is their paper in Nature. They have spun off a company, CrayoNano AS, to commercialize the process.
This development came out of earlier work in manipulating the crystal structure of GaSa and other semiconductor materials as they were built up by MBE. The use of one-atom-thick graphene as a substrate, in place of the more common silicon (which is millions of times thicker), points to the possibility that, over time, graphene could replace silicon as a component in electronic circuits. Additionally, the graphene process could find application both in LEDs and in photodetectors for solar cells. CrayoNano is already beginning experiments with growing GaN crystals on graphene.
LED light may aid skin
This isn't refereed and published work -- it was presented as a poster at the American Institute of Chemical Engineers conference -- but it is of interest in alleviating concerns about the long-term health effects of LED lighting. A group of chemical engineering undergraduates at Stony Brook University developed a senior thesis, "The Effects of Color LED exposure on Human Dermal Fibroblast Proliferation, Mitochondrial Activity and Cell Morphology."
The team worked under Miriam Rafailovich, Distinguished Professor of Materials Science & Engineering, exposing fibroblast cultures to red, green, blue, and white LED light. The exposures varied in duration to equalize the power delivered to the specimens by the different frequencies of light. The team found no evidence that the light was harmful to human skin cells. In fact, the students found some indications that it could be beneficial in healing wounds.
Bloomberg invests $5 million for cheap solar lamps in Africa
The foundation started by the former New York mayor has agreed to put the money into the European social enterprise Little Sun. The project is an artfully designed, hand-portable solar lamp. Four hours' exposure to sunlight gives five hours of LED light. The Little Sun is in use in seven countries in sub-Saharan Africa. Bloomberg's commitment marks the first time the foundation has invested for social good, not just for increase of capital.
See the related posts below for more of our coverage of LED lights for Africa. Most of them (unsurprisingly) are solar-powered.
New World Trade Center can put on an app-controlled light show
We have written several times about the Empire State Building's LED light shows (see related posts), as well as the lighting of the spire at 1WTC. Now it seems that the new tallest building in the Western Hemisphere doesn't want to be left out of the light-show buzz. Or perhaps its resident digital-media artist, Mark Domino, doesn't want to come second to the ESB's Marc Brickman. "Domino has real-time control over the lighting program via his phone, though he says he doesn't know whether management will let him use this custom-built software when 1WTC opens later this year," Wired reports. That sounds like a pretty casual arrangement compared to the ESB's elaborate choreographed shows synched to music broadcast over local radio stations.
— Keith Dawson
Related posts:
- More Lights for Africa
- Indiegogo Projects Light the Way
- Fishing With Light on African Lakes
- Pay-as-You-Go SSL Solution Brings Light to Africa
- LEDs Transforming Cityscapes
- Monday Roundup: Iconic
- Monday Roundup: High Lights
- LEDs on High
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