Posted on 01/01/2008 5:08:49 PM PST by PeaceBeWithYou
Brighter LEDs pave the way for a new type of home interior lighting
The LED, or Light Emitting Diode, has been around since the late 60’s but only over the last few years have LEDs made headway into commercial mainstream use.Some new vehicles now use LED’s in headlights and taillights. The benefits of this are brighter light and much improved life span for the bulbs. Some stop lights also use LEDs to combat against the hazard of a stop light burning out.
Of more interest to technophiles is the advent of LEDs for use as backlighting in our notebook computers, such as the recently announced Dell Latitude XT tablet PC, and other personal electronic devices. LEDs promise less power consumption in out notebooks thereby increasing battery life. LEDs are also slowly making their way into our flat panel TVs such as the Samsung 31-inch OLED panel DailyTech reported on last week.
Scientists also have their eye on LEDs for use in the home to replace the incandescent and florescent light bulbs. The big benefit for consumers to using LED lighting in the home is much greater lifespan and less power consumption.
While some scientists are hard at work on methods to add more natural spectrums to current LED lights, other scientists announced a breakthrough last week to help defeat the problem with low light output from LEDs.
A new method for increasing the light output from LEDs involves a process called nano-imprint lithography. Scientists at Glasgow University along with the Institute of Photonics at the University of Strathclyde invented a process that makes millions of microscopic holes on the surface of a LED bulb, which increase the amount of light the LEDs give off.
Project leader Dr. Faiz Rahman who told the BBC, “As yet, LEDs have not been introduced as the standard lighting in homes because the process of making the holes is very time consuming and expensive. However, we believe we have found a way of imprinting the holes into billions of LEDs at a far greater speed, but at a much lower cost."
According to Rahman the days of the humble light bulb may soon be over.
More like scraping the coating off of a soft white incandescent.
Can't wait to have some of these flashlights. I use the LED flashlights now. So much light for such a little bulb.
More low energy lighting ping.
Whats this got to do with LED’s???
So, the LED flashlights are good? I’ve seen maglite advertising them, but didn’t know how good they are.
LED flashlights are excellent; in many cases they’re brighter than conventional flashlights and the batteries last nearly forever. You can even get LEDs that can be recharged by turning a crank for a few minutes.
Right now with the Cree Q5 emitter available in top end EDC (every day carry)flashlights the lumens output is now over 225, several years ago it was 105 and that flashlight cost about $180 from Surefire. Check out the Fenix brand flashlights. http://www.fenixtactical.com/fenix-t1.html
My only problem is the Stylus penlight is very easy to lose. It's just like a pen but I use it at work all the time.
Point is that the LED has been in the hands of the consumer for a LOOONG time. They do not burn out - at least, not suddenly - and any advances in this efficient and reliable technology are a positive.
The gas discharge tube was another interesting light emitting technology, used in seven-segment displays (common in VCRs for a time), greyish/white in color. I have not seen this for awhile.
I love those flashlights. Used one (with the handcrank) working under a new sink hooking up the plumbing and water fittings a bit over a year ago. Had just had cataract surgery in both eyes, but there were no bright spots ~ just nice, steady, bright light over an area.
I was still wearing sunglasses to drive at night just to give you an idea of what LED light is like compared to high powered incandescent bulbs out on the streets.
It appears that light output is now limited by the maximum temperature the LED chip can stand, which in turn is controlled by how much heat the mounting can pull away. A glance at the spec sheet from Cree for a LED used in flashlights (the X-Lamp XR-E) shows the max junction temp of 150 deg C is reached at 1000 ma.
http://www.cree.com/products/pdf/XLamp7090XR-E.pdf
The reason they were "almost always" red was because that was the only color they could make (at least in production quantities and reasonable prices). The first red LEDs were extremely dim by today's standards.
Very. The light is very even, none of the shadows that a tungsten filament lamp shows.
The LED(s) are very robust, totally unfazed by dropping on concrete.
A standard flashlight bulb may last a few hundred hours, an LED lamp has a rated life of 100,000 hours, that's nearly 10 years of continuous use.
Speaking of continuous use, a couple D cells will provide solid weeks of illumination.
I'm still using an HP-45 calculator I bought in '73...
bump
That is a CLASSIC!
One of the highlights of my then young career was developing a simple process technique that boosted the brightness of National Semiconductor's red LEDs by 70%.
For a while they were the brightest on earth...
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.