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Posts Tagged ‘LED lens’

Intematix Delivers Remote-phosphor Optics Family

26 Jan

Luminaire makers can rely on blue LED lights sources and use Intematix’s phosphor-coated optics to offer products such as downlights in color temperatures ranging from 2700 – 4000K.

Intematix has long supplied phosphors to LED manufacturers that allow blue LEDs to produce white light, and is now supplying phosphor-coated optics for remote-phosphor solid-state lighting (SSL) designs that utilize blue LED sources. At launch, the ChromaLit family includes 45- and 61.5-mm diameter, phosphor-coated plastic optics that offer conversion efficacies ranging from 170 – 196 lm/W.

Intematix director of product marketing Julian Carey claims that the remote phosphor approach delivers a 30% gain in system efficacy compared to designs that utilize white LEDs and a secondary optic such as a diffuser. The ChromaLit optic both includes the phosphor and diffuser function in one element. According to Carey a diffuser can account for a 9% light loss in luminaires.

Blue LEDs and a mixing chamber

Since taking over as Intematix CEO in August 2010, Mark Swoboda has pledged to focus on a materials-centric business leveraging its phosphor technology, believing that phosphors dictate the quality of light. Swoboda said, “Phosphor is the arbiter for light quality. It has a direct effect on the color of light, the color rendering, and the color consistency.”

Intematix’s Carey states that the ChromaLit approach will prove much simpler for luminaire makers. Carey claims that the remote phosphor will eliminate the need for manufacturers to bin LEDs. Intematix recommends that designs use blue LEDs with a dominant wavelength of 457.5 nm, but won’t require binning of the LEDs to ensure color consistency.

Luminaires based on ChromaLit only require the blue source, a mixing camber, and the ChromaLit optic. Carey said, “The ChromaLit source is intrinsically diffusing” and he asserts that the design reduces glare.

Carey also pointed out that luminaire manufacturers can take advantage of the remote-phosphor efficacy in several ways. The efficacy will give manufacturers the option of offering brighter products, or to cut cost by using fewer LEDs. Designs can also reduce drive current for lower power consumption and a simpler thermal design according to Carey.

Remote optic dictates color temperature

Initially the ChromaLit family includes 2700k, 3000K, 3500K, and 4000K optics in both 61.5- and 45-mm sizes. Those sizes immediately enable the design of downlights, spot lights, and modular light engines. Indeed the larger size is a match for popular 6-inch downlights. The first products rely on phosphor printed on a plastic substrate, although Intematix has plans to offer glass substrates as well.

The company also plans to develop more complex shapes relative to the initial flat and round optics. Carey said, “We will make domes and spheres and even custom shapes for customers.”

Intematix also believes that the remote-phosphor technology will prove useful in other applications such as automotive signaling applications. Carey stated that the company can use the technology to yield red and yellow lights.

Intematix has already begun sampling the ChromaLit components. They expect customers to launch ChromaLit-based products in the coming weeks.

Swoboda concludes, “We will be a disruptive alternative for making general lighting systems. Manufacturers can now start with a blue light source and combine that with a ChromaLit component.” And Swoboda believes that approach will yield higher-quality and lower-cost SSL compared to designs based on white LEDs.

 

Bayer Develops Thinner Polycarbonate for LED Lenses

08 Jan

Makrolon FR7067 polycarbonate plastic achieves UL flame retardant requirements in 1.5-mm-thick LED lenses that offer near 90% light transmission.

Bayer MaterialScience has developed a new polycarbonate plastic for LED lenses – especially for solid-state-lighting (SSL) applications – that can meet the UL-94 V0 ratings for flame-retardant characteristic at half the thickness of most polycarbonate lenses. Lenses made with the 1.5-mm-thick Makrolon FR7067 material can improve light transmission efficiency to almost 90%.

“Thicker lenses or covers translate into an unnecessarily heavier and bulkier part. This additional thickness is also undesirable because more light will be lost as it is transmitted through the lens or cover, making the component less efficient,” said Gerry DiBattista, market segment leader, IT, Electrical/Electronics Polycarbonates, Bayer MaterialScience LLC. “When it comes to LED lenses and covers, thinner is better.”

DiBattista’s first point is that OEMs and injection-molding specialists enjoy a significant cost advantage when a lens uses less material. The fact that you get better light transmission adds to that advantage.

The LED lens doesn’t necessarily have to meet flammability standards, but there is a payoff for a lens that does. DiBattista said, “Another added benefit is that when a lens meets the required UL flame ratings, the OEM can avoid costly power-supply isolation or a separate UL test on the final component.”

Bayer is also quick to point out that its lenses add to the environmentally-friendly characteristics of LED lighting. The polycarbonate material is amenable to recycling, reprocessing, and reuse. That characteristic fits well with the fact that LEDs reduce energy usage in lighting applications and don’t contain hazardous materials such as mercury.

“Bayer MaterialScience’s latest flame retardant polycarbonate plastic provides OEMs a transparent, UV-stabilized material that not only meets key industry guidelines and regulations but does so with a thinner profile and environmental benefits, too,” DiBattista said.

Last year, Bayer introduced Makrolon FR7087 polycarbonate, which meets UL-94 5VA rating at 3.0 mm with good transparency.

“This builds on several other new products geared toward this industry, underscoring our commitment to support advances in the LED lighting industry,” concluded DiBattista.

 

LED Lens – Helping to Increase the Illuminating Efficiency of the LED

08 Jan

A lens is an excellent accessory for improving the optical efficiency of light-emitting diodes (LEDs). The criterion for determining an LED lens depends on the application for which the LED is used; i.e., the (target) illuminating body. The characteristics (for example, beam) of the LED will also play a significant role. Lenses are generally manufactured from optically clear materials such as polycarbonate or glass, although colored materials are occasionally used to obtain particular results.  Lenses require curvature on one or both sides in order to achieve the proper effect.

How Lenses Work:

The curved surface of a lens refracts light — it bends light rays and forces them to focus at a different point.  (A full technical explanation of this phenomenon is beyond the scope of this article.)  There are two types of lenses, convex and concave, and each is used to produce a different result.  A convex lens will force light to converge and focus nearer to the lens; a concave lens will force light rays to diverge, or focus farther away from the lens.  This is the same principle as that of the human eye, which contains a lens that focuses light on the retina.

Lenses for Use with LEDs:

When a lens is used in association with an LED, it’s referred to as a secondary optic.  In general, LEDs emit light on a directional basis, and the angle of the beam falls between 15-120 degrees.  This focused use of light allows for greater efficiency when compared to traditional light sources that diffuse light over an entire area, as a lower amount of power can provide a similar amount of light.  However, to use LEDs in a light fixture, this 15-120 degree beam must be concentrated by use of secondary optics such as lenses or reflectors.

Improving Light Efficiency:

The lens position is crucial for optimum light efficiency.  If the lens is too high or low from the LED, then it will not focus light at the correct place.  Ensuring that the lens axis is properly aligned with respect to the LED is also vital to achieve the correct output.  Both measurements must be precisely determined and followed, or the lens will produce light that is fractured or too diffuse. A typical value for acceptable accuracy is within ±0.2 mm.

Panel Lenses:

Lenses can be mounted on panels for a variety of uses.  A traditional method is to mount the LED so it can stick out through a hole in the panel.  Other approaches to installing LEDS include such options as using glue to attach them to panels.  However, this method has a number of drawbacks:  the angle of the LED will be reduced; it is susceptible to issues relating to push-through; and electro-static discharges can pass through the LED and negatively affect components on the circuit board.

 
 
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