#led optics

Several articles can be found regarding the lifetime of Light Emitting Diode (LED) luminesces, although the primary focus has always been on the lifetime of the LED diode itself. Given that the LED luminesces is a system, it is important to diagnosticate all aspects of the system that can affect or limit lifetime. The LED lighting revolution plastic optics have been made primarily from acrylic (PMMA), polycarbonate or a modified version of either material (for example PMMI). More recently, the market share of silicon-based optical materials have also grown quite well. These silicone resins are suitable for precise molding and can be used for refractive lenses, TIR lenses, reflectors, diffusers and other optical components. Polycarbonate materials are utilized for LED optic and lens applications, especially when heat, flame, or impact resistance is required. Conventional transparent polycarbonate can show signs of hazing and yellowing when they are exposed to intense LED radiation in the 450-550-nm range and long-term direct outdoor sunlight exposure.  In order to mitigate the absorption of this intense LED light, LED polycarbonate grades had been developed to extend the optical performance.  A UV infusion process has also been described to produce parts that exhibit minor changes in yellowness similar to acrylic after UV exposure.

Most luminesce designers are prosaic with the need to optimize thermal performance evidenced by the large number of articles written on the subject. LED die lifetime has been shown to be driven primarily by junction temperature and to a lesser extent by current density, although the effects of current density and current spreading have been largely overlooked. LED luminaire designers are much less aware, however, of the importance of selecting the proper optical materials for the primary and secondary optics that comprise the luminaire with respect to lifetime degradation due to aging of the optics.

Different parts of a LED lamp require different properties of materials. There are four different product types for the various requirements.

● LED grades - With transparent polycarbonate, it’s possible to efficiently design and manufacture LED parts with complex geometries that would not be producible with glass. OFH LED grades are specially developed for use in lenses and secondary optics. They have an extremely high purity and thus a much better stability against LED light in comparison to standard or optical grades. Yellowness index and haze after long-term illumination with LED light are highly reduced, transmission remains on high levels.

● Diffusion colors - For ambient lighting, materials with high diffusion are smitted that have at the same time a high transmission value. Those two basically opposing properties can be balanced by color formulation experts according to customer needs with special diffusion color recipes. Close collaboration with customer in terms of desired transmission values, wall thickness of the diffusor, half power angle and lighting setup leads to perfect match for almost every customer requirement. Grades with and without UV protection and different viscosities  are available in diffusion colors as well as diffuser sheets.

●  Highly reflecting materials - Diffuse reflectors can be used for indirect lighting. OFH has developed special grades called RW (reflective white) that have high efficiency in reflecting visible light. Compared to the standard white grades, almost a reflection value up to 95% increased lead to very high brightness. For specular lighting metallization of standard grades is possible.

●  Thermally conductive materials - Heat management in LED lamps is of utmost importance. It requires thermally conductive materials. Traditionally, metals are used which limit design possibilities. A thermal conductivity of around 20W/Km is an extremely good value for a thermoplastic material allowing replacing alumina in LED heat sinks.

●  Polycarbonates - These are another strong contender that addresses the specific needs of LEDs. The LED-grade materials are designed to tolerate long-term heat exposure, transmit light effectively, and have good clarity. A diffusion additive can also be added to polycarbonates to mitigate glare.

Lighting is foundational to everything that we encounter and interact with in our daily lives. We integrates the arts, sciences and business of illumination design and implementation far beyond concerns of visibility. We have decades of experience delivering innovative, cost-effective illumination engineering services. We can help you quickly realize your design goals for a broad range of systems, including LED optics, backlights for LCDs, illuminators for scientific and industrial instruments, and other unique illumination products. We take full advantage of advanced design and optimization capabilities to meet your design requirements. Optics is that branch of physics that deals with the properties of light and its behaviour. Different organisations require optical designs to meet their varied business needs. The best of optical design consultants always deliver optical products including imaging or illumination system and reflector for an LED for use in electronics, mechanics, and such other domains at a very cost-effective price.

LED Imaging or Illumination System: The optical design LED illumination systems that consist of high-powered LED chip. Such imaging systems are designed to offer brighter and steadier lighting than your previous LED system. All quality LED illumination system provides high level of brightness and stability leading to excellent signal to noise ratios. LED imaging or illumination system is also used in multiple biological applications. For example, highly advanced imaging systems are used for detecting fluorescent signals. They are also used as a light stimulator for cells that show light-activated proteins during an experiment.

Reflector for an LED: Reflector is an optical part of a luminaire that regulates the glowing flux from the light source by reflection from the reflector material such as LED lamps, etc. Reflectors fall into two groups - first group consists of elliptical, zonal, hyperbolic, and parabolic reflectors and the second group includes square or asymmetric reflectors. The best of reflector designs know about the limitations associated with designing a reflector. There are certain parameters to keep in mind when designing reflectors such as source diameter, reflector entrance diameter, reflector exit diameter, wall diffusivity, and diffuse front glass. The beam angle and peak intensity for certain reflectors are limited.

Simple and Compound Lens: Companies who want to get high quality lens for various applications can get in touch with experienced optical design consultants at optivs for hire to get the same at an affordable rate. Lens is an optical device that has seamless or approximate axial symmetry for transmitting and refracting light as well as converLED Imaging or Illumination System: The optical design LED illumination systems that consist of high-powered LED chip. Such imaging systems are designed to offer brighter and steadier lighting than your previous LED system. All quality LED illumination system provides high level of brightness and stability leading to excellent signal to noise ratios. LED imaging or illumination system is also used in multiple biological applications. For example, highly advanced imaging systems are used for detecting fluorescent signals. They are also used as a light stimulator for cells that show light-activated proteins during an experiment.

Reflector for an LED: Reflector is an optical part of a luminaire that regulates the glowing flux from the light source by reflection from the reflector material such as LED lamps, etc. Reflectors fall into two groups - first group consists of elliptical, zonal, hyperbolic, and parabolic reflectors and the second group includes square or asymmetric reflectors. The best of reflector designs know about the limitations associated with designing a reflector. There are certain parameters to keep in mind when designing reflectors such as source diameter, reflector entrance diameter, reflector exit diameter, wall diffusivity, and diffuse front glass. The beam angle and peak intensity for certain reflectors are limited.

Simple and Compound Lens: Companies who want to get high quality lens for various applications can get in touch with experienced optical design consultants at optivs for hire to get the same at an afforon axis. Lenses are usually made of glass or translucent plastic.

Designing, Prototyping and Delivering Optical Products: We offer world-class optical designing services covering all aspects of imaging and illumination design from generating required specifications to prototyping opto-mechanical designs with necessary manufacturing drawings. We also design, prototype and deliver illumination systems. Searching a highly processional optical design consultant is necessary to meet your lens designing and evaluation needs, developing ultra violet to far infra-red lens, simple single lens to complex zoom lens and high resolution imaging to illumination systems. Moreover, an optical design consultant also specializes in providing high quality small endoscope designs, LED lighting solutions and so on for use in residential, commercial areas and scientific instruments.

We have decades of experience delivering innovative, cost-effective illumination engineering services. We can help you quickly realize your design goals for a broad range of systems, including LED optics, street lights, automotive lighting, aircraft lighting, backlights for LCDs, illuminators for scientific and industrial instruments, solar collectors, projection displays or unique illumination products. Our engineers are expert users take full advantage of the tools’ advanced design and optimization capabilities to meet your design requirements.

Optics for Hire is one of the leading companies having highly skilled and knowledgeable Ukrainian optical design consultants. The experienced team at Optics For Hire of designers and engineers are constantly working hard to meet the optics design needs of varied industries. Optical instruments are created for use in optical media, biomedical devices, illumination and imaging systems and metrology tools. The engineers of the Optics for Hire will sit with each client to understand their specific needs and based on the discussion will start with the designing work.

“Let there be light” takes on new meaning in the era of LEDs. Light from solid state light sources can be focussed and shaped by optics and lenses, and it is significantly easier to obtain specific colours or adjust the colour of the light. The innovations brought about by LED lighting technology are described in our Lenses and Optics guide. 

Optics

The term ‘optics’ refers to components that are used to collect, shape and direct light in order to produce a usable light source with effective light output. Asymmetrical lenses are being used more and more in applications such as street lighting to direct the light beam effectively without generating stray light or glare. There are essentially three types of LED optics:

Primary: attached directly to the LED. Primary optics are usually part of the LED package, with the lenses integrated into the LED package, especially with SMT and high-power devices. This may cause the luminous flux emitted by the LED to have a particular radiation pattern.

Secondary: fitted directly over or around the LED. Secondary optics consist of lenses and reflectors that are fitted on top of the LED to provide the desired form of light output.

Tertiary: external devices. Tertiary optics include a wide variety of optical devices used to diffuse or direct light. A typical example is a light guide.

Lenses and reflectors

Lenses are usually classified as secondary optics and are fitted directly on the LED. They usually produce a light beam with a large optical viewing angle and a circular cross-section. Reflectors are additionally fitted on lenses to improve the bundling and steering of the light beam. This results in highly focussed light, such as a spotlight. High-quality reflectors are characterised by low stray light. In applications such as pocket torches, moveable reflectors can be used to adjust the focus of the light beam.

Light guides

Light guides are external LED lighting technology devices classified as tertiary optics. Their characteristics help optimise the use of LEDs. Light guides are used to diffuse, direct and transport light. LEDs can be switched and modulated very quickly by controlling their operating current. The high modulation rate of LEDs is important for use in optoelectronics and in data transmission using fibre-optic light guides. Fibre optics are usually made from glass, quartz or plastic.

Optical viewing angle and radiant power

The optical viewing angle is one of the key characteristics of LEDs. Incandescent lamps radiate light in all directions, but LEDs emit light in a cone-shaped beam with a specific optical viewing angle. LEDs always illuminate only part of the area around them. Multiple LEDs are necessary for all-round lighting.

Typically, when we think of LED optics, what comes to mind in a plastic lens of some sort used over the LED itself to focus or disperse the light. We need to take a step back and realize the LED itself has a protective casing called the primary optic. The primary optic serves two purposes: to protect and to shape the light output of the diode.

So why aren’t optics used everywhere then? Well there are disadvantages of secondary optics with some of them being pretty significant:

They can be expensive. They typically add between 25%-50% to the cost of each LED. 

With few exceptions, they create a harsh transition from bright to dark. In other words, the “edges” of the cone-shaped light pattern can be very distinct. This creates a “flashlight effect”, where everything within the light beam is very bright, and everything just outside the beam is very dark. 

They hinder color blending. Since most of us like the actinic effect of all blue lighting, and since most of us prefer a cooler color than the coolest white LED available, we must use a combination of royal blue and white LEDs in our systems. When secondary optics are added, you may see obvious white and blue spots in your tank. This effect can be reduced by reducing the center to center spacing of each LED, so that the cones effectively overlap, but it may still be very apparent as our corals grow towards the top of the tank. Also, our rock formations and corals cast shadows, which may be distractingly blue or white under secondary optics.  

We expect the market for LED's to continue to grow and other advanced lighting and we will continue to bring you more quality information on the advances in this promising technology. 

Optics design is an integral part within the field of LED light development. LED, the full form of which is Light-Emitting Diode, emits light by electronic excitation rather than heat generation unlike the normal light bulbs. Diodes are electrical valves that allow electrical current to flow in only one direction. Optical engineers produce a variety of LED optics for shops, offices, industrial plants and street lighting.

There are different optics shapes available for selection depending on particular usage, including circular, square and linear. All LED optical products are made of high-quality materials such as PMMA, silicone, and are available with different radiation angles - narrow/broad beam, asymmetrical or combinations.

Design

Desirable optical properties such as color, brightness, and efficiency must be optimized without an unreasonable electrical or physical design. These properties are affected by the size of the diode, the exact semiconductor materials used to make it, the thickness of the diode layers, and the type and amount of impurities used in the semiconductor.

Lens Manufacturing Process

LED optical products are designed after identifying the purpose of use. The designer selects the optical materials, production-compliant optics design, suitable tooling solutions and the appropriate method for manufacturing the final product. Usually, injection-molding method is used by the optical manufacturers.

For LED lens manufacturing, silicone is mostly used as a raw material. LEDs of latest generation, including High Brightness LEDs and COB LEDs, achieve very high temperatures which could put pressure on the conventional polymers such as PMMI, PMMA, and PC. It is because of this that silicone is used to create high-end LED products.

Silicone is an isotropic material that provides LED optics with high flexibility which allows an easy fit as well as a perfect compensation for the construction mechanical tolerances typical of the final application.

Silicone is mostly preferred because of its high temperature resistance, strong heat aging resistance and high chemical resistance as well as ultraviolet (UV) stability, purity, clarity, and stable mechanical properties at a temperature ranging from 40°C to 200°C.

Engineers also use new optical techniques that allow sharpening the extreme angles and elaborate specific geometries developed in order to make the innovative lenses able to achieve a superior optical refractive index, while delivering best optical performance.

LEDs manufactured using silicone considerably reduces the manufacturing process time than lens made of a conventional polymer (PMMA, PMMI or PC). Reduced manufacturing time helps to reduce the production costs and also saves energy. However, it requires a great deal of technical expertise and skill for implementing this procedure. Also, when a lens is considerably large, the transformation process becomes much more complicated. Great care and technical mastery are needed either when the silicone is injected or when the molded part is removed from the mold during the de-molding process.

Injection molding production process forms the basis for manufacturing different optical components including LED. Most optical products are manufactured using either poly (methyl) methacrylate (PMMA) or polycarbonate (PC). An injection molding machine, raw material, and a mold is used for injection molding. The raw materials are melted in the injection molding machine and then injected into the mold, where it cools and solidifies into the final part.

After the product is manufactured, it is sent for quality inspection where it goes through rigorous testing to ensure high quality standard is maintained at all times. After assuming the products pass through quality testing, final assembly of the individual pre-tested components are performed using advanced tooling solutions then concludes the process.

Dow Corning to Launch Moldable Optical Silicone Technology for LED Optics https://www.kiwilighting.com/blog/dow-corning-launch-moldable-optical-silicone-technology-led-optics/ Moldable-Optical-Silicone[/caption] At PennWell Corporation’s Strategies in Light Europe 2013, Dow Corning will launch an new moldable optical silicone technology, deliver a presentation called “How Silicone Enables the Next Generation of Secondary Optics for LED Lighting,”...

Dow Corning to Launch Moldable Optical Silicone Technology for LED Optics

Moldable-Optical-Silicone[/caption]

At PennWell Corporation’s Strategies in Light Europe 2013, Dow Corning will launch an new moldable optical silicone technology, deliver a presentation called “How Silicone Enables the Next Generation of Secondary Optics for LED Lighting,” and exhibit its portfolio of LED silicone optics.

Strategies in Light Europe 2013 will be held at the M.O.C. Event Centre in Munich.

The new moldable optical material is Dow Corning’s latest addition to its family of optical-grade silicones for LED lamp and luminaire applications. According to the company, the material significantly increases LED light output, improves overall energy efficiency, and extends device life and reliability.

The Dow Corning presentation will be delivered by Hugo da Silva, global industry director, LED Lighting at Dow Corning. It will focus on the use of optical-grade silicones as next-generation solutions to help meet the LED industry’s increasing need for products that overcome the challenges and limitations of traditional optical materials. It will also discuss how advances in silicone chemistry and processing give LED designers and original-equipment manufacturers (OEMs) greater freedoms to explore new systems and applications and enable more advanced light and luminaire designs.

The presentation will be given on Thursday, Nov. 21 from 11:30 a.m. to 12:00 p.m. in Room K1 at the M.O.C. Event Centre, session number TTS4P3. Dow Corning’s moldable optical-grade material, along with the company’ portfolio of LED lamp and luminaire solutions, can be seen at Booth B25.

About Dow Corning

Dow Corning to Launch Moldable Optical Silicone Technology for LED Optics https://www.kiwilighting.com/blog/dow-corning-launch-moldable-optical-silicone-technology-led-optics/ Moldable-Optical-Silicone[/caption] At PennWell Corporation’s Strategies in Light Europe 2013, Dow Corning will launch an new moldable optical silicone technology, deliver a presentation called “How Silicone Enables the Next Generation of Secondary Optics for LED Lighting,”...

Dow Corning to Launch Moldable Optical Silicone Technology for LED Optics

Moldable-Optical-Silicone[/caption]

At PennWell Corporation’s Strategies in Light Europe 2013, Dow Corning will launch an new moldable optical silicone technology, deliver a presentation called “How Silicone Enables the Next Generation of Secondary Optics for LED Lighting,” and exhibit its portfolio of LED silicone optics.

Strategies in Light Europe 2013 will be held at the M.O.C. Event Centre in Munich.

The new moldable optical material is Dow Corning’s latest addition to its family of optical-grade silicones for LED lamp and luminaire applications. According to the company, the material significantly increases LED light output, improves overall energy efficiency, and extends device life and reliability.

The Dow Corning presentation will be delivered by Hugo da Silva, global industry director, LED Lighting at Dow Corning. It will focus on the use of optical-grade silicones as next-generation solutions to help meet the LED industry’s increasing need for products that overcome the challenges and limitations of traditional optical materials. It will also discuss how advances in silicone chemistry and processing give LED designers and original-equipment manufacturers (OEMs) greater freedoms to explore new systems and applications and enable more advanced light and luminaire designs.

The presentation will be given on Thursday, Nov. 21 from 11:30 a.m. to 12:00 p.m. in Room K1 at the M.O.C. Event Centre, session number TTS4P3. Dow Corning’s moldable optical-grade material, along with the company’ portfolio of LED lamp and luminaire solutions, can be seen at Booth B25.

About Dow Corning