LED optical design that thing

The incredible “lumens-per-watt packages” have become a reality, and lighting distributors and end users are interested in this. Chris Bailey, Hubbell's solid-state lighting SSL technology strategist, said: "We are a little intoxicated."
Solid state lighting
Due to the rush to bring products to market, early attention paid little attention to the optical properties of solid-state lighting SSL and the opportunities it brings. LED luminaires designed by OEMs and luminaire manufacturers still have the same look and function as other luminaires in the history of 130 years of electric light source. Bailey said: "Because the technology is far worse than today, we can't realize the interaction between people and products. We invented the light, but we have not been able to go one step further." When the comfort, glare, uniform and other lighting needs are put on the agenda On the agenda, manufacturers and lighting designers are re-examining the way they want to go.
Difference interpretation
To understand the difference between LEDs and traditional (filament) sources, you must know how they work. The diode is a photon-filled hole generated by the two poles of the semiconductor to generate current luminescence. Incandescent lamps generate light by high temperature thermal radiation.
Figure: LED lighting principle
Source: OMS lighting
Light distribution is another difference between different light sources. The light distribution of a conventional light source is a spherical shape of 360 degrees, and the distribution of the LED light source is 180 degrees. Peter Ngai, vice president of research and development at the Acuity lighting brand, said: "So we must customize optics based on this feature."
The directionality of the LEDs and the forward illuminating characteristics mean that retrofitting traditional luminaires is by no means just as simple as changing a light source. For example, a reflector for an incandescent or compact fluorescent lamp may have no effect at all for the LED source. Because the back of the LED does not emit light, the reflector can be reflected without light. In most of the retrofit cases, Nagi said, “The light distribution is very different. If you want to replace existing fixtures with LEDs correctly, you need to replace the previous reflectors, lenses and other internal optics, and replace them with LED light sources.
The quantity is also critical. Bailey said that LED luminaires use multiple diodes (equivalent to multiple small light sources), each of which "generates a large amount of light", which requires control of their brightness and proper redistribution, otherwise it is prone to discomfort Glare and pixelated distribution, rather than continuous uniformity throughout.
LED light fixture
Figure: Example of LED pixelation application. In the whole lamp, it is necessary to avoid pixelation of the light source point as much as possible.
Source: OMS lighting
optical instrument
For traditional luminaires, manufacturers use a combination of reflector cups and lenses to spread and project light onto the target. But these optics, such as the frosted glass bowl (DOME), can cause up to 50% of light loss. Maria Topete, a senior application specialist at Prius, said: A lot of light has been absorbed.
Therefore, in the LED application of this performance-name game, those suppliers of lamps using traditional optics, "have suffered a fatal blow." Topete said, “So when we design, we become smarter. Those optical solutions that look similar have actually many ideas and techniques that are better.”
LEDs, like traditional light sources, want to eliminate glare and must enlarge the light-emitting area to make it diffuse. Topete said: "Although OEMs want to get as much light as possible from the smallest package, this can cause visual discomfort.
LED luminaires typically have two optical layers. Primary optics, using a lens similar to a glass hemisphere, aligns and distributes light according to the expected luminosity specification; secondary optics further parallels, diffuses, or directs light according to the needs of light distribution and orientation. In this case of secondary optics, the size of the light source is increased. In the opposite case, the primary optics use a diffuser to control light, and the secondary optics use a lens or reflector to control light.
Figure: LED optical design structure
Source: Network
Adjust traditional technology
Topete says that the use of optics depends on several factors, including the application scenario, but in any case, the key to efficient use of light is to "allow light to exit" and reach the illuminated surface.
Since the LED's illumination angle is within 180 degrees, "In most cases, the lens is a suitable method to control the light output," Nagi said. The small size of the LED means that the complete lens is comparable to the size of the light source, and a compact, or Fresnel lens can be used to calibrate the light. In this way, light loss and dispersion can be reduced from the source.
Manufacturers are also improving the quality of lenses. Bailey said that we are changing the inner surface of the lens to form a plurality of matte surfaces, thereby largely eliminating the reflected light caused by the reflection of the internal surface of the lens.
The increase in diffusion technology allows for better control of light while maintaining luminous efficiency. Topete says that unlike glass or polycarbonate lenses that are frosted or internally filled with scattering particles, manufacturers can customize the shape and surface of the appropriate plastic lens for LED applications, which can reduce light loss by about 10%.
5 diffusion technology
Figure: An embedded LED light panel that uses a prism diffuser to evenly distribute light.
Source: Courtesy Hubbell Lighting
In contrast, the LED emits less heat forward, so it can be attached to a lens or a diffusion medium in front of it, together with materials such as films and sheets. And this is obviously not possible with traditional light sources that generate high heat.
Luminaire manufacturers and OEMs also use parabolic or hyperbolic reflectors to control light and prevent light from entering the field of view directly, thereby reducing glare. However, although a parabolic reflector causes sufficient light to be spherically distributed, it may not be able to control the escape of light near the central axis of the source, which is a significant fraction of a 180-degree LED. As a result, some luminaire manufacturers have attempted to use LED arrays in different directions inside the parabolic reflector to improve control of the light output direction.
Future new technology
Existing optical technologies do not fully meet the needs of luminaire applications.
Manufacturers are tapping the potential of refractive technology. Bailey said that we are developing prisms to replace the reflector cup. Total internal reflection (TIR) ​​optics combines a reflective cup and a refractive lens to control the direct and reflected light of the LED. The beam of the central axis of the LED can enter and pass through the refractive lens, while the total internal reflection surface can control the beam range.
6 lens
Figure: The small size of the LED allows the luminaire to be smaller and more efficient, with higher precision optics. The picture above shows a TIR total internal reflection lens.
Source: Courtesy Hubbell Lighting
In order to make effective use of internal reflection, luminaire manufacturers also use "photoconductive materials" to distribute the intense light from the LEDs mounted on the side of the luminaire. Nagi said, "The optical design of the light-guide material is to make better use of the light. After the light is injected, they can be redistributed due to the total internal reflection characteristics of the light-guide material."
7 light guide plate
Figure: A practice of using an ultra-thin light box with a light guide
Source: Network
Lighting manufacturers also use holographic films such as polycarbonate and polyester to experiment. The microstructure of these diffusers eliminates the imaging and pixelation effects of the LEDs, changing the distribution of light to form different beam angles, and efficiently transmitting light.
Injection molded acrylic and plastic optics have also attracted the interest of LED and luminaire manufacturers. Optical engineers are constantly experimenting with micro-surfaces and micro-features on lenses. Bailey said: "These seemingly minimal features on the lens have a huge impact on the presentation of products and light."
8 light guide plate
Figure: A downlight using a high-precision injection molded acrylic wall mirror.
Source: Courtesy Hubbell Lighting
Manufacturers now have another new technology for customizing LED optics: 3D printing. Norwegian Luxexcel's patented technology, "Optical Printing Method", enables diode-level printing. Utilizes an improved, multi-format, industrial-grade inkjet printer that eliminates the need for any tools, any molds, or die casting, and requires only CAD files to print out flat and 3D optics, including lenses, prisms, microstructures, and Multi-color, multi-surface laminate. Luxexcel's marketing manager said that several luminaire manufacturers around the world have begun experimenting with this technology.
9 linear prism
Figure: Green Linear Prism Printed by Luxexcel
Source: Courtesy Luxexcel
10 spherical microlens
Figure: A spherical microlens printed by Luxexcel that allows light to be parallel, divergent or diffuse, and to mix colors.
Source: Courtesy Luxexcel
The size, performance and reliability of LEDs have opened the door to optics and luminaire design, which manufacturers are just beginning to realize. At the same time, advances in electroluminescence and remote phosphor technology are equally impressive. Bailey said that the lighting industry has been "rebirth of the bath... this is an exciting time, we can use this new technology to freely create beautiful light."

2.0mm Male Header

2.0mm (0.079") Pitch Pin Headers
2.0mm pin headers are board-to-board or PCB to PCB Connectors rated for 250VAC and an industry-leading current of 3.0A. Antenk offers numerous configurations for this pin header. Designed for low-profile applications, this pin header is made from high-temperature thermoplastic and is offered with several means of connections and mounting styles such as through-hole (THM) or surface mount (SMT) and can be in vertical (straight), elevated or at a right angle configuration/orientation

Pin header customization is also available upon your request. The 2.0mm pitch pin header is highly recommendable for signal and low power PC board connections when space is at a premium and when 1.0mm and 1.27mm pitch headers cannot dissipate the required current. In addition, the 2.0mm pitch pin header holds an excellent mating quality that fits with various types of female connectors.


Applications of 2.0mm Pitch Pin Headers
Automotive, Heavy Duty Military and Marine
2.0mm pitch pin headers are for not only suitable for densely packed equipment requiring weight reduction and downsizing but also for automotive connections, built to be robust in tough and harsh conditions.
Battery Connections
Rechargeable battery packs, battery balancers, battery eliminator circuits. Battery connections rely on the ability of the current to pass reliable and solid current. This prevents overheating in the circuit and voltage drop.
Medical Diagnostic and Monitoring equipment
Communications: Telecoms and Datacoms

Industrial and Automotive Control and Test


Mount Type: Through-hole vs Surface Mount

2.0mm pitch pin (male) headers are offered in either Surface-mount or Through-hole mount termination. At one side of this pin header is a series of pins which can either be mounted and soldered directly onto the surface of the PCB (SMT) or placed into drilled holes on the PCB (THM).


Through-Hole (Poke-In)
Best used for high-reliability products that require stronger connections between layers.
Aerospace and military products are most likely to require this type of mounting as these products experience extreme accelerations, collisions, or high temperatures.
Useful in test and prototyping applications that sometimes require manual adjustments and replacements.
2.0mm vertical single row header, 2.0mm vertical dual row header, 2.0mm Elevated single row pin header, 2.0mm Elevated dual row pin Header, 2.0mm Right-angle single row header and 2.0mm Right-angle dual row header are some examples of Antenk products with through-hole mount type.

Surface-Mount
The most common electronic hardware requirements are SMT.
Essential in PCB design and manufacturing, having improved the quality and performance of PCBs overall.
Cost of processing and handling is reduced.
SMT components can be mounted on both side of the board.
Ability to fit a high number of small components on a PCB has allowed for much denser, higher performing, and smaller PCBs.

2.0mm Right-angle Dual Row pin header, 2.0mm SMT Single row pin header, 2.0mm SMT Dual row pin header and 2.0mm Elevated Dual Row Pin Header are Antenk`s SMT pin headers.


Soldering Temperature for 2.0mm Pitch Pin Headers
Soldering SMT pin connectors can be done at a maximum peak temperature of 260°C for maximum 60 seconds.


Pin-Type: Vertical (Straight) and Right-Angle
2.0mm pitch headers may be further classified into pin orientation as well, such as vertical or straight male header or right-angle male header.

Vertical or Straight Pin (Male) Header Orientation
One side of the series of pins is connected to PCB board in which the pins can be at a right-angle to the PCB surface (usually called "straight" or [vertical") or.


Right-Angle Pin (Male) Header Orientation

Parallel to the board's surface (referred to as "right-angle" pins).
Each of these pin-types have different applications that fit with their specific configuration.


PCB Connector Stacking
Elevated Pin Header Orientation
Elevated pins aka Stacked Pins or Mezzanine are simply stacked pin headers providing an exact distance requirement between PCBs that optimizes electrical reliability and performance between PCB boards.
Profile Above PCB
This type of configuration is the most common way of connecting board-to-board by a connector. First, the stacking height is calculated from one board to another and measured from the printed circuit board face to its highest insulator point above the PCB.

Single, Dual, Triple and Four Row Number of Rows
For a 2.0mm straight or vertical male pin header, the standard number of rows that Antenk offers ranges from 1 to 4 rows. However, customization can be available if n number of rows is needed by the customer. Also, the number of contacts for the single row is about 2-40 pins. For dual row, the number contacts may vary from 2-80 pins. For triple row, it`s 2-120 pins, while for four-row, it`s 2-160 pins.

Pin Material
The pins of the connector have been designed with copper alloy. With customer`s demand the pins can be made gold plated.

Breakaway design
The pin headers are also equipped with a breakaway design making them fully compatible with their female receptacles.

Custom 2.0mm Pitch Pin Headers
Customizable 2.0 mm pitch pin headers are also available, making your manufacturing process way faster as the pins are already inserted in the headers, insulator height is made at the right size and the accurate pin length you require is followed.
Parts are made using semi-automated manufacturing processes that ensure both precision and delicacy in handling the headers before packaging on tape and reel.

Tape and Reel Packaging for SMT Components
Antenk's SMT headers are offered with customizable mating pin lengths, in which each series has multiple number of of circuits, summing up to a thousand individual part number combinations per connector series.
The tape and reel carrier strip ensures that the headers are packaged within accurately sized cavities for its height, width and depth, securing the headers from the environment and maintaining consistent position during transportation.
Antenk also offer a range of custom Tape and reel carrier strip packaging cavities.

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ShenZhen Antenk Electronics Co,Ltd , https://www.antenkelec.com