Machine Vision Solves Solar Problems Across the Spectrum

"Solar cell manufacturing has been a bright spot for the machine vision industry during recent years. Not just because of increased demand and investment, but also because of the nature of solar cell manufacturing, driven by their various designs, and the many process steps that can benefit from machine vision quality control systems. The latest developments in solar-centric machine vision can be found across the spectrum – the electromagnetic spectrum, that is. Whether its monocrystaline, polycrystalline, or thin-film photovoltaic (PV) panels, machine vision is helping manufacturers to boost yields and set the stage for a renewable energy revolution.

A Bright Spot

Energy consumption for today’s modern world is growing by approximately 10% every 5 years while fossil fuel reserves are finite. In an effort to match supply with demand, government has increased financing for photovoltaic development by 400%, while private funding tripled in 2007, and then tripled again in 2008, according to Peter Klaerner, Staff Process Engineer at SolFocus Inc., and keynote presenter at The Vision Show in 2009. The AIA’s Director of Market Analysis, Paul Kellett, estimates that the solar cell market will grow from $13 billion in 2009 to $30 billion by 2012

As Kellet points out in his article, the solar cell market is similar in many ways to the semiconductor inspection market, especially as it relates to silicon wafer based photovoltaics (PV). As cheaper thin-film PVs have grown in efficiency, machine vision companies can also pull from their expertise serving the LCD flat panel industry because thin-film solar cells are in many ways similar to an LCD glass with applied anti-reflective and color filters. The larger size of thin-film PVs compared to silicon-based PV cells, along with their easier, cheaper manufacturing processes, are driving money into thin-film PV development and manufacturing.

Basler Vision Technologies (Ahrensburg, Germany) is one company using its LCD panel expertise to help the thin-film PV manufacturing market. “One of the most serious problems our customers are facing is glass breakage during the coating process caused by defects in the glass that are propagating during thermal and mechanical stress,” explains Enzio Schneider, Basler Sales Engineer and PV Specialist. “We’ve built a system that can do 100% inspection of the glass as it comes into the manufacturing line. At this point the glass may have a Transparent Conductive Oxide (TCO) coating, which we can inspect for voids and other defects. At the same time, we inspect the edge of the glass, which is usually made using mechanical grinding. If there are any microcracks or edge chips along the edge caused by the grinding process, the glass is more likely to break during subsequent manufacturing steps. By implementing our system, one manufacturer was able to avoid 95% of glass breaks. Usually, a glass would break once a month, and cause up to 8 hours in downtime. The return on investment of our system in this case was less than two months.”

Looking Beyond the Visible

Microcracks are too small to see with the unaided human eye, but they’re not the only hidden defect when it comes to solar cell manufacturing. Sinfrared, a XenICs (Leuven, Blegium) company, sells short-wave infrared (SWIR) cameras to the solar manufacturing industry to check a variety of manufacturing steps, from the TCO layer to silicon wafers.

Thin-film PVs essentially work like a reverse LED, using the electron band gaps inherent to different semiconductor materials to convert light (photons) into electrons, rather than the other way around. Therefore, applying an electric charge can cause a thin-film PV material to emit faint light. The color of the light depends on what layers have been applied to the glass. When it comes to TCO and several of the metal oxide layers, the emitted light is in the SWIR part of the spectrum. This phenomenon can help PV manufacturers to check the quality of the ‘invisible’ coating prior by applying an electric field, taking a SWIR image of the glass, and looking for intensity variations that indicate gaps, thin spots, or corrosion of a specific layer."

~ Source: MachineVisionOnline.org

Proud to support the Make-A-Wish Foundation

Fiberoptics Technology, and fiber optic cable manufacturer, is proud to support The Make-A-Wish Foundation.

Since 1980, the Make-A-Wish Foundation® has enriched the lives of children with life-threatening medical conditions through its wish-granting work. The Foundation's mission reflects the life-changing impact that a Make-A-Wish® experience has on children, families, referral sources, donors, sponsors and entire communities.

The Make-A-Wish Foundation was founded in 1980 after a little boy named Chris Greicius realized his heartfelt wish to become a police officer. Since its humble beginnings, the organization has blossomed into a worldwide phenomenon, reaching more than 174,000 children around the world.

Although it has become one of the world's most well-known charities, the Make-A-Wish Foundation has maintained the grassroots fulfillment of its mission.

There are four steps to granting a wish. Each step builds on the next to help create the amazing experiences that delight wish kids and their families. A wish experience is frequently a source of inspiration for children undergoing difficult medical treatments and a positive force that helps them overcome their obstacles. A wish experience is often more than a dream come true: It’s the catalyst that rekindles their belief in themselves and the promise of their future.

The four steps include:
Step 1: Referral
Step 2: Medical eligibility
Step 3: Finding the true wish
Step 4: Creating joy

Need Accessories?

FTI offers a complete range of fiber optic accessories to expand standard product versatility. Some advantages of these accessories are listed below:

* Increase the light output of a lightline by a factor of 10 by using a cylindrical lens.
* Increase contrast of colored objects using a contrasting color filter to absorb the predominant background color.
* Make light output "cool" with the use of a heat reflecting dichroic mirror in the light source input.
* Reduce or eliminate specular reflection with a polarizer/analyzer combination.
* Create specular effects on raised or spherical surfaces with dark field lighting accessories.
* Control the light source with a computer interface.
* Maximize light source output by changing the lamp type used.
* Use other manufacturer's fiber optics with adapters designed for use with SOL-R light sources.

Lenses, filters, lamps, light source add-ons and replacement parts are stocked for immediate shipment.

Product Spotlight: Medical Headlights

Our medical headlights work equally well in an industrial or medical environment. Made from dependable, rugged and comfortable materials, FTI headlamp systems offer the following features:



* Adjustable, lightweight rigid head band with flexible (removable) or rigid (adjustable) crown support.
* Fixed 100mm spot or 10-75mm adjustable spot at 16” (406mm).
* Integral autoclavable joystick for accurate and easy positioning.
* Ergonomically designed lensing system is unobtrusive, yet perfectly positioned to put light wherever the user wants to see.
* 7.5 ft (2.29M) 5mm bifurcated multi strand glass fiber optic light guide for dependable long life.
* Threaded universal adapter accepts Storz, Olympus, Pilling, Wolf, ACMI and many other input tips. In addition, a standard FTI input can be selected for use with the entire line of FTI illuminators.
* 1 year warranty.
* CE (IEC 601-1), UL(2601) certified as Class I equipment, type BF continuous operation.
* FDA Class II product.

New LED Light Engine

POMFRET, CT, December 2009 - Fiberoptics Technology Inc. (FTI) announces the launch of a high power LED light engine for large active diameter industrial applications.

The patent pending device will be certified by ETL under the UL lab/industrial protocol, and will be CE certified. The unit will be manufactured at the company’s new electronic assembly facility in Pomfret CT beginning in April 2010. FTI began designing and manufacturing light source products in 2004.

Using a very simple but effective coupling strategy, engineers at FTI can couple the light from a monocolor single die into a fiber optic cable at high efficiency rates. The resulting output exceeds the power of a similarly coupled EKE halogen lamp in active diameter sizes up to 12mm.

The company plans to provide a product with true color balance, excellent uniformity, improved electrical efficiency, along with a measureable return on investment (ROI) in a small package compatible in size to existing halogen lighting technology, and can replace it without altering existing systems or components.

“After nearly 4 years of research and development, our team has made a second important breakthrough; an LED source capable of generating as much power as an EKE lamp at the full 12mm spot size. This will enable our customers to update their industrial process and vision systems with a long lived, bright, and dependable source, eliminating down time associated with lamp change. I believe the introduction of this unit signals the beginning of the end for the traditional 150W Quartz Halogen source.”, said Steve Giamundo, the company’s VP of Sales and Marketing.

FTI’s LED light engine technology provides the following features:
* More power than an EKE lamp within a 12mm focal spot.
* Long life (50000) hours – no lamp to change.
* Stable output throughout the usable life.
* Active heat management with integral cooling fan.
* Available in a white-only or Red, Green and Blue only versions.
* 6000K color temperature for the white only version.

The company has made a Beta unit for testing and evaluation, which is available now to interested OEMs, integrators and end-users. The core light engine is available for sale immediately.

For more information on FTI, and our fiber optic accessories, please visit our site!