Ultraviolet light is a significant factor when dealing with unfiltered light. While our eyes cannot see it, the camera does. What we refer to as visible light is light radiation that falls between 400 nm and 700 nm. When you look at a rainbow you can see the spectrum of visible light where the shorter wavelengths of light closer to 400 nm are blue and the longer wavelengths of light closer to 700 nm are red. When you look at the red and blue edges of a rainbow, you should notice that the color seems to fade a bit the farther out you go. This is not because the light isn’t there, it’s because your eyes aren’t capable of seeing those wavelengths.

Color film photography presents an interesting problem when it comes to UV light. Color film essentially has three color sensitive layers, one of which is blue. The blue layer responds to blue light, but it also responds to UV light. When taking color film photographs in an area with unfiltered light, outdoors for instance, then you run the risk of overexposing the blue layer and ending up with photographs that have a distinctive blue tinge. Our eyes and brains tend to be trained not to see this blue tinge when we are used to seeing it, but then you see a photograph that doesn’t have it and it’s like seeing the world through new eyes. Using a UV blocking glass while taking color film photographs will drastically reduce the blue tinge effect.

Digital Photography doesn’t really have the same problem that color film photography has, and while that is good news for digital camera users, there are still other problems to be resolved. One such problem is called “scatter”. This effect is most noticeable when photographing distant subjects and shows up as a bluish haze that reduces the crisp clarity often sought when photographing subjects like mountain ranges or cityscapes. Another difficulty with digital photography in relation to UV is “purple fringing” or PF. This most commonly occurs when a dark subject is backlit on a bright background, such as tree leaves against a clear sky. UV blocking glass filters also help to alleviate this problem.

There are other ways to alleviate all of these problems, either through photo manipulation after the fact, or by limiting your choices of subject matter to studio scenes where the light can be filtered at the source. In all of these alternatives, you are limiting the quality and choice of subject matter and not truly solving the problem of ultraviolet light filtering. The best pictures are taken with equipment that solves the problem up front so that quality of the photograph is not adversely affected in development or touch up.

To learn more about ZC&R’s UV blocking glass or to discuss how it may benefit your specific application, call 800.426.2864 or email us.

LCDs utilize organic components that are susceptible to ultraviolet degradation, which can manifest as a shift in color or a washed out look. Displays used in outdoor environments or in close proximity to Fluorescent black lights and other long wave UV emitters are at considerable risk of Ultraviolet degradation. Outdoor LCD devices are at high risk, but with more indoor UV emitter applications being developed it has become apparent that sunlight based ultraviolet radiation is not the only concern. Indoor UV emitter applications are being developed or are currently in use by medical and forensics groups for example.

The atmosphere itself blocks a significant portion of sunlight Ultraviolet radiation up to 280 nm, which is the top end of the UV C range. Oxygen is the primary element responsible for the atmospheres filtering effect on UV C. Indoor UV C emitters are in relative close proximity to the LCDs they would potentially affect and thus are not likely to benefit as much from the filtering effects of the atmosphere. UV C is also damaging to people and so high intensity emitters use protective barriers to contain the UV C radiation. For this reason, LCDs within the application would need a protective UV Blocking Glass.

UV B is less blocked by the atmosphere, but is still significantly blocked by ordinary glass (although this is not generally true for Silica or quartz glass). In situations where an application uses UV B radiation, it is recommended that the application be sealed to prevent excessive human exposure. Any application that needs an LCD to be exposed to UV B radiation regularly should utilize a UV Blocking Glass coating to ensure that the LCD does not degrade.

While ordinary glass blocks a significant portion of UV B this still leaves a significant portion of the UV A range that permeates the front of an LCD. It is this UV A range that has often eluded efforts to prevent ultraviolet degradation. Its effects are often not as obvious, but can be seen in many everyday situations where carpet, drapes or other natural and synthetic polymer objects are left in a window for long periods of time. They fade, crack or disintegrate due to the unblocked UV A radiation that passes through ordinary glass.

ZC&R’s UV Blocking Glass solutions act as a mirror to ultraviolet radiation. In combination with a hot mirror (IR Reflector), this coating helps preserve the performance of an LCD exposed to unfiltered broadband lighting while retaining the visibility and clarity of the display.

For more information on ZC&R’s UV Blocking Glass solutions please call 800.426.2864, email us or visit our heat control page at zcrcoatings.com/heat-control/.

There are certainly other ways to protect us from low intensity ultraviolet light and new products come out all the time that offer this protection in various ways. Vast amounts of research and effort have been put into finding out just how dangerous UV light damage is and how to prevent it. Lotions, glasses and even clothing have been developed to prevent the carcinogenic effects of UV light exposed to our skin and eyes. These protection are effective when the source of the ultraviolet light is the sun, but what do you do when the sun is not the source?

While the sun is widely recognized as the most significant source of UV light it is not the only source we must work to protect ourselves from. Ultraviolet light is known to emanate from many different man made sources like high pressure arc lamps and fluorescent lamps as well as incandescent lamps and solid state light sources (LED’s, OLED’s and PLED’s). In fact it is known that broadband or “white” light sources are almost guaranteed to produce at least some UV light along with the visible light intended.

Among all the light sources that we use just to see the world around us, there are also light sources that are used for other purposes. For a while now, Medical research and care facilities have been using light to treat patients as well as conduct experiments. One such treatment is light therapy used on the skin of someone who has acne vulgaris or a child that has neonatal jaundice. Other skin conditions that can be treated specifically with UVA (315 – 400 nm) or UVB (280 – 315 nm) light are psoriasis and eczema. Light therapy is also used by directing light into the eyes in order to help treat circadian rhythm disorders such as delayed sleep phase syndrome and can also be used to treat seasonal affective disorder. Another medical application for light is during surgery, where light from a high intensity arc lamp is funneled to the surgical site through optical fibers. It is critical to use UV and IR filtering in this application so that the unprotected internal tissue is not damaged by the light needed to see what the surgeon is doing.

Other medical uses for ultraviolet light are for protein analysis through UV-visible spectroscopy, DNA sequencing, drug discovery and medical imaging of cells. Through these applications, UV light becomes a valuable resource and a tool for accomplishing important tasks that not only help researchers find the source of health problems, such as errors in DNA but UV light is also being used to help correct health problems through development of new drugs and other medical technologies. In all of these tasks it is important that the UV light be contained or isolated through the use of UV blocking glass.

Just like fire and many other forces harnessed for use as tools, ultraviolet light must be used with knowledge, caution and protection. While there are many ways to protect ourselves from the damaging effects of UV light, it is most important to recognize that protection is needed. Once that is determined, then the appropriate form of protection can be acquired and implemented. ZC&R’s UV blocking glass is an excellent example of a form of protection that filters the light at the source, or through isolating UV light so that it is directed to the appropriate point of use without adversely affecting unintended tissue.

To learn more about ZC&R’s UV blocking glass or to discuss how it may benefit your specific application, call 800.426.2864 or email us.

Many UV Blocking Glass solutions are said to provide a certain percentage of protection from UV light, often ranging between 96% and 99.9%. It is important to note that there are different kinds of UV light and the amount of protection provided for each kind of UV light is as important as its overall protection against UV. UV B and UV C radiation for instance are significantly blocked by regular glass, but UV A radiation isn’t significantly blocked. If an overall rating were given to regular glass it might deceive someone into thinking that their artworks were perfectly fine behind regular glass, when in fact UV A radiation can be virtually unhindered as it passes right through regular glass. Taking this into account means knowing that the UV Blocking Glass you’ve opted to use doesn’t just protect versus UV in general, but is specifically blocking significant portions of the entire range of ultraviolet radiation.

In addition to utilizing UV Blocking Glass it is also important to adhere to the following guidelines when displaying valuable artwork:
• Use just enough light to display the artwork as intended. Even though implementing a UV Blocking Glass solution, it is important to reduce light levels in the display area because the small amount of UV that does pass through adds up over time. Reducing light levels reduces the amount of UV the artwork is exposed to.
• Do not expose artwork to direct sunlight. The sun is a significant source of UV B and UV A (most of the UV C and shorter wavelengths are blocked by the atmosphere). It is also a high intensity light source that conveys much higher levels of UV radiation than regular artificial light sources.
• Use Incandescent, not fluorescent light sources. Fluorescent lights produce much more UV light than incandescent lights do.
• Other environmental concerns can hazardously affect your artwork as well. Any museum quality artwork should be contained in a controlled environment. Humidity and oxygen are traditional culprits for artwork degradation. In these situations it may be ideal to use a hermetically sealed viewing case.
• Do not allow the use of flash cameras. The intense and unfiltered light from a flash camera adds up over time. Allowing artwork to be exposed to hundreds of thousands of flashes will likely have a perceptible effect on the piece.

ZC&R UV Blocking Glass is a high quality solution at a good price. If unique and irreplaceable artwork is to be preserved in a viewing area with minimal exposure to irreparable ultraviolet degradation, then our UV Blocking Glass solution is the right way to go.

For more information on how UV Blocking Glass is used to preserve artwork and museum pieces, please call 800.426.2864, email us or visit our heat control page at zcrcoatings.com/heat-control/.

ZC&R and Abrisa will be exhibiting at Booth 1740, where we will have staff on hand to discuss what is going on in the industry right now and how our precision thin film optical coatings from the UV spectrum to the longwave IR are helping your projects meet with success. We provide OEM custom engineering, design and support services for defense, medical, display and lighting markets.

Stop by our booth to talk with us or email us or call us at 800-426-2864 to set up an appointment.

SPIE Photonics West – Booth 1740

Extreme weather conditions are familiar territory for the military as they are called upon to operate in hostile environments throughout the world, and have spent a significant amount of research time to determine what specific measures should be taken to assure that equipment will continue to function properly. In arctic conditions the military takes special care to ensure that cameras, liquid crystal displays and handheld devices are kept above temperatures that risk damage to their optics such as LCD failure due to freezing. Transparent heater windows help to mitigate these conditions by keeping the components at elevated temperatures.

Outdoor security cameras are a prime example of optical equipment that are susceptible to cold weather conditions and must be kept above a minimum operating temperature to avoid electronics malfunction. Security camera manufacturers offer systems that help to address these concerns by heating the camera housing. In addition to preventing the electronics from malfunctioning it is also important to prevent the housing window from frosting over or collecting condensation and blocking the field of view of the camera. In some cases Transparent heater windows use an electrical current variation system to monitor and adjust the window temperature so that it is always slightly warmer than ambient conditions with a lower limit that is just above freezing temperatures.

One obstacle to overcome when developing a transparent heater window is transparency itself. The goal of any window is to provide protection while allowing as much light as possible to pass unhindered by the window. In order to achieve this goal, LuxVu Transparent Heater Windows utilize a unique process combined with specific chemicals to create a transparent conductive coating. This coating incorporates index matching layers in such a way that the reflectance of the conductive surface can be less than plain window glass thus allowing more light to pass through the window.

ZC&R’s LuxVu Transparent Heater Windows use IMITO (Index Matched Indium-Tin Oxide) as the semiconductor coating material. This material has a low IR emissivity property that also allows this coating to be valuable in environments where the camera housing is being cooled to prevent heat related malfunctions. This would help to reduce the amount of heat entering the housing through the window while helping to prevent condensation on the outside of the window. Furthermore, the coating used is also an EMI shield, which can help address electro-magnetic interference security concerns by acting as a barrier and helping to prevent the EMI from entering through the window and potentially damaging the electronics inside.

LuxVu Transparent Heater Windows can also be used in a variety of other applications and more are being developed and implemented every year. Currently the military uses transparent heater windows in aircraft to prevent frost and condensation on the windshields that could cause difficulty in piloting. This same application is also being expanded for use in ground vehicles.

For more information about Transparent Heater Windows or how LuxVu ITO coatings can benefit your application please call 800.426.2864 or email us.

Transparent Heater Windows were originally developed during World War II for use on the windshields of aircraft. Certain aircraft were deployed to high altitude or cold weather environments and were susceptible to frost forming on the windshield which obscured the vision of the crew.

Several different types of Transparent Heater Windows exist. The most common form can be seen used in the rear window of an automobile as a de-fogger. The obvious flaw in using that particular iteration of the technology is the fact that it has visible lines which can obscure vision. For that reason Transparent Conductive Oxide coatings are used. TCO’s come in several forms, but the three most common are Fluorine-doped Tin Oxide (SnO2:F), Indium-Tin Oxide (ITO), and thin stacks of oxides and metallic silver. ITO coatings are robust and suited for a variety of industrial uses.

Using a TCO in a transparent heater window also has another note worthy property. The metal oxides used not only conduct electricity, but also reflect heat. Without a TCO the glass surface absorbs heat as a high-emissivity material. Adding the coating allows the glass to reflect heat as a low-emissivity material.

Transparent Heater Windows are used in a wide variety of applications today. They are used in supermarket freezers and cold item displays to reduce the amount of environmental heat that reaches the contents while allowing customers to view what is inside. These windows are also used in outdoor security camera housings to prevent frost from forming and obscuring the view of the camera. Please call us to discuss how this technology is, or could be, used in your application.

For more information about transparent conductive oxide coatings or LuxVu Transparent Heater Windows please call 800.426.2864 or email us.

There are many situations where an EMI shielding window may need contrast enhancement. Varying conditions often require different solutions. Several regularly used solutions are; anti-reflection coatings, matte finishes, optical color transmission filters or special laminates such as polarizers. Anti-reflection coatings drastically reduce the amount of light reflected off the window, and allow it to pass through. This can reduce the amount of glare, and increase the readability of the display. Other solutions, such as matte finishes or circular polarizers can be used with varying results.

One concern that may arise with an EMI shielding window is the need to clean it on a regular basis and how that potentially abrasive cleaning process might affect the window. An ideal cleaning process would be one that does not leave residue that might interfere with the windows performance. When using a cleaning process like this for an extended period of time the window may start to degrade from the abrasiveness of the cleaning process. This is more noticeable in situations where an optical coating is used on the viewer side of the window. In this case it may become necessary to use an abrasion resistant coating that would help protect the EMI shielding window from damage while allowing the window to be cleaned and maintained. ZC&R’s LuxVu IMITO films include ion-assisted scratch resistant surfaces for high durability requirements.

For more information about anti-reflection coatings or LuxVu IMITO EMI shielding windows please call 800.426.2864 or email us.

When determining what kind of EMI shielding window is needed for an application, it is important to know what that application’s highest threat frequency is. The highest threat frequency is defined to be the highest frequency that creates a concern for equipment degradation or application failure. Once the highest threat frequency is determined then you can establish which kinds of EMI shielding windows are appropriate for the application. Generally speaking, woven wire mesh screens have the highest dB shielding effectiveness for any given threat frequency. Electrically conductive transparent coatings, are often considered to be slightly less effective. Knitted wire mesh screens are generally considered to have the least dB shielding effectiveness. The dB shielding effectiveness for each wire mesh screen is adjusted slightly through varying the diameter of the wires and/or the openings per inch. You can also vary the dB shielding effectiveness of an ECTC by changing the thicknesses and types of coating material.

The next thing that must be taken into account is the required optical transmission for a given application. Knitted wire mesh screens are considered to be fairly optically transmissive due to the large openings between the wires, while woven wire mesh screens are typically less optically transmissive because of their many tightly woven wires. An ECTC’s optical transmission quality is not determined by numbers of wires, but thickness of the coating as well as the specific material used in the coating and manner in which it is applied. An associated concern is the moiré effect associated with wire mesh screens. In applications that utilize moderate to high resolution displays, the wire mesh screens create a visual effect where the wires overlap the lines in the display and create areas of darkness. These areas appear in a pattern and can adversely affect the application. ECTC’s do not have wires and therefore do not create this moiré effect, nor do they require special attention to align the EMI shielding window to reduce the effect.

LuxVu IMITO EMI shielding window coatings further add to the advantage that ECTC’s have by being custom made to specific applications. This allows for greater control and adherence to demanding specifications. With the ability to dictate the thickness and specific material used in these custom IMITO coatings, particularly specific and demanding application specifications can be met with considerable attention to quality.

For more information about LuxVu IMITO EMI shielding windows for displays please call 800.426.2864 or email us.

EMI Shielding Windows are utilized in many different applications that require electro-magnetic separation between two regions while maintaining at least a minimum optical transmission. There are a number of reasons why you would do this. In emergency medical environments where EMI sources are not guaranteed to be denied entry, it is imperative that EMI sensitive equipment be shielded properly to ensure that they function as intended. To prevent equipment malfunction on the battlefield, many different pieces of EMI sensitive military equipment must be shielded from known and unknown EMI sources. Many different kinds of equipment need to be shielded either so that they can be protected from external EMI sources or so that their internally generated EMI does not interfere with external equipment, or cause harm to people.

There are three generally accepted types of EMI shielding windows. The three different types each have their own strengths and weaknesses. There are knitted wire mesh screens, woven mesh screens and transparent conductive coatings. All three types generally use either clear plastic or glass sheets as the substrate. Both the knitted and woven wire mesh screens rely on small diameter wires (between .001” and .0045” diameter) combined with typically 10 to 30 openings per inch for knitted wire mesh or 80 to 150 mesh (wires per inch) for woven wire mesh to determine the optical transmission of the EMI shield. The third type of coating is referred to as an Electrically Conductive Transparent Coating (ECTC) and does not use wires. ECTC’s utilize deposited electrically conductive material onto the surface of an optically transparent substrate.

For more information about EMI Shielding Windows please call 800.426.2864 or email us.