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electronic products and technology • august 2012
Optoelectronics & Displays
Redefining multi-touch technology Canadian firm leads the way with ShadowSense technology By Anthony Gussin, director of marketing Baanto International Ltd., Mississauga ON Baanto ShadowSense technology is an innovative and patented optical position-sensing technology. Applicable to both 2D and 3D applications, the technology was developed by Baanto’s parent company Nytric Ltd.; Baanto was created to commercialize and market ShadowSense-based products.
Unlike other optical technologies that utilize cameras or imaging arrays, ShadowSense is a unique approach that uses high-performance analog sensors to provide unprecedented performance, stability and accuracy. Featuring an efficient sensor architecture coupled with elegant position-detection algorithms, ShadowSense technology overcomes many of the challenges faced by traditional optical designs. Perhaps the best analogy for ShadowSense technology is the sundial. The shadow cast by a sundial instantly and accurately responds to the position of a light source without the use of lenses, with an infinite depth of field and
without the need for any form of exposure control. ShadowSense technology exploits these same characteristics for touch applications, resulting in one of the highest performance, most robust and most cost-effective optical touchscreen solutions available in the market today. What is special about Baanto’s ShadowSense? Well, to answer that we need to first take a look at other touch technologies that have been in existence for some time. These existing approaches all have their own, sometimes significant, drawbacks. The touch detection is bezel-based, thus decoupled from the protective glass used to cover the touch surface
Let’s start with resistive and capacitive touchscreens. With these technologies, the touch sensor is implemented by depositing a very thin layer of opticallytransparent metal, indium tin oxide or ITO, on a sheet of glass. The sensor is then placed over the display and serves to both protect the underlying display and detect touches on the glass surface. These technologies are prone to damage from abrasive or sharp objects in everyday use and, because the ITO layer is not 100% optically clear, reduce the optical quality of the display. Capacitive touch is further limited by requiring ‘bare-finger’ touch, making products like cell phones very userunfriendly during cold winters. The cost of these technologies also increases substantially as the display size increases. While inexpensive in small sizes used for smart phones or tablets, manufacturing larger touchscreens is either extremely expensive or technically impossible. To try to avoid these problems there are numerous implementations of optical touch technologies in use. These solutions generally fall into one of two categories – infra-red or camera based. However these approaches also have their own limitations. Many infra-red systems suffer from problems relating to ambient light and are not suitable for bright or outdoor environments. They are also prone to debris that may accumulate on the display or bezel, which can block one or more of the infrared light sources. Camera-based systems can become overly complex due to their video processing requirements and the algorithms associated with processing millions of bytes of data. These systems require sophisticated digital signal processors that may take up significant CPU cycles on the host machine driving them. In addition, problems related to a camera’s field of view and lensing can cause significant performance constraints and anomalous behavior. Lastly, camera-based systems are plagued by alignment issues, complicating the manufacturing and integration process as well as causing stability issues in the field. One other technology used for touchscreens is Surface Acoustic Wave (SAW).
DISPLAY FOR THE MOST DEMANDING ENVIRONMENT Noritake offers variety of Vacuum Fluorescent Display modules to fullfill your environmental requirements.
• Up to 400% of brightness boost for high ambient conditions. • -40°C to +85°C operating temperature VFD modules. • Operating humidy of 20% to 80% RH (non-condensing). • VFD modules are rugged with high tolerance to vibration and shock. VFD Module Features • Easy to read vibrant emmissive display. • Available in character and dot matrix displays. • Quick responsive displays. • Color filters can be applied to alter the emitted light.
Ask us about the color filters and VAP options.
Noritake Co., Inc. 2635 Clearbrook Drive Arlington Heights, IL 60005
(847) 439-9020
www.noritake-elec.com/
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