Test Your Industrial LCD/LED User-Interface IQ

Yasoob Ahmed, Lumex

LCD and LED technologies have grown rapidly in popularity for industrial control applications over the past five years. Although many of the benefits of LCD and LED technologies – energy efficiency and long life – are well known, recent years have seen several technological advances that are particularly beneficial to industrial control applications.

There are several important aspects to consider when selecting user-interface technology for industrial applications, and manufacturers must make sure to have the tools necessary to select the best display for a particular application. They also must be up-to-date on the latest technical developments in the field of industrial user interfaces and be aware of how emerging technologies can help.

Traditional and automatic meter reading power-distribution and -metering applications are adopting extreme-temperature LCD displays. Photos courtesy of Lumex.

The following true-or-false questions can help you hone your “Industrial Control Display” IQ.

Extreme temperatures

Displays for industrial control – more than any other industry – often need to operate in extreme heat or extreme cold. These rugged conditions present significant technological challenges.

T or F: One of the key criteria for selecting the best-suited LCD for my particular application is the operating temperature.

Extremely cold temperatures can reduce LCD response time, resulting in the “ghosting” effect visible on this fuel pump. User interfaces designed for extreme cold can eliminate this problem. Photos courtesy of Lumex.

(T) To create a successful product design, a vital first step is to have a clear and comprehensive understanding of the environment in which your technology will need to perform. Operating temperature range is one of many key components of this analysis; so is storage temperature range. It is also essential to anticipate any additional environmental impact from the elements, such as wind or product vibration.

T or F: The maximum reliable performance temperature range for LCDs is −20 to 70 °C.

(F) Previously, −20 to 70° C was indeed the standard performance temperature range for LCDs. However, new technology developments now allow for the production of cost-effective custom LCDs that provide reliable performance from −40 to 85 °C. These same advances have dramatically enhanced the reliability, visual performance and cost-effectiveness of LCD technologies that operate in extreme heat and extreme cold.

The InfoVue high-/low-temperature series enables production of cost-effective custom LCDs that provide reliable performance from −40 to 85 °C. Photos courtesy of Lumex.

T or F: Extreme-temperature LCDs will require more space to accommodate bulky heaters or coolers.

(F) LCDs operating in extreme cold or extreme heat used to require bulky built-in coolers or heaters to ensure performance. The latest generation of extreme-condition LCDs uses a special liquid crystal formulation that eliminates the need for coolers and allows for the use of low-power, ultrathin heaters.

T or F: Custom extreme-temperature LCD technology will be more expensive than alternative technologies.

(F) The elimination of the need for coolers and the ability to use low-power heaters have significantly lowered the cost of custom extreme-temperature LCD displays and also provided significant real estate savings. Custom LCD solutions are growing in popularity as latest-generation technology allows engineers to create designs that address the exact needs of their particular applications at a lower price, with a wider temperature range and better visual performance than was previously available for off-the-shelf technologies.

Custom LCDs also offer significant cost savings compared to alternative technologies. Many factors, such as energy efficiency, play a key role in determining true expense: LCDs can reduce power requirements by up to 80 percent compared to vacuum fluorescent interfaces. Today, custom LCD displays can provide up to a 50 percent overall savings in technology costs compared to vacuum fluorescents.

T or F: The reliable performance temperature range for LEDs is −40 to 85 °C.

(F) Although more attention has been paid to the dramatic emergence of extreme-temp LCD displays, recent years have also witnessed the introduction of LED displays with wider temperature ranges. New technology developments now allow for the production of seven-segment LED displays that provide reliable performance outside the traditional range of −40 to +85 °C. For example, the QuasarBrite high-temperature seven-segment numeric LED display technology from Lumex provides bright, crisp display performance in temperature ranges up to 105 °C (compared to 85 °C for standard seven-segment LED displays). High-temperature seven-segment LED displays are suitable for a range of industrial control applications that require performance in extreme heat conditions.

LED and LCDs: together at last

Increasingly, LCD and LED technologies are being used together in user-interface displays for industrial control applications.

T or F: Extreme-condition displays can see enhanced performance when LED and LCD technologies are combined.

(T) There are many more visual display options available today than in the recent past. For example, it used to be the case that monochromatic LCDs were only available in alphanumeric options with relatively poor contrast. The latest generation of displays provides full graphic capability with almost limitless customization, including daylight visibility. When combined with LED backlighting technology, a wide range of color options are available. Users can either opt for a monochromatic screen with any color of LED backlight, or select a negative-image option with lighter monocolored pixels and a dark background.

This medical freezer controller features a negative-image graphic LCD module.Photos courtesy of Lumex.

T or F: A supplier who has both LED and LCD expertise can provide integrated solutions.

(T) Industrial control applications have a unique set of engineering challenges. These applications also commonly transition from simple LEDs to arrays, to alphanumeric displays and then to full graphic displays.

By the way, pinpointing your exact visual display needs will prove essential in designing an effective user interface for industrial control applications. A quality supplier will help you talk through questions such as: Is it important that your display be available in color or monochromatic? Do you need full graphic or only a simple alphanumeric capability? What resolution image is needed for your application? How important is full daylight visibility? The answers to these questions will help you select the best user-interface technology for your application.

Suppliers should be able to meet evolving technology needs and provide support in integrating emerging technologies, encompassing not only any relevant LED and LCD technologies but all of the optics, switches, connectors, printed circuit boards and other relevant components. Receiving a single integrated solution can speed time to market, reduce product mortality and simplify product design.

Also, rather than juggling myriad different part numbers, you can work with a single bill of materials and have the peace of mind that comes with knowing that all the components of your user-interface technology have already been fully integrated and designed to work together for maximum performance.

A quality supplier will provide off-the-shelf or custom technology specifically tailored for a particular industrial control application. Times have changed in terms of production capabilities: Previously, some user-interface technology suppliers were set up for volume, and others exclusively for more costly custom technology creation. This is no longer the case. Today, many user-interface technology suppliers are adept not only in efficiently meeting volume orders, but also in providing cost-effective custom solutions for small and mid-volume orders.

Understanding is key

Both LEDs and LCDs provide significant benefits to industrial control applications. In addition to well-documented benefits – such as a 70 to 80 percent reduction in energy requirements, enhanced durability/shock/vibration resistance and extended lifetime – recent technological advances have generated additional, particularly beneficial features. New extended temperature ranges for both LCD and LED displays, nonbulky heaters and cost-effective custom solutions have revolutionized user-interface displays for industrial control applications. Identifying a supplier with expertise in both LED and LCD technologies, as well as in integrated solutions, is key. Combining this with value-added services allows design engineers to develop user interfaces that provide cost savings, reliability and enhanced visual performance in even the most challenging of industrial environments.

Meet the author

Yasoob Ahmed is the display technology manager at Lumex in Carol Stream, Ill.; email: engineering@lumex.com.

Value-Added Services

An important element that is often overlooked is identifying a supplier with the right value-added services. Today’s design teams are facing ever-growing demands, often with reduced resources. To be successful, they must identify suppliers who can provide not only basic LED and LCD technology, but also expert design support.

Quality user-interface suppliers should provide access to dedicated design specialists who can work as an integrated part of your design team to help you identify the best technology for your specific application needs. These experts can save valuable time and money by providing insights into a wide range of off-the-shelf as well as custom wavelengths and optics, and provide insightful feedback on how to most efficiently create a design for your specific performance needs.

Access to expert design engineers should be an integrated part of service at no additional expense. Those experts should have deep expertise in the industrial control industry, be familiar with relevant new and emerging technology, and understand how to effectively reduce total cost of product design.