LCD Technologies for Use in Outdoor LCD displays

Outdoor LCD displays can be seen in many industries and environments. The world has gone digital and many companies are looked at as antiquated unless their display and technology reflect this perception. No company wants to be labeled “old school” unless possibly if you are a rapper. Pushing limits and giving the most benefit for the least cost is what today’s consumer wants. Gone are the days when only high-end companies use technology to proclaim their worth. The average Joe’s Main Street store is responding to the digital age by implementing LCD displays in a variety of applications not before seen. This exponential growth of the use of LCD’s addresses the need to display information to a wider audience with the desire to tap into new and growing markets.

Outdoor LCD Displays Operate In A Variety Of Environments

The term outdoor LCD display does not limit its use to outdoor locations; displays that operate outdoors can just as easily be moved to an indoor controlled environment. What “outdoor” really means is that the LCD unit you are purchasing or creating can withstand the intensity of our ever-changing climate.

Consequently, the snow and ice of Alaska is no big deal. High temperatures with direct sunlight in Phoenix are laughable. The high humidity that normally plays havoc on electronics in Florida becomes no sweat. These units are the ultimate in versatility being able to swing up to 200+ degrees Fahrenheit (e.g. -40 °F to 185 °F) without blinking a digital eyelash.

Current applications for outdoor LCD displays

Current applications that make use of outdoor LCD displays include:

Airports and train stations
- The business and leisure traveler need to see departure/arrival times as quickly as possible. It is also important that the information be visible from a distance. People do not have time to walk up to a computer monitor to see if they are late or their flight has been canceled. They need to know quickly as they are running by juggling their luggage, the ticket, and the coffee they just bought knowing they will have to throw it away in the security line.
Child care centers located in Churches, Synagogues, fitness centers, shopping centers, etc.
- Child care away from home allows the parent to participate in workouts, shopping, or religious services. A large LCD screen can display a number with a code that notifies the parent when their child needs attention. This is much better solution than when an announcement was made over a loud speaker disrupting others and embarrassing the parent.
Stores/Outdoor markets
- Bright color infomercials pull customers away from their current activity and introduce the consumer to a new product that they “can’t live without”. LCD Display modules can be seen to play videos of product launches or new additions to a favorite line of products.
Restaurants/Cafes
- The simple sandwich shop is simple no more. Chalk and cursive hand writing are a thing of the past. The sandwich of the day, the special, or the soup du jour are all shown in a clear and legible script that can be changed with a few key strokes.
Highway/Road signs
- Road conditions, speed limits, and closures notify the driver far enough ahead of time for them to make the necessary corrections.
- Another valuable service LCD displays play in road-side awareness is in issuing Amber Alerts so that every driver becomes the seeker of a lost or stolen child.

Outdoor LCD displays that make use of LED’s

LED (Light-Emitting Diode) display technology has been in use longer than any other technologies discussed in this article. While it may be older, it will not be going away anytime soon. It is a standard in the industry.

LED’s are in use in such products as flashlights, light bulbs, and dashboard warning indicators. The uses don’t stop there; LED’s have been used in outdoor LCD displays for many years. Below is a photo of a typical application of a LED driven outdoor LCD display.

AN ADVANTAGE OF LED’S IN AN OUTDOOR LCD DISPLAY:

Long half life
- Half-life is when the light will be half as bright as when it was first turned on. (This is not when the LED will burn out.) An LED’s half-life is rated between 50K hours to 70K hours. This is critical if the display will be used for 24 hours a day and 7 days a week (24×7) nonstop operation.
Brightness
- LED’s stand out during the day in direct sunlight and can be seen at night from a great distance. The brightness of LED’s can be adjusted from full illumination during the day to much dimmer luminescence at night.
Operating temperature of LED’s
- LED’s operate at temperatures as low as -40ºC (-40ºF) and as high as 85ºC (185ºF).

A DISADVANTAGE OF LED’S IN AN OUTDOOR LCD DISPLAY:

Power Hungry
- There is no way to get around it; if you want a bright bold display in full daylight the reality is that LED’s can draw a great deal of power when on full brightness. This is not an issue for outdoor displays that have unlimited power or are connected to the grid; however, this can be a problem if the sign is being powered by a battery and power conversion is important.

Outdoor LCD displays that make use of OLED’s

OLED (Organic Light-Emitting Diodes) display technology has been in use for the last few years. OLED’s are not very common in outdoor LCD displays, but that could change in the next few years. This technology allows the sign to display more than 64 million colors.

OLED’s are in use in such products as cell phones, tablets and soon to be TV’s.

ADVANTAGES OF OLED’S IN OUTDOOR LCD DISPLAYS:

Operating temperature of OLED’s.
- OLEDs operate at temperatures as low as -40ºC (-40ºF) and as high as 85ºC (185ºF).
Great range of colors that can be produced on an outdoor display.

DISADVANTAGES OF OLED’S IN OUTDOOR LCD DISPLAYS:

Short half-life for the color blue.
- One major setback for OLED’s is the half-life of the blue color. At this time the half-life rating is between 14K to 17K hours. Fortunately, half-life doesn’t refer to when the color burns out; rather it refers to when it becomes half as bright as when it was first turned on. All that to say, the color blue won’t disappear from your display, it just won’t hold the same brilliance that it did after its half-life is reached. This is not critical if your display is only on for short periods of time such as a cell phone. If your display needs to run 24×7, however, then OLED is not a good option.
Limited size.
- OLED’s technology is still advancing. One reason you do not see OLED’s used on very large displays is that they are limited in size. At this time the largest size OLED in development is from LG and when released will be 55 inches from corner to corner.

Outdoor LCD displays that make use of UWVD’s

A UWVD (Ultra-Wide Viewing Display Technology) display is a new display technology that offers the brightness of an LED (light-emitting diode), a viewing angle that exceeds FSTN (Film compensated Super Twisted Nematic), and a life time that is 20x longer than EL (Electro Luminescent) or the blue color found in an OLED. This makes the UWVD display a multi-functional and highly successful solution for outdoor LCD displays.

UWVD’s are in use in such products as medical devices, dash boards, and measurement equipment to name a few. Below is a photo of a typical application of a LED driven outdoor LCD display. Below is a photo showing the brightness of a UWVD display.

ADVANTAGES OF UWVD’S IN AN OUTDOOR LCD DISPLAY:

The main advantage to a UWVD is its wider viewing angle.
- A display that is used in an outdoor LCD display needs to be readable at a wide viewing angle so that as many people can see it without having to reposition themselves. A truncated viewing angle has long been the problem with outdoor LCD displays; however, the technology has moved forward exponentially increasing the number of acceptable degrees of viewing. All LCD display technology is readable when you are looking directly at the display and are eye level with the display. However, once you move the display above or below eye level, or when you move to the left or right, readability is diminished. The change in angle makes the display difficult to read; and consequently, the more extreme the angle, the more difficult it is to read. Viewing angle is measured in degrees from the center. So, if you are at eye level with the display and you lower it a few inches, you are now looking at the display from a 20% viewing angle. Older display technology had a limit of 40 to 50 degrees above/below/left or right of the display. Beyond those degrees the display was unreadable. UWVD allows the user to read the display up to 70 degrees in any direction.
UWVD displayed used in outdoor displays can be customized.
- A second advantage of UWVD technology is they can be customized by the customer with an affordable tooling cost and low MOQ’s. Custom UWVD displays allow the customer to design their outdoor display with faster proto-typing, thereby decreasing time to market.

DISADVANTAGES OF UWVD IN AN OUTDOOR LCD DISPLAY:

The UWVD suffers from the same set back as the OLED. The size of the display is not large enough for a road-size sign. This will change over time as UWVD glass becomes larger.

Outdoor LCD displays that make use of FSC technologies

FSC (field sequential color) LCD is a new custom color LCD display module technology that allows the customer to design a color display to fit their product. They produce a sharp contrast and ultrafast response time at a fraction of the tooling cost for an OLED.

Field sequential color displays provide all seven colors in each display. You do not need to pre-order the color you need. The color of the display is changed through the customer’s software. Standard colors include red, green, blue, yellow, cyan, purple with a black or white background.

ADVANTAGES OF FSC’S IN OUTDOOR LCD DISPLAYS:

Contrast ratio of sharpness of the FSC.
- The FSC offers a contrast ratio that is 2x that of a TFT (Thin film transistor)
The FSC is customized to meet the customer’s requirements.
- FSC can be customized with a lower MOQ (minimum order quantity) than custom TFT’s and an affordable tooling fee.

DISADVANTAGE OF FSC’S IN OUTDOOR LCD DISPLAYS:

Limited size at this time.
- The FSC suffers from the same set back as the OLED and the UWVD when it comes to outdoor LCD Displays. The size of the display is not large enough as you wizz by it doing 60 in your car. This will change over time as manufactures increase the available glass size.

There are definitely ups and downs to each technology featured in this article, but LCD display technology is advancing at a rapid pace. Make sure that you have experts, like those at Focus LCDs, working to give you all the options available for your product. Your customers want the best; let us help you give it to them.