thermal management of lcd displays price

BoldVu® displays deliver unparalleled visual performance in outdoor environments. With luminance ratings up to 5000 nits, their high-efficiency LED backlight and obsessively engineered optical stack achieve incredibly bright imagery in the face of intense sunlight – and will do so day-in and day-out for 10 full years. So bring on the sun, BoldVu’s got it managed.

Nothing will destroy a display faster than inadequate thermal management. CoolVu® is BoldVu’s multi-patented thermal management technology that extracts and expels heat from inside the BoldVu®, without exposing display electronics to ambient air or environmental contaminants, like dust, dirt and moisture and without the use of air filters – which means typically no periodic maintenance required. With CoolVu®, BoldVu® displays can operate in environments up to 122°F (50°C) without any degradation in visual performance.

BoldVu® displays are designed to live in a world of turbulence. ToughVu® cover glass shields delicate electronic components from the effects of adverse weather and vandalism. And with its low diffuse reflection, low haze, and anisotropy and bi-refringence qualities, ToughVu® glass ensures that digital imagery shines with brilliance and delivers maximum contrast, color accuracy, color saturation, and viewing angles.

As an added layer of intelligence, BoldVu® displays are equipped with a MEMS sensor which detects and reports on shock and impact events, so in the event of attempted vandalism, you’ll be in the know.

The world is full of spectacular color, and BoldVu® ensures that every one of them is accurately reproduced. The meticulously engineered optical stack achieves ultra-bright whites and super deep blacks so that every color in-between appears as vibrant as you could hope for. A billion colors never looked so good.

At the heart of BoldVu® is a sophisticated logic controller that receives data from electronic components within the display and autonomously optimizes parameters affecting image quality, chassis thermals, and power draw. With built-in intelligence, BoldVu® takes care of itself so you don’t have to.

With an embedded media player and a 13-megapixel camera capable of 4K video at 30fps, BoldVu® makes delivering amazing, interactive campaigns easier than ever. Output gorgeous graphics, measure audience engagement1 via the USB camera, and translate insights into more effective campaigns.

InfiniteTouch® is a next-gen PCAP touch sensor exclusively available on BoldVu® displays. Comprised of multiple layers of glass with index-matched sputter ITO conductors, containing no plastic films, InfiniteTouch® delivers high transmission, low reflection, and true tablet-like responsiveness, making it an incredible platform for delivering engaging interactive experiences.

The Internet of Things (IoT) is changing the way we live, work, and how cities and venues are able to offer digital services to the citizens and visitors they serve. As the IoT continues to grow the need for communications and data processing infrastructure grows with them.

An optional structure affixed atop BoldVu®, the Comms Cap is an additional housing for IoT and connectivity devices designed to extend functionality beyond the edges of the digital screen.

When you place a display out in the world, you never know what to expect. BoldVu® displays self-monitor and report on over 150 operating parameters and settings to the SmartVu® Portal. Via the secure web interface you can see how displays are performing, adjust what they’re doing, and troubleshoot errant behavior, all from anywhere you can access the internet.

BoldVu® LT Semi-Outdoor displays are designed for placement in areas protected from direct sun exposure, like in shopping malls and subway stations where its 850 nit operating luminance is bright but not overbearing.

BoldVu® outdoor displays are intended for deployment in areas out in the open and exposed to the elements. With a daytime operating luminance of 3500 nits BoldVu® is an excellent fit for a wide array of outdoor venues.

BoldVu® XT displays are for outdoor venues with big skies and ultra-bright sunlight like stadiums and raceways. When the sunglasses come out, the 5000 nit daytime luminance of BoldVu® XT still shines bright.

The CoolVu® thermal management system operates without air filters or coolants, requiring zero regular maintenance, while ensuring on-spec performance across temperature extremes (-40°C ~ +50°C / -40° F ~ +122° F).

With full product development, engineering, fabrication, assembly, and configuration under one roof, BoldVu® is a turnkey solution that makes deployment as easy as bolting to the ground, connecting power, and standing back in awe.

BoldVu® is built for as many components to be field replaceable as possible so in the event of part failure or vandalism, displays can be serviced in their installed position and back online with minimal downtime.

2 Intel, the Intel logo, and other Intel names and brands are the sole property of Intel Corporation or its subsidiaries in the US and/or other countries.

4 Power consumption based on full luminance with a white display field, averaged over 10 years of 24/7 use. All figures subject to change without notice.

BoldVu® displays deliver unparalleled visual performance in outdoor environments. With luminance ratings up to 5000 nits, their high-efficiency LED backlight and obsessively engineered optical stack achieve incredibly bright imagery in the face of intense sunlight – and will do so day-in and day-out for 10 full years. So bring on the sun, BoldVu’s got it managed.

Nothing will destroy a display faster than inadequate thermal management. CoolVu® is BoldVu’s multi-patented thermal management technology that extracts and expels heat from inside the BoldVu, without exposing display electronics to ambient air or environmental contaminants, like dust, dirt and moisture. With CoolVu®, BoldVu® displays can operate in environments up to 122°F (55°C) without any degradation in visual performance.

BoldVu® displays are designed to live in a world of turbulence. ToughVu® cover glass shields delicate electronic components from the effects of adverse weather and vandalism. And with its low diffuse reflection, low haze, and anisotropy and bi-refringence qualities, ToughVu® glass ensures that digital imagery shines with brilliance and delivers maximum contrast, color accuracy, color saturation, and viewing angles.

As an added layer of intelligence, BoldVu® displays are equipped with a MEMS sensor which detects and reports on shock and impact events, so in the event of attempted vandalism, you’ll be in the know.

The world is full of spectacular color, and BoldVu® ensures that every one of them is accurately reproduced. The meticulously engineered optical stack achieves ultra-bright whites and super deep blacks so that every color in-between appears as vibrant as you could hope for. A billion colors never looked so good.

At the heart of BoldVu® is a sophisticated logic controller that receives data from electronic components within the display and autonomously optimizes parameters affecting image quality, chassis thermals, and power draw. With built-in intelligence, BoldVu® takes care of itself so you don’t have to.

With an embedded media player and a 13-megapixel camera capable of 4K video at 30fps, BoldVu® makes delivering amazing, interactive campaigns easier than ever. Output gorgeous graphics, measure audience engagement1 via the USB camera, and translate insights into more effective campaigns.

InfiniteTouch® is a next-gen PCAP touch sensor exclusively available on BoldVu® displays. Comprised of multiple layers of glass with index-matched sputter ITO conductors, containing no plastic films, InfiniteTouch® delivers high transmission, low reflection, and true tablet-like responsiveness, making it an incredible platform for delivering engaging interactive experiences.

The Internet of Things (IoT) is changing the way we live, work, and how cities and venues are able to offer digital services to the citizens and visitors they serve. As the IoT continues to grow the need for communications and data processing infrastructure grows with them.

An optional structure affixed atop BoldVu®, the Comms Cap is an additional housing for IoT and connectivity devices designed to extend functionality beyond the edges of the digital screen.

When you place a display out in the world, you never know what to expect. BoldVu® displays self-monitor and report on over 150 operating parameters and settings to the SmartVu® Portal. Via the secure web interface you can see how displays are performing, adjust what they’re doing, and troubleshoot errant behavior, all from anywhere you can access the internet.

BoldVu® LT Semi-Outdoor displays are designed for placement in areas protected from direct sun exposure, like in shopping malls and subway stations where its 850 nit operating luminance is bright but not overbearing.

BoldVu® outdoor displays are intended for deployment in areas out in the open and exposed to the elements. With a daytime operating luminance of 3500 nits BoldVu® is an excellent fit for a wide array of outdoor venues.

BoldVu® XT displays are for outdoor venues with big skies and ultra-bright sunlight like stadiums and raceways. When the sunglasses come out, the 5000 nit daytime luminance of BoldVu® XT still shines bright.

The CoolVu® thermal management system operates without air filters or coolants, requiring zero regular maintenance, while ensuring on-spec performance across temperature extremes (-40°C ~ +50°C / -40° F ~ +122° F).

With full product development, engineering, fabrication, assembly, and configuration under one roof, BoldVu® is a turnkey solution that makes deployment as easy as bolting to the ground, connecting power, and standing back in awe.

BoldVu® is built for as many components to be field replaceable as possible so in the event of part failure or vandalism, displays can be serviced in their installed position and back online with minimal downtime.

2 Intel, the Intel logo, and other Intel names and brands are the sole property of Intel Corporation or its subsidiaries in the US and/or other countries.

4 Power consumption based on full luminance with a white display field, averaged over 10 years of 24/7 use. All figures subject to change without notice.

It’s a known fact that most, if not all, electronics operate best in cool, dry conditions. Ever been inside an underground data center? They keep those rooms pretty chilly. Heat build-up or “hot spots” are one of the leading causes of electronic failures/malfunctions.

When considering deploying digital displays, especially for outdoor applications, it’s important to anticipate that over-heating could become a problem.

Most outdoor digital displays will be exposed to high ambient temperatures and direct sun-load at some point throughout the year. Considering that these digital displays need to be “sealed” to protect them from rain, snow, and dust, placing them inside a sealed enclosure further compounds the problem of internal heat build-up.

These same outdoor displays also need extra powerful backlights to produce 2500+ nits of brightness so they can be seen when the sun is shining. This additional backlight power adds to the existing heat load created by the sealed enclosure.

CoolVu® is our answer to the cooling conundrum. Our engineers used computational fluid dynamics to model airflow and heat build-up on a display subjected to variable ambient temperatures and sun load, while producing 3500+ nits of luminance. This model allows us to see how hot spots form inside a “sealed” enclosure and provide us insight as to how we could design around this problem. This led to the development of our patented CoolVu thermal management system, a design feature that allows our outdoor displays to run at peak luminance at any ambient temperature up to 50°C (122°F), without loss in display brightness.

There are two general approaches to cooling the optical surfaces and electronics of an outdoor digital display. The first involves using air conditioners to blow cold air into the display cabinet. This approach works well for keeping things cool, but it introduces some new problems, biggest of which is the formation of condensation within the display enclosure resulting in water on and failure of the display electronics. This approach also requires periodic draining of condensation to the exterior of the display.  Air conditioners are also expensive to operate and maintain. They’re noisy and just aren’t a great solution for street side displays.

LG-MRI BoldVu® displays are a little different. In our CoolVu® system we don’t use air conditioners or air filters and we never expose electronics, display surfaces, optical films, or backlight assemblies to ambient air. CoolVu® is a heat exchanging system that cools electronics with a sealed volume of air that continually circulates across the surface of the LCD and over the electronic components. A separate volume of air passes through isolated channels and exhausts the heat out of the display chassis. In this system, all electronics are kept in a cool, dry and clean environment, which prolongs their life and significantly reduces field failures and associated maintenance costs.

BoldVu® displays do not need an environmental enclosure to cool them in the outdoor environment. CoolVu® is a zero maintenance thermal management system that ensures that display not only survive but thrive outside.

LCD displays are commonly used today in devices that require information to be displayed in human-perceptible form. LCD displays are typically comprised of an enclosure, a LCD module, backlights and supporting electronics. Since LCD displays use thin depth LCD modules to display information as opposed to larger in depth cathode ray tube (CRT) displays for similar sized screens, LCD displays are often used in devices that have packaging and/or space constraints. Unlike LCD displays, the tube in a CRT display increases substantially in depth as the screen size increases.

Electronic devices, such as fuel dispensers and automatic teller machines (ATM) for example, use displays to display information to users of these devices. Such information may be instructions on how to use the machine or a customer"s account status. Such information may also include other useful information and/or services that generate additional revenue beyond the particular function of the device, such as advertising or newsworthy information. Through increasingly easier and cheaper access to the Internet, it has become even more desirable for electronic devices to use displays that are larger in screen size and employ higher resolution color graphics without substantially increasing the depth of the display due to packaging limitations. Therefore, LCD displays are advantageous to use in displays in electronic devices because of the thin nature of LCD modules.

LCD displays used in outdoor devices typically use an environmentally-sealed enclosure since LCD displays include internal components, such as electronics, backlights and display modules, whose operations are sensitive to outdoor conditions, such as water and dust. However, the backlights and the electronic circuitry generate extreme heat during their operation thereby raising the ambient air temperature inside the enclosure. The ambient temperature in the enclosure rises even more in outdoor devices due to sunlight heat. If the ambient temperature in the enclosure is not managed, components of the LCD display 10 may fail. For example, the LCD module may start to white or black out if the ambient temperature inside the enclosure rises above a certain temperature.

One method keeping the ambient air temperature lower inside the enclosure is to provide a larger enclosure so that it takes more heat generated by the internal components of the LCD display and external sources, such as the sunlight, to raise the ambient air temperature inside the enclosure. However, increasing the size of the enclosure is counter to the goal of using a thin depth enclosure for a LCD display.

Therefore, a need exists to provide a thin LCD display enclosure that is sealed from the environment and is capable of efficiently dissipating heat generated by the internal components of the LCD display and external heat, such as sunlight.

The present invention relates to a thermal management system for a liquid crystal display (LCD) that is placed inside a thin depth enclosure and may be incorporated into an outdoor device. The thermal management system efficiently transfers and dissipates heat in the ambient air of the LCD display enclosure generated by components of the LCD display and external heat, such as sunlight.

In one embodiment of the present invention, the LCD display comprises an environmentally-sealed, heat conducting enclosure with a backlight assembly having at least one backlight. The backlight assembly is connected to the inside rear portion of the enclosure. A heat sink is attached on the outside rear portion of the enclosure. Heat generated by the backlights is transferred using natural convection from the enclosure to the heat sink, and the heat sink dissipates such heat to the atmosphere.

In another embodiment of the present invention, the LCD display contains the backlight assembly as discussed in the preceding paragraph. The LCD display also contains a lens on the front portion of the enclosure and a LCD module between the lens and the backlight assembly. The LCD module is placed in between the top and bottom of the enclosure to provide air gaps inside and at the top and the bottom of the LCD module to form a circular airflow path around the LCD module. A fan is placed in the airflow path to forcibly move heated air inside the enclosure from the front of the LCD module to the rear portion of the enclosure for heat dissipation through the heat sink and to the atmosphere.

The LCD display may be placed in any type of electronic device, including but not limited to a kiosk, a fuel dispenser, a personal computer, an elevator display, and an automated teller machine (ATM). The LCD display may display information and other instructions to a user of an electronic device incorporating the LCD display. If the LCD display has a touch screen, the LCD display may also act as an input device.

FIG. 1 is a schematic diagram of one embodiment of a thin depth LCD display enclosure having a thermal management system according to the present invention;

The present invention relates to a thermal management system for a LCD display having a thin depth enclosure, and that may be placed in and outdoor environment and/or device. A thermal management system aids the LCD display 10 in overcoming the effects of internal heat generated by components of the LCD display 10 and heat from sunlight heat, if the LCD display 10 is placed in sunlight. The thermal management system also allows a thinner depth enclosure to be used for the LCD display. Use of a thin depth LCD display may be useful for addressing space and packaging issues for devices requiring a display.

A LCD display 10 according to one embodiment of the present invention is illustrated in FIG. 1. The LCD display 10 comprises an environmentally-sealed enclosure 12 that has a front portion 14 and a rear portion 16. The environmentally-sealed enclosure 12 protects the internal components of the LCD display 10 from external elements that may affect the proper operation, such as water, dust, etc. The enclosure 12 is constructed out of a heat conducting material, such as sheet metal, aluminum, or copper for example, so that heat generated by components of the LCD display 10 can be dissipated outside of the enclosure 12 to the atmosphere using convective heat transfer. In one embodiment, the depth of the enclosure 12 is approximately 40 millimeters.

The enclosure 12 includes a transparent lens 18 at the front portion 14 of the enclosure 12 for external viewing of the LCD display 10. The lens protects the internal components of the LCD display 10 and also allows the LCD module 26 to be viewed from outside of the enclosure 12. The lens 18 may be constructed out of clear plastic, glass, Plexiglas, or other transparent material so long as the LCD module 26 can be viewed from outside the enclosure 12. The LCD module 26 may be an active or passive matrix display, may include color, and may pass or block light to provide information for external viewing.

A backlight assembly 20 is provided in the rear portion 16 of the enclosure 12. The backlight assembly 20 holds one or more backlights 22. The backlights 22 project light towards the rear of the LCD module 26 so that the LCD module 26 can be properly viewed through the lens 18. In this particular embodiment, the backlights 22 are flourescent light bulbs. When power is provided to the backlights 22, light is projected from the backlights 22 towards the LCD module 26. The LCD module 26, depending on its design, either blocks the light or allows the light to pass through to display information for external viewing in human-perceptible form through the lens 18.

The LCD display 10 also includes a thermal management system for convectively moving and dissipating heat generated by internal components of the LCD display 10, such as the backlights 22 and electronic circuitry (not shown) in the enclosure 12, as well as external heat on the enclosure 12, such as sunlight. Heat generated by these sources raises the ambient air temperature inside the enclosure 12 thereby possibly causing the LCD display 10 to not function properly. Although the backlights 22 are designed to operate at higher temperatures, the heat generated by the backlights may affect the performance of the LCD module 26. For example, if the LCD module 26 is a color module, the color will start to fade as the ambient temperature inside the enclosure 12 increases beyond designed operating temperatures of the LCD module 26.

It may be desirable for a LCD display 10 in an outdoor device to be brighter than would otherwise be required in an indoor device due to light and glare created by sunlight. Increasing the brightness of the backlights 22 causes the backlights 22 to generate more heat and/or the power to the electronic circuitry to be greater. Because the enclosure 12 is environmentally-sealed, heat generated by the backlights 22, the electronic circuitry, and external sources needs to be dissipated outside of the enclosure 12 in order for the LCD module 26 to operate at a lower temperature. For example, some LCD modules 12 may need to be kept at temperatures at or lower than 70 degrees Celsius to operate properly. One solution is to reduce the power to the backlights 22 that in turn lowers the heat generated by the backlights 22, but this also reduces the brightness of the LCD display 10.

The present invention may be used to avoid having to reduce the brightness of the backlights 22. Heat generated by the LCD display 10 may be convectively dissipated in two manners. The LCD display 10 dissipates heat inside the enclosure 12 using one or more heat sinks 24 attached to the rear portion 16 of the enclosure 12. The heat sink 24 may contain one or more fins 25 to create greater surface area on the heat sink 24 for dissipation of heat. This heat sink 24 ensures that the internal surface temperature of the enclosure 12 is kept as close to the atmospheric temperature as possible to ensure that the heated air inside the enclosure 12 is absorbed by the enclosure 12. FIG. 1 illustrates the heat dissipated by the heat sink 24 to the atmosphere using arrows pointing upward on the outside of the rear portion 16 of the enclosure 12.

Heat generated by the backlights 22 is dissipated through the heat sink 24. The backlight assembly 20 is located against the surface of the rear portion 16 of the enclosure 12. In one embodiment, the center of the backlights is approximately 3.25 millimeters from the rear portion 16 of the enclosure 12. In this manner, heat generated by the backlights 22 is convectively transferred to the atmosphere, using natural convection. The heat generated by the backlights 22 is transferred to the rear portion 16 of the enclosure 12 and to the heat sink 24. The closer the heat sink 24 is to the backlights 22, the faster heat generated by the backlights 22 can be transferred outside of the enclosure 12 thereby reducing the chance of such heat to increase the ambient air inside the enclosure 12.

Heat generated by the backlights 22 that is not immediately dissipated through the rear portion 16 of the enclosure 12 and the heat sink 24 causes the ambient air temperature inside the enclosure 12 to rise. Heat generated by electronic circuitry inside the enclosure 12 and any external heat on the enclosure 12, such as sunlight, also causes the ambient air temperature inside the enclosure 12 to rise. To dissipate the heat in the ambient air, thereby cooling the LCD module 26, an airflow path 30 is created around the LCD module 26 by placement of the LCD module 26 between the lens 18 and the backlight assembly 20. In one embodiment of the present invention, the back of the LCD module 26 is placed approximately 12.9 millimeters from the backlights 22 to properly diffuse and evenly backlight the LCD module 26. The front of the LCD module 26 is placed approximately 9.4 millimeters from the lens 18 so that any protrusion on the lens 18 does not damage the LCD module 26. Spacing between the lens 18 and the LCD module 26 also allows air to be routed across the LCD module 26 for thermal management, as discussed below. The LCD module 26 is also placed between the top and bottom of the enclosure 12 in the vertical plane so that air gaps 28A and 28B are formed on the top and bottom of the LCD module 26. In this manner, air is free to flow around the LCD module 26 in a circular fashion, as illustrated by the counter-clockwise airflow arrows moving around the LCD module 26 in FIG. 1.

In order to dissipate heat in the ambient air in the enclosure 12, a fan 32 is placed in the airflow path 30. The fan 32 provides forced convection of the ambient air inside the enclosure 12 to the rear portion 16 of the enclosure 12 for dissipation. In one embodiment, the fan 32 is placed at the top of the enclosure 12 above the LCD module 26. During operation, that fan 32 rotates counter-clockwise to create the counter-clockwise circular airflow path 30. The ambient air is routed to the rear of the LCD module 26 and to the rear portion 16 of the enclosure 12 for dissipation through the enclosure 12 to the heat sink 24 and to the atmosphere.

The fan 32 may be any type of air movement device that can create the airflow path 30; however, one embodiment of present invention employs a laminar flow fan 32 manufactured by Delta Corporation. An example of such a laminar flow fan 32 is disclosed in U.S. Pat. No. 5,961,289 entitled “Cooling axial flow fan with reduced noise levels caused by swept laminar and/or asymmetrically staggered blades,” incorporated herein by reference in its entirety. A laminar flow fan 32 creates a sheet of air, rather than turbulent air, across the LCD module 26. The laminar airflow is more efficient than turbulent airflow for moving air and transferring heat from the front of the LCD module 26 to the rear portion 16 of the enclosure 12. A more efficient fan 32 allows selection of a fan 32 that is smaller in size since it may require less rotations of the fan 32 to move an amount of air desired and/or move the same amount of air in a smaller airflow path 30. Each of these factors contributes to a smaller fan 32 size that in turn contributes to a thinner depth enclosure 12. In one embodiment, the fan 32 operates at approximately 3400 revolutions per minutes (RPM). However, the present invention may use any type of fan 32, including those that generate turbulent air. The fan 32 speed may also be adjusted to move air in the desired manner and efficiency.

FIG. 2 illustrates one embodiment of a device that incorporates the LCD display 10 known as a “kiosk”34. A kiosk 34 is any type of interactive electronic device that provides an input device, an output device, or both. Kiosks 34 are typically used in retail environments to sell products and/or services to customers. Some common types of kiosk 34 include vending machines, fuel dispensers, automatic teller machines (ATM), and the like. FIG. 2 illustrates one example of a kiosk 34 that includes the LCD display 10 illustrated in FIG. 1 as an output device for displaying information. Soft keys 36 are located on each side of the LCD display 10 as an input device for customer selections; however, an input device may also take others forms, such as a keypad 38, touch screen keys on the LCD display 10 (not shown), card entry device, magnetic or optically encoded cards for example, voice recognition, etc. The LCD display 10 of the present invention is particularly suited for kiosks 34 that are located in outdoor environments where the enclosure 12 of the LCD display 10 is environmentally-sealed. However, the LCD display 10 may be placed in any type of kiosk 34 regardless of whether the kiosk 34 is placed in an outdoor environment.

FIG. 3 illustrates one embodiment of a communication architecture used for the LCD display 10. The LCD display 10 comprises a display CPU board 40 that contains electronics and software. In this particular embodiment, the display CPU board 40 contains a single display microprocessor 42 and display software 44. The display software 44 contains both volatile memory 46, such as RAM and/or flash memory, and non-volatile memory 48, such as EPROM and/or EEPROM. The display software 44 contains program instructions for the display microprocessor 42 and may also contain information to be displayed on the LCD module 26. The display microprocessor 42 may also manages information received from external sources and controls the operation of the LCD module 26.

In this embodiment, information is communicated from one or more external devices to the display microprocessor 42 to then be displayed on the LCD module 26. A main controller 50 is provided as the interface to the display microprocessor 42. The main controller 50 may be any type of control system, including a point-of-sale system for example. The main controller 50 may be coupled to more than one display microprocessor 42 for managing multiple LCD modules 26. The main controller 50 may also be connected to a local server 56, located in close proximity to the LCD display 10, that sends information to be displayed on the LCD module 26. A remote server 52, located remotely from the LCD display 10, may also be provided to send information to the LCD module 26. The remote server 52 may send information over a network 54 directly to the display microprocessor 42, through the main controller 50, and/or through the local server 56 to be eventually displayed on the LCD module 26. The remote server 52, the local server 56, the main controller 50, and the display microprocessor 42 may be coupled each other through either a wired or wireless connection or network 54 using any type of communication technology, including but not limited to the Internet, serial or parallel bus communication, radio-frequency communication, optical communication, etc.

Examples of Internet information management that may be used with the present invention to send information to a LCD display 10 and/or communicate information entered into a LCD display 10 having a touch screen or other electronic device incorporating an LCD display 10 are disclosed in U.S. Pat. Nos. 6,052,629 and 6,176,421 entitled “Internet capable browser dispenser architecture” and “Fuel dispenser architecture having server” respectively, both of which are incorporated herein by reference in their entirety.

FIG. 4 illustrates another exemplary outdoor device that may incorporate the LCD display 10 of the present invention known as a “fuel dispenser” 60. A fuel dispenser 60 may also be considered a type of kiosk 34 depending on its configuration and features. The illustrated fuel dispenser 60 contains a LCD display 10 for providing instructions and/or information to a customer at the fuel dispenser 60. The fuel dispenser 60 is comprised of a housing 62 and at least one energy-dispensing outlet, such as a hose 64 and nozzle 66 combination, to deliver fuel to a vehicle (not shown). As illustrated in FIG. 2, the fuel dispenser 60 may have other input and/or output devices for interaction with a customer, such as price-per-unit of fuel displays 72, soft-keys 36, a receipt printer 68, a radio-frequency identification (RFID) antenna 74, and a cash acceptor 70.

Also note that the LCD display 10 may also be placed external to the fuel dispenser 60 and attached to the fuel dispenser 60 as disclosed in co-pending patent application entitled “Multiple browser interface,” filed on Apr. 23, 2001.

Certain modifications and improvements will occur to those skilled in the art upon a reading of the foregoing description. It should be understood that the present invention is not limited to any particular type of component in the LCD display 10 including, but not limited to the enclosure 12, the lens 18, the backlight 22 and backlight assembly 20, the heat sink 24, the LCD module 26, and the fan 32. Additionally, the LCD display 10 may be used in any type of device having or using a display, including but not limited to a personal computer, a kiosk 34, an elevator, an ATM, and a fuel dispenser 60. Also for the purposes of this application, couple, coupled, or coupling is defined as either a direct connection or a reactive coupling. Reactive coupling is defined as either capacitive or inductive coupling.

One of ordinary skill in the art will recognize that there are different manners in which these elements can accomplish the present invention. The present invention is intended to cover what is claimed and any equivalents. The specific embodiments used herein are to aid in the understanding of the present invention and should not be used to limit the scope of the invention in a manner narrower than the claims and their equivalents.

The pace of development in the electronics and telecommunication fields has been accelerating in all aspects of the business. For example, electronics/telecommunications equipment has traditionally been housed in large buildings, smaller buildings (sheds) and outdoor cabinets.  The introduction of electronics to the outdoor environment has imposed serious constraints on enclosure design since temperature and humidity are the two major causes of electronics failure. Since most electronic systems do not include environmentally hardened designs, the enclosure must provide an environment in which they can survive. Among the equipment/systems involved are displays such as LCD, LED and other monitors.

The use of LEDs (Light Emitting Diodes) has been increasing exponentially in the last few years. In the beginning, heat dissipation was not a worrisome problem because of the low power the LED’s used. However, their power consumption and their useful life and reliability are dependent on how their temperature can be controlled, especially in view of high-power LEDs used for illumination and outdoor signage applications. The most important goal in LED cooling is to maintain junction temperature (Tj, the temperature at the p-n junction) from rising above prescribed levels since the junction temperature is a good predictor of the useful life of the LED component. In addition, the junction temperature in many cases must be kept relatively constant since fluctuations and shifts affect the intensity and the color of the LED light output. From a thermal standpoint, junction temperature, as with many other electronic components and systems, is influenced by power levels, heat sinking (high conductivity materials, convection cooling, extended surfaces, heat spreading, heat pipes, etc), ambient temperature, interface materials, applied pressures (clamping to reduce thermal contact resistance).

Thermal management of LEDs can range from the use of natural convection to the use of liquid cooling loops that allow for far higher heat removal rates than employing gases as the cooling medium. Air natural and forced convection, up to very recently, have been the cooling methodology of choice when cooling with a fluid. At the system level, and especially for outdoor applications, liquid cooling is normally not suitable; therefore, only cooling solutions that use natural or forced air convection are employed such as fans, blowers, air-to-air heat exchangers, air-conditioners and other passive cooling techniques.

What is more, display devices such as monitors have incorporated LED technology and must also be thermally managed outdoors since they require hardened enclosures to carry out their tasks.

The objective here is to cover the thermal management of LEDs at the system level, both discrete LED modules or outdoor enclosures (LED walls or LED monitors). This assumes that LED and board level thermal management has been dealt with separately. Nowadays, enclosures that contain LEDs are being installed in various environmental conditions. Most will be fitted with either air conditioning/thermoelectric cooling or air-to-air heat exchangers as needed because of relatively high heat dissipation requirements; for lower heat generation levels, flow-through fan cooling is sufficient. For example, there has been an unprecedented growth of the application of LEDs for outdoor (and indoor) signage or video systems such as sports displays, advertising billboards, and gas station pump customer information displays. These all are enclosures with one wall comprised of LEDs. In addition, recently LED display monitors have been installed in outdoor enclosures and therefore require thermal management. Figure 1 shows an illustration of these two types of enclosures.

The goal is to maintain peak temperatures in the enclosures below a certain level that is normally prescribed (the lowest junction temperature of the LED components) by the manufacturers. Humidity levels are of concern, but since most enclosures are either sealed or its temperatures are much higher than the air’s dew points, humidity is generally not a problem (after the transient effect of opening/closing the enclosure is eliminated.)

The designer should be aware that the air temperatures within the enclosures will be a function of: the amount of heat generated by all the electronic equipment in the enclosure; the amount of heat generated by auxiliary and cooling equipment (fans, etc.); ambient conditions (outdoor air), particularly temperature, solar radiation, wind speeds, etc.; objects surrounding the enclosure (shading, ground reflections, buildings, trees, etc.); enclosure design (surface area, shape, paint’s radiation characteristics, etc.) and air exchange with the outside air, either passive by infiltration, or active by fans or blowers.

Let us consider an enclosure that has installed LED equipment that dissipates a certain amount of heat. The first step is always to realize that the design temperature is that temperature that the enclosure air will attain when there is heat balance, or in equation form:

where, Qequipment comprises the LEDs and its electronics heat dissipation, Qsolar load is the solar heat load and Qcooling-system is the amount of heat removed by the cooling system. The solar load is a complicated term because it includes contributions from all modes or heat transfer. For example:

Normally, the value of Qradiated will always be positive (towards enclosure) but the other two can be either positive or negative, depending on the enclosure’s temperature. Thus, if Qbalance is not zero, this means that the temperature inside the enclosure is either higher/lower than the set temperature and the enclosure is losing/gaining heat by convection and conduction.

Furthermore, since incident solar radiation varies during the daylight hours, the designer must decide whether to conduct a steady state or transient analysis. Moreover, since Qradiation is a very complex term that includes, among other effects, solar declination, latitude, time of year, solar azimuth, atmospheric absorption, atmospheric clearness, re-radiation from other walls, buildings, ground etc., and incident wall surface properties, some simplifying measures must be taken into account. The result is that one can effectively double or triple the amount of heat flux being added into the enclosure depending on the calculation method. The calculation of the cooling load is carried out using several methods. One of these methods is the ASHRAE’s cooling load calculation methods. Normally, when calculating cooling loads, one would include a) Space heat gain, b) Space cooling load, and c) Space heat extraction rate. Space heat gain is the rate at which heat enters or is generated within the space at any given instant. This includes for the enclosure heat transferred into the conditioned space from the external walls and roof due to solar radiation, convection and temperature differential.

One normally includes instantaneous solar radiation effects and delayed effects. The delayed effects include the slow build-up of energy that the external walls accumulate as they absorb solar radiation. This happens because walls are normally thick and massive; making energy absorbed important. For LED enclosures this is not included since its walls are thin (at the most 3 cm when insulation might be added) and should not be included. Another component of heat gain is latent heat due to moisture infiltration. For sealed LED outdoor enclosures, the power electronics are kept in an airtight enclosure with negligible contribution.

where, α -absorptance of solar radiation surface, It – total solar radiation  [W/m2], ho– coefficient of heat by long wave radiation and convection  [W/K-m2], ε – hemispherical emittance, and ΔR a radiation correction factor [W/m2]. Figure 2 shows typical Sol-Air temperatures for various latitudes.

For roofs: ΔR =63 W/m2, for walls: ΔR = 0, for dark surfaces, α/It = 0.052, which is the maximum value for any surface. To calculate heat transfer into the conditioned space,

where U is the overall heat transfer coefficient for the wall and A is the surface area for the wall. The term, U, includes convective and radiation effects by the internal and external airflow (See AHSHRAE’s Fenestration Chapter for more details, ASHRAE, 1981, 1986) and the wind outside, in addition to conduction through the walls. The solar load calculated will be added to the equipment load to find the total cooling load. The solar load will include three surfaces that can be illuminated simultaneously, with the roof always included.

Display/signage enclosures have evolved. Typical LED system design has been the display shown in Figure 3. They typically were metal enclosures measuring 5-10 m wide, 250 mm deep and 5 m high. These enclosures could have thousands of LEDs each measuring, typically,5- 8 by 5-8 by 3 mm and dissipating an average of 1W each, all installed on the largest vertical wall. Therefore, the total amount of heat dissipation for this enclosure (including the electronics needed to control and manage the LEDs) could reach thousands of Watts. Figure 3 shows a CFD model of this enclosure using Phoenics by CHAM Ltd of the UK.

In the last few years, display outdoor enclosures are also being designed to house various display signage equipment configurations such as LED monitors with dissipating heat rates ranging from 200 to 1500 W, depending on the size and type of auxiliary equipment. These enclosures are installed in various environmental conditions, and typically the enclosures, without major structural modifications, may be fitted with fans, air conditioning or air-to-air heat exchangers as needed. Figure 4 shows at typical enclosure (CFD model).

Equipment housed in these enclosures include TV LED monitors that have been initially designed for indoor use and have been slightly hardened to be placed in a hot, dry environment without the support of an enclosure. Many manufacturers sell these monitors.

The goal of the designer is to maintain the peak temperatures in the enclosures, which are below a certain level that is normally prescribed by the electronic equipment manufacturer. Humidity levels are also of concern, but since in most enclosures, its temperatures are much higher than the air’s dew points, humidity is generally not an issue (after the transient effect of opening and closing the enclosure is eliminated). However, typically, the LED monitors are not fully outdoor rated, that is they must be protected from rain and moisture, therefore they must be installed in IP55/56/66 enclosures.

Most enclosures need to be designed to keep the system operating with slight internal overpressure. Cooling air is guided to flow into a gap between the LED screen surface and external transparent wall guided by guide-vanes, and the cooling system also must allow for air to flow to the rest of the enclosure, in addition to the flow in the LED/Wall gap. Overpressure is used to maintaining IP55 and IP66 design and a fan and filter inlet system construction allows for proper solar mitigation technology. For further solar mitigation purposes, if used, a solar shield overhang can reduce solar loading.

Finally, of paramount importance is to keep the LED surface (especially when in full solar exposure) under a maximum temperature. For the above LED monitor, this temperature is 110 C. Since, maximum solar radiation for latitudes below 35 N or S can generate surface temperatures higher than 110 C, then a typical construction would involve a gap between the outdoor facing glass plane and the LED monitor (see Figure 5).

Liquid crystal displays (LCD) have become an essential component to the industry of display technology. Involved in a variety of contexts beyond the indoors like LCD TVs and home/office automation devices, the LCD has expanded its usage to many environments, such as cars and digital signage, and, thus, many temperature variations as well.

As with any substance that requires a specific molecular characteristic or behavior, LCDs have an operating temperature range in which the device, if within, can continue to function properly and well. In addition to that, there is also an ideal storage temperature range to preserve the device until used.

This operating temperature range affects the electronic portion within the device, seen as falling outside the range can cause LCD technology to overheat in hot temperatures or slow down in the cold. As for the liquid crystal layer, it can deteriorate if put in high heat, rendering it and the display itself defective.

In order for the LCD panel to avoid defects, a standard commercial LCD’s operation range and storage range should be kept in mind. Without adaptive features, a typical LCD TV has an operating range from its cold limit of 0°C (32°F) to its heat limit of 50°C (122°F) (other LCD devices’ ranges may vary a bit from these numbers).

The storage range is a bit wider, from -20°C (-4°F) to 60°C (140°F). Though these ranges are quite reasonable for many indoor and even outdoor areas, there are also quite a few regions where temperatures can drop below 0°C or rise above 32°C, and in these conditions, LCDs must be adapted to ensure functionality.

Heat, can greatly affect the electronics and liquid crystals under an LCD screen. In consideration of heat, both external heat and internally generated heat must be taken into consideration.

Seen as the liquid crystals are manipulated in a device by altering their orientations and alignments, heat can disrupt this by randomizing what is meant to be controlled. If this happens, the LCD electronics cannot command a certain formation of the liquid crystal layer under a pixel, and the LED backlighting will not pass through as expected, which can often lead to dark spots, if not an entirely dark image. This inevitably disrupts the display’s readability.

Depending on the upper limit of the operation temperature range, LCD device can be permanently damaged by extreme heat. With long exposure to extreme heat, besides the destruction of the liquid crystals, battery life can shorten, hardware can crack or even melt, response time may slow to prevent even more heat generation from the device.

The LED backlight and the internal circuitry, typically TFT-based in the common TFT LCDs, are components that can generate heat that damages the device and its display. To address this concern with overheating, many devices use cooling fans paired with vents.

But this leads to another problem: how can moisture be prevented from entering through the vent? If moisture enters the device and high heat is present, condensation can occur, fogging the display from inside, and in some cases, short-circuiting may cause the device to turn off. In order to circumvent this issue, the shapes of the air vents are specific in a way that allows only for air movement, not forms of moisture.

In the opposite direction is extreme cold. What typically occurs in the cold is “ghosting” (the burning of an image in the screen through discoloration) and the gradual slowing and lagging of response times. Like heat-affected LCD modules, the extreme temperature can affect the liquid crystals. This layer is a medium between the liquid and solid state, so it is still susceptible to freezing.

An LCD device can be left in freezing temperatures because it will likely not be permanently damaged like in the heat, but it is important to understand the device’s limits and how to take precautions when storing the device. The standard and most common lower-bound storage range limit is -20°C, below freezing, but if possible, it would be best to keep it above that limit, or else there is still a risk of permanent damage.

Display types have a lot of variation. Choices like alphanumeric or graphic LCD, human-machine interactive LCD modules and touchscreen panels capabilities, the width of the viewing angle, level of contrast ratios, types of backlighting, and liquid crystal alignment methods are often considered. For example, the twisted nematic LCD provides for the fastest response time at the lowest cost, but cannot offer the highest contrast ratio or widest viewing angle.

Environment-based factors must consider things besides the obvious temperature like UV exposure and humidity/moisture, as they all are necessary in finding the perfect fit extreme temperature LCD module.

Besides the LCD modules, recent new products have opened doors in wide temperature range displays, such as OLED displays. OLED displays offer better displays in regard to contrast, brightness, response times, viewing angles, and even power consumption in comparison to traditional LCD displays.

These benefits, in addition to its ability to achieve a wide temperature range, provide more options for consumers in search of high quality displays for extreme climates.

Here is a picture inside the TV without the rear cover. The power supply includes the inverter stage for the backlight panel using only two HV transformers. Such design idea sounds very good because all EEFL tubes are connected in parallel avoiding the use of small transformers/inverters stages for each lamp minimizing in this way electronic issues on the backlight stage.

Compared to former CCLF, the new EEFL shows superior performance and applications. This incredible technology combines low power consumption and enhanced luminescence as compared to similar lighting sources. The most attractive feature of EEFL (External Electrode Fluorescent Lamp) is the absence of electrodes in the discharge tube, which is the main factor limiting lamp life. Electrode burn-out is the main cause of fault in CCFL. Because each CCFL lamp need its own ballast the new EEFL technology is simpler in electronics circuitry reducing in this way the rate of failures. EEFL lamps consist of a completely enclosed glass tube with external metal electrodes at both ends. This design minimizes electrode burn-out and results in a longer lamp life. Because the electrodes in former CCFL technology are in direct contact with the rare gasses, CCFL run warmer than the EEFL which are completely cool. On average, EEFL lamps have a lamp life of over 50,000 hours.

I figured out that three main areas on the circuit layout requires additional cooling. The hottest part was the digital class D audio amplifier (STA381BW) because overheats to much (manufacturer datasheet claims approx 3 watts of heat dissipation !!!) so I put a passive aluminum cooler to cool it down. Because the rear plastic cover touched the cooler I cut one of the corners. Using a smaller one was to weak to cool down the device at safe temperatures.

The digital scaler image MT5366 processor and glue logic ICs are located below a metallic RFI shield acting at the same time as a heatsink. Unfortunately the metal shield in use affects the efficiency on thermal conductivity of heat because is to thin leading to hot spots on the components. To correct such design issue the most convenient is to install a passive cooler. To cool down the MT5366 system on chip platform processor an older 486 mother board heatsink (the black one after changes third picture below) do the job well. The use of a thicker heatsink improves the thermal conductivity (spread of heat) avoiding hot spots on the devices.

The last part that requires additional cooling was the HDMI switch inputs selector (SiI9185 device schematic picture above) soldered on the right corner next to the HDMI inputs. Its based on the HDMI 1.3, DDC, HDCP specifications including a CEC (consumer electronics control) single wire bus interface to transmit I/O remote commands through a home network and EDID display identification (plug & play feature stored on serials EEPROMs). Researching datasheets from other versions I figured out that the device in operation consumes approximately 1.5 watts average but such information is not released by manufacturer. The device reach a working temperature of approximately 100 grads Celsius when HDMI inputs are enabled receiving stream data. Watching TV channels (digital DVB or analog cable) the HDMI switch remains cool because is in power down/suspend mode. At glance the HDMI switch overheats only when the inputs are enabled. Without an appropriate heatsink the life endurance of the device is affected because such operating condition can lead to a short circuit on terminals due silicon breakdown !!! . The HDMI switch integrates electrostatic discharge protections on its inputs up to 2kV discarding any possibilities of damages due weak ESD spikes but strong lightning electromagnetic discharges are a big problem without ESD protectors.

In the case of factory cooling all mentioned devices use the "ePad" enhancement, a small metal surface below the IC core case to transfer the silicon heat to PCB board. Despite the idea to reduce manufacturing costs avoiding in this way the use of external heatsinks such cheap PCB cooling solution is not appropriate at all. We verified on all the mentioned devices an excessive heat that unfortunately can lead to operational malfunctions/issues leading to a short durability.

After changes the overall heat is reduced due the improvements on heat conductivity and air convection cooling reducing the average working temperature on overall components avoiding at the same time hot spots on digital ICs (core of the silicon device).

To improve more the cooling on the T-Con LCD panel board we put a SinoGuide TCP400 series thermal pad on the main IC to increase the heat transfer on the metallic shield (this is more thick in diameter and seems to be OK for cooling purposes).

The human cognitive ability to perceive and process data from several heterogeneous outputs and react correctly to the information is greatly enhanced with the proper representation of graphical data. Large format displays allow for the consolidation of multiple heterogeneous displays, fonts, dials, gauges, numbers, into a single homogeneous representation of situational awareness.

For example, for many years, firemen first to arrive on scene have been met with screeching fire alarms, indicator lights on a fire panel and “as built” drawings locked in a cabinet with a special key. Today they could now be greeted by a large format LCD with a 3D view of the building, smoke flow diagrams, and other information to help them understand the situation and make better decisions faster. Occupants leaving a building can also benefit from graphical mass notification information which can be tailored for the situation.

Ship systems comprised of different steam gauges and manual operations such as sticking tanks and closing valves can now be automated with their instruments consolidated on a single screen or redundant large screens, showing graphically status of fuel, water, and ballast, improving productivity and decreasing workload.

Similarities exist on industrial control systems where several CRTs or smaller LCDs are being replaced by a large LCD with clever graphics designed for human factors and perception.

The challenge of these applications is the proper integration of the COTS LCD technology to meet requirements of availability, reliability, and intended use.

Large LCD panels are coming out of the factory with brilliant colors and near perfect viewing angles using ASV (Advanced Super View) and IPS (In Plane Switching) innovations driven by consumer TV requirements. The challenge is ruggedizing a display to preserve as much of this as possible, this while shielding against objects, liquids, sunlight and EMI. These surface choices may adversely affect the optics of the panel, which can be reduced through bonding techniques to eliminate air gaps.

Depending on its intended use, mission critical displays may be required to operate in an environment subject to dust, sand, fog, chemicals, falling or spraying liquids (broken pipes, sprinklers, etc). Protection of the LCD panel involves designing an outer enclosure capable of keeping dust and liquids out while keeping the display operating in its proper temperature range.

In addition to isotropic display clearing, long-term reliability is adversely affected by running panels at or near the clearing temperature. Depending on the application, enclosures can be de signed to circulate air through filtered and louvered vents. This can prevent dust and water ingress while providing a cooling mechanism capable of keeping the panel within specified operating temperatures.

The transition of display backlights from CCFL to LED has also helped reduce the amount of energy in a panel, which has been a great benefit to thermal management. Displays that are used in direct sunlight, however, have to deal with solar gain which can add as much as 1000W /m2 to the problem on a sunny, cloudless day at high noon. The amount absorbed depends on the enclosure’s material and color, but typically blocking IR films or a laminar flow of air over the display are used to prevent the display from “blacking out”. In sub freezing environments, such as outdoor, or non temperature controlled areas, supplemental heaters may be required to prevent slow response of the LCDs due to low temperature.

The deployment of large screen LCDs in control rooms, ships, industrial areas, or public venues requires consideration of tampering, vibration, and shock. It is important to understand the nature of the vibration or shock in magnitude and frequency to which the screen may be subjected. Sources can be motors, conveyors, engines, propeller blades or even seismic events. In many industries, there are published standards, which represent shock and vibration experienced by the display in both transit and operation. Some of the component considerations when designing a display requiring ruggedization are listed in Table 3.

There are several touchscreen technologies available, each having its own set of strengths and weaknesses. It is important to understand the end use and user to choose the best solutions. For instance, using an infrared touch screen in an outdoor location at night can attract insects which can actually cause false touches if they land on the screen and break the IR light beam. Other touch screen technologies such as capacitive are sensitive to metal enclosures making them difficult choices for very rugged applications. Some of the more popular technologies and their strengths and weaknesses are listed in Table 4.

Parts within a large screen display are considered to have a large Mean Time Between Failures (MTBF) usually measured in tens of thousands of hours or higher. The first reaction is to divide this number by 8760 hours per year and feel assured your 24X7 display will last that many years before it fails. However the MTBF is just a probability of failure and is calculated during the “useful life” of a part, typically at room temperature. As a part starts to wear out, or gets used at high temperature, its reliability can decrease rapidly. Solid-state components such as ICs are thought of as lasting virtually forever, but within an LCD there are several components that, when routinely maintained or changed out, will keep the reliability at its maximum. The use of intelligent health monitoring such as temperature, brightness, fan speed or air flow to trigger maintenance events will increase overall reliability and availability.

Leveraging the performance and value of large format commercial off the shelf (COTS) displays requires careful attention and understanding of the environment and operation by the end user. Using this information to develop specific design requirements, engineering a design that meet these requirements, and finally developing test steps that validate the product meets these requirements will ensure a successful large format COTS display implementation.

At low temperatures, the liquid crystal fluid maintains its viscosity, allowing the IC to refresh the data logic without any latency in the response time. At the high extreme of the operating temperature spectrum, the polarizer and adhesive materials are able to withstand the heat without warping the film and damaging the optical performance of the LCD module.

In addition to meeting the stringent quality requirements to withstand high temperature and humidity exposure, our displays also support “smart management” features, in form of a visual interface designed to help control the overall PV or EV application.

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