Core Components of an LED Display
FAQs about LED Display Structure
Since the earliest understanding of "Let there be light," humans desire the clarity and capacity that light provides. One result of this was Thomas Edison's 1879 invention of the light bulb, augmenting natural illumination with a source that we can activate and de-activate on command. Yet this incandescent bulb, for all its benefits, has a relatively short productive life. Enter the light-emitting diode (LED), a semiconductor that generates light when electric current streams through it. The difference is that LED light flows from smaller devices at stronger intensity for a much longer time frame. Furthermore, its applications extend tom displays afforded by modern technology.
In order for viewers to discern images on an LED display, the multiple lights need to be concentrated on a single board. This is the module. Modules come in myriad shapes and sizes, and are central to all kinds of lighting and electronic signage. Types of modules include:
The control system works to regulate brightness, intensity etc. This hardware directs module circuits through data transmission in order to affect appearance, colors and other display features. It can also provide for fading features and voice activation, among other options.
LED display designs frequently employ a switching power supply that both controls and converts the voltage that moves through the system. The LED display might demand an alternative type of direct current that circuits do not deliver. So, the power supply
component modifies the current into a more usable form.
In LED-speak, cabinets are modular units with which the full screen display is put together. Cabinets are diverse in dimension, in constituent materials and in specific modifications.
TRANSMITTING CABLE -- these are two intertwined wires that convey signals from the control system to the screen.
SPECIAL VIDEO AND MULTI-FUNCTION CARDS -- these are distinct from the central processing unit (CPU) and provide the capacity for features like video editing, three-dimensional modeling and advanced gaming.
SCANNING CONTROL BOARD -- regulates the time on/time off ratio of gray control cycles while temporarily storing data and projecting scan signals.
The material through which a viewer sees a display is not insignificant. Because transparency admits light passage on each side of the display, the decision on what sort of transparent cover is best hinges on several factors, size being one of them. Large format LED screens, for example, are comprised of moderately-sized cabinets ranging from 0.5 to 1.0 square meters each. Used for massive events and exposure, often outdoors, acrylic better defies the elements ofs weather better than glass. On the other hand, glass is easier to keep clean and is less vulnerable to scratches.
Black matrix is the industry term for the dark space that exists between the pixels that compose the display. It provides demarcation between the red, green and blue (RGB) sub-pixels. The black matrix serves to buffer superfluous light that would otherwise distort the intended color contrast. Since LED matrices are low-resolution, maintaining color contrasts are essential for a clear and visible presentation. The entire display is mad black when the RGB elements are switched off.
As noted above, the LED module supports the many lights that are housed by the LED display structure. These are applicable to a whole range of indoor and outdoor displays. Modules receive power from batteries and/or alternating current. Central to the module is an electrified semiconductor that projects light energy in the form of photons, i.e. energy released when electrons move among atomic shells. These are produced in a variety of colors, hues and tints -- a very powerful function in advertising and marketing contexts. Recently manufactured modules can come with integrated circuits that enable plug-and-play technology; remote phosphor that helps maintain temperature and promotes energy efficiency; or Bluetooth wireless capacities.
The reflective layer employs ambient light to project an image. By way of contrast, transmissive displays use backlight or front light to accomplish this. The reflective layer in an LED display structure instead redirects the natural light of the environs for a fully illuminated display. Of course, when ambient light is weak, the energy efficiency conveyed by reflective technology is offset by a debilitated display. However, newer technologies are embracing both transmissive and reflective components. The materials that compose a reflective layer are many and varied, from liquid crystal layers flanked by glass to electrochromic materials, or chromophores.
The backlight is a transmissive means to irradiate a display. This polarizing filter admits some light waves while blocking others. The backlight makes the image or text in the display more visible and resolute. Plus, brightness is consistent no matter what the viewing angle. LED TVs with a backlight are environmentally friendlier and have greater longevity than those with cold cathode fluorescent lamp bulbs. Meanwhile the LED backlight consumes less energy, making this technology optimal for smaller displays and devices.
Taken by itself, a pixel is literally a "picture element." In the context of LED displays, however, the pixel is a light-emitting diode that is individually governable -- with its own digital control chip -- from a computer. Whereas the LED module is set up to control diodes as clusters, an LED pixel arrangement can do so singly or in groups. This can be of benefit with regard to smaller display structures in terms of management and affordability.
Pixel pitch is a term that denotes the compactness of pixel clusters in an LED display, i.e. how densely packed together the pixels are. An image has higher resolution when pixel pitch is lower because pitch refers to the space dimensions between pixels. This has implications for how far away a viewer can apprehend the display. Accordingly, LED display designers must determine the optimal viewing distance before setting the pixel pitch. Key to understanding pixel pitch is that more space between pixels equals a lower resolution.
Essentially, the same principle for mixing paint applies. Viewed close-up with the naked eye, an LED screen display conveys just three colors: red, green and blue. This has to do with the receptor cells in the eye that discern these colors. Other hues are combinations and permutations of these three shades. So, for example, the appearance of yellow results when when the blue and red ocular receptors are in action. Accordingly, the RGB lights in an LED display are activated in combination and at varying intensities to convey the other colors that viewers see. "black light" occurs when all lights are de-activated; white light when all are on at full strength.
LED technology is continuously progressing so the basic components and functions can change over time. For the present, at any rate, the light sources, modules, pixels, connectors, controls and power supplies work in tandem to present messages and images in a striking, attractive or straightforward manner. Some elements are swapped out for others, e.g. ambient light vs. internally-generated light. Yet the fundamental presence of light emitting diodes is central to the generation of the display.
