Front accessible LED sign:
The Front accessible LED sign include magnetic module Front accessible LED sign and hydraulic prop up structure cabinet Front accessible LED sign.
ERALED display is a fast growing energy saving, high tech green products which taking place of the old traditional products rapidly nowadays. You can ignore the existence of the LED display. However, the LED display will never ignore you! The LED display is appearing in every corner of the world and touching with us every second. We are living and touching with the LED display every second even we don't know it is called “LED display”.
LED Display is modernizing our life, our town, our city. It's so fashion that if an important events were held without the LED display. It is called “out”, “failed”, etc.
Every downtown, street, shop, school, church, window was also installed the giant LED display now!
LED display is the basic necessary equipment for every country's Central Television station. Even every small town's TV station has a huge LED display now!
LED display is also the basic necessary equipment for every important sports stadium. No matter NBA, or football World Cup LED display is always the necessary equipment. Even for some sports which you may never care also equipped with the LED display, for example: Badminton, Tennis, Soccer,Volleyball,Goalball,Softball,Speedball,Handball,Rugby,Aikido,Skiing,Wrestling,Archery,Beagling,Swimming,Cue sports,Dancing,Fencing,Fishing,Golf,Grappling,Gymnastics,Hockey,Hurling,Judo,Racing,Tennis,Trampolining, etc.
Even the more and more taxi tops were equipped with the LED display now!
However, what is LED display in end?
Before we know completely what LED display is, we’d better know some basic parts first. Like: What is an LED, what is LED pixel, what is LED module, what is LED module, what is LED cabinet, etc? LED display is a new display media which using LED lamps to display the content. Each LED display is composed by a certain quantity of LED cabinets in line and columns, each LED cabinet is composed by a certain quantity of LED modules in line and columns, each LED module is composed by a certain quantity of LED pixel in line and columns, each LED pixel is composed by a certain quantity of LED lamps, each LED lamps is composed by a certain quantity of LED chip.
So the most basic smallest unit of the LED display is LED chip or LED lamps. So, let’s start from the very beginning: concept of the LED, LED chip and LED lamp:
1.Concept or define of the LED chip: LED chip is a semiconductor which can converts electric energy into visible light. The chemical compound used within an LED determines its color, brightness and power efficiency.
2.Concept or define of LED lamps: LED is short for 3 words: Light Emitting Diode
According to the LED chip’s encapsulation type, LED lamps have several different types, like:
SMD(Surface Mountinging Device), DIP(Dual In Line package),Dot matrix, etc.
Generally speacking the LED lamps come in two basic forms:SMD and DIP.
SMD LED display is more and more popular since the Advantages of perfect: color blending capability, no color shift at extreme angles, much wider viewing angle comparing to DIP. More important reason why SMD is more popular is the resolution of SMD LED display is much higher than DIP LED display. For example, the smallest pixel for DIP LED display is 10mm. However, the smallest pixel pitch for SMD LED display is 3.2mm which means 9 times resolution higher than DIP LED displays. Furthermore, the SMD LED display is more energy saving and cost is also lower than DIP LED display
Acoording to the SMD LED’s encapsulation size, SMD LED can be classified to several models, like: 0606 SMD,0808 SMD,0909 SMD,1010 SMD,1515 SMD, 2020 SMD,2121 SMD,3528 SMD,1921 SMD,2525 SMD,2727 SMD,3535 SMD,5050 SMD etc
SMD 1921, 2525, 2727, 3535, 5050 is used for outdoor waterproof models, others is used for indoor non-waterproof models.
Acoording to the SMD LED’s encapsulation color:, SMD LED can be classified to Black LED lamps and white LEDs.
SMD Black LED lamps:
SMD white LED lamps:
Black SMD is 50% lower brightness, but can be viewed more clearly under the sunshine because the contrast ratio is higher, gray grade is higher as you can see from the below 2 SMD white LED display and SMD Black LED display’s actual comparison under the sunshine condition. Below picture to show: left is white SMD LED display, right is total black SMD LED display:
Each SMD LED lamp contains red, green and blue LED chip, meanwhile each DIP LED lamps only contains one color LED chip of either red color LED chip, green color LED chip or blue color LED chip.
Dual In Line LED lamps
Dual In Line LED lamps use a reflector cup and an epoxy lens package with dual legs, that is why it’s called DIP. This combination as well as the type of chip used, plays a role in determining the elliptical viewing angle produced. A Dual In Line LED's reflector cup focuses the light emitted by the chip into a specific viewing area.
DIP LED display is very popular before the year of 2015, 90% of outdoor full color LED video display were made of DIP LED lamps. However, SMD LED display taking place of the DIP LED lamps rapidly after the year of 2016. Nowadays, 95% of the full color LED display is made of SMD LED lamps.
3.Concept or define of LED pixel: Pixel is short for picture elements, are points of light that illuminate to form letters, words, graphics, animations and video images. One pixel can be made up of a single LED lamp, multiple LED lamps of the same color or multiple LED lamps of different colors. They are the smallest elements of the electronic display system that can be individually controlled and turned off or on at various brightness levels. Pixel is also called dot, is also the most basic and smallest unit of resolution. For example, when we say HD, UHD resolution: normally refers to how many pixels or dots in length and how many pixels or dots in height. HD means the resolution should be 1920 pixels in length, 1080 pixels in height. UHD means the resolution should be 3840 pixels in length, 2160 pixels in height, or even 7680 pixels in length, 4320 pixels in height. LED pixel is also the basic and smallest unit of LED module since each module is composed by a certain amount of LED pixels.
4.Concept or define of pixel pitch: pixel pitch means the distance between the 2 most close neighboring pixels in line and column. For example, if the distance between the 2 closest neighboring pixels in line and column is 8mm and 3mm, then we call this LED display model: pixel pitch Indoor Rental LED display . Pixel Pitch is normally just called PH, or P. So, PH8mm equals to P3mm.
5.Concept or define of LED module: LED module is the basic unit of LED cabinet which were composed by a certain amount of LED pixels.
6.In order to ensure our LED display product quality, durability and performance, ERALED established the most comprehensive testing systems done in the lab continue to provide much needed data to our engineers. We test ERALED products more rigorously than any other manufacturer. In fact, some of our lab test equipment is similar to that used by the automobile and aerospace industries.
ERALED outdoor LED display has passed StormTest, the most rigorous test in LED display industry
Before product release, ERALED puts products through a variety of stress tests. Our lab technicians place entire video boards through a massive 4,500 cubic foot environmental chamber (Solar Thermal Simulation Area: 22' L x 11' H), in order to simulate extreme climate conditions, such as:
•Blistering Heat (74° C, 165° F)
•Freezing Cold (-34° C, -29° F)
•Humidity (15% to 90% RH)
The Temperature/Humidity Chamber simulates worse-case environments to test component sensitivity towards humidity, corrosion and electrical property changes. This assures that product components are as tough as their displays, by undergoing:
•Chamber Transitions (5° C/min, 9° F/min)
•Humidity Testing (10% RH to 98% RH)
Thermal Shock Chamber
This chamber ensures product durability by conducting unpowered thermal shock testing. In less than five seconds, products are transferred between hot and cold compartments.
Highly Accelerated Life Testing (HALT)
To determine product functioning limits, the HALT chamber combines environmental variables, such as temperature shock and vibration, to stress products to the point of failure.
Spray Test Chamber
To test how well enclosures protect components, this chamber drenches display parts with high-pressure water jets to assure performance against moisture.
Salt Fog Chamber
To gauge a component's capacity to withstand the corrosive effects of salty coastal air, this chamber punishes ERALED products with a 5% salt solution at a sweltering 35° C (95° F).
LED Display Color depth
"Dimming" and "shading" refer to entirely different functions and the terms should not be interchanged. The word “dimming” refers to a uniform brightness adjustment across the entire display to correct the intensity for ease of reading different ambient light conditions. "Shading" or color depth, affects the light output variations of each individual red, green and blue LED to create images within the display.
Color depth chat
Bits per color
Resulting shades per color
Resulting RGB color capability
25 * 25 * 25 = 32,768 colors
Calculation explanation: Each individual red, green and blue LED be in one of two states, either on or off. This example uses a color data processing of 5 bits for each color is 2 to the 5th power and multiplying each color’s depth provides the overall color depth of 32,768 colors.
Although "dimming" and "shading" have different meanings, some manufacturers will combine greyscale shading values with dimming values to create a color specification that appears more impressive on paper than it is capable of producing in the field.Combining shading values with overall dimming values is a deceiving and misleading practice. Below is an incorrect calculation that includes dimming as part of the color depth:
25 * 25 * 25*32 dimming = 1 million colors
What LED lamps brand to choose when buying a LED display
The LED's are surely the most important quality criteria when it comes to LED video displays. They determine the image quality of the display and are decisive in determining how the image quality is retained over time. The quality characteristics for LED's are very diverse, and, here too, the maxim applies: the most expensive choice is not always the best choice. To highlight an example from the automobile industry: You are sure to be able to spontaneously list a variety of luxury sedans, though you may not generally consider these when selecting a new vehicle. Price and purpose play major roles in the decision of which model to choose. And also, luxury sedans differ in many ways, although they often all meet the highest quality standards.
The quality of an LED is determined primarily by the chip used. It determines the service life of the LED and how the lighting behavior of the LED changes over time. The mayor Chip manufacturers of LED's are:
The prevailing opinion on the market today is that LED's made by Nichia are the best for use in LED video displays. However, they are also undeniably the most expensive LED's on the market by a wide margin. The price of LED's varies on average from less than one cent per LED to up to 15 cents and more, depending on the type of LED (RGB LED's with three chips in one housing are often more expensive). An extensive price difference can arise in manufacturing, depending on the LED's used.
The most important factor for purchasing a LED display and determining which LED's to choose are:
•Brightness: The brightness of the LED's is measured in mcd (milli-candela). The higher the brightness, the better. You can run the display at a lower brightness, thus increasing the service life or increasing visibility during the day when the sun is shining.
•Electrostatic Discharge(ESD): The LED chips produced by various manufacturers differentiate themselves through a varying sensitivity to the effects of electrostatic discharge (for example due to contact). Display failures caused by electrostatic discharges can be prevented by implementing safeguarding measures against ESD in the production process. The following LED chips listed are indicating the voltages that the LED's can withstand in case of electrostatic discharges:
●Taiwanese LED Chips: 800V
●Chinese LED Chips: 200~800V
•Sensitivity to Temperature Variations: Poor LED chips can fade faster, i.e. their service life can shorten, if they are exposed to high temperature variations. Depending on the country, temperatures can become extremely hot or cold during the summer or winter months, respectively. As a result, a poor LED quality could cause premature fading of the overall, expensive LED display.
•General Service Life: The general service life of the LED's often lies between 50,000 and 100,000 hours. (100,000 hours equates to 10 years of continuous display operation at full white, if no other factors exist which reduce the service life; such as increased heat in the display housing, or operating the LED's at overvoltage in order to balance brightness reduction.
•Brightness Reduction due Aging: Below is a table indicating the lighting reductions which arise within the first 10,000 hours: LED brightness reduction after the first 10,000 hours, sorted by manufacturer:
For the advertising screens we recommend always Silan LED’s, or the Cree LED’s which are a little more expensive than the Silan LED’s. Nichia LED’s, which are at least twice as expensive than Silan LED’s, for LED display is mostly used for the professional industry like on stages or for television programs where quality is of high importance due to the high brightness and longer lifetime, and professionals invest a higher amount to have the screen performance and quality optimal at all times if not they are out of business and glamour is important in those industries. For advertising screens which are placed outside that quality is not necessary to be as optimal as the professional industry like stages or television programs because the screen is seen as an investment to shorten the ROI to less than 1 year and using the screen for advertising for over a period of at least 5 years to 8 years and gain 5 to 7 years from advertising.
If investing in Silan LED’s the initial investment is about 25%(Cree) to 50%(Nichia) lower than investing in Cree and Nichia LED’s. So for that Silan LED’s will have an ROI of around 1 year depending on the portfolio of clients that the screen owner has, the place where it is placed and price of the advertisements. When advertisers want to publish their products on the screen, of course quality is important but in practical terms the selling price of the commercial space on the screen will be the same if used Nichia or Silan or Cree LED’s because they don’t care about the lifetime and differences of brightness between Nichia, Silan or Cree LED's, they just want to be seen and promote their products and or services on the screen. What is important for the publicity clients is the resolution, if it doesn’t look pixelated they do see that as a plus and will attract more advertisers because the better the resolution the higher the impact of the advertisement and the higher the company’s goodwill of the product announced. Also for Nichia and Cree LED’s the ROI is one and a half to twice the time in comparison to Silan LED’s which is two years at least.
Normally Silan and Cree LED’s need 100,000 hours to reach around 40% of its total original brightness, Nichia will need 100,000 hours to reach 60% of its total original brightness. This is because the materials used are much more expensive for the Nichia LED’s than for the Cree and Silan LED’s and are better conductors. Besides Nichia uses around 50% of the energy used to burn the LED’s in comparison to the Silan and Cree LED’s. For example 1sqm of 16mm pixel pitch Silan and Cree LED’s consumes around 1200W/m2 and Nichia 575w/m2 which is less than 50% to get the same amount of brightness.
Many of the quality factors for LED's play a role in how they behave over time. Nichia LED's are the only ones for which it is generally known that they thoroughly meet the required criteria, positively setting themselves apart from other LED's on the market. The long-term values for some of the other manufacturers were not available. Many developments in the LED field are so new that long-term values over five, ten, or more years don't exist yet. If price and performance should be balanced, we recommend LED's with Silan chips. In terms of overall service life, Silan LED's are 1/3 weaker than Nichia LED's but they cost significantly less. With the service life of Silan LED's, you can run your display for 6 years of continuous operation at full white, although running the screen at full white is never done in reality. In displaying average video image content, the effective service life increases by two to four times as much, that is, 14 to 28 years, depending on the image content. In contrast to the still very expensive Cree LED's, Silan LED's age more evenly and also don't have as much lighting reduction after 10,000 hours. This proves particularly lucrative when exchanging individual pixel cards, since the calibration requirement is lower.