6 Common Sense That You Must Know Before Buying an ...

Lucky Product Page

1.LED screen resolution

The key to a quality image on a large-format video LED screen is to buy the highest resolution you can afford. A LED screen&#;s resolution is defined by it&#;s total number of vertical and horizontal pixels (dots that form the picture). The video signal that the LED screen will be reproducing has a native resolution of about 486/576 (NTSC/PAL) vertically and anywhere from about 240 to 720 horizontally (depending on the quality of the source). To reproduce these signals with no loss of image resolution, you want a minimum LED screen resolution of about 648 x 486 (NTSC) or 768 x 576 (PAL). If you use a LED screen with fewer pixels than the input source, the images will have less resolution than the source.

However, if the LED screen is designed properly it can still give an acceptable appearance for video images. LED screens of approx 1/3 of VGA resolution can provide a very acceptable video image, so around 200×150 pixels are OK. For example, to achieve a 640×480 (VGA) resolution on a medium-size (3 m by 2.25 m) LED screen, we would need pixels spaced around 4.5 mm apart. (This distance between pixels is called pixel pitch, and is usually measured in millimeters.)

Typically, pixel pitches for indoor LED screens are 6 mm, 10 mm, 15 mm and 20 mm. Pixel pitches for outdoor LED screens are 15 mm, 20 mm, 25 mm and 30 mm- outdoor LED screens tend to be larger than indoor screens, as the viewing distance is often greater. We could, for example, use a 6 mm pitch and a slightly bigger LED screen to achieve a full VGA resolution, or a more cost effective solution would be to use a bigger pitch with a lower resolution LED screen. The finer the pixel pitch, the more expensive the LED screen, so the ideal solution will always be a combination of cost and resolution.

As most LED screen products come in fixed blocks of pixels built onto circuit boards (e.g.: 16×16 or 32×16), you may have to adjust your overall LED screen size slightly to accommodate a whole number of blocks. A consideration is that the larger the pixel pitch, the more prone the image is to pixelization &#; you can start to see the pixel structure, much like looking at a newspaper photograph with a magnifying glass. This is a function of the distance between the viewer and the LED screen, and needs to form part of the design calculation. Surface-mount LED (SMD) packages are now available to allow 10 mm and 6 mm and possibly smaller pitches &#; a 12 mm pitch is about the limit for conventional lamp type LED packaging.

At 12 mm spacing the conventional lamps have poor contrast, and produce a lot of heat. The choice of pixel pitch and screen resolution is dictated by: any physical size constraints you may have; viewing distance and sight lines; and, of course, budget &#; these displays are costed by area.

2.LED screen color compound distance

When pixels are seen at close range, the RGB light-emitting diodes appear as independent dots. The distance from the LED screen where these LED&#;s mix from a single color is known as the &#;color compound distance&#;. The superior color compound ability allows images to appear clear and sharp at close range, which is a vital factor in indoor LED screens. For outdoor lamp-type individual LED screens, the color compound distance can be calculated by the pixel pitch multiplied by 500.

For indoor surface mounted three-in-one RGB LED devices, this figure is 250, as the LEDs are very close together. Therefore for the screen model LVP this value is 2.5 m. This is also sometimes mistakenly called the minimum viewing distance. E.g. for screen model LVP 16 mm (pixel pitch) x 500 = 8 m.

3.LED screen minimum viewing distance

This is calculated by the pixel pitch multiplied by 750 to . This value will produce a smooth image. Closer viewing will produce an image with individual LEDs appearing as dots. E.g. for screen model LVP 16mm (pixel pitch) x = 16 m.

4.LED screen maximum viewing distance

This is generally 20-30 times the LED screen height. E.g. A 4.8 meters high screen: 30 x 4.57 m = 137 m.

5.LED screen video processing

Once you have two competitive LED screens of similar technology, the same size, and the same resolution, the differences in LED manufacturers, drive electronics, and LED mounting methods can be evaluated. A standard video signal cannot be directly displayed on an LED screen without first being processed. It is the quality of this processing, that is most often overlooked by prospective buyers of this technology.

The primary rule of all broadcasting should apply, garbage in = garbage out. Video images are made up of a number of horizontally scanned lines, but these don&#;t all appear on a television screen at the same time. In the first 1/60th of a second (1/50th for PAL) the odd lines are shown, and in the second 60th the even lines are shown.

Everyone&#;s television works this way, and we call this an interlaced display. As most displays don&#;t use this broadcast signal directly, we must first de-interlace the video. The simplest way to do this is to take the first set of lines (field), double it up, and show it &#; ignoring the second field. Some low-end video processors do this, and throw away half of the original picture information.

More sophisticated approaches involve storing the first line information, and then combine it with the second line information 1/60th of a second later. You can then display a complete frame. However, if an object was moving rapidly it may be in a different position in the second line than in the first line and this can lead to unacceptable video effects (flickering).

Resolving this requires interpolation of the two sets of lines, done in real-time and then we have to scale the image to fit the output screen (this is normally a different resolution than the source). The combination of these processes, especially the scaling, requires a lot of powerful processing to generate clean, artifact-free, and fast-moving flicker-free video.

Generally, this is done by dedicated video processing equipment and will be relatively expensive if you want a good result. There are considerable differences in how to display manufacturers process the video signal for display, and obtaining this information from the LED screen manufacturers is sometimes not an easy process. It is a very worthwhile endeavor, since the processing can make a dramatic difference to the quality of the displayed image.

6. LED screen brightness and contrast

The unit of measurement for LED screen brightness is the nit (cd/m2) with higher numbers meaning a brighter display. As a general rule, you will need no less than nits for an indoor LED screen and nits or more for outdoor LED screens. The way to measure this is at a normal angle to the LED screen (i.e. in front) using a light meter.

The color temperature of the LED screen should normally be set to K for indoor LED screens, and K for outdoor LED screens. If set this way, a full white signal should be measured at several points (usually 12, being the center and then evenly spaced around the LED screen) from the normal minimum viewing distance. The LED screen should be set to black, and then re-measured for the ambient reflected light (one measurement at the centre is OK).

The LED screen brightness is an average of the 12 points of white, minus the measured ambient when the LED screen is black. The viewing angle is normally defined at the point when the brightness is 50% of the maximum. If you walk around the LED screen you will see the brightness change, and it is advisable to review the three primary colors (and white) when walking around the LED screen to see if the color remains uniform at all angles. LED screens have a problem that is unique to this technology called &#;shouldering&#;, where a color shift is caused by one LED blocking the view of another LED at extreme angles.

The viewing angles should really include color shifts, and if a significant color shift occurs before the LED screen brightness falls to 50%, then this is the viewing angle. Adding a louver between the pixels or rows of LEDs reduces the effect of glare from other light sources, and enhances contrast. It also reduces the vertical viewing angle, but usually this is not a problem for most applications. If the LED screen manufacturers drive the LEDs using high currents, they can quote brightness figures in excess of nits. The problem with this is that high drive currents lead to faster degradation in the LEDs, and the LED screen uniformity can shift dramatically in short periods of time. Quoted life figures for the LED&#;s range from 20 000 to 100 000 hours.

These figures are clearly only meaningful if they are determined at the actual drive current that will be used under real display conditions &#; and certainly at the drive levels used to produce the LED screen brightness measurement. When evaluating any large-format video LED screen, always ask for references (for both the manufacturer and the installer). Try to ensure that these previous customers are in a similar situation to your own (e.g.: if you have an indoor arena, a comparison with an outdoor venue may not be completely useful).

Before you buy an LED screen

• estimate the size and location of your LED screens;
• work out the minimum viewing distances;
• how many and what type of sources will you use;
• will the LED screen be permanent or will it need to move.

Determining these factors beforehand will allow a LED screen manufacturer/supplier to estimate the pixel pitch and nature of the LED screen you may need. When you budget for any screen, and especially an LED screen, you should be aware that without consideration for the content, the final effect will be poor. It is a better idea to determine the content first and use a sample of the content in the format you plan to demo your LED screen. In particular, scenes with a lot of motion and camera pans will create certain LED screen processor problems. Look for objectionable noise artifacts in large expanses of a single color (especially black or very dark areas).

For more led display companyinformation, please contact us. We will provide professional answers.

Always remember, the LED screen manufacturer&#;s demo is designed to emphasize the best points about the LED screen, and it is up to you to make them prove how good it really is. Test patterns, for color, grayscale and motion are essential. Take these with you to a demo, in the format you will use with your final LED screen. When you have the final 2 or 3 companies defined, you should give serious consideration to a &#;shoot out&#;, with competing LED screens set up side by side- fed from the same source video. While this can be expensive, it is the only way to truly compare the competitor&#;s products. Suppliers reluctant to engage in this kind of event may give you some insight into how confident they are of their product, and what their after sales support will be like!

David Thilwind is the International Marketing Manager for Lighthouse Technologies, a manufacturer solely dedicated to developing and producing LED screens for staging, rental, and outdoor productions. The article was published in web journal tfwm.com.

Outdoor LED signage has become indispensable for organizations looking to offer relevant, easily updated information, alerts and advertising.

But before purchasing LED outdoor signage for your business, you must ensure you&#;re making a well-informed investment. Your digital signage is likely to last at least 10 years; careful planning will help ensure a successful experience, longer lifetime and lower cost.

Here are eight key factors to consider as you look for the best outdoor LED display screen to meet your needs:

1. Environmental ruggedness

Depending on where your outdoor digital sign is located, you may need to consider how it operates in hot or cold temperatures, as well as in rain, snow, wind, dust and humidity. Against these elements, the design of your screen and its enclosure is critical to the continuous operation and lifespan of the LEDs.

In terms of environmental factors, your first consideration should be removing heat from both the LED elements and their driving electronics. Ask any vendor about their thermal management solution and its ability to maintain LED temperatures within the elemental conditions you anticipate. To protect your signage from the elements, check that the enclosure design meets specifications for resistance to water, dust, humidity, etc. &#; whatever concerns apply to your location.

2. Support every step of the way

Can your potential supplier offer support and advice for the screen&#;s design and permitting process? Will they listen to all stakeholders and design a solution that fits their needs? Can they work with a customer project leader or recommend a qualified installer?

Hopefully, the answer to these questions is yes. You want a partner in this process, not simply a vendor.

3. Maintenance and servicing

Once your LED outdoor signage is installed, routine maintenance and servicing are critical to ensuring it always looks great and lasts as long as possible. Ask your vendor how often calibration is required &#; and how easy it is to accomplish &#; to ensure consistent image quality for years to come.

Similarly, establish how and when the screen will be serviced. Some vendors, such as Samsung, offer a network operations center (NOC) option to constantly monitor your sign and send a technician to fix any issues before you may even be aware of them. To avoid downtime, servicers will need easy access, too, so establish protocols for that.

4. A successful track record

How long has your potential LED supplier been in business? What are other customers&#; experiences? Will the supplier be around in 10 years? Will they be responsive to any needs you may have after installation?

To ensure you get the best outdoor LED display possible, ask for references and referrals from their previous customers, especially for jobs done five or more years ago, to get insight into the provider&#;s integrity.

How to plan and deploy direct view LED signage

Everything you need to know about choosing your LED displays for optimal viewing indoors and out. Download Now

5. Attention to safety

To local and state governments, your display brightness can be a major safety concern. A sign that&#;s too bright may distract drivers and make it difficult to drive at night. Check if your LED display has an auto-dimming capability to lower the screen&#;s brightness relative to surrounding light, which should minimize it at night, saving power and keeping drivers&#; eyes on the road.

The materials used in the LED screen and its enclosure can also lower the risk of dangerous signage failures and assuage any safety concerns. Look for products certified by Underwriters Laboratory (UL), which imposes strict safety requirements.

6. Price and warranty

You may be tempted to choose the least expensive LED signage option, but you&#;re likely to get what you pay for. Low-cost suppliers use lower-quality materials &#; not military-grade components. Their design teams may not ensure the safety and longevity of your signage. And they may under-specify the screen&#;s performance to lower the cost.

Many signage suppliers offer a warranty, but check the fine print to make sure you understand the exceptions and limitations. Here&#;s where you may be better off going with a trusted brand, even if it costs a bit more.  Ultimately, smartly designed and well-built LED advertising screens will deliver greater overall savings.

7. Choose the best integrator

Your LED supplier may not always be the organization that physically installs the screen. In many cases, you may end up hiring an architect, consultant or project manager to oversee or carry out the installation. Is your LED supplier ready and willing to work with these managers?

You may also simply want to appoint an installer who can manage the entire project. Can your supplier suggest a qualified installer? Again, check their references and ask about the success of previous installations.

8. Visual quality

Outdoor signage is meant to draw the attention of passersby and communicate a message about your brand. The vividness of the image has a significant impact on how that message is received. Your outdoor LED signage should be bright and vibrant, and it should display colors accurately. Skin tones that look washed out, for example, will draw negative attention, so check the LED supplier spec sheet to be sure the display shows true-to-life color.

Another key consideration is pixel pitch, in other words, the space between RGB pixels. It&#;s important you choose a vendor that will match the right pixel pitch for the viewing distance. Over specifying the pitch may cost more, but if the pixel pitch is too large, the visual quality may suffer.

Establishing an outdoor LED signage solution can be a daunting task with many moving parts &#; and concerns about visual quality, cost, safety and reliability. Starting with these eight tips in mind, you&#;ll be prepared to ask the right questions and set your project up for success.

For an array of innovative display options, check out the full lineup of LED outdoor signage by Samsung, designed to weather and outshine all sorts of unpredictable environments. Whether it&#;s one screen or dozens, you can configure and tailor their messaging in real time using an integrated CMS, as explained in this free complete guide.

Contact us to discuss your requirements of LED Screen Manufacturer. Our experienced sales team can help you identify the options that best suit your needs.