To the untrained eye, a flat panel display is a flat panel display. Go down to the local big box store and you are confronted with rows and walls of displays gleaming at you. You quickly observe that they all look a little different. The first thought that crosses your mind is the multitude of sizes of flat panel displays and that they all look different but perhaps you toss this off to different products from different manufacturers simply being different. Upon closer examination you observe the differences in the look and feel between LCD and plasma displays. For the truly keen observers you might notice the difference in resolution, contrast, brightness, and dynamic range. All of these "differences" aside, a flat panel display is a flat panel display. Right? The correct answer to this question is "wrong". It all depends upon your application and for the sake of this article; we will compare consumer televisions to the needs of the digital signage market.
A disturbing trend has been developing over the last several months as flat panel displays have become more ubiquitous and the digital signage market has been growing at such a rapid pace. We are seeing digital signage purveyors simply buy the least expensive flat panel display from any source and utilize this in their systems. After all, conventional wisdom suggests that flat panel displays are basically alike or so it is assumed. We understand that one of the major challenges of the digital signage industry is cost containment and the ever present return on investment aka ROI. We further understand that by "saving" $100 to $200 on a given flat panel display when you may be purchasing 1000 or more displays is not insignificant. Good fiscal control should be applauded when it stands up under scrutiny but when apparent cost savings evaporate in the end and the project is compromised for the end user, a clear understanding of the differences between consumer and commercial display products is in order.
Before going further, let's begin with the key factor of display failure in a digital signage system. Most of us are aware that there are only a few manufacturers of the actual LCD or plasma "glass" that is the foundation for flat panel displays. We are also aware that these manufacturers supply the "glass" to various vendors with a wide array of capabilities. Recognizing that the panel is the most obvious part of the display, the manner in which it is incorporated into the package and the quality of the components used to drive the display will determine the lifespan of the product in the field. Nowhere is this more important than in digital signage. One horror story that recently unfolded involves the purchase of several thousand 32" LCD televisions from an off brand supplier because the price was so attractive. My contacts at Samsung, LG, and NEC were left out in the cold. Speaking of cold, the temperature of the digital signage company became decidedly hot when over 25% of the bargain displays have failed and this is "only" referring to failures to date!
The old adage that you get what you pay for is not just an idle thought especially in the constant use world of digital signage. Climbing down from my pulpit, there are other differences besides pure build quality to consider before you lay down your project dollars at the local warehouse super store and buy a consumer display. There is no better place to start with than the warranty. When consumer displays are used in a commercial environment the warranty may be null and void or, at best, it will revert to 90 days over the counter requiring the display to be shipped back or taken to a service center for repair. Imagine how convenient it will be to go to North Dakota in the winter and take down the dispto send in for service. On the other hand, commercial displays from the major manufacturers like Samsung, LG, NEC and a few others on the LCD side offer as much as a 3 years parts and labor warranty on site. For plasma displays, companies like Panasonic, Pioneer, Samsung, LG, and even new comers like Visual Appliances provide 2 years parts and labor on site. It helps to know that the support is there when and where you need it.
We have all heard about plasma "burn-in" and more recently, but not as well publicized, "image retention" on LCD displays. As a side note, these problems are not as pervasive as some would have you think. Commercial plasma displays from Pioneer, Samsung, and NEC to name a few offer advanced anti-burn in algorithms beyond what is included in consumer televisions thus reducing the risks of ghost images remaining on screen. Without these advanced features on commercial displays, the risk is greater.
Digital signage is characterized by long hours of operation and extreme heat conditions. Commercial displays are designed to withstand long operating hours with thermal characteristics built into the internal design for proper heat dissipation in both portrait and landscape modes. Commercial plasma displays typically incorporates additional fans to dissipate heat. Consumer Displays on the other hand are designed for limited on time operation with the intent of long off times. They are not appropriate for 24/7/365 operation environments.
Contrary to popular belief, the incorporation of a flat panel display in a digital signage environment is not just a plug and play scenario. There are numerous design aspects to take into consideration, for example, internal scalers/algorithms. Commercial displays — recognize all PC resolutions including wide formats and different refresh rates (1024x768 @60, 72, 75, 85Hz) in addition to TV/video resolutions. Consumer displays are designed specifically for TV/video formats with very limited PC resolutions. One important differentiator is the connector interface. Commercial displays incorporate the standard RS-232 external control/connector with PC and video loop-through connector capability facilitating multiple display configurations from a single PC or video source. In addition they include industrial BNC locking connectors. Consumer displays typically do not offer RS-232 external display control/connector, video loop through capability or multiple display configuration capability and they do not offer BNC connectors.
From a picture dynamics point of view there is a difference between consumer and commercial displays as well. Each type of display utilizes a different backlight configuration for addressing grayscale. Commercial displays will produce a full grayscale with good linear color tracking from black to white showing all 256 different levels of luminance (brightness.) This is necessary for the diversity of PC applications. For consumer televisions, grayscale is skewed for more of the bright white end of the scale relative to the narrow broadcast standards that they must meet.
There are few other issues to consider. First of all, commercial displays are designed to operate in both landscape and portrait modes. In terms of mounting capabilities, commercial displays typically utilize VESA compliant standard mounting connections to complement standard industry mounting devices. This makes for easier installations and less unique inventory to carry. Consudisplays typically need special mounting brackets and sometimes cannot use third party mounts. Last but not least, we have the issue of public display security features. Commercial displays take this into consideration and incorporate measures to protect controls in a public environment including locking of front panel and IR remote lockout while consumer displays offer no way to lock the controls.
We are not saying that consumer displays are not excellent for their intended use. On the contrary, we urge a person looking for a home theater to look at televisions from the consumer side of the major flat panel display manufacturers. What we are saying is that commercial displays are designed for heavy duty 24/7/365 commercial applications and the manner in which they are built, the features they incorporate, and the warranties that support them are clear indicators of their focus. The decision as to which way to go should be driven by the application, customer satisfaction, and for the finance guys who need a reason to listen, the total cost of ownership. The bottom line is that a flat panel display is not just a flat panel display.
Reprinted with permission from DSEG
This white paper is for informational purposes only and is subject to change without notice. C2G makes no guarantees, either expressed or implied, concerning the accuracy, completeness or reliability of the information found in this document.