An Expert’s Advice – Flat Panel Displays
Hello. I started Innovative Home Media over six years ago but have been interested (or as my wife says, obsessed) in everything having to do with Audio and Video for as long as I can remember. Yeah, I was one of those geeky guys who was riding his bike to Radio Shack back in the 70s to get parts for the speakers I was building from scratch.
My goal with this Blog is to take questions that I am often asked by my clients and share my answers with you. I will also, from time to time, attempt to clear up misconceptions regarding products or technologies. I’ll try to help you cut through some of the marketing hype to determine if the latest and greatest AV product is really worth you replacing your existing one. Why pay for something that will not make a change that you can really hear or see?
The information presented here will be based upon experience, training and sometimes simply personal opinion. The intent will always be to make you a more informed, educated consumer.
Flat Panel Displays
Over the years I have been asked countless times what is the best TV. Surprisingly the answer lies more in the room that the display will live in or what the primary use for the display will be rather than the technology itself. First let’s look the basic technology behind current day flat panel televisions and then we will explore the Pros and Cons of the different types of flat panel displays.
Unlike their predecessor, CRT (Cathode Ray Tube) or the old ‘Tube’ TVs, current day flat panel screens are made up of thousands and thousands of pixels. These pixels are little individual rectangles, or light engines, placed very close together that work in unison to make up the picture we see. The way that these pixels create their ‘light’ changes from technology to technology, i.e., Plasma, LCD.
The number of these pixels a set has in a vertical row determines its resolution, i.e., 480, 720 or 1080. These numbers relate to the number of pixels found in a vertical row on a particular set. You will often see 1080 resolution referred to as 1920×1080, which can be a bit confusing. The 1920 is the number of pixels from side to side and the 1080 is the number from top to bottom. It is this top to bottom count that is the one that is used when referring to a set’s resolution.
The ‘i’ or the ‘p’ that you will often see behind one of these numbers has to do with how the display refreshes the image. In America, our television system operates on a standard that dictates that the image on our televisions refresh, or paints a new frame 60 times every second. Our TVs scan each new frame a row of pixels at a time, moving side-to-side, starting at the top and working its way down. Regardless of the size of the set, it ‘paints’ a new image on the screen 60 times every second, one horizontal row at a time. As for the letters that you often see behind the resolution numbers, the ‘i’ stands for Interlaced and the ‘p’ stands for Progressive or Progressive scan. The difference is that with Interlaced, only every other horizontal line of pixels is refreshed on the first scan and then it starts over at the top and fills in the remaining lines on a second scan. With Progressive scan, all of the lines are refreshed on the first pass. Interlacing can cause what is referred to as the ‘jaggies.’
Imagine you’re watching a NASCAR race and they are showing a close up of a car passing by. The display makes its first scan and paints every other line. When it goes back to fill in the remaining lines, the car has moved slightly forward. The vertical line of the back of the car isn’t a straight line. All of the lines painted on the second pass are slightly further ‘forward’ than those painted on the first pass. It makes for a jaggy vertical line. Progressive scan doesn’t suffer from this as it paints every line on every pass, thus yielding a smoother image.
So why do we have Interlaced? Programming done with progressive scanning requires more bandwidth to broadcast or to store on a disc. Due to bandwidth restrictions, currently broadcast providers such as cable or satellite only broadcast in maximum resolution of 1080i. Standard DVDs only had enough room to store a typical movie in 480i.
As high definition televisions became more popular, the need for source components to match the resolution capabilities of HDTV became needed. As a solution, most DVD and Bluray players, and a growing number of other source components are equipped with “upscaling” and “deinterlacing” capabilities to better match the performance of non-high definition source material with the capabilities of the today’s HDTV’s. These components utilize internal software to upscale, or convert standard 480 resolution programming to 1080 and to convert Interlaced programming into Progressive scanned programming. Most of these programs do a good job at making these sources look better than they would otherwise appear on our HDTV displays.
A bit of trivia: The first-ever flat panel display was invented in 1964.
In our next entry we will examine the different flat panel technologies and their strengths and weaknesses.