HOLY GRAIL

ARTICLE

FLAT SCREEN DISPLAYS:
The Holy Grail, or Pandora's Box

by Peter H. Putman, CTS

By now, it should be pretty obvious to readers of S&VC that flat-matrix imaging technologies (LCDs, DLP, Plasma, etc.) are approaching "king of the hill" status when it comes to the design, specification, and installation of electronic displays. The projector market in particular has been turned upside-down by a flood of high-brightness, lightweight products. There is no reason to assume the same thing won't happen to the video and presentation monitor markets.

Considering what these products are replacing, we're reaping plenty of benefits. Gone are the need for heavy-duty installation brackets. Gone too, is the need for converging 3-tube front projection systems. High-gain front projection screens - and their associated hot-spot problems and narrow viewing angles - are also headed for the endangered species list.

Plasma and LCD monitors bring similar advantages. Now, we can mount direct-view monitors anywhere our heart desires. We can even use low-profile recessed mounts. Heavy-duty carts? Forget about them. High ambient light levels? Not a problem.

It would appear that there is no downside to switching from tube to matrix imaging. Yet; as many dealers and systems integrators are finding out, flat-matrix displays bring along their own problems - many of which aren't all that easy to solve.

That's not to say you should stay away from flat-matrix imaging. Far from it! What you should do is learn as much as you can about the characteristics of flat-matrix imaging, and how different video and computer signals are processed by liquid-crystal displays, digital micromirror devices, and gas plasma panels.

BY THE NUMBERS

The largest limiting factor to flat-matrix displays is their fixed image resolution. By that, I mean the structures of pixels that constitute the active imaging area. When we buy a display using picture tubes or projection tubes, we have a vague idea of its resolution capability. Until that tube is turned on, though; it has no resolution whatsoever and waits obediently to trace the desired horizontal and vertical dimensions for us.

Flat-matrix displays, on the other hand, have a specific, quantified resolution whether they are sitting in a box in a dealer's stockroom, or hanging from the ceiling in a conference room. As a result, flat-matrix displays always present their best image when displaying any input signals that precisely match that fixed resolution.

Signals that fall above or below the total pixel count of the display are problematic, as they must be electronically enlarged or reduced in size to fit the available imaging area. This re-sizing trick is not at all easy to pull off, and requires some pretty smart digital signal processing on the part of the manufacturer. There's also the question of aspect ratios to deal with. High-resolution projection systems may have 1280x1024 (5:4) or 1365x1024 (4:3) pixels for SXGA resolution, which results in either a horizontal "squeeze" on incoming signals, or black bars on the top or bottom of an image.

There's also the question of lost image detail. Workstation resolutions such as 1280x1024 and 1600x1200 require a fair amount of compression when moving down to 1024x768 pixels, resulting in character fragments, broken lines, and loss of detail. These are all direct results of the need to compress data to fit the available imaging area; a problem that didn't exist with CRT imaging.

Video scaling presents its own headaches. In addition to the conversion from an interlaced signal in another component format, video images must be enlarged several times to fit 1024x768 and 1280x1024 displays. The usual result is a collection of digitally-created motion and pixel artifacts that will be unsatisfactory to the customer. (Again, no such problem exists with CRT imaging).

As if we didn't have enough headaches already, along come plasma panels with their wide aspect ratios and "out-of-left-field" pixel counts. Not only do we have to deal with video conversion and RGB pixel scaling, we frequently wind up with unused image area when viewing a steady diet of 4:3 and 5:4 images. What customer wants to pay for 100% of a display and use only 70% of it? Not many.

The low price points associated with many desktop and installation projection systems don't allow for more than functional image scaling. The obvious answer is to conduct a thorough test of the scaling performance of the desired projector or monitor, as well as investigate the end-user's screen resolution needs, before making any promises.

The good news is that some manufacturers are on top of the problem. I have found certain projectors that do an excellent job of re-sizing and processing RGB images. (Check out for more detailed information on specific models.)

It's also an excellent idea to add a quality third-party video/RGB scalar or scaling switchers for any flat-matrix installation. These boxes can solve a multitude of problems and provide expansion for future signal format headaches, such as digital television (DTV).

In the case of 16:9 native displays such as plasma panels, the customer should be made fully aware of the format incompatibility with standard computer aspect ratios. At present, there are few video display cards for computers and workstations that support the Wide VGA (852x480 and 853x480) and Wide XGA (1280x768 and 1365x768) plasma formats. (Simply expanding the image digitally to fill the screen is but a short-term solution that introduces image distortion.)

SIGNAL FORMATS AND TIMING

In one sense, the move to flat-matrix imaging couldn't have come at a worse time. That's because our new digital television system is in the larval stage, and manufacturers seem pretty happy at present to go their own way with regards to signal distribution formats and the interpretation of sync signals.

While videophiles are content to stay in a world of composite, component Y/C, and component YUV video, computer display veterans are still juggling component (RGBHV), composite (RGBS), and sync-on-green (RGsB) formats. Now, the digital newcomer will rock the boat even more with yet another component signal format - YPbPr, with tri-level or bi-level sync.

Systems integrators are finding more often than not that customers are at least inquiring about - if not demanding outright - HDTV compatibility in their next project. Some have even gone ahead and purchased set-top boxes (STBs) at consumer electronics retailers to take advantage of low prices, only to discover a format incompatibility problem.

One good example is RCA's DTC-100 HDTV set-top box. From the standpoint of a consumer, it's a dream come true - an all-in-one box that receives and decodes DTV broadcasts off-air, over cable, and off satellite (DirecTV). At a suggested list price of $650, it is the cheapest STB currently offered for sale.

From the standpoint of a systems integrator - particularly those in the home theater business - the DTC-100 is not a dream, but a potential nightmare. RCA has elected to use an output signal format more in line with the computer display world - progressive-scan RGBHV signals with bi-level sync through a 15-pin VGA style connector. The intent is to have customers buy RCA's matching TV sets and simply plug in the cables.

Difficulties arise because many Japanese display manufacturers have decided that 15-pin RGBHV/RGBS connections with bi-level sync are basically a computer signal - not an HDTV decoder. As a result, there is at least one 42" plasma display that will interpret this format incorrectly, resulting in a jumbled picture.

Suffice it to say that third-party interface manufacturers will be busy developing products to transcode both color space and sync formats. In the meantime, it would be prudent to test any set-top boxes and STBs to ensure both signal and cable compatibility. (Of course, CRT imaging systems will readily accept decoded HDTV in just about any format without these "preconceived notions".)

As a rule, you should always check out the horizontal and vertical sync specifications for a given flat-matrix device. A hands-on test is the best way - just because manufacturer's specs say a given projector or monitor can handle horizontal sync up to 85 kHz doesn't mean it will always do so. Restricted bandwidth and clock tracking errors may result in banded images, crushed images, or no image whatsoever.

I have tested front projectors that quickly synced up to any test format I threw at 'em, while others sat there forever with "perfecting image" or "adjusting image" displayed on a blue field. That's not a message your clients will want to see often - if at all.

Once again, third-party manufacturers are coming to the rescue with outboard scalars. These boxes can convert oddball signal formats to one standard resolution, allowing "no glitch" signal switching. More and more clients demand seamless switching between signal format, and could care less about bi-level and tri-level sync, not to mention RGBHV, YPbPr, RGsB, or any other "alphabet soup" lingo.

The addition of dissolves and luminance/chrominance key functions to scaling switchers makes them all the more attractive, and justifies the additional cost in many customer's minds. Multi-purpose rooms that display video and computer images on a regular basis will benefit tremendously from scaling switchers. Add one to the parts list for your next flat-matrix installation project.

LIFE AND DEATH

Some of the more mundane aspects of flat-matrix imaging remain daunting. Now, instead of replacing projection tubes, we are replacing projection lamps. And those lamps may not last as long as the manufacturer claims. When the first metal halide lamps came out in the mid 1990s, it wasn't unusual to hear claims of 2000 to 3000 hours before replacement. We now know that figure is closer to 1000 to 1500 hours.

Ditto the compact high-efficiency lamps (UHP, UHE, etc.). At one time, a certain manufacturer based in Holland made the astounding claim of 8000 hours of bulb-life for a UHP lamp. That claim, of course, turned out to be grossly inflated, and a 2000 to 4000 hour span is considered more reasonable.

Projection lamps give off heat - plenty of it. That means the manufacturer must address the often contrary design requirements of smaller form factors and greater cooling area. Sony has tackled this problem by using cast magnesium housing for many of their projectors (in effect turning the entire projector into a heat sink). Others have employed clever air circulation systems and added more and more fans.

Projectors are dust magnets; plain and true. It's likely that more projector problems will be caused by clogged or dirty air filters than anything else. While sales and marketing literature entice potential customers by claiming virtually unlimited installation capability, the truth is that projectors need lots of cooling airflow. The brighter the image, the more airflow that is needed.

While it's true that an ultraportable projector is bright enough to light up a 100" diagonal screen in a room with high ambient light levels, chances are it will get hotter than a pistol if employed in a rigorous duty cycle. You'd be better off using a larger model projector (it's installed anyway, so size is not as important) that has greater cooling capacity.

If the projector is to be installed in a smoky environment, it will be at greater risk. Many LCD projectors sold into restaurants and bars where smoking is allowed are already showing evidence of "yellowing" from nicotine residue. A sealed airflow system is preferable here.

For environments where the projector isn't readily accessible, choosing a model with excess lumens capacity and running the lamp at reduced voltage will boost lamp life considerably without compromising image brightness. A 90-pound box rated at 4000 lumens may make a better choice than a 14-pound box rated at 2000 lumens for this reason, particularly in 24/7 operation.

BURN, BABY, BURN

Early adopters of plasma display technology have gotten some rude shocks in recent years. Not only is there the issue of video image quality (a major problem that is being overcome slowly with scalars), but the life of the phosphors turned out to be on the short side. As a result, image burn-in and pixel failures were common.

The problem lies in the voltages used to switch plasma pixels on and off. Older models required several hundred volts to create the initial cell charge, using much lower voltages to sustain charges. Newer models can initiate the charge-discharge cycle with lower voltages. But individual pixels are being driven harder in some models to increase brightness.

I tested 6 current models last summer, and all but two suffered from image burn-in after less than 60 seconds. Bright images such as desktop computer displays (Windows^®) are particular troublemakers, leaving a ghost image that may take several minutes to fade away completely. The problem is aggravated as manufacturers drive pixels harder to boost image brightness, and is a difficulty familiar to users of CRT monitors and projectors.

The answer is intelligent control of ambient room lighting and driving the panels at sustainable levels. "Orbiting" circuits - used to preserve CRT displays - are smart choices here. A few manufacturers are addressing burn-in with reversing cell charge circuits, and at least one is including an "orbiter" function .

The jury is still out on the use of plasma displays for 24/7 operation with static graphics - existing public display installations haven't yet logged enough hours for us to draw specific conclusions about brightness levels and phosphor life. If you are uncertain which way to go, rear-projection systems using LCD or DLP light engines are safer choices as the only likely failure (the lamp) won't be a catastrophic one.

CABLING

The last potential trouble area is in the area of cabling and connectors. Once again, the connector complement on many projectors and monitors is largely dictated by the blurring of "consumer" and "professional" among the Asian manufacturers. BNC jacks have all but disappeared from the majority of desktop projection systems, although they are still offered on installation-grade projectors.

Plasma manufacturers are wishy-washy about connectors. Panasonic and Toshiba have deserted BNCs in favor of 15-pin VGA HD jacks for RGB interfacing, and use the lowly RCA jack for connecting video and HDTV. Pioneer goes 50-50 with both BNCs and RCA jacks, while only Sony provides a full complement of BNCs and 15-pin jacks for systems integration.

NEC's newest 42" and 50" plasma displays offer both 5xBNC and 15-pin HD inputs, a departure from last year's models which were strictly all RCA jacks. BNCs (and any other "secure" connection, like screw-in 15-pin plugs) are preferred for installations where accessibility is restricted or the installation environment is rigorous. RCA jacks and plugs can fail simply because of dirt buildup, corrosion, or mechanical vibration.

The question of compatibility will become moot in the near future as more manufacturers migrate to digital inputs such as PanelLink and IEEE-1394. Video connections will move to single-wire BNC ports as serial digital video interfaces are increasingly supported. Both digital connector formats offer greater reliability when compared to RCA plugs, DIN plugs (another cheap and fragile connector) and 15-pin VGA HD plugs.

THERE'S ALWAYS A CATCH

Keep in mind that flat-matrix imaging is still in the "baby steps" stage. Many problems such as scaling, false contouring on plasma panels, and phosphor burn-in are being addressed with vigor. It is certain that with the continual drop in prices of microelectronics and increased density of semiconductors, high-quality image scaling will eventually reach a point where it will add little to the cost of a projector or monitor.

Screen resolutions will continue to go up. Reflective LCD panels with 2048 x 1536 resolution will be introduced by at least one manufacturer this year, and transmissive 1600x1200 panels will probably follow next year. DMD chips are already at 1280x1024 and 1600x1200 is the next likely step for them. Scaling will become less of a problem as virtually all signal formats will be upconverted; not downconverted.

Plasma panels won't change much in resolution, but their video scaling and sampling circuits will see great improvements. The familiar "moss" effect seen from dynamic false contouring will eventually be eliminated with pixel redesign and addressing. Concurrent with these developments will be a drop in the price of plasma glass, making them more competitive with CRTs. Burn-in will still be a problem for some time to come.

Large LCD monitors are also challenging the primacy of CRTs in a battle they are expected to eventually win. The same scaling tricks will be applied to these 25" to 30" flat panels, which are already displacing CRT monitors in many applications. LCD panels are already available with resolutions as high as 1600x1200, and that number will increase. Best of all, LCD panels don't suffer from image burn-in.

Let's face it: Flat-matrix displays are here to stay, and are forcing changes in systems integration business models due to their lower prices and simpler installation and operation requirements. Your customers will be asking for them in increasing numbers. The trick for you will be to make these displays interface smoothly and look their best!

Copyright ©2000 Peter H. Putman/Primedia Intertec.

This article originally appeared in the May 2000 issue of Sound & Video Contractor.


						ARTICLE
					FLAT SCREEN DISPLAYS: The Holy Grail, or Pandora's Box


					by Peter H. Putman, CTS By now, it should be pretty obvious to readers of S&VC that flat-matrix imaging technologies (LCDs, DLP, Plasma, etc.) are approaching "king of the hill" status when it comes to the design, specification, and installation of electronic displays. The projector market in particular has been turned upside-down by a flood of high-brightness, lightweight products. There is no reason to assume the same thing won't happen to the video and presentation monitor markets. Considering what these products are replacing, we're reaping plenty of benefits. Gone are the need for heavy-duty installation brackets. Gone too, is the need for converging 3-tube front projection systems. High-gain front projection screens - and their associated hot-spot problems and narrow viewing angles - are also headed for the endangered species list. Plasma and LCD monitors bring similar advantages. Now, we can mount direct-view monitors anywhere our heart desires. We can even use low-profile recessed mounts. Heavy-duty carts? Forget about them. High ambient light levels? Not a problem. It would appear that there is no downside to switching from tube to matrix imaging. Yet; as many dealers and systems integrators are finding out, flat-matrix displays bring along their own problems - many of which aren't all that easy to solve. That's not to say you should stay away from flat-matrix imaging. Far from it! What you should do is learn as much as you can about the characteristics of flat-matrix imaging, and how different video and computer signals are processed by liquid-crystal displays, digital micromirror devices, and gas plasma panels. BY THE NUMBERS The largest limiting factor to flat-matrix displays is their fixed image resolution. By that, I mean the structures of pixels that constitute the active imaging area. When we buy a display using picture tubes or projection tubes, we have a vague idea of its resolution capability. Until that tube is turned on, though; it has no resolution whatsoever and waits obediently to trace the desired horizontal and vertical dimensions for us. Flat-matrix displays, on the other hand, have a specific, quantified resolution whether they are sitting in a box in a dealer's stockroom, or hanging from the ceiling in a conference room. As a result, flat-matrix displays always present their best image when displaying any input signals that precisely match that fixed resolution. Signals that fall above or below the total pixel count of the display are problematic, as they must be electronically enlarged or reduced in size to fit the available imaging area. This re-sizing trick is not at all easy to pull off, and requires some pretty smart digital signal processing on the part of the manufacturer. There's also the question of aspect ratios to deal with. High-resolution projection systems may have 1280x1024 (5:4) or 1365x1024 (4:3) pixels for SXGA resolution, which results in either a horizontal "squeeze" on incoming signals, or black bars on the top or bottom of an image. There's also the question of lost image detail. Workstation resolutions such as 1280x1024 and 1600x1200 require a fair amount of compression when moving down to 1024x768 pixels, resulting in character fragments, broken lines, and loss of detail. These are all direct results of the need to compress data to fit the available imaging area; a problem that didn't exist with CRT imaging. Video scaling presents its own headaches. In addition to the conversion from an interlaced signal in another component format, video images must be enlarged several times to fit 1024x768 and 1280x1024 displays. The usual result is a collection of digitally-created motion and pixel artifacts that will be unsatisfactory to the customer. (Again, no such problem exists with CRT imaging). As if we didn't have enough headaches already, along come plasma panels with their wide aspect ratios and "out-of-left-field" pixel counts. Not only do we have to deal with video conversion and RGB pixel scaling, we frequently wind up with unused image area when viewing a steady diet of 4:3 and 5:4 images. What customer wants to pay for 100% of a display and use only 70% of it? Not many. The low price points associated with many desktop and installation projection systems don't allow for more than functional image scaling. The obvious answer is to conduct a thorough test of the scaling performance of the desired projector or monitor, as well as investigate the end-user's screen resolution needs, before making any promises. The good news is that some manufacturers are on top of the problem. I have found certain projectors that do an excellent job of re-sizing and processing RGB images. (Check out for more detailed information on specific models.) It's also an excellent idea to add a quality third-party video/RGB scalar or scaling switchers for any flat-matrix installation. These boxes can solve a multitude of problems and provide expansion for future signal format headaches, such as digital television (DTV). In the case of 16:9 native displays such as plasma panels, the customer should be made fully aware of the format incompatibility with standard computer aspect ratios. At present, there are few video display cards for computers and workstations that support the Wide VGA (852x480 and 853x480) and Wide XGA (1280x768 and 1365x768) plasma formats. (Simply expanding the image digitally to fill the screen is but a short-term solution that introduces image distortion.) SIGNAL FORMATS AND TIMING In one sense, the move to flat-matrix imaging couldn't have come at a worse time. That's because our new digital television system is in the larval stage, and manufacturers seem pretty happy at present to go their own way with regards to signal distribution formats and the interpretation of sync signals. While videophiles are content to stay in a world of composite, component Y/C, and component YUV video, computer display veterans are still juggling component (RGBHV), composite (RGBS), and sync-on-green (RGsB) formats. Now, the digital newcomer will rock the boat even more with yet another component signal format - YPbPr, with tri-level or bi-level sync. Systems integrators are finding more often than not that customers are at least inquiring about - if not demanding outright - HDTV compatibility in their next project. Some have even gone ahead and purchased set-top boxes (STBs) at consumer electronics retailers to take advantage of low prices, only to discover a format incompatibility problem. One good example is RCA's DTC-100 HDTV set-top box. From the standpoint of a consumer, it's a dream come true - an all-in-one box that receives and decodes DTV broadcasts off-air, over cable, and off satellite (DirecTV). At a suggested list price of $650, it is the cheapest STB currently offered for sale. From the standpoint of a systems integrator - particularly those in the home theater business - the DTC-100 is not a dream, but a potential nightmare. RCA has elected to use an output signal format more in line with the computer display world - progressive-scan RGBHV signals with bi-level sync through a 15-pin VGA style connector. The intent is to have customers buy RCA's matching TV sets and simply plug in the cables. Difficulties arise because many Japanese display manufacturers have decided that 15-pin RGBHV/RGBS connections with bi-level sync are basically a computer signal - not an HDTV decoder. As a result, there is at least one 42" plasma display that will interpret this format incorrectly, resulting in a jumbled picture. Suffice it to say that third-party interface manufacturers will be busy developing products to transcode both color space and sync formats. In the meantime, it would be prudent to test any set-top boxes and STBs to ensure both signal and cable compatibility. (Of course, CRT imaging systems will readily accept decoded HDTV in just about any format without these "preconceived notions".) As a rule, you should always check out the horizontal and vertical sync specifications for a given flat-matrix device. A hands-on test is the best way - just because manufacturer's specs say a given projector or monitor can handle horizontal sync up to 85 kHz doesn't mean it will always do so. Restricted bandwidth and clock tracking errors may result in banded images, crushed images, or no image whatsoever. I have tested front projectors that quickly synced up to any test format I threw at 'em, while others sat there forever with "perfecting image" or "adjusting image" displayed on a blue field. That's not a message your clients will want to see often - if at all. Once again, third-party manufacturers are coming to the rescue with outboard scalars. These boxes can convert oddball signal formats to one standard resolution, allowing "no glitch" signal switching. More and more clients demand seamless switching between signal format, and could care less about bi-level and tri-level sync, not to mention RGBHV, YPbPr, RGsB, or any other "alphabet soup" lingo. The addition of dissolves and luminance/chrominance key functions to scaling switchers makes them all the more attractive, and justifies the additional cost in many customer's minds. Multi-purpose rooms that display video and computer images on a regular basis will benefit tremendously from scaling switchers. Add one to the parts list for your next flat-matrix installation project. LIFE AND DEATH Some of the more mundane aspects of flat-matrix imaging remain daunting. Now, instead of replacing projection tubes, we are replacing projection lamps. And those lamps may not last as long as the manufacturer claims. When the first metal halide lamps came out in the mid 1990s, it wasn't unusual to hear claims of 2000 to 3000 hours before replacement. We now know that figure is closer to 1000 to 1500 hours. Ditto the compact high-efficiency lamps (UHP, UHE, etc.). At one time, a certain manufacturer based in Holland made the astounding claim of 8000 hours of bulb-life for a UHP lamp. That claim, of course, turned out to be grossly inflated, and a 2000 to 4000 hour span is considered more reasonable. Projection lamps give off heat - plenty of it. That means the manufacturer must address the often contrary design requirements of smaller form factors and greater cooling area. Sony has tackled this problem by using cast magnesium housing for many of their projectors (in effect turning the entire projector into a heat sink). Others have employed clever air circulation systems and added more and more fans. Projectors are dust magnets; plain and true. It's likely that more projector problems will be caused by clogged or dirty air filters than anything else. While sales and marketing literature entice potential customers by claiming virtually unlimited installation capability, the truth is that projectors need lots of cooling airflow. The brighter the image, the more airflow that is needed. While it's true that an ultraportable projector is bright enough to light up a 100" diagonal screen in a room with high ambient light levels, chances are it will get hotter than a pistol if employed in a rigorous duty cycle. You'd be better off using a larger model projector (it's installed anyway, so size is not as important) that has greater cooling capacity. If the projector is to be installed in a smoky environment, it will be at greater risk. Many LCD projectors sold into restaurants and bars where smoking is allowed are already showing evidence of "yellowing" from nicotine residue. A sealed airflow system is preferable here. For environments where the projector isn't readily accessible, choosing a model with excess lumens capacity and running the lamp at reduced voltage will boost lamp life considerably without compromising image brightness. A 90-pound box rated at 4000 lumens may make a better choice than a 14-pound box rated at 2000 lumens for this reason, particularly in 24/7 operation. BURN, BABY, BURN Early adopters of plasma display technology have gotten some rude shocks in recent years. Not only is there the issue of video image quality (a major problem that is being overcome slowly with scalars), but the life of the phosphors turned out to be on the short side. As a result, image burn-in and pixel failures were common. The problem lies in the voltages used to switch plasma pixels on and off. Older models required several hundred volts to create the initial cell charge, using much lower voltages to sustain charges. Newer models can initiate the charge-discharge cycle with lower voltages. But individual pixels are being driven harder in some models to increase brightness. I tested 6 current models last summer, and all but two suffered from image burn-in after less than 60 seconds. Bright images such as desktop computer displays (Windows^®) are particular troublemakers, leaving a ghost image that may take several minutes to fade away completely. The problem is aggravated as manufacturers drive pixels harder to boost image brightness, and is a difficulty familiar to users of CRT monitors and projectors. The answer is intelligent control of ambient room lighting and driving the panels at sustainable levels. "Orbiting" circuits - used to preserve CRT displays - are smart choices here. A few manufacturers are addressing burn-in with reversing cell charge circuits, and at least one is including an "orbiter" function . The jury is still out on the use of plasma displays for 24/7 operation with static graphics - existing public display installations haven't yet logged enough hours for us to draw specific conclusions about brightness levels and phosphor life. If you are uncertain which way to go, rear-projection systems using LCD or DLP light engines are safer choices as the only likely failure (the lamp) won't be a catastrophic one. CABLING The last potential trouble area is in the area of cabling and connectors. Once again, the connector complement on many projectors and monitors is largely dictated by the blurring of "consumer" and "professional" among the Asian manufacturers. BNC jacks have all but disappeared from the majority of desktop projection systems, although they are still offered on installation-grade projectors. Plasma manufacturers are wishy-washy about connectors. Panasonic and Toshiba have deserted BNCs in favor of 15-pin VGA HD jacks for RGB interfacing, and use the lowly RCA jack for connecting video and HDTV. Pioneer goes 50-50 with both BNCs and RCA jacks, while only Sony provides a full complement of BNCs and 15-pin jacks for systems integration. NEC's newest 42" and 50" plasma displays offer both 5xBNC and 15-pin HD inputs, a departure from last year's models which were strictly all RCA jacks. BNCs (and any other "secure" connection, like screw-in 15-pin plugs) are preferred for installations where accessibility is restricted or the installation environment is rigorous. RCA jacks and plugs can fail simply because of dirt buildup, corrosion, or mechanical vibration. The question of compatibility will become moot in the near future as more manufacturers migrate to digital inputs such as PanelLink and IEEE-1394. Video connections will move to single-wire BNC ports as serial digital video interfaces are increasingly supported. Both digital connector formats offer greater reliability when compared to RCA plugs, DIN plugs (another cheap and fragile connector) and 15-pin VGA HD plugs. THERE'S ALWAYS A CATCH Keep in mind that flat-matrix imaging is still in the "baby steps" stage. Many problems such as scaling, false contouring on plasma panels, and phosphor burn-in are being addressed with vigor. It is certain that with the continual drop in prices of microelectronics and increased density of semiconductors, high-quality image scaling will eventually reach a point where it will add little to the cost of a projector or monitor. Screen resolutions will continue to go up. Reflective LCD panels with 2048 x 1536 resolution will be introduced by at least one manufacturer this year, and transmissive 1600x1200 panels will probably follow next year. DMD chips are already at 1280x1024 and 1600x1200 is the next likely step for them. Scaling will become less of a problem as virtually all signal formats will be upconverted; not downconverted. Plasma panels won't change much in resolution, but their video scaling and sampling circuits will see great improvements. The familiar "moss" effect seen from dynamic false contouring will eventually be eliminated with pixel redesign and addressing. Concurrent with these developments will be a drop in the price of plasma glass, making them more competitive with CRTs. Burn-in will still be a problem for some time to come. Large LCD monitors are also challenging the primacy of CRTs in a battle they are expected to eventually win. The same scaling tricks will be applied to these 25" to 30" flat panels, which are already displacing CRT monitors in many applications. LCD panels are already available with resolutions as high as 1600x1200, and that number will increase. Best of all, LCD panels don't suffer from image burn-in. Let's face it: Flat-matrix displays are here to stay, and are forcing changes in systems integration business models due to their lower prices and simpler installation and operation requirements. Your customers will be asking for them in increasing numbers. The trick for you will be to make these displays interface smoothly and look their best! Copyright ©2000 Peter H. Putman/Primedia Intertec. This article originally appeared in the May 2000 issue of Sound & Video Contractor.