Philips 42PF9831D LCD HDTV

Can hot cathodes increase your viewing pleasure?

The battle of flat-screen technology is heating up, and LCD makers are fighting each other for technological superiority. As we reach the end of 2006, the production of 40-to-42-inch LCDs has grown, while pricing has reached parity with plasma displays in this size range. The list of competitive makers of LCDs in this size is exploding, creating a race to innovate. Enter Philips' latest flat panel, the 42PF9831D. This top-of-the-line LCD has a number of industry firsts, including Philips' own Aptura backlight. Aptura is designed to sharpen fast-moving images, solving one of LCD's common shortcomings. The 42PF9831D is a 1,366-by-768 high-definition display with Ambilight Full Surround technology, Philips' exclusive four-sided screen lighting system (more on this later). It also features Clear LCD signal processing—which works with the Aptura backlight for faster response time—CableCARD, a memory-card reader, and Pixel Plus 3 upconversion.


The 42PF9831D's biggest innovation is Aptura. The backlight is located in the back of the LCD panel and creates panel illumination. Nearly all LCD panels use many thin lamps called cold cathode fluorescents (CCF). The new Philips Aptura lighting technology, on the other hand, is a hot cathode fluorescent (HCF). In fact, it represents the first use of this technology in LCD panels. According to Philips, the use of HCF sharpens fast-moving images by reducing the hold time. Instead of illuminating the frame for its full duration, the screen is darkened for a portion of each frame. The output of each HCF bulb is three times that of a CCF bulb, while its duty cycle is about one-quarter. The overall result is darker blacks at about the same light output. Combined with the HCF is Philips' Clear LCD drive-overdrive technology, which is designed to coax the crystals to move faster. The overall result is a rated response time of just 4 milliseconds, which is fast enough to reduce or eliminate motion lag, one of LCD's bugaboos. (Most LCD HDTVs are rated between 6 and 12 ms.) I take a closer look at motion in the Performance section ahead.

As I unpacked the 42PF9831D, I was immediately struck by its appearance, which is unlike that of any other flat-panel display. A shiny, all-black bezel flanks the dark-tinted, antireflective screen, and a white frame extends about 3.5 inches past the bezel. The frame provides a white surface to reflect the Ambilight Full Surround screen lighting. Underneath each of the four sides of the black bezel lie red, green, and blue fluorescent lamps. Similar in concept to sound-activated disco lamps that change color and intensity with the frequency and beat of the music, the Ambilight changes color and intensity by analyzing the picture content. For example, if the scene is a blue sky with white sand, the lamps will display blue on the top and sides of the screen and white along the bottom. Additional Ambilight controls increase peak brightness, tint, and rate of change. According to a Philips spokesperson, consumers overwhelmingly prefer the enhancement that Ambilight provides. That may be, but, to me, it felt like there was a disco light connected to the TV. It was, in a word, irritating. There is an Ambilight control setting called Color, which allows the user to lower the light's intensity, change the lamp's tint, and maintain a constant illumination level with a near-neutral color (6,500 K). The latter was the most preferable position. With the room lights off, though, the Ambilight's brightness was still too high for my taste (even in the lowest "0" setting), so I chose the Off setting.

Next, I adjusted the set's user controls and connected a number of sources. The 42PF9831D has two HDMI inputs and two HD component inputs, along with a couple of S-video and composite video inputs. One of the component inputs also serves as an RGBHV PC input. There is a CableCARD slot, so you can view standard and premium cable content without a high-definition cable box. I checked out CableCARD service using Verizon FiOS fiberoptic service, which is new to my area (Nassau County, New York). After I slid the CableCARD into the slot and activated it via a call to Verizon headquarters, the card worked flawlessly. I could tune in all of the channels using direct access via Philips' remote control. The remote is slender but unremarkable, with no direct input buttons and no backlight. Its black-on-black color scheme made me wonder if anyone at Philips considered how difficult it is to identify the buttons in the dark.

Let's begin with signal processing. Standard-definition channels fall around the middle of the pack in terms of the quality of upconversion. It is better than many sets I have sampled but not as clean as some others. In other words, it is acceptable but not outstanding for an HDTV. On the other hand, the TV has a number of issues with HD programs. First is the downconversion of 1080i to the set's native 1,366-by-768 resolution. Silicon Optix's latest HD DVD test disc confirmed that the 42PF9831D does not properly deinterlace 1080i material. Instead of internally converting to 1,920 by 1080p in the set's internal scaler, it processes each field of 1,920 by 540 prior to conversion to 768p, which results in a loss of detail. The Philips will not accept 1080p/60 signals from the Samsung Blu-ray player or any other source. Furthermore, the set will only process single fields using the 3:2 cadence test. It also did a poor job of reducing jaggies in the diagonal-line test.

1206philips.6.jpgNext came the bandwidth test. With the 720p multiburst pattern from a Sencore signal generator, single, alternating black and white vertical lines should appear. In this case, they did not; they were obscured by an apparent lack of bandwidth in the TV. This loss of fine detail was obvious with real program material during the New Orleans Saints' home-season opener on the ESPN HD Monday-night broadcast.

Archie Manning, father of Eli and Peyton (and former Saints quarterback), was being interviewed wearing a light-blue dress shirt with fine dark vertical stripes. With a tight shot, the stripes on the shirt—each several pixels wide—were clearly visible. As the camera zoomed out, the stripes became smaller and smaller, until—poof—they disappeared. The Philips could not resolve the stripes as they dipped below two pixels in width. A shirt changing from striped to solid is not a good thing, and this problem is not limited to the Philips. I have noticed a number of other 2006-model HDTVs that limit fine detail. (See my Hook Me Up column in the November issue for more on this subject.)

The Clear LCD and Aptura backlight did deliver, with very bright images and no distracting motion blur on any of the material I viewed. This is the first LCD I've seen that doesn't exhibit the motion-lag artifact. The black level wasn't as deep as it can be with better plasmas, but it appeared darker than a number of competing LCDs. The level was acceptable with the room lights on but was a tad too high with the lights off. Fortunately, if you switch on the Ambilight, the condition will be less noticeable. Dark detail was also better than with many other LCDs, although I noticed that the Philips buried some of the darkest content near the black level.

On the other hand, there are a number of other items that I found to be less than desirable. Yellow had a distinct green component that was noticeable in SMPTE color bars; it was enough to skew Homer Simpson's skintone to a greenish-yellow pallor. The Philips doesn't have a service adjustment for color matrix to correct this. Also, the 42PF9831D has a 176-degree viewing angle. However, Philips and other LCD manufacturers neglect to mention a drop-off in contrast ratio as you move off axis, either vertically or horizontally, in which blacks appear lighter and whites appear darker. Emissive technology (CRT and plasma) maintains contrast and brightness far better than any LCD, although some LCDs do a better job with off-axis viewing than this one does.

Philips succeeds in their goal of fast response, as the 42PF9831D is currently the largest LCD on the market without motion lag. Despite its shortcomings—some of which are inherent to LCD technology—it's an ideal choice for someone who wants a flat panel to view sports and other fast motion in a very bright environment, such as a room with large curtainless windows or a skylight. In homes with controlled lighting conditions, I believe one of the top-rated plasmas would provide a more pleasing viewing experience.

• At last, a 42-inch LCD without motion lag
• Better black levels than competing LCD HDTVs
• Accepts CableCARD for HDTV without a cable box

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