PCTech Magazine: DLP Projectors

PCTech Magazine: DLP Projectors: "SONY VPLDX15 This powerful mobile business projector is ideal for mid-sized conference rooms and classrooms. It features native XGA resolu..."

DLP Projectors

SONY VPLDX15

   This powerful mobile business projector is ideal for mid-sized conference rooms and classrooms. It features native XGA resolution, 3000 lumens color light output and accepts a wide range of input signals, including both PC and video sources. The VPL-DX15 is a Windows® Vista compatible Network Presentation Projector featuring network file viewing; remote monitoring and maintenance; streaming video viewing; and “Remote Desktop,” which allows the user to view files and folders from their PC and access web browsers without needing proprietary software – all without bringing their PC along.

Highlights:

• XGA Native Resolution
• 3000 Lumens Brightness
• Compact, lightweight & portable
• Windows Vista compatible Network Presentation Projector
• USB File Viewer
• Off & Go Technology
• Anti-Theft Features: Password Authentication, Control Panel Key Lock, Security Lock
• Direct Power On/Off

• Floor, Ceiling and Rear Installation Flexibility
• 4x Digital Zoom
• Freeze Function
• Picture and Audio Muting
• 12-bit 3D Gamma Correction
• ID Function for Multi-Projector Installation
• The lamp in this product contains mercury. Disposal of these materials may be regulated due to environmental considerations. For disposal or recycling information, please contact your local authorities or the Telecommunications Industry Association Electronic Industries Alliance.

 

Optical Specifications	Detail:
Projection System	3 LCD Panels 1 lens projection system
Image Device	0.63 inch XGA LCD panel
Color Light Output	3000 lumens
Color Light Output (low lamp mode)	2400 lumens
Light Output	3000 lumens (lamp mode high) 2400 lumens (lamp mode low)
Contrast Ratio	700:1
Lamp	200W UHP
Lamp Life	approx. 2000H (lamp mode high), approx. 3000H (lamp mode low)
Projection Lens	1.2 times zoom lens f18.63 to 22.36 mm F1.65 to 1.8
Throw Ratio	1.5-1.8:1
Screen Coverage	40 to 300 inches (viewable area measured diagonally)

Input/Output Specifications	Detail:
S-Video In	Y/C Mini DIN 4-pin
Composite Video In	RCA phono jack
Analog RGB/Component In	HD D-sub 15-pin (female) x 1
Network	Wired: RJ45 Wireless: IEEE.802.11.a/b/g
Variable Audio Out	Stereo mini jack
USB	Type A

Electrical Specifications	Detail:
Native Resolution	XGA: 1024 x 768 Pixels
Video Resolution	750 TV lines
Color System	NTSC3.58 PAL SECAM NTSC4.43 PAL-M PAL-N PAL60
Acceptable Computer Signals	fH: 19 to 80 kHz fV: 48 to 92 Hz Up to SXGA+ (fv 60 Hz)
Acceptable Video Signals	15k RGB, Component 50/60 Hz Component 50/60 Hz Progressive Component 50/60 Hz DTV (480/60i / 575/50i / 480/60p / 575/50p / 720/60p / 720/50p / 1080/60i / 1080/50i) Composite Video Y/C Video

General Specifications	Detail:
Dimensions (W x H x D)	11 5/8 x 2 29/32 x 8 1/32 inches (295 x 74 x 204 mm)
Weight	4.14 lbs 2.2 kg
Power Requirements	AC 100 to 240 V 3.6 - 1.6 A 50/60 Hz
Power Consumption	Max 320 W Standby 5.5 W Standby (low) <1.0 W
Speaker	Mono 1 W (max.) x1
Fan Noise	37dB (lamp mode low), 42 dB (lamp mode high)
Vertical Keystone Correction Range	Max. +/- 30 degrees (auto)
Horizontal Keystone Correction Range	N/A
Operating Temperature	32 to 95 °F (0 to 35 °C)
Operating Humidity	35 to 85% (no condensation)
Heat Dissipation	990 BTU
Storage Temperature	-4 to 140 °F (-20 to 60 °C)
Storage Humidity	10% to 90%

Other Specifications	Detail:
Safety Regulations	CB (IEC60950-1) DEMKO (EN60950-1) FCC Class B IC Class B JEITA UL60950-1 cUL (CSA 60950-1) VCCI eK (K60950-1 +EMC) C-Tick (EN55022(B)) CE (LVD, EMC, R & TEE) MIC JATE

Acer® P7290

The Acer® P7290 projector is equipped with leading technologies for high-impact, professional business presentations. This DLP® certified projector provides bright, lifelike visuals and guarantees big power savings, thanks to Acer ePower Management technology.

 

 




Exceptional display
Advanced Acer ColorBoost II presents vivid graphics and enhanced details via powerful image processing and advanced lamp illumination technology. XGA resolution depicts sharp details even for fine print and allows you to select the level of display detail required for your particular usage scenario. 5000 ANSI lumens brightness and a 3000:1 contrast ratio project crystal clear, vibrant images from a long distance on a large screen.


Versatile installation
The Empowering Key provides easy access to the useful suite of Acer Empowering Technology tools. Acer SmartFormat technology offers complete multiformat support for instant projection of wide-format content without complicated resolution settings. And the convenient Installation Menu means you no longer need signal input before setting up, making it easier to install your projector.

 

Empowering usability
An HDMI™ port delivers uncompressed digital signals and multi-channel audio for exceptional HD viewing and the highest-quality video and audio currently available. Furthermore, a fully digital DVI-D port supports HD digital and analog signals as well as HDCP for a secure connection to a variety of media sources, while S/PDIF allows connectivity of a 5.1-channel sound system for an immersive sound experience. The Acer® P7290 projector is also equipped with two sets of D-Sub and audio connectors, allowing dual-PC source input for more flexible connectivity and instant switching.


Earth-friendly functionality
Acer EcoProjection technology cuts standby power consumption to a single watt for environment-friendly energy management. Up to 3000 hours of lamp life saves lamp replacement costs and ensures long-term, dependable projector use. ECO Mode extends lamp lifespan and reduces noise and power consumption. The low 29 dBA noise level ensures clear and audible presentations. With Acer Instant Pack technology, you can safely unplug the power cord right after the Acer® P7290 is turned off -- you don't have to wait till it cools down, so you can pack up and go immediately! The Acer® P7290 automatically performs a safety shutdown if there is no input for an extended period of time. 

Display Technology	DLP™, Digital light processor
Native Resolution	Native XGA (1,024 x 768)
Compressed Resolution	Maximum UXGA (1,600 x 1,200), WSXGA+ (1,680x1,050)
Typical Colors	1.07 Billion Colors
Brightness (ANSI lumens)	5,000 ANSI Lumens (Standard), 4,000 ANSI Lumens (ECO)
Contrast Ratio	3000:1
Noise Level	35 dBA (Standard mode), 29 dBA (ECO mode)- w/o dust filter
Weight	5.4Kg (12 lbs)
Dimensions	404 x 315 x 120 mm (15.9" x 12.4" x 4.7")
Computer Compatibility	IBM PC and Compatibles, Apple Macintosh, iMac, and VESA Standards WSXGA+ (1,680 x 1,050), WXGA+ (1,440 x 900), WXGA (1,280 x 800, 1,280 x 768), UXGA (1,600 x 1,200), SXGA+ (1,400 x 1,050), SXGA (1,280 x 1,024), XGA (1,024 x 768), SVGA (800 x 600), VGA (640 x 480)
Video Compatibility	NTSC (3.58/4.43), PAL (B/D/G/H/I/M/N), SECAM (B/D/G/K/K1/L), HDTV (720p, 1080i, 1080p), EDTV (480p, 576p), SDTV (480i, 576i)
Aspect Ratio	4:3 (Native), 16:9
Picture in Picture (PiP)	Yes
Digital Zoom	8x
Horizontal Scan Rate:	27 ~ 92 kHz
Vertical Scan Rate	50 ~ 85 Hz
Projection Distance	3.9' (1.2m) ~ 31.4' (9.6m)
Projection Screen Size (Diagonal):	31" (79cm) ~ 300" (762cm)
Keystone Correction	+/-40 Degrees (Vertical), +/-15 Degrees (Horizontal), Manual
Audio	Two Internal Speaker with 3 watts Output
Lamp Life	2,000 Hours (Standard), 3,000 Hours (ECO)
Lamp Type	Philips 350 W user replaceable P-VIP lamp
Power Consumption	460 Watts (Operation), 1 Watts (Standby)
I/O connectors	Analog RGB/Component Video (D-sub) x 2, Composite Video (RCA) x 1, S-Video (Mini DIN) x1, Component (3 RCA) x 1, HDMI (Video, Audio, HDCP) x 1, DVI (HDCP) x 1, PC Audio (Stereo mini jack) x 2, Output interface: Analog RGB (D-sub) x 1, SPDIF Audio (RCA) x 1, Control interface: USB (Type B) x 1 RS232 (Mini DIN) x 1 Wired remote control port (Mini jack) x 1
Bundled Accesories	AC power cord, VGA cable, Composite video cable, DVI cable, S-Video cable, Component cable, Remote control, Battery x 2 for remote control, Detachable cable holder, Duster filter x 2, Lens cap, Carrying case, User's guide (CD-ROM), Quick start guide, Security card
Ceiling Mounting Capability	Yes
Warranty	All of Acer projectors support a two year carry-in warranty and 90 days for the lamp.

Dell 2400MP DLP Portable Video Projector

Overview

The Dell 2400MP projector incorporates the latest generation of DLP technology with LVDS data transmission technology which increases the switching speed of the DLP chip for enhanced video performance. The 2400MP combines super high brightness, DarkChip3^TM and BrilliantColor^TM the latest in color reproduction technology from Texas Instruments to deliver the ultimate in projector performance.

Features

• Bright 3,000 ANSI Lumens (Max)
• Excellent high contrast ratio of 2100:1 (Full on/Full off)
• 5.5 lbs. (2.5kg) and only 4" (101mm) high
• Integrated zoom lenses and automatic vertical keystone correction
• DLPTM  LVDS technology from Texas Instruments
• Native XGA (1024 x 768), with autosync up to UXGA (1600 x 1200)
• Eco-mode option for quiet operation and extended lamp life2(up to 2500 hours)
• Full connectivity — Supports PC, S-video, composite video, component video via VGA and RS-232 connectors
• Supports full range of television and video standards, including NTSC, NTSC 4.43, PAL, PAL-N, PAL M, SECAM and HDTV (480i/P, 576i/P, 720P, 1080i)
• Up to 5-years limited warranty3 with Advanced Exchange5 Service (90 days on bulb)
• Includes all relevant cables, a remote and a drop-tested hard carrying case.

Specifications

Brightness	3000 ANSI Lumens (Max)
Light Valve	Single chip DLPTM LVDS technology
Contrast Ratio	2100:1 (Full on/Full off)
Lamp	260-watt, user-replaceable P-VIP lamp; 2000 hours (2500 hours in Eco-mode)
Resolution	Native XGA (1024 x 768), with autosync up to UXGA (1600 x 1200)
Displayable Color	16.7 Million true colors
Projection Lens	F/ 2.4 ~ 2.7, f = 28.0 ~ 33.6 mm with 1.2x Manual Zoom Lens
Projection Screen Size	Adjustable from 24.6" to 295.3" Diagonal (62.5 - 750cm)
Projection Distance	3.9ft - 39.4ft (1.2m - 12m)
Video Compatibility	NTSC, NTSC 4.43, PAL (B/D/G/H/I/M/N), SECAM (B/D/G/K/K1/L) and HDTV (480i/P, 576i/P, 720P, 1080i) compatible
H. Frequency	15kHz-92kHz horizontal scan
V. Frequency	50Hz-85Hz vertical refresh
Keystone Correction	Vertical: Horizontal: +/- 40 degree (80 degrees) Vertical: +/- 15 degree (30 degrees)
Multimedia Audio	One internal speaker with 2 watt output
Power Supply	Universal 100-240V AC 50/60 Hz
Power Consumption	325W at full power (285W at Eco-Mode)
Noise Output	36 dBA (normal operation); 33dBA (eco-mode)
I/O Connectors	Power: AC power input socket Computer Input: One VGA 15 pin D-sub Computer Output: One VGA 15-pin D-sub Video Input: One Composite Video RCA, one RGB/component and one S-Video USB: One USB port
Weight	5.5 lbs (2.5 kg)
Dimensions (W x H x D)	10.8" x 8.3" x 4" (273.7 x 212 x 101mm)
Environmental	Operating Temperature: 5o C - 35o C (41o F-95o F) Storage Temperature: -20o C to 60o C (-4o F to 140o F) Humidity: 80% maximum

 INFOCUS IN1100

The InFocus IN1100 projector series is designed for teams that want it all - mobility, performance, and ease-of-use. With DisplayLink™ USB connectivity the IN1100 series takes seconds to set up & project and uses a much smaller cable. Utilizing filter-free DLP® with BrilliantColor™ technology, the IN1100 brings superior visual performance to any meeting space.

Ease-of-use At a mere 2.75lb and 2400cc, the lightweight & compact nature of the IN1100-series makes it easy to move between floors and easy to travel with. With a much smaller footprint than a piece of notebook paper, every tabletop has room for this projector.

Performance The IN1100-series provides vivid colors and ample brightness. DLP® with BrilliantColor™ technology offers true-to-life color reproduction with up to 2200 lumens and an 1800:1 contrast ratio; a trifecta other mobile products cannot match. Leveraging high speed processing the IN1100 series accepts WUXGA & 1080p high resolution content. Additionally, the IN1100-series offers XGA and WXGA native resolutions to perfectly display from 4:3 or 16:10 widescreen computers.

Peace of mind
Plug-in, power-on, project. The IN1100-series is the first projector to utilize DisplayLink™ technology to eliminate the need to resize computer screens or toggle function keys when setting up an IN1100 series projector. 

Native Aspect Ratio:	4x3
Supported Aspect Ratio:	16:9, 4:3, 5:4
Brightness: (max ANSI lumens)	High Bright: 2100 Lumens Eco Mode: 1550 Lumens
Contrast Ratio:	1800 : 1 Full On/Full Off
Display Technology:	DLP by Texas Instruments: 0.55" XGA DMD with Brilliant Color
Data Compatibility:	VGA (640x480), SVGA (800x600), XGA (1024x768), SXGA (1280x1024), SXGA+ (1400x1050), UXGA (1600x1200)
Video Compatibility:	Full NTSC, PAL, SECAM, 480i, 576i, 480p, 576p, 720p, 1080i, 1080p/60
Color Wheel (DLP Only):	5-segment
Native Resolution:	XGA
Projector Placement:	Front Projection, Rear Projection
SMPTE Brightness:	Not Available
Lamp Wattage:	High Bright: 165 Watts Eco Mode: 132 Watts
Lamp Life:	High Bright: 3000 Hours Eco Mode: 4000 Hours
Minimum Image Size:	Not Available
Maximum Image Size:	Not Available
Standard Lens Zoom:	1.1 : 1
Standard Lens Throw Ratio:	1.95 - 2.15 (Distance/Width)
Standard Lens Image Offset Ratio:	115%
Standard Lens Projection Distance:	3.9 - 39 ft (1.19 - 11.89 m)
Digital Keystone Correction (Vertical):	+30°/-30°
Digital Keystone Correction (Horizontal):	Not Available
Lens Shift:	Not Available
Inputs and Outputs
USB:	Not Available
DVI:	Not Available
M1:	Not Available
HDMI:	Not Available
BNC:	Not Available
Component (RCA):	Number of Inputs: 1 requires optional VGA to Component adapter.
VESA (HD15):	Number of Inputs: 1 15-pin VGA
S-Video:	Number of Inputs: 1 4-pin mini-DIN
Composite (RCA):	Number of Inputs: 1
Standard Definition TV:	Composite RCA, S-Video
Enhanced Definition TV:	VGA
High Definition TV:	VGA
Computer:	USB (DisplayLink), VGA
HDCP Support:	No
Stereo RCA Jacks Inputs:	No
Stereo 3.5 mm Mini-jack Inputs:	Yes
12v trigger for motorized screens (3.5 mm mini-jack):	No
Projector Control:	Projector Keypad, Remote, USB
Speakers:	1 Watt mono speaker
Monitor Output:	No
Audio Output:	Not Available
Compatibility
Data Compatibility:	VGA (640x480), SVGA (800x600), XGA (1024x768), SXGA (1280x1024), SXGA+ (1400x1050), UXGA (1600x1200)
H-Sync Range:	31 - 92kHz
V-Sync Range:	50 - 85Hz
Video Compatibility:	Full NTSC, PAL, SECAM, 480i, 576i, 480p, 576p, 720p, 1080i, 1080p/60
General
Audible Noise:	35 dB
Actual Dimensions:	Height: 2.5 in (6.35 cm) Length: 7.2 in (18.29 cm) Width: 8.3 in (21.08 cm)
Actual Weight:	2.75 lbs (1.25 kg)
Shipping Dimensions:	Height: 11.42 in (29.01 cm) Length: 15.5 in (39.37 cm) Width: 7.28 in (18.49 cm)
Shipping Weight:	7.5 lbs (3.4 kg)
Projector Warranty:	2 years - Filter Free Design and 24 hour operation compatible, 5 year DLP imager warranty
Lamp Warranty:	6 months
Accessories Warranty:	90 days
Operating temperature: (at sea level)	41 - 95° F (5 - 35° C)
Maximum Altitude Supported:	10000 ft (3048 m)
Typical Power Consumption:	164 Watts
Maximum Power Consumption:	185 Watts
Power Supply:	100 - 240 Volts at 50 - 60 Hz
Menu Languages:	English, French, German, Italian, Korean, Norwegian, Portuguese, Russian, Simplified Chinese, Spanish, Traditional Chinese, Swedish, Dutch, Polish, Turkish, Danish, Finnish
Approvals:	UL and c-UL (US/Canada), FCC (US/Canada), CE (CE member countries), GOST (Russia), TUV GS (Germany), CCC (China), IRAM (Argentina), NOM (Mexico), C-Tick (Australia), MIC & eK (South Korea), PSB (Singapore), WEEE (EU), South Africa, RoHS, China RoHS

 

Connecting a Monitor/Projector to Your Laptop

• Getting Set Up

    Advancements in processors, other hardware, and operating systems (OSs) now make multitasking easier than ever. A typical computer session may include browsing the Web while downloading music, or editing a photo while virus scan runs in the background. For example, Intel's latest mobile processors allow laptop users to simultaneously run multiple, resource-intensive programs while consuming very little power.

Because of the increase in energy efficiency and performance, laptops in general have become smaller, thinner, and lighter. Most new models come equipped with dual monitor support and accelerated video technology, making connecting an additional monitor a simple operation. 

Why use a second monitor?

   Dual monitor configurations make complex projects easier to work on. Graphic designers, for example, often have several editing programs running at the same time. Adding an additional monitor doubles visual "real estate," giving users more room to work and play. Your desktop view can either be replicated on the second screen or stretched across it to form a larger work area.

Smaller laptop screens are great for traveling, but can be hard on your eyes for extended use. Connecting a full-size monitor to your laptop computer allows you to choose screen resolutions and refresh rates that cause less eye strain.

Whether you plan to make a presentation, are working on a massive project or your laptop screen suddenly stops working, learning how to connect a monitor to your laptop can save you a lot of time and frustration.

Connect a monitor to your laptop

    Laptops usually have one or more digital visual interface (DVI), video graphics array (VGA), or separate video (S-Video) ports. DVI ports are used to connect some flat panel LCD displays, while VGA ports can connect either LCD or older style CRT monitors. In addition to monitors, S-Video ports can also be used to connect video cameras, DVD players, and TVs.

If you have an older laptop that does not have a monitor port, you can purchase a USB 2.0-to-SVGA video adapter. The adapter plugs into one of your USB 2.0 ports. With it, one or more LCD or CRT monitors can be connected to your computer. They are reasonably priced and can be found online or through your local computer dealer.

Let's get started.

• Shut down your laptop and unplug it. Set the monitor next to the laptop on a secure surface.
• Determine which type of connector your monitor has and plug it into the corresponding port on the back or side of your laptop. DVI ports are usually white, and most VGA ports are blue (refer to your laptop owner's manual if necessary). If your monitor uses a different connector than what is available on your laptop, you can get an adapter to make them work. Tighten the connector screws, and then turn on the monitor.
• Plug your laptop in and turn it on. If the monitor does not show your OS loading, go to the next step.
• On your laptop keyboard, locate the FN key and the display function key (typically F5, F7 or F8), which usually has a picture of a monitor or the words CRT/LCD on it. To activate the monitor display, hold down the FN key, then press the display function key. It may take a few seconds for the monitor to respond. Refer to your laptop owner's manual if you have trouble locating or using the display function key.

Configure the screens

    Most laptops mirror your desktop on the second monitor by default. By changing a few settings, you can extend your desktop across both monitors, allowing you to drag open programs from one screen to the other.

In Windows Vista*:

• Right-click on your desktop and select "Personalize" then "Display Settings."
• Arrange the two virtual monitor displays by dragging the boxes to correspond to the location of your actual monitors. For example, if your laptop is located on the left of the monitor, drag the two boxes so that Monitor 1 is on the left and Monitor 2 is on the right.
• Select the additional monitor from the drop-down menu, check the box beside "Extend the desktop onto this monitor" then click "Apply."
In Windows XP*:
• Right-click on your desktop, then select "Properties." In the Display Properties dialog box, click the "Settings" tab.
• Arrange the virtual monitor displays if necessary. Select the additional monitor, check "Extend my Windows desktop," then click "OK".
Connecting a monitor to your laptop is that easy. Other OSs such as Linux use slightly different software configurations, but they are very similar overall. Experiment with different settings and monitor combinations to get the most out of your new dual-screen workstation.

What is DLP Projector?

    Digital Light Processing (DLP) is a trademark owned by Texas Instruments, representing a technology used in some TVs and video projectors. It was originally developed in 1987 by Dr. Larry Hornbeck of Texas Instruments.

DLP is used in DLP front projectors (small standalone projection units) and DLP rear projection television.

   DLP, along with LCD and LCoS, are the current display technologies behind rear-projection television, having supplanted CRT rear projectors. These rear-projection technologies compete against LCD and plasma flat panel displays in the HDTV market.

The single-chip version of DLP and 3LCD are the two main technologies used in modern color digital projectors, with the two technologies being used in over 95% of the projectors sold in 2008.

   DLP is also one of the leading technologies used in digital cinema projection.

In March 2008, TI announced the initial production of the DPP1500 chipset, which are micro projectors to be used in mobile devices. Availability for final products would show up in the market early 2009.

  

Digital micromirror device

   In DLP projectors, the image is created by microscopically small mirrors laid out in a matrix on a semiconductor chip, known as a Digital Micromirror Device (DMD). Each mirror represents one or more pixels in the projected image. The number of mirrors corresponds to the resolution of the projected image (often half as many mirrors as the advertised resolution due to wobulation). 800x600, 1024x768, 1280x720, and 1920x1080 (HDTV) matrices are some common DMD sizes. These mirrors can be repositioned rapidly to reflect light either through the lens or on to a heat sink (called a light dump in Barco terminology). Rapidly toggling the mirror between these two orientations (essentially on and off) produces grayscales, controlled by the ratio of on-time to off-time.

  

Color in DLP projection

   There are two primary methods by which DLP projection systems create a color image, those utilized by single-chip DLP projectors, and those used by three-chip projectors. A third method, sequential illumination by three colored light emitting diodes, is being developed, and is currently used in televisions manufactured by Samsung. Yet another method, color LASERs, is currently in use by Mitsubishi in their LASERVUE products.

Single-chip projectors

 In a projector with a single DLP chip, colors are produced either by placing a color wheel between a white lamp and the DLP chip or by using individual light sources to produce the primary colors, LEDs or LASERs for example. The color wheel is divided into multiple sectors: the primary colors: red, green, and blue, and in many cases secondary colors including cyan, magenta, yellow and white. The use of the secondary colors is part of the new color performance system called BrilliantColor which processes the primary colors along with the secondary colors to create a broader spectrum of possible color combinations on the screen.

The DLP chip is synchronized with the rotating motion of the color wheel so that the green component is displayed on the DMD when the green section of the color wheel is in front of the lamp. The same is true for the red, blue and other sections. The colors are thus displayed sequentially at a sufficiently high rate that the observer sees a composite "full color" image. In early models, this was one rotation per frame. Now, most systems operate at up to 10x the frame rate.

 

The color wheel "rainbow effect"

DLP projectors utilizing a mechanical spinning color wheel may exhibit an anomaly known as the “rainbow effect.” This is best described as brief flashes of perceived red, blue, and green "shadows" observed most often when the projected content features high contrast areas of moving bright/white objects on a mostly dark/black background. The scrolling end credits of many movies are a common example, and also in animations where moving objects are surrounded by a thick black outline. Brief visible separation of the colours can also be apparent when the viewer moves their eyes quickly across the projected image. Some people perceive these rainbow artifacts frequently, while others may never see them at all.

This effect is caused by the way the eye follows a moving object on the projection. When an object on the screen moves, the eye will follow the object with a constant motion, but the projector will display each alternating color of the frame at the same location, for the duration of the whole frame. So, while the eye is moving, it will see a frame of a specific color (red for example). Then, when the next color is displayed (green for example), although it gets displayed at the same location overlapping the previous color, the eye will have moved toward the object's next frame target. Thus, the eye will see that specific frame color slightly shifted. Then, the third color gets displayed (blue for example), and the eye will see that frame's color slightly shifted again. This effect is not perceived only for the moving object, but the whole picture.

The effect varies with the rotational speed of the color wheel and the frame refresh rate of the video signal. There is a maximum rotational speed limit for the wheel, typically 10,000 to 15,000 RPM. Video framerate is usually measured in frames per second and must be multiplied by 60 to find the wheel speed, whereas 60 frames/sec equals 3,600 frames/minute. If the color wheel spins 4 times per frame, it is rotating at a speed of 14,400 RPM. (Projector specifications often list the wheel speed at specific framerates as 2x, 3x, 4x, etc.)Increasing the video refresh rate to 85 frames per second does not necessarily further reduce the rainbow effect since this rate would increase the wheel speed to 20,400 RPM, potentially exceeding the safe limits of wheel rotation and requiring the projector to drop back to 3x speed, at 15,300 RPM.

Multi-color LED-based and LASER-based single-chip projectors are able to eliminate the spinning wheel and minimize the rainbow effect since the pulse rate of LEDs and LASERs are not limited by physical motion.

 Three-chip projectors

   A three-chip DLP projector uses a prism to split light from the lamp, and each primary color of light is then routed to its own DLP chip, then recombined and routed out through the lens. Three chip systems are found in higher-end home theater projectors, large venue projectors and DLP Cinema projection systems found in digital movie theaters.

    According to DLP.com, the three-chip projectors used in movie theaters can produce 35 trillion colors, which many suggest is more than the human eye can detect. The human eye is suggested to be able to detect around 16 million colors, which is theoretically possible with the single chip solution. However, this high color precision does not mean that three-chip DLP projectors are capable of displaying the entire gamut of colors we can distinguish (this is fundamentally impossible with any system composing colors by adding three constant base colors). In contrast, it is the one-chip DLP projectors that have the advantage of allowing any number of primary colors in a sufficiently fast color filter wheel, and so the possibility of improved color gamuts is available.

Light source

   The main light source used on DLP-based rear screen projection TVs is based on a replaceable high-pressure mercury-vapor metal halide arc lamp unit (containing a quartz arc tube, reflector, electrical connections, and sometimes a quartz/glass shield), while in some newer DLP projectors high-power LEDs or LASERs are used as a source of illumination.

Metal-halide lamps

   For metal-halide lamps, during start-up, the lamp is ignited by a 5000 volt pulse from a current-regulating ballast to initiate an arc between two electrodes in the quartz tube. After warmup, the ballast's output voltage drops to approximately 60 volts while keeping the relative current high. As the lamp ages, the arc tube's electrodes wear out and light output declines somewhat while waste heating of the lamp increases. The mercury lamp's end of life is typically indicated via an LED on the unit or an onscreen text warning, necessitating replacement of the lamp unit.

    Older projectors would simply give a warning that the lamp life had expired but would continue to operate. Newer projectors will not power up until the lamp is replaced and the lamp hours are reset. Most devices include a lamp hours reset function for when a new lamp is installed, but it is possible to reset a projector to continue to use an old lamp past its rated lifespan.

   When a metal-halide lamp is operated past its rated lifespan, the efficiency declines significantly, the lightcast may become uneven, and the lamp starts to operate extremely hot, to the point that the power wires can melt off the lamp terminals. Eventually, the required startup voltage will also rise to the point where ignition can no longer occur. Secondary protections such as a temperature monitor may shut down the projector, but a thermally overstressed quartz arc tube can also crack and/or explode, releasing a cloud of hot mercury vapor inside and around the projector. However, practically all lamp housings contain heat-resistant barriers (in addition to those on the lamp unit itself) to prevent the red-hot quartz fragments from leaving the area.

LED-based DLPs

    The first commercially-available LED-based DLP HDTV was the Samsung HL-S5679W in 2006, which also eliminated the use of color wheel. Besides long lifetime eliminating the need for lamp replacement and elimination of the color wheel, other advantages of LED illumination include instant-on operation and improved color, with increased color saturation and improved color gamut to over 140% of the NTSC color gamut. Samsung expanded the LED model line-up in 2007 with products available in 50", 56" and 61" screen sizes. For spring 2008, the third generation of Samsung LED DLP products are available in 61" (HL61A750) and 67" (HL67A750) screen sizes.

   Ordinary LED technology does not produce the intensity and high lumen output characteristics required to replace arc lamps. The special patented LEDs used in all of the Samsung DLP TVs are PhlatLight LEDs, designed and manufactured by US based Luminus Devices. A single RGB PhlatLight LED chipset illuminates these projection TVs. The PhlatLight LEDs are also used in a new class of ultra-compact DLP front projector commonly referred to as a "pocket projector" and have been introduced in new models from LG Electronics (HS101), Samsung electronics (SP-P400) and Casio (XJ-A series). Home Theater projectors will be the next category of DLP projectors that will use PhlatLight LED technology. At InfoComm, June 2008 Luminus and TI announced their collaboration on using their technology on home theater and business projectors and demonstrated a prototype PhlatLight LED based DLP home theater front projector. They also announced products will be available in the marketplace later in 2008 from Optoma and other companies to be named later in the year.

LASER-based DLPs

    The first commercially-available LASER-based DLP HDTV was the Mitsubishi L65-A90 LASERVUE in 2008, which also eliminated the use of a color wheel. Three separate color LASERs illuminate the digital micromirror device (DMD) in these projection TVs, producing a richer, more vibrant color palette than other methods. See the laser video display article for more information.

 Digital cinema

    DLP is the current market-share leader in professional digital movie projection, largely because of its high contrast ratio and available resolution as compared to other digital front-projection technologies. As of December 2008, there are over 6,000 DLP-based Digital Cinema Systems installed worldwide.

DLP projectors are also used in RealD Cinema for 3-D films.

Manufacturers and market place

   Texas Instruments remains the primary manufacturer of DLP technology, which is used by many licensees who market products based on T.I.'s chipsets. The Fraunhofer Institute of Dresden, Germany, also manufactures Digital Light Processors, termed Spatial Light Modulators, for use in specialized applications. For example, Micronic Laser Systems of Sweden utilizes Fraunhofer's SLMs to generate deep-ultraviolet imaging in its Sigma line of silicon mask lithography writers.

    DLP technology has quickly gained market share in the front projection market and now holds roughly 50% of the worldwide share in front projection. Over 30 manufacturers use the DLP chipset to power their projectors.

 Pros

• Smooth (at 1080p resolution), jitter-free images.
• Perfect geometry and excellent grayscale linearity achievable.
• Usually great ANSI contrast.
• No possibility of screen burn-in.
• Less "screen-door effect" than with LCD projectors.
• DLP rear projection TVs generally have a smaller form factor than comparable CRT projectors.
• DLP rear projection TVs are considerably cheaper than LCD or plasma flat-panel displays and can still offer 1080p resolution.
• The use of a replaceable light source means a potentially longer life than CRTs and plasma displays (this may also be a con as listed below).
• The light source is more-easily replaceable than the backlights used with LCDs, and on DLPs is often user-replaceable.
• New LED and LASER DLP TVs and projectors eliminate the need for lamp replacement.
• Using two projectors, one can project full color stereoscopic images using polarized process (because beams can be polarized).
• Lighter weight than LCD and plasma televisions.
• Unlike their LCD and plasma counterparts, DLP screens do not rely on fluids as their projection medium and are therefore not limited in size by their inherent mirror mechanisms, making them ideal for increasingly larger high-definition theater and venue screens.
• DLP Projectors can process up to 7 separate colors giving them strong color performance
• DLP projectors do not suffer from “Color Decay” often seen with LCD projectors in which the image on the screen turns yellow after extended periods of usage.

 Cons

• Some viewers are bothered by the "rainbow effect," explained above.
• Not as thin as LCD or plasma flat-panel displays (although approximately comparable in weight), although some models as of 2008 are becoming wall-mountable (while still being 10" to 14" thick)
• Replacement of the lamp / light bulb. The average life span of a TV light source averages 2000-5000 hours and the replacement cost for these range from $99 – $350, depending on the brand and model. After replacing the bulb a few times the cost can easily exceed the original purchase price of the television itself. Newer generations units use LEDs or LASERs which effectively eliminates this issue, although replacement LED chips could potentially be required over the extended lifespan of the television.
• Some devices may have fan noise.
• Dithering noise may be noticeable, especially in dark image areas. Newer (post ~2004) chip generations have less noise than older ones.
• Error-diffusion artifacts caused by averaging a shade over different pixels, since one pixel cannot render the shade exactly.
• Response time in video games may be affected by upscaling lag. While all HDTVs have some lag when upscaling lower resolution input to their native resolution, DLPs are commonly reported to have longer delays. Newer consoles such as the Xbox 360 do not have this problem as long as they are connected with HD-capable cables.
• Reduced viewing angle as compared to direct-view technologies such as CRT, plasma, and LCD.