Video Projector

Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Video Projector shopping experience:

1. Compare - without doubt the biggest advantage that the Video Projector offers shoppers today is the ability to compare thousands of Video Projector at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.

2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about

3. Testimonials - don't know anybody that has bought a Video Projector? Wrong! If the Video Projector is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.

4. Questions - Got a question about Video Projector then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....

5. Reputation - Never heard of the company selling Video Projector? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Video Projector and build up a picture of their reputation for sales, returns, customer service, delivery etc.

6. Returns - still worried that even after all of the above your Video Projector wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.

7. Feedback - happy with your Video Projector then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.

8. Security - check for the yellow padlock on the Video Projector site before you buy, and the s after http:/ /i.e. https:// = a secure site

9. Contact - got a question about Video Projector, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.

10. Payment - ready to pay for your Video Projector, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.

.

A video projector takes a video Signalling (telecommunication) and projects the corresponding image on a projection screen using a lens (optics) system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other inconsistencies through manual settings. Video projectors are widely used for conference room presentations, classroom training, and home theatre applications.

A video projector may also be built into a cabinet with a rear-projection screen (rear-projection TV, or RPTV) to form a single unified display device, now popular for “home theater” applications.

Common display resolutions for a portable projector include SVGA (800×600 pixels), XGA (1024×768 pixels), 720p (1280×720 pixels), and 1080p (1920×1080 pixels).

The cost of a device is not only determined by its resolution, but also by its light output, acoustic noise output, contrast, and other characteristics. While most modern projectors provide sufficient light for a small screen at night or under controlled lighting such as in a basement with no windows Lumens guide. ProjectorPeople.com., a projector with a higher luminous flux (measured in lumen (unit), abbreviated “lm”) is required for a larger screen or a room with a higher amount of ambient light. A rating of 1000 to 1500 American National Standards Institute lumens or lower is suitable for smaller screens with controlled lighting or low ambient light. Buying guide. TvSpecialists.com. Between 1500 and 3000 lm is suitable for medium-sized screens with some ambient light or dimmed light. Over 3000 lm is appropriate for very large screens in a large room with no lighting control (for example, a conference room). Projected image size is important; because the total amount of light does not change, as size increases, brightness decreases. Image sizes are typically measured in linear terms, diagonally, obscuring the fact that larger images require much more light (proportional to the image area, not just the length of a side). Increasing the diagonal measure of the image by 25 % reduces the image brightness by 35 per cent; an increase of 41 per cent reduces brightness by half.

Projection technologies

CRT projector using cathode ray tubes. This typically involves a blue, a green, and a red tube. Minimal maintenance is required (unlike projectors that use expensive lamps which must be periodically replaced after they burn out). This is the oldest system and falling out of favor largely because of the bulky cabinet. However, it does provide the largest screen size for a given cost. CRT projectors are suitable only for fixed installations.
LCD projector using LCD light gates. This is the simplest system, making it one of the most common and affordable for home theaters and business use. Its most common problem is a visible “screen door” or pixelation effect, although recent advances have minimized this.
DLP using Texas Instruments’ DLP technology. This uses one, two, or three Microfabrication light valves called digital micromirror devices (DMDs). The single- and double-DMD versions use rotating color wheels in time with the mirror refreshes to modulate color. The most common problem with the single- or two-DMD varieties is a visible “rainbow” which some people perceive when moving their eyes. Systems with 3 DMDs never have this problem. More recent projectors with higher speed (2x or 4x) and otherwise optimised color wheels have minimized this artifact.
Liquid crystal on silicon using Liquid crystal on silicon.
D-ILA JVC’s Direct-drive Image Light Amplifier based on LCOS technology.

Obsolete technologies

Eidophor oil-film projectors
Talaria projector oil-film projectors
ILA (Image Light Amplifier) light valves
Schmidt-Cassegrain telescope-CRT, developed by Kloss Video Corporation

See also

Large-screen television technology
Projector for a directory of projector types
Projection screen
Screen door effect
Comparison of display technology
Digital cinema

Major manufacturers

3M
Barco
BenQ
Christie (company)
Digital Projection International
EIKI
Epson
Hewlett-Packard
Hitachi
InFocus
Kloss Video Corporation (defunct)
Lenovo
Lumens
Matsushita (Panasonic)
Mitsubishi
NEC
Optoma
Sharp Corporation
Sony
Texas Instruments (component supplier of DLP technology)
Toshiba
Viewsonic

References

.

A video projector takes a video Signalling (telecommunication) and projects the corresponding image on a projection screen using a lens (optics) system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other inconsistencies through manual settings. Video projectors are widely used for conference room presentations, classroom training, and home theatre applications.

A video projector may also be built into a cabinet with a rear-projection screen (rear-projection TV, or RPTV) to form a single unified display device, now popular for “home theater” applications.

Common display resolutions for a portable projector include SVGA (800×600 pixels), XGA (1024×768 pixels), 720p (1280×720 pixels), and 1080p (1920×1080 pixels).

The cost of a device is not only determined by its resolution, but also by its light output, acoustic noise output, contrast, and other characteristics. While most modern projectors provide sufficient light for a small screen at night or under controlled lighting such as in a basement with no windows Lumens guide. ProjectorPeople.com., a projector with a higher luminous flux (measured in lumen (unit), abbreviated “lm”) is required for a larger screen or a room with a higher amount of ambient light. A rating of 1000 to 1500 American National Standards Institute lumens or lower is suitable for smaller screens with controlled lighting or low ambient light. Buying guide. TvSpecialists.com. Between 1500 and 3000 lm is suitable for medium-sized screens with some ambient light or dimmed light. Over 3000 lm is appropriate for very large screens in a large room with no lighting control (for example, a conference room). Projected image size is important; because the total amount of light does not change, as size increases, brightness decreases. Image sizes are typically measured in linear terms, diagonally, obscuring the fact that larger images require much more light (proportional to the image area, not just the length of a side). Increasing the diagonal measure of the image by 25 % reduces the image brightness by 35 per cent; an increase of 41 per cent reduces brightness by half.

Projection technologies

CRT projector using cathode ray tubes. This typically involves a blue, a green, and a red tube. Minimal maintenance is required (unlike projectors that use expensive lamps which must be periodically replaced after they burn out). This is the oldest system and falling out of favor largely because of the bulky cabinet. However, it does provide the largest screen size for a given cost. CRT projectors are suitable only for fixed installations.
LCD projector using LCD light gates. This is the simplest system, making it one of the most common and affordable for home theaters and business use. Its most common problem is a visible “screen door” or pixelation effect, although recent advances have minimized this.
DLP using Texas Instruments’ DLP technology. This uses one, two, or three Microfabrication light valves called digital micromirror devices (DMDs). The single- and double-DMD versions use rotating color wheels in time with the mirror refreshes to modulate color. The most common problem with the single- or two-DMD varieties is a visible “rainbow” which some people perceive when moving their eyes. Systems with 3 DMDs never have this problem. More recent projectors with higher speed (2x or 4x) and otherwise optimised color wheels have minimized this artifact.
Liquid crystal on silicon using Liquid crystal on silicon.
D-ILA JVC’s Direct-drive Image Light Amplifier based on LCOS technology.

Obsolete technologies

Eidophor oil-film projectors
Talaria projector oil-film projectors
ILA (Image Light Amplifier) light valves
Schmidt-Cassegrain telescope-CRT, developed by Kloss Video Corporation