Blogger Template by Blogcrowds.

Saturday, January 23, 2010

LCD projector



An LCD projector is a type of video projector for displaying video, images or computer data on a screen or other flat surface. It is a modern analog of the slide projector or overhe


Overview
To display images, LCD (liquid crystal display) projectors typically send light from a Metal halide lamp through a prism that separates light to three poly silicone panels -- one each for the red, green, and blue components of the video signal. As polarised light passes through the panels (combination of polarizer, LCD panel and analyzer), individual pixels can be opened to allow light to pass or closed to block the light. The combination of open and closed pixels can produce a wide range of colors and shades in the projected image.
Metal Halide lamps are used because they output an ideal color temperature and a broad spectrum of color. These lamps also have the ability to produce an extremely large amount of light within a small area: current projectors average about 2,000-4,000 ANSI lumens.
Newer technologies, such as DLP and LCOS are becoming more popular in video projection. In practice, the term "LCD Projector" is often used as a catch-all for any type of computer projector, regardless of the technology being used.


Projection surfaces
Thanks to small Metal Halide lamps and the ability to project an image on any flat surface, LCD projectors tend to be smaller and more portable than other types of projection systems. Even so, the best image quality is found using a blank white or grey surface, so dedicated projection screens are often used.

Perceived color in a projected image is a factor of both projection surface and projector quality. Since white is more of a neutral color, white surfaces are best suited for natural color tones; as such, white projection surfaces are more common in most business and school presentation environments.

However, darkest black in a projected image is dependent on how dark the screen is. Because of this, some presenters and presentation space planners prefer gray screens, which create higher perceived contrast. The trade-off is that darker backgrounds can throw off color tones. Color problems can sometimes be adjusted through the projector settings, but may not be as accurate as they would on a white background.

เขียนโดย Mintrukpare ที่ 6:10 PM | 0 ความคิดเห็น  

Friday, January 22, 2010

Which Projector Should I Rent?



LCD projectors work better for static Microsoft PowerPoint® presentations or detailed financial spreadsheets. DLP works better for full motion video.

LCD stands for Liquid Crystal Display and DLP stands for Digital Light Processing.
LCD is an analog-based display technology employing three fixed panels of pixels (one panel each for the RED, GREEN, & BLUE components of an NTSC video image). LCD also delivers a somewhat sharper image than DLP at any given resolution.

LCD projectors usually produce significantly higher ANSI lumen outputs than do DLP projectors with the same wattage lamp.DLP projectors have a much higher pixel “fill factor” than LCD. DLP-based projectors generally produce a much smoother looking image compared to LCD-based projectors of similar resolution.

DLP-based projectors have a high contrast ratio and efficient use of light. Contrast ratio compares the ratio between the brightest white and the darkest black that a projector can produce. Generally, a better contrast ratio leads to better black levels and, therefore, a more realistic presentation of darker scenes in movies and TV programs.

DLP projectors tend to be more compact because they have fewer components.

All of the current 3-pound portable projectors on the market are DLP projectors. Most LCD projectors are five pounds and up. The higher lumen models are significantly heavier and larger. High lumen projectors are not considered portable.

You need to match the brightness of the projector to your audience and room size. Large rooms and audiences require high bulb strength brightness. (Projector bulb strength brightness is measured in ANSI lumens or lumens).

All projector rentals range from about 1000 up to 6000+ lumens in brightness. The higher the lumen the brighter the projector.

Up to 1000 lumens -good for low ambient light, presentations.

2000 lumens -These are the most popular units being sold and rented today. Very practical and will work with some ambient light.

3000 lumens -Much Larger unit than the1000 to 2000 lumen units. Good for audiences of less than a hundred with ambient light.

5000 lumens - For audiences of 100 or more under brighter lights

6000+ lumens - For large events like conventions, conferences and tradeshows where thousands of people need to view a presentation at the same time.

Another consideration is portability of the projector. Lower lumen units are the most portable.
As a general rule, as you increase bulb strength brightness, you reduce portability. High lumen projectors are larger and weigh more than low lumen projectors.

เขียนโดย Mintrukpare ที่ 12:44 PM | 0 ความคิดเห็น  

Thursday, January 21, 2010

Benefits of a High-Quality LCD Projector Lamp for Your LCD





In terms of multimedia presentations LCD projectors
have proven to provide impressive image quality and high resolutions. However, if your projector suddenly fails to work and you need to present a proposal with potential clients, it could cause your business to lose money, or worse, it could cause your job.

The most common problem of projectors
is the sudden burn out of LCD projector lamps. Fortunately, these LCD projector lamps can be easily replaced. Although anyone can replace the lamps for your LCD projector, choosing the lamp can be an overwhelming task. You need to ensure that the type of lamp you buy is compatible with your projector.

A high-quality LCD projector lamp
should be able to operate for over 4,000 hours. However, the measurements of lamp life are not reliable because the lamp can still work, even if it becomes dimmer. For this reason, you need to check the “peak lamp life” listed in most manufacturers of LCD projector lamps, which provides users with information of the total brightness a particular lamp could provide.

Choosing a high-quality lamp for your LCD projector
should be your first concern, instead of price. Compared to the affordable halogen lamps that last about 70 hours, metal halide lamps can work up to 500 hours. Meaning, the more expensive LCD projector lamp you choose, the longer-lasting life it would provide.

How to Choose an LCD Projector Lamp
There are only two types of lamps used in LCD projectors – metal halide and tungsten halogen. In order to choose a quality lamp, you have to understand how each one works.

A metal-halide lamp provides better brightness, but lower consumption of power. Be aware that lamp wattages do not reflect the brightness. Metal-halide LCD projector lamps are more efficient because it could provide your projector with a very white light until the end of its life.
On the other hand, tungsten-halogen lamps produce whiter lights because it runs at a higher temperature than other lamps. Although the white light will become yellow during its lifetime, it provides a longer lamp life because of its low-pressure and high temperature features.

Although metal-halide LCD projector lamps are more expensive, they could provide over 2,000 hours compared to the tungsten-halogen lamps’ 70 hours of operation. Be aware that lamps of your projectors could last longer when you operate them in “economy mode”, which automatically cools down when the projector becomes idle.

เขียนโดย Mintrukpare ที่ 1:50 PM | 0 ความคิดเห็น  

Wednesday, January 20, 2010

About - LCD Projectors




LCD projectors are the modern equivalent of the slide and overhead projector. LCD projectors use a small and usually colored LCD panel placed before a bright lamp, with the images on the screen provided by sources such as a DVD, VCR or a computer. LCD projectors are generally smaller in size and more easily transportable than former systems. Armed with a lens capable of projecting the images on any surface with a flat plane and not requiring supporting furniture like a big-sized television would, LCD projectors are getting increasingly viable with each passing day.

There are certain things to take into account when purchasing an LCD projector. The projector's resolution generally determines the price; the higher the resolution, the greater the price. If the need is for minute details to be precisely displayed, then higher resolution projectors are the way to go. The LCD projector's light output depends on the lumens rating, i.e. the higher the lumens rating the brighter the light output. For classrooms, projectors of 1000-2000 lumens suffice; for big conference rooms, the ideal projectors would be those between 2000-3000 lumens.

The ratio between the brightest and darkest spots of an image is called the projector contrast. When purchasing LCD projectors, it is feasible to go for contrasts of 400:1 or higher. This way the best and the clearest pictures are achieved.

If the projector is to be carried around to different locations, then it is best to purchase a light projector. Many LCD projectors today weigh below five pounds. The lighter projectors generally cost more though. Also, it is viable to get an LCD projector with multiple ports, in the event that you want to connect multiple video or computer sources to the projector simultaneously. Another factor that should be considered is the durability of the lamp. Replacements can be an exorbitant deal. A lamp life of 2000 hours is just about ideal.

เขียนโดย Mintrukpare ที่ 11:46 AM | 0 ความคิดเห็น  

Tuesday, January 19, 2010

Video projector


A video projector
takes a video signal and projects the corresponding image on a projection screen using a lens 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, a projector with a higher light output (measured in lumens, abbreviated “lm”) is required for a larger screen or a room with a higher amount of ambient light. A rating of 1000 to 1500 ANSI lumens or lower is suitable for smaller screens with controlled lighting or low ambient light. 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.

เขียนโดย Mintrukpare ที่ 9:04 AM | 0 ความคิดเห็น  

Older Posts

Subscribe to: Posts (Atom)