Cathode Ray Tube (CRT)
In CRT Projectors, Cathode Ray Tube is used for generating high-brightness image. A lens is used in front of CRT face for enlarging and focusing image onto the projection screen. CRT projectors can display images up to 1920*1200 pixels resolution. These are video projectors and used in cinemas.
Liquid Crystal Display (LCD)
LCD projectors are another type of video projectors, used for displaying high quality images and videos on projection screens or flat surface. Small metal-halide lamps are used for projection in these projectors making them capable for projecting image to any flat surface. LCD projector are smaller in size and portable than CRT and DLP projectors.
Digital Light Processing (DLP)
DLP projectors use digital micro mirror device as projection technology. These projectors are used in 85% cinemas for projection. Some DLP technology Pico-chips are used in mobile phones for projection. These projectors create smooth (1080p resolution) and jitter free images. DLP projectors can process 7 separate colors at the same time. They are light in weight than LCD and SRT projectors.
- Projector’s brightness is measured in lumens. Brighter projector has higher lumens rating.
- In projectors, we talk about two types of brightness one for color brightness and other one for white brightness.
- How much brightness you require in your projector depends on the light condition in room where you will install projector.
- For a home theatre projector with ambient light in room, minimum 1500 lumens brightness is required.
- For classrooms and conference rooms, minimum 2500 lumens brightness is required.
“1600 lumens brightness for home theatre projectors and 2500 lumens brightness for business projectors is recommended”.
- Contrast ratio is the difference between number of light and dark point on the screen.
- If you purchase a projector with contrast ratio 1000:1, it means that the brightest white point will be 1000 times brighter than the darkest black point.
“High Contrast ratio is recommended for projectors, which gives clear and more visible image”.
- Projector’s throw ratio is used when projectors are used for controlling images resolution.
- If any projectors throw ration is 2:1 and projector is installed 20 feet away from the projection screen. Then the projected image’s width will be 10 feet.
“Recommended throw ratio for projectors is 2:1”.
- Resolution is the capacity of printer of displaying number of dots or pixels on 1 square inch of projection screen.
- Higher resolution means that more dots or pixels are required for displaying an image which results in clear image.
- Higher resolutions are required for displaying graphics and high definition videos.
- Resolution is expressed in combination of numbers of numbers e.g. 800*600. This indicates 800 dots horizontally across 600 lines dots vertically making total 48000 dots for making an image.
Business Projector Resolution
- SVGA (800*600 pixels resolution, 4:3 aspect ratio): these are low-resolution projectors and are affordable and suitable for projecting simple images and short video clips.
- XGA (1024*768 pixels resolution, 4:3 aspect ratio): these are most widely used projectors, in computers XGA is used as native resolution, so it is common practice of using XGA projectors with computers.
- WXGA (1280×800 pixels resolution, 16:10 aspect ratio): these projectors are widescreen version of XGA but produce 20% more vertical resolution than XGA.
- WUXGA (1920*1200 pixels resolution, 16:10 aspect ratio): these projectors are used for displaying high-definition videos and are now being deployed as large-venue projectors.
Home Theatre Projector Resolution
- 720p (1280*720 pixels resolution, 16:9 aspect ratio): these projectors are used for front-end movie projection, these match the 720p HDTV standard.
- 1080p (1920*1080 pixels resolution, 16:9 aspect ratio): these projectors are used as home theatres. These match the 1080i/1080p HDTV standard.
Wireless & Wired Projection
- Advance projectors have built-in wireless LAN (802.11 b/g/n). By plug in LAN module into the projector and connecting with projector you will be able to project wirelessly to projector screen.
- USB: USB is a plug n play device. USB may be connected and removed from the projector when device is in operation. Using USB you may project your images and videos in seconds which makes projection easy.
- HDMI: HDMI is the latest digital connectivity technology which allows you to connect projector with laptops and other media players for projecting high definition videos.
- Display Port: Display port is the standard display technology in projectors, which is used for connecting with computers, laptops, cameras, DVD players and televisions for displaying images and videos.
- Latest projectors may be shared over a network.
- Many computers may use same projector without changing cables over a network.
- Up to 16 computers may use the same projector in a network.
- Power consumption of LCD projectors with lumens rating from 2000 to 3000 consume power from 250W to 400W.
- Power consumption may vary with manufacturer and which projector you bought.
- LCD projectors consume lowest power than DLP and CRT projectors.