What Is an LCD Projector?
LCD projectors are essential to everyday business presentations. They are modern devices that allow us to display a large, crisp image on a screen effortlessly. These magnificent devices are relatively simple, operating on the same principles as every other light projector, but somehow utilizing those principles to create a superb image.
Other People Are Reading
-
The Difference Between an LCD Projector and a Slide Projector
-
An LCD projector works similarly to other projectors in that it projects light through a filter to create an image. However, because it uses a malleable LCD filter to create a projection, instead of physical slides, it can display video, as well as hundreds more slides than a conventional slide projector.
Inside an LCD Projector
-
The filters in an LCD projector are actually three small LCD screens. These three screens are situated at right angles to each other. They form what looks like three sides of a square. The fourth side is left open to let out the light to be projected. These LCD screens have light shown through them to create an image. LCD projectors use only three colors of light to create a full-color image. Each LCD screen receives one of the three colors of light used, which are red, blue and green. The red, blue and green light for the three LCD screens is produced by a metal halide lamp, then filtered and reflected into the LCD screens. As the final touch on the device, there is a prism in the center of the three LCD screens that overlays and focuses the three images into one and projects that image through a lens and onto a screen.
-
How an LCD Projector Creates the Image
-
To create the image, red, blue and green lights beam through their respective LCD screens, then overlay to create an image. This is done with the use of mirrors. Light from the metal halide lamp moves through a dichroic mirror. This special dichroic mirror only lets red light through, but reflects the rest of the light. The rest of this light goes through another dichroic mirror that only lets the blue light through but reflects the green light. Hence, the red light is shown through a mirror and reflected into its LCD screen while the green light is reflected into its LCD screen. Then, the remaining blue light that passed through the second dichroic mirror is reflected two times onto its LCD screen. The three LCD screens block some of the light passing through them. This causes an image to be formed. After the LCD screens create three separate red, blue and green images, the three images are overlaid by a prism to form a single color image. This entire process is regulated by a computer inside the LCD projector. The computer is told what images should be displayed on each LCD screen. This controls the final image produced.
History
-
Gene Dolgoff invented the first LCD projector in 1984. This model was nothing like the LCD projectors you see today. In fact, it did not even have its own light source. It had to be set in front of an external light source, such as an overhead display, to function. Once Dolgoff had created a working model, he began to sell the technology to companies such as Panasonic and Samsung. As of today, only Epson and Sony manufacture the LCD panels necessary for LCD projectors.
The Advantages of an LCD Projector
-
LCD projectors are so commonly used mainly because they can display images from a portable computing device, such as a PDA, phone or computer. However, they also provide the advantage of being completely self-contained. All they need is a power source and a blank screen on which to project. This means that no slides or overheads are needed. Additionally, LCD projectors can be much smaller and more portable than other projectors, some even fitting right inside a backpack or briefcase.
-
References
- Photo Credit http://www.plasma.com/philipsprojectors
