Portable Video Projector
Portable Video Projector – What You Need to Know
A small child walks into a room carrying a device capable of displaying a 100 inch wide, HD-quality picture. Seems impossible? Welcome to the world of Portable Video Projector. They are also commonly known as handheld, pocket, or mobile projectors. An portable video projector in a hand held device is used in these projectors.
The main feature that makes portable video projectors so attractive is their compatibility with other portable devices like personal digital assistants, play station portables, mobile phones and digital cameras that have enough storage for presentation material but don’t have display, big enough to show magnified images in a big room.
The images that are being projected can be displayed on any nearby viewing surface like wall. The main parts of construction of portable video projectors are the laser light sources, the combiner optic, and the scanning mirrors.
The working principle of portable video projector is first the electronic system turns the image into an electronic signal. Next the electronic signals provide laser light sources with different colours and intensities down different paths. Different light paths are combined into one path in the combiner optic, demonstrating a palette of colours. Finally, the mirrors copy the image pixel by pixel and can then project the image.
Currently, there are three basic types of video projector technology in use: CRT, LCD, and DLP. There are also variations of these three types (including D-ILA and LCOS), but for the purposes of this article, I will focus on the first three that I have listed. The following is a brief overview of each of the three major projector types.
When video projectors first arrived on the scene, television technology was based on the Cathode Ray Tube (CRT), on which the viewer sees the television image. Three small CRTs (one for each primary colour), coupled with a light magnifying lens, can project a colour image onto a large screen in a darkened room. With the proper video processing circuitry, CRT size, and lens combination, a CRT projector can produce excellent high resolution images.
The image in a CRT projector is scanned with an electron beam (just as in regular tube TV) and is not limited to a fixed pixel field, as are other video projector types (to be discussed, in more detail, later in this article). This makes the CRT projector the best option where the flexibility of displaying variable resolutions is the main consideration.