Since being introduced to the world as a Zoopraxiscope in the 1870s, projectors have come a long way. Nowadays, the projector has gained immense popularity and can be found in a large variety of places including classrooms, conference rooms, homes, and yards as well. They are used to deliver lectures and presentations to large groups of students or watch movies and videos at the backyard home theatre. There are various makes and models available on the market nowadays which range in size and capabilities.
A projector is basically an optical device which can be used to project images, videos or texts on any screen, commonly called a projection screen. The video projector is one of the most common kinds of projector used today. An image engine forms the heart of every video projector. It can use different technologies like liquid crystal display, digital light display or cathode ray display. An image is produced inside the projector for display on any projection screen. The video projector’s optics consists of a series of mirrors and prisms which reflects and splits the light into its constituent colors, performing the function of transferring the image from the internal engine onto the projection screen for viewing. The internal processes are controlled by the projector’s mainboard. Plastic or metal cases are also present to protect the internal mechanisms. They may also contain control knobs or switches for performing several functions.
From handheld devices that require a dark room to deliver a viewable image to high-powered devices that can be easily read, a wide variety of projectors are available in the market. LED, LCD, and DLP are the major types of projectors used today. Introduced in the 1980s, the LCD projector has been chosen by many people because of its high-performance features. They are free from any rainbow artifacts and are compatible with a zoom lens and lens shift which enables support in larger rooms. Most LCD projectors use a technology that combines three liquid crystal displays. This technology is called a transmissive medium because the light is passed through the panels rather than bouncing it away.
The DLP projectors depend on a DLP chip which comprises nearly 2 million tiny mirrors. Each of the mirrors in the chip can adjust independently to create a light or dark pixel. A DLP projector made of 3-chip architecture can deliver up to 35 trillion colors. They have a filter-free sealed chip design which doesn’t allow dust to settle and cause image spots. Also, they are not subject to misalignments and are effectively immune to color decay. The Pico projector is another type of projector that uses LED technology. They are handheld devices that use liquid crystal on silicon which is a reflective panel. These projectors replace the traditional lamp with more efficient LEDs in colors of blue, red and green. The LED lamps are long lasting and can last up to 20000 hours. They don’t require a warm-up or cool down time and are low-maintenance.