Projectors have become an integral part of offices, schools, and universities. Projectors help improve the movie viewing experience, but their utility is not limited to movie theaters. Projectors are also used in boardrooms, meeting rooms, meeting rooms, classrooms, and many other places to improve the overall user experience. So, how does this versatile technology work? In this article, we will discuss what a projector is, how it works, its various types of applications, advantages, and disadvantages.
Table of Contents
What Is A Projector
In simple terms, projectors basically use the working principle of image projection, that is, the projector accepts video/image input, processes it with the help of a built-in optical projection system consisting of lenses and light sources, and projects the enhanced output onto the projection screen.
A projector is an optical device that projects graphics or pictures onto a surface. This surface is usually light in color and maybe a projection screen, a white screen, or sometimes a wall. In large gatherings, a projector can be used as a replacement for a TV or monitor.
Read More: What Is A Film Strip Projector?
Advantages of Projector
The advantages of projectors include:
- large image size
The front projector can produce the largest photo size. You can use them to create a very large commercial cinema display experience at home. Most projectors are capable of taking stunning pictures 90″ to 120″ diagonal, which is much larger than a flat-screen or rear-projection TV.
- The best choice for a big-screen TV
Projectors are cheap alternatives to 60-inch plasma TVs. The projected picture is usually very bright, and the projector can be used with some room lights on.
- low cost
Front-facing projectors can be the cheapest alternative to big-screen video in your home. Some projectors are designed specifically for home theater and are now down to under $1,000, which is a good deal; less expensive than a flat-screen or rear-projection TV.
Given the lower prices of many entry-level projectors, this is the cheapest way to get a big-screen experience at home. While you may need to install an extra speaker, you’re getting a much better experience for the price.
- save space
A small projector that sits on a back shelf, bookshelf, or ceiling doesn’t take up any floor space in the room. It’s barely visible when not in work mode.
- easy to install
They are so light that one can pull them out of the box, hang them up, and hang an image on the wall with little effort.
Disadvantages of a Projector
Disadvantages of projectors include:
- Darkrooms often require the use of projectors.
- It requires regular maintenance.
- In some cases, the installation cost may be higher because it depends on the installation method.
- Most projectors require a separate audio system.
Types of a Projector
On the basis of their display property, Projectors can be classified into three types. They are:
- Cathode Ray Tube (CRT)
- Liquid Crystal Display (LCD)
- Digital Light Processing (DLP)
CRT
A CRT projector is basically a video projection device. It uses tiny cathode ray tubes with high brightness to generate images. There is a lens on the front of the CRT that focuses and magnifies the image onto a large projection screen.
CRT projectors focus an image or video through a lens and project it onto a screen. The images were processed with the help of CRT tubes of three different colors (red, green, and blue).
CRT projectors are bulky and heavy, making them inconvenient to carry. They also consume a lot of power due to the three light guns. In the initial stage, it may be difficult to install a CRT projector, but users say that the CRT projector has excellent image quality. People say, though, that these projectors are more recent than newer technology and are compatible with new improvements.
LCD
The meaning of an LCD monitor is roughly clear from its name. The word LCD is similar to the two states of matter, liquid and solid. LCD monitors use liquid crystals to project images or objects.
These types of display panels are commonly used in computers, laptops, televisions, portable video games, and cell phones. LCD technology displays are much thinner than CRT technology.
DLP
Digital Light Processing (DLP) is a video innovation by Texas Instruments for front and rear projection units. DLP is used for rear and front projection. It is commonly used for rear projection in televisions and also for front projectors in organizational and classroom units.
There are two noteworthy structures of DLP, namely 1-chip DLP and 3-chip DLP. Digital light processing uses micromirrors called digital micromirror devices to reflect light and shadows onto the screen. These micromirrors are located in semiconductor chips and are small in size. Most DLP chips are made by Texas Instruments.
How Do CRT Projectors Work?
CRT projectors are not as outdated as many think. Due to their larger size, they appear less conspicuous.
A cathode ray tube projector uses a cathode ray tube. This tube produces high-brightness images.
The resulting images were processed through three different CRT tubes. Each tube has a color: red, green, and blue.
It also has a lens on the front for magnifying the image. This lens focuses on the image magnifies it, and projects it onto the screen.
CRTs are known for their excellent image quality. They also have advanced digital technology and accept data from HDMI sources.
They are built to last; most lamps have a lifespan of about 10,000 hours. They don’t lose brightness over time like DLP and LCD.
The disadvantage of this technology is its large size and high energy consumption. This makes it unsuitable for home use.
How Do LCD Projectors Work?
LCD projectors are digital devices. They use a projection technique called liquid cathode display.
LCD projectors use panels that contain thousands of small mirrors. These mirror images are called pixels.
The mirrors are movable; they are either in the closed or open position. Depending on their position, they either reflect or deflect light.
The most advanced LCD projectors are 3LCD projectors. They used a total of 3 panels to create the image.
The light beam from the light source enters the dichroic mirror. It is divided into red, blue, and green beans.
These different beams are reflected onto the three LCD panels. One of each shade.
Pixels on an LCD panel reflect or deflect colored light. They created this image with different shades.
Three different versions of the image; red, blue, and green; through a dichroic prism.
They recombine in the prism to form an image. This image passes through the lens and appears on the screen in millions of colors.
LCD projectors display data from various media sources such as DVDs and computers. They don’t consume a lot of energy.
Also, 3LCD projectors don’t have a rainbow effect. They have high contrast.
Single-panel LCD projectors work a little differently. They may experience a rainbow effect.
How Do DLP Projectors Work?
DLP projectors are a relatively new technology. The instrument was first developed by Texas Instruments in 1987.
This technology is called digital light processing technology. It uses a microchip containing 2 million tiny mirrors.
The mirror on the DMD (Digital Micromirror Device) chip is tilted in the closed or open position. An electronic circuit determines the tilt of the individual mirrors.
In the open position, they reflect the light of any color. In the closed position, they deflect the light away from the lens.
The off position is responsible for creating the dark parts of pictures and videos.
The color wheel is placed in the beam path. This wheel will be colored light red, blue, and green in succession.
Colored light falls on the DMD chip. Its mirrors reflect light onto the screen through the projector’s lens.
The images are formed in different colors, but this switching is very fast. The human eye sees RGB changes as a color image.
DLP projectors are susceptible to rainbow effects. This is a visual anomaly associated with the color wheel.
DLP projectors have three chips. Each RGB color has a different chip and doesn’t use a color wheel.
White light passes through the prism, where it is split into three parts; red, blue, and green. These beams reach their respective chips.
Mirrors reflect colored light through prisms. This prism combines the light from the 3 chips.
When light passes through the lens, it is projected onto the screen as a colored picture.
DLP projectors are known for their color accuracy due to their high number of pixels. They are portable and cheaper than LCDs.
Applications of a Projector
Projector applications include:
- in the classroom
Projectors are used in the field of school education to describe topics. With the help of a projector, videos or photos become more interesting and kids can learn easily in a fun way. Also, we can easily zoom in or out of the image to clear the vision and search for secondary points.
- in the company
Projectors are used for conferences, presentations, and conference purposes in large multinational corporations and corporations.
- at home
The projector is even used as a home theater, allowing you to watch a movie or any series on a huge screen with top-notch sound that makes you feel like you’re watching it live.
Summary
The projector has come a long way since its invention. This journey is over a century old and has a lot to show.
These devices are a great way to get an immersive viewing experience anywhere. They compete with TVs in cost and efficiency.
