How projectors work

How projectors work

How projectors work

Before we discuss how projectors work, we shall look into the categories of projectors. There are many categories of projectors classified according to several factors. The first way of classifying projectors is based on the type of lamps used. In this category, there are laser projectors, LED projectors, and xenon lamp projectors. The other category is based on what is used to display the images. In this category are the digital light processing projectors and the LCD projectors.

History of projectors

The first projector was subtly engineered in the year 1984.  It was an LCD projector. Its inventor was Gene Dolgoff after experimenting with the idea in 1968. Today, despite the countless and unceasing advancements in display technology, projects remain relevant. The first projectors worked efficaciously in a simple way.

LCD projectors proved to use less power than the CRT and were more so reliable and lighter. Additionally, they have been smaller and cheaper. On its own, the LCD project is useless and it requires a wall or a screen from where all the images are projected. A white sheet will suffice.

Method of projection

There are only two types of projection; frontend and backend projection. The traditional projectors -LCD, LASER, and DLP– work using front-end projection. This means that the screen is placed in front of the audience. You could be wondering how backend projection works. Well, the audiences are behind the screen. This is how the current television sets and other modern display screens work.

How it works

The process begins with the production of very bright light. This beam is directed to a group of mirrors.  There are two special dichroic mirrors (they have a special coating). Dichroic mirrors special attributes make them reflect only one type of wavelength. Once the light hits the mirrors, it is split into three primary colors light, blue, green, and red.

The light is made to pass through the LCD screens.  There are three such screens in a projector. LCD screens have a special attribute that makes them either allow light to pass through or block when electrons pass through them. An LCD screen contains numerous tiny pixels. Now when the light passes through the three LCD screen is tilted red, blue, and green. However, each screen can tilt only one color only.  To produce a colored image, the image is finally passed through a dichroic crystal which gives birth to countless colors. This is how projectors work in general.

Pros and Cons of an LCD

Now that we know how best LCD projectors work, we can take a look at the advantages and disadvantages of LCD projectors.

Advantages of LCD projectors

You will realize that there are both advantages and disadvantages that are associated with the LCD. Despite their unceasing persistence in the market, LCD has numerous disadvantages that have led engineers to seek ways to improve them; and sometimes seek better alternatives. However, let us look at their advantages first.  What can the 3 LCD projectors do that other types of display cannot do? Well, for starters, the image is very clear and detailed using only 25% less electricity than other projector technology.

Secondly, you do not have to worry about wearing out the film or the data storage since they rely on the external source of data.  For instance, most projectors rely on either a camera, DVD, or a computer.

Thirdly, LCD projectors do not have the rainbow effect that the DPL projectors experience. DPL projectors have a color wheel that spins. Additionally, LCD projectors enjoy a high contrast ratio that makes them have sharper images. Finally, they are very cheap compared to the LCD. For instance, the DPL projectors could be going for more than $ 34,000 while LCD projectors cost less than $ 10,000.

Read more on the best ultra short throw 4K projectors.

Disadvantages of LCD projectors

The disadvantage of LCD projectors is that they require maintenance and upkeep. It is common knowledge that pixels burn out and with time the quality of the image reduces. Further, dust is known to settle on the LCD screens making the image appear smudged.

Currently, many projectors require a separate audio system such as Bluetooth speakers, etc. which means that if you need to listen to the sound, a separate system will have to be carried out.  This makes using them a very tedious endeavor. Most of these devices require a dark room for the images to be clear. Today, there are special projectors that can be used even when the lights are on in a room.  Take a look at the best outdoor projectors for daylight.

Benefits of projectors

I desired to make you understand how projectors work before you consider dismissing them as not suitable for various uses. Here are the benefits that projectors have over other types of displays.

Portability: projectors of whichever kind are highly portable today because of their light mass and small sizes.  This is not the case with the current 56″ screens whose likelihood of being broken outweighs their need for mobility. Further, projectors come with special bags from which you can carry them around. Their lightness makes sure you can carry them for prolonged periods or long distances without exhaustion. Church projectors have benefitted so much from this.

Enlarged images: the images from projectors can be very large depending on the distance between the screen and the projector. Additionally, such images with being sharper, detailed, and very clear due to the high resolution and contrast ratio of the projector. Unlike a 24” screen a single projector can be used in a room full of 100 or so people.

Eye comfort: eye comfort is a function of the amount of light from a screen. Unlike make LED, LCD, and OLED screens, the brightness of the projector can be adjusted as much as you wish. Furthermore, the type of screen used for the projector can always be changed accordingly. The above-mentioned types of screens have blue light from pixels emitted with higher intensity than other primary colors. This is the primary cause of strains you experience when watching a movie.

Adjustable image size: Unlike all other types of display, projectors possess an attribute where you can adjust the sizes of the images as much as you would like. The ability to adjust images have been exploited in make LED projectors suitable for Christmas.


as was indicated on our projector buyers guide, projectors have unceasingly evolved. Their uses and benefits are undeniably many so even are their varieties and type. Today, the most common uses of projectors are PowerPoint presentations at the workplace or as a display screen for other devices such as computers and DVDs.  You have unlimited options to choose from depending on their uses and your budget. However, there are several factors you need to consider before going for a projector.  Such factors include lenses, base stage, and lamp life cycle among others.



DLP projector (Digital light processor)

Laser projector