How Does a Digital Projector Work ( Detailed Explanation )

How Does a Digital Projector Work,If you visit the cinema and take in the large screen and its characters that are larger than life, Have you ever wondered how images are created on the screens? As you are aware, the answer is with projectors. Projectors aid in improving the enjoyment of watching films. However, their use does not stop at the movie theater.

Projectors can also be used in conference rooms, boardroom classes, and other settings to enhance the overall experience. So, how can such a multi-purpose technology piece work?

There are two kinds of projection systems for digital display. The older, less expensive type employs three transparent liquid-crystal-display (LCD) panels, one for each of the primary colors (red, green, and blue). The transmissivity of light for each pixel depends on the data obtained through the computer. The light of a lamp is directed through LCD panels, collimated with lenses, and projected onto the screen.

The unit design is comparable to the slide projector, but the “slide” comprises three LCD panels placed close to the focal point of the lens that projects. LCD technology’s benefits include high efficiency, easy brightness and adjustments to contrast, and the ability to display high-quality images.

Read More: How to Project mobile screen on wall

A more modern, expensive method is called Digital Light Processing (DLP), a unique technology created through Texas Instruments. In the DLP display, tiny mirrors are employed in place of translucent panels. Each mirror represents a single pixel. Instead of being reflected through the panel, the light is reflected off it.

The mirrors rotate forward and forward, changing the quantity of light reaching the lens of projection from each one of the pixels. Color is produced through passing illumination from the lamps through a wheel adorned with green, red, and blue filters. It exposes the mirrors to light in every primary color through a quick rotation.

The result is a color-modulated image that our eyes perceive as natural colors. The advantages that come with DLP technology include its light mass, brilliant contrast, and no pixels.

Types of projectors

To catch a fish you have to think like a fish, and for you to understand every nit bit of such complex machinery, dissecting every part of it is necessary for you to get a grip on how does a digital projector works.

Inside a projector, there is special machinery used that divides the category of digital projectors into three types.

  • LCD
  • Digital light processing projector ( DLP)
  • LCOS

LCD projector or Liquid crystal display Projector

Numerous kinds of projectors were used in time past. However, the ones we’ll be looking at are LCD and DLPprojectors. At present, LCD projectors look obsolete. However, we’ll look because this model established the foundation for projectors to become a massive product.

To better understand the workings of an LCD projector, we must start at the point where the light beam starts. What first occurs is the creation of a powerful stream of light. The light beam gets reflected off a set of two dichroic mirrors. These mirrors are dichroic and have an exclusive coating that only reflects light with a single wavelength. White light is reflected off them, and each one is remembered with the beam of blue, red, and green lights.

The beams of red, blue, and green are reflected through an LCD that is made up of thousands of tiny pixels. A fascinating contradiction is created when you look at this… how could crystals be liquid? An LCD is a material that exhibits properties of solid and specific properties of the liquid.

With a tendency towards the liquid aspect of liquids, the LCD is unique in its ability to stop light from passing through or allow light to pass through when electricity is passing through it. In the projector, there are three LCD screens.

These three LCD screens will be responsible for projecting the same image or moving images using grayscale. When the light of a particular color traverses the three-screen, they transmit three different versions of the scene: one with a tinted red, another tinted green, and one tinted blue.

What happens when the image emerges to the correct color? The tinted images go through dichroic crystals, creating millions of colors!

Read More: What Does Short Throw Projector Mean.

Digital light processing (DLP) projector

The latest technology that has replaced LCD projectors is DLP projections. They were created around the year 1980 in the 1980s by Texas Instruments scientist Dr. Larry. J Hornbeck. DLP technology is built around a microchip, also known as Digital Micromirror Device or DMD.

The DMD is a microchip that has nearly the size of two million mirrors within an equilateral grid. They are incredibly tiny and are only one-fifth the width of human hair! They are mounted on a microscope, which is responsible for tilting the mirror that is mounted on it in one direction in the reverse direction.

A circuit with an electronic component is included, which assists in determining the direction that each mirror takes. A bright light source is projected onto the DMD, and the electronic circuit independently tilts every mirror in a row back and forward. If one of the mirrors is tilted to its lamp, it will shine its light onto the screen. This mirror is representative of a single pixel. If the mirror is angled away from the light source, it will not reflect the bright light source and leaves the screen area blank or dark.

Each mirror functions independently, and the two million mirrors work together to create an image of high resolution. So how is the color created, you think? The DLP employs a bit of technology to give color to displayed images. It is an emulsion wheel placed within the path of light reflected through the reflections on the DMD.

The wheel is composed of the colors blue, red, and green. This combination bounced on the mirror and joined, creating an unending array of colors in high definition. A lens then captures all the lights that bounce off to create an image.The next time you sit back with a bowl of popcorn at the theater, you’ll better understand how the magic of a movie can be created!

LCOS Projector or Liquid crystal on silicon Projector

They’re not just equipped with the most sophisticated technology built into them but also require the most expensive amount. However, as technology and progress in industrialization are progressing, the situation is beginning to appear positive regarding price costs as companies have launched a budget-friendly LCOS projector that can meet every kind of consumer needs and needs.

Liquid Crystal Technology (LCTS), or Liquid crystal on silicon is a more advanced and enhanced version of DLP and LCD projectors. It offers higher-quality images and is free of the rainbow effect, which you frequently see in DLP projectors.Although it is commonly referred to as hybrid technology, it’s far more than that since it can perform task better than its counterparts.

 Because it combines the capabilities that come from each LCD and DLP projection device, without any disadvantages in either technology, without the requirement for a spinning wheel of color.

It is because it has the unique 3-chip technology, which simultaneously provides a variety of green, blue, and red hues and combines it to create its image, which is more significant than a DLP projector.

But, as lots of hardware processes lighting and display on the projector’s screen, it can get heavy and affect the performance and portability. And that’s why DLP projectors are more favored in terms of their lightness compared to liquid crystal technology used in silicon projectors.

Want to know How Does a Digital Projector Work?

Now it’s time to discuss the working principle of all three types of projector i.e. LCD, DLP, and LCOS so that you can get a better understanding of this machinery.

How Does a Digital Projector Work
How Does a Digital Projector Work

How LCD projectors work

To understand the working principle you need to know the components of LCD projectors which are given below.

Components of LCD technology:


-2 Dichroic mirrors.

-LCD panels.

-Dichroic prism.


Working principle of LCD projectors

After you have mastered the parts It’s time to learn the principle behind their operation, which is as follows.

The light that a lamp produces is first reflected by the dichroic mirror which reflects light and lets some light be able to pass. The reflections of light turn red since this mirror is only reflective of light sources that have an opacity of red. These lights are then passed through a mirror, which will reflect the light on the LCD screen.

what is the purpose of LCD panel in LCD projector?

LCD panels actually modulate and control the amount of light that is being passed. This is done with the help of liquid crystals that are present in these LCD panels because when an electric field is applied to these liquid crystals, they actually change their alignment.

And when this happens, it actually allows more or less light to pass through it. So, when the electric field is turned on, more light is allowed to pass and when it’s turned off, less light is allowed to pass.

On the other hand, the lights that were allowed to pass through the first dichroic mirror are then again subjected to a second dichroic mirror which reflects green lights on an LCD panel, and only blue lights are allowed to pass. These blue lights are then reflected by mirrors and pass through an LCD panel.

Finally, all these lights that have been reflected by different mirrors and passed through different LCD panels are then united by a dichroic prism. Then it projects images through the lens.

Read More: How To Connect A Speaker To A Projector

How DLP projectors work

As we have mentioned before, we need to know the components first. So, let’s see these:

Components of DLP technology:

-Laser diode.

-Dichroic mirror.

-Phosphor wheel.


-Color wheel.

-DMD chip.


-Projection lens.

Working principle of DLP projectors:

Projectors of this type use the technology known as a digital micromirror device, or DMD. It is a device that contains a number of tiny mirrors, and the laser diode is utilized as a source of light for DLP projectors.

The light from the laser diode initially hits the dichroic mirror. Dichroic mirrors are an example of a filter that allows only specific wavelengths of light through.

The light wavelengths passing by the dichroic mirror are then transmitted to the Phosphor wheel. Certain lights go through the wheel while another light reflects off of it.

The mirror reflects the light that is passing through the wheel. The mirror reflects light onto the wheel. It is a spinning disc that is colored differently. It converts light into green, red, and blue hues.

And the reflection lights turn yellow due to the wheel of phosphor. They also pass through the color wheel but remain yellow, and the RGB light sources are reflected from mirrors. The mirror can reflect light onto the DMD chip.

The DMD chip is comprised of millions of mirrors. Each mirror represents a single pixel in the display. The angles of each mirror are adjustable. The light reflected off the DMD chip is reflected off the mirrors and onto the prism.

A prism can be described as a piece of glass with three sides. First, the prism reflects the light onto its second. Then, its second part reflects the light onto one side. And the light is then reflected off the first face and away from the projector’s lens, and you will get the projector’s images.

How LCOS projectors work

It’s time for our last projector-type LCOS projector. As before let’s know the components first.

Components of LCOS technology:


-LCOS panels.


Working principle of LCOS projectors

LCOS projectors are the type of projectors that uses a technology called liquid crystal on silicon or LCOS. the lamp is used as a light source in these projectors.

The lights from the lamp firstly fall on prism mirrors. From there the lights go on different LCOS panels and create RGB color lights. These RGB lights then enter another prism and create images through the lens.

Read More: Convex Lens? Why Does a Movie Projector Have One?

Different Attributes of a projector

A projector has many other features that differentiate it from one another, although these attributes differ on the basis of manufacturer and price point, most of them have the same principles and features.

  • Aspect ratio
  • Resolution size
  • Throw distance
  • Lumen brightness
  • Interfaces
  • Contrast ratio

These are the attributes that make a projector a whole and all of these technologies have a great deal of impact on the output of these attributes.


What makes 3d and 2d projectors different from each other?

A 3D projector uses an exclusive lens that transmits images to the screen. It’s similar to binoculars. It is crucial because it permits you to display the images on the monitor from multiple angles. Two-dimensional Projectors, however, on the other hand, only project images onto the screen at a specific angle. It means you cannot see your image either from one side or directly above or below the screen.

Do I need to buy a tripod for my projector?

You will require an appropriate tripod when using a projector with lenses that are not attached to the stand. The tripod lets you place the projector on your wall or ceiling so that light can shine through the lens.

What is the difference between a traditional projector and a digital projector?

A traditional projector is one that has a spinning color wheel. The light shines through the color wheel and a prism reflects the light onto a screen. A digital projector uses an LCD panel and a digital chip to deliver the image.

What are the benefits of a digital projector?

The benefits of a digital projector are numerous. The main benefit is the ability to make a much larger screen and it is much brighter than a traditional projector.