Parts of a Projector (Internal & External)

Projectors stream images from their source to a screen, allowing you to view visual presentations and videos for work, school, or leisure. The typical modern projector consists of four main parts. While these may vary from model to model, they typically include the color wheel, the lamphouse and bulb, the projection lens system, and the cooling system.

Because projectors make images large enough to be seen by many people, they can enhance your viewing experience immensely. These machines are available in several configurations, but most of them share the same components. Let’s review all the parts of a projector.

External Parts

The external parts of a projector are designed primarily to protect the internal components or allow you to control the functions without tampering with the inside. They are also crucial to image production and the proper running of the projector. They include:

Case and Controls

The internal parts of a projector are usually encased in a metal or plastic case for protection. The case houses the cooling fans that regulate the projector’s temperature and provides somewhere to mount electronics.

Additionally, it also contains switches or control knobs that you can use to move the lens and control the image size and focus or vary the brightness and contrast. The case is also where you will find the infrared sensor that receives signals from the remote control.

Power Supply

The bulbs and mainboard in a projector require a power supply to function. The motorized lenses in the projector also use this power to manipulate the lens by driving the electric motors.

In some cases, the power supply can be housed internally, but it is usually present as a power adapter found outside the projector. This configuration is especially common in smaller models.


Projectors have several buttons on the case to help you manipulate and control the system. Arrow keys allow you to navigate the system interface, and the Enter button helps you select settings. If you cannot find your remote, the Menu button gives you access to the interface. Other buttons present include:

  • Power Button
  • AV Mute button
  • Input Search Button


The Power AC socket is the most important port on a projector because it allows the system to get power supply. Other ports found on the outside of a projector include:

  • Audio Output Port: Used to connect the system to external headphones and speakers.
  • VGA Port: Used to input video signals from a PC or laptop with a VGA output port.
  • Video In Port: Used to input video signals through the RCA cable from a video player.
  • USB Port: Used to plug small devices with USB males.
  • LAN Port/Ethernet Port: Used to complete internet or wired network connections.
  • HDMI Port: Used to input video signals from a source with an HDMI output port.
  • Security Slot/Safe Slot: Protects the projector from theft.


Projectors run hot after operating for a while, and the case is fitted with cooling vents to dissipate the heat. It also has intake vents that let in cold air from around the projector to cool the internal parts.

Other Features

Projectors also feature speakers to deliver the audio feed from the video signals and adjustable feet to adjust the projector’s height from the ground.

Internal Parts

Projection Lens System

The projection lens system comprises an optical system created by connecting several lenses in a sequence. The system focuses light from the lamp to the lens to produce the image you see.

Depending on the model, the projection lens system can be located inside or outside the lamphouse. It is mounted onto a lens-shimming mechanism or adjustable base that allows you to adjust focus, perform keystone correction, and track magnification.


The optics in a projector are responsible for transferring internal images onto a screen so you can view them. They comprise a series of prisms and mirrors that split and reflect the light entering the projector into its component colors.

Essentially, a bulb shines on a complete image through a mirror, and the light goes through the projector lens to the screen.


The mainboard of a projector is a computer board with electronics and chips that control all the system’s internal processes. It drives the projector’s image engine, enables the external controls, ad regulates the cooling system. Simply put, it is the brain of the projector.

Lamphouse and Bulb

The lamphouse houses electrical controls and the projector’s lamp. The controls adjust the output from the lamp to promote optimum color fidelity and brightness, and the system’s lamp is the light source.

In more modern models, the lamp is actually a bulb comprising of multi-element lamps that generate blue, red, and yellow lights. The whole system projects light onto the screen in the form of images.

Image Engine

The image engine is arguably the most important part of the projector. It is responsible for producing images within the system and displaying it on the screen.

Depending on the model, it will usually be driven by cathode ray tube (CRT), digital light processing (DLP), or liquid crystal display (LCD) technology.

Color Wheel

The color wheel is a rotating disc comprising green, blue, and red sections that spin in front of the light beam to produce different colors. This process is called interference and helps you view your images and video streams in full color.

Cooling System

A projector’s cooling system is made up of a refrigeration unit, condenser fans, and a compressor. As the name suggests, it is responsible for keeping the projector at optimum temperature. The refrigeration unit can be either an evaporator or coil and cools the lamphouse and liquid crystal panel.

Focus Lens and Keystone Mechanisms

The keystone correction mechanism corrects anamorphic distortions on the corners of the screen, while the focus lens mechanism is responsible for producing sharp images by adjusting the lens.

Offset/Perspective Correction Mechanism

This mechanism compensates for the horizontal and vertical displacements caused by your eye’s movements. They ensure the stream consists of steady images throughout.


The tracking system in a projector is designed to compensate for slight image movements caused by an uneven projector screen. It mainly consists of rollers and gears and is found inside the optical system.

Lens Shift

Also called the lens offset, the lens shift mechanism compensates for horizontal and vertical movements in the image source caused by mounting height variations.


These are the main parts of a projector, and they all play an important role in your viewing experience. As mentioned, some of these parts will be located in different places on some projector models or have slightly different names, but they play the same roles.

The external parts protect the internal parts and help you control the system’s functions. Other external parts like the vents and ports are also central to the workings of the projector. Meanwhile, the internal parts are central to video streaming.

Leave a Comment