Computer monitors have evolved over the years, and image quality has followed suit. This article will explain what a monitor is and the different types you can get.

We will also explain more about the various types and how they connect to a computer. The connectors also evolve to keep up with the demands of newer display technology.

What is a monitor?

computer monitor

A monitor is a display device like a TV screen that interprets and displays the graphical output signal from your computer’s graphics card and displays it on the screen.

This enables you to view the display interface to interact with the computer using various peripherals like a mouse or keyboard from output devices like graphics cards.

Different types of monitors and how they work

Knowing about the different types is beneficial to have a better understanding of what a monitor is.

Display technology in various applications has evolved, sharing the same base technology.

Both the television and computer screen started using the vacuum CRT (Cathode Ray Tube).

CRT Monitors

crt monitor

This type of monitor required more power and electronics to operate. A lot of the analog circuitry was cumbersome and took up a lot of space with a small screen by today’s standards.

How they work depends on the type of CRT components and how they work together to deliver a similar result.

For the sake of this article, I’ll stick to explaining the most common types of CRT monitor components and how they work.

The complete outline of how a CRT monitor works would in itself be a full article, so I will try to keep this as brief as possible.

A CRT (Cathode Ray Tube) monitor works by taking the information from the various electronics PCBs that have processed the incoming signal from the computer’s display card.

From there, processing and splitting up the colors with a signal sent to the CRT tube base board connected to the back of the CRT tube.

Electron guns for each color fire electrons onto a phosphorous area for the specific color related to it.

The shadow mask

A shadow mask is a protective layer with holes in it aligned to the specific phosphorous areas where electrons are meant to strike, preventing the electrons from landing in the wrong location.

You could say then that the shadow mask essentially prevents color purity issues.

The shadow mask is constructed from metal and, because of this, is influenced by magnetic fields.

That’s why a degaussing coil is fitted around the front area of the CRT where the shadow mask is located and is fired up for a short moment each time the monitor is turned on to degauss the shadow mask, thus preventing color purity issues.

Deflection coils

If it wasn’t for a set of deflection coils located at the neck of the CRT, electron beams would simply fire in a single dot in the center of the screen from the electron guns’ original firing trajectory.

Deflection coils are powered by the CRT’s electronics circuits to get the electronics to be pulled in the proper direction.

The vertical deflection aspect of CRTs is referred to as the frame, and the horizontal is referred to as the line.

The beams are directed from top left to right in successive lines until the bottom of the screen to complete one total frame.

The final anode

An extra high voltage anode called a final anode is attached to the side of the CRT to help accelerate the electrons toward the phosphorous coatings inside the display area’s glass.

The line output transformer

This voltage of around 55 to 60 kV is produced from a line output transformer located on the main chassis circuit board.

This transformer also provides a high voltage, up to 600 volts, to assist with the focus, which is connected via the tube base board and supplied to the G3 control grid.

It also produces the voltages for the G1 (brightness) and G2 (flyback voltage) control grids, which affect image brightness or prevent flyback lines or brightness cut-off, respectively.

A voltage to the cathode heater is also supplied from the transformer.

The inside of a CRT screen with the main parts identified.

Impractical aspects

The CRT requires a certain distance between the screen area and the electron guns at the end of the neck, leading to a part of the heavy space requirements.

So apart from being heavy, bulky, and harsh on your eyes, they actually have a decent viewing angle.

The other obvious downfall is the obvious fact that it couldn’t be used for a laptop monitor.

Common CRT resolutions

Here are some of the common resolutions for CRT monitors based on display size:

CRT Monitor SizeCommon Resolution in Pixels
17 Inch (4:3 Aspect Ratio)800 x 600
19 Inch (4:3 Aspect Ratio)1280 x 1024
20 Inch (4:3 Aspect Ratio)1600 x 1200
20 – 22 Inch Widescreen (16:10 Aspect Ratio)1680 x 1050
24 Inch Widescreen (16:10 Aspect Ratio)1920 x 1200

LCD Monitors

lcd monitor

LCD (Liquid Crystal Display) Monitors replaced the CRT. Initially, they had performance issues to do with response times, but eventually, those problems were solved.

Liquid crystal molecules are placed between two electrodes. The amount of light that can pass through the liquid crystal molecules is determined by the amount of electrical charge applied to the electrodes.

LCD Monitors require backlighting to illuminate the image for us to see. This backlighting technology has also undergone some revolutionary changes.

In the beginning, CFL(Compact Fluorescent Lamps) were used. Inverters were used to step up the voltage to power them up and ended up being a common component that failed over time.

Thankfully, the CFLs were replaced with LEDs. This made LCD monitors way more reliable.

We will go into the various backlight technologies further down in this article.

Common types of Active Matrix LCD panels:

IPS Panels

In-Plane Switching panels were created to solve the poor viewing angles and low-quality color of the TN panels.

They are more commonly used in professional environments because the refresh rates aren’t the best for gaming.

But when it comes to image quality, it delivers great results. And, it comes with a little extra on the price.

The response times are faster than VA panels but slower than the TN panels.

TN Panels

Twisted Nematic panels are the most commonly purchased by consumers. They deliver reasonable response times at a reasonable price.

Common styles of LCD monitors

There are different styles of LCD computer monitors that are designed for use in different industries.

  • Rackmount: Designed to mount onto standard 19-inch racks, they can be done as fold away or fixed rackmount style, depending on your needs.
  • Desktop: A standard computer monitor that uses the default stand provided by the manufacturer.
  • VESA Mount: A standard mount of either 75mm x 75mm, 100mm x 100mm, or 200mm x 200mm for mounting to brackets for swiveling or wall mounts. Many standard computer monitors have these mounts built into the back of them.
  • Panel mount: A flat mounting style with a flange designed to be mounted in a cut-out of some kind like a wall, to mention one example.
  • Open frame: These monitors are designed with multiple mounting options created on a metal or aluminum frame. These monitors are ideal for products such as kiosks, arcade video games, or interactive music systems.

As you may have noted, computer monitors come in various designs for many applications.

Common LCD resolutions for desktops

Here is a list of common native resolutions for LCD panels of various sized and aspect ratios:

LCD Monitor Size and Aspect RatioCommon Native Resolution (Pixels)
15 Inch (4:3)1024 x 768
17 Inch (5:4)1280 x 1024
19 Inch (5:4)1280 x 1024
20 Inch (4:3)1600 x 1200
17 Inch Widescreen (15:9)1280 x 768
19 Inch Widescreen (16:10)1440 x 900
21 – 28 Inch Widescreens (16:9)1920 x 1080
29 Inch Ultrawide (21:9)2560 x 1080
30 Inch Widescreen (16:10)2560 x 1600
32 Inch Widescreen (16:9)3840 x 2160
34 Inch Ultrawide (21:9)3440 x 1440
38 Inch Ultrawide (12:5)3840 x 1600
49 Inch Ultrawide (32:9)5120 x 1440

LED Monitors

Light Emitting Diode monitors are essentially LCD monitors with LED backlighting to illuminate the LCD image.

Personally, I’m not a fan of this name for this type of product. If it is truly an LED monitor, shouldn’t the pixels themselves be produced by an LED itself?

Although, that technology is on its way. Television manufacturers are putting their interest in micro-LEDs. This is where microscopic LEDs are placed in an array to form the pixel itself.

I have no doubt that this technology will make its way into computer monitors.

QLED Monitors

QLEDs or Quantum Dot Displays are used to convert the backlight to emit pure basic colors.

These semiconductor nanocrystals are placed in a Quantum Dot layer in order to help RGB color filters by reducing light losses and color crosstalk.

Electro-emissive versions are in their experimentation stages. This means that by applying an electric current to inorganic nano-particles, a pixel is formed by a Quantum-Dot Light Emitting Diode (QD-LED).

This would allow for great color ranges and near-perfect black levels on the display.

Recommended Monitor

Samsung Odyssey G7 32 Inch

24 022 816 S10

I like it for the curved display and the well-rounded features. Once you experience the 240Hz, the 1ms response time, GSYNC and FreeSync compatible, HDR 600, and QLED technology, all packed into one solid monitor.

Different types of video connectors

Here are some typical video input connectors you will find on the back of computer monitors.

These connections allow your monitor to connect to your computer’s graphics card to display information.

VGA

a VGA connector up close

Video Graphics Array is a technology that is obsolete. It has been around for a long time, but an analog video signal is no longer the desired standard. It is not able to carry an audio signal.

DVI

a male DVI plug that connects to a monitor or graphics card

Digital Visual Interface is a digital video signal connector that is used not only in computer monitors but in other consumer electronics too.

Dual-link DVI carries twice the data rate compared with that of single-link DVI. This has allowed for higher resolutions and refresh rates.

Dual-link has a maximum data of 9.90Gbit/s @ 165 MHz.

No audio signal can be carried over this connection.

HDMI

an HDMI connector closeup shot

There are 5 types of High-Definition Multimedia Interface connectors:

  • Standard (A)
  • Dual-Link (B)
  • Mini (C)
  • Micro (D)
  • Automotive (E).

This is a replacement for analog video standards and can transmit uncompressed video data and compressed/uncompressed audio data.

Incremental versions have arrived over time with improvements.

HDMI is used in a broad variety of consumer electronics, even when it comes to computers.

Version 2.1 is capable of delivering a maximum total data rate of 42.5Gbit/s.

DisplayPort

a display port connector close up

DisplayPort is more commonly used in the computer market, rather than in general consumer electronics.

The latest version 2.0 has a maximum total data rate of 77.37Gbits/s.

DisplayPort comes in two sizes, the standard size and a Mini DisplayPort.

Thunderbolt

a thunderbolt plug closeup

The previous versions (v1 and v2) use the same connector as a Mini DisplayPort.

The latest Thunderbolt version 3 uses a standard USB C connector.

Thunderbolt combines PCI Express and DisplayPort into 2 serial signals and provides DC power.

USB C

a usb type c connector up close

USB C Monitors are quite new to the market and tend to be a popular trend for mobile monitors.

You will most likely need a cable that can connect your monitor from USB C to Display Port or HDMI, for example.

Two different styles of power connectors

power brick or power supply for monitor
External Brick Power Supply
iec power plug inlet monitor
Internal Power Supply Using An IEC Mains Cable

Some monitors are built with internal power supplies, and others rely on external power bricks.

Those with an internal power supply usually require a power cable that goes straight from the mains power to an IEC plug that plugs directly into the back of the monitor.

For displays that require an external power supply, power goes from the wall socket into the power brick.

The power brick steps down and converts the mains supply to DC. It is very common for the monitor to run off 12 Volts DC.

While the external power brick makes life a bit harder when it comes to cable management or keeping things tidier, it has one major advantage.

Quite often, monitors go faulty because of a fault in the power supply. It’s way easier and cheaper to replace a common power brick than to get the whole screen repaired or replaced.

The advantage is that by having components crammed inside the monitor, the internal operating temperature should be reduced.

Aspect Ratios

The aspect ratio is the horizontal width of the display with respect to the vertical height.

Different types of aspect ratios are used for different applications.

Multi-Monitor Arrangements

Computer graphics cards have the capability to output to multiple monitors at once and span the display across them to treat them as a single one.

This is particularly nice for gaming.

Orientation

For some types of professionals, monitors are physically rotated 90 degrees so that the screen is vertically taller than wide.

One example is to help computer programmers see more code at once. Not all programmers do this, just thought I’d mention that.

Some monitor models have this capability built into them, so no modifications are necessary.

Resolution

The resolution is specified by the number of pixels starting with horizontal and followed by vertical.

For example, 1024×768 means that the resolution contains 1024 pixels in width and 768 pixels in height.

Pixel pitch

Pixel pitch is the amount of space between each pixel. This greatly impacts the quality of an image on a screen.

If the pixel pitch is too large, it won’t matter how high the resolution of your monitor is, the image will be poor.

Refresh rate

The refresh rate is the number of times the entire screen can be updated per second.

For example, if the screen has a 60Hz refresh rate, the screen can be fully drawn 60 times in one second.

Nowadays, a 144Hz monitor is more common and doesn’t affect the overall price of a computer monitor as much anymore.

Response Time

This is the rate at which a pixel can be changed from black to white or from one shade of grey to another.

While you can count the rate at which other color shades of pixels change, black, grey, and white are most the extreme opposites in contrast with respect to each other.

Therefore, they will be noticed first.

Response time is usually written on the millisecond scale.

Desirable response times are anything starting at 5ms or lower.

Touch screen monitors

Touch screen monitors are used in many commercial and industrial sectors and for personal use.

From point-of-sale devices to laptops and desktop computer monitors, touch screen monitors offer a different way to interact with a computer.

It can replace the need for a mouse in some cases but can require a need for a larger DPI for a user interface if no stylus is available.

Touch screen monitors are essentially standard LCD monitors with a touch screen glass panel mounted over them.

These glass overlay panels have a few different types of touch screen technologies. We will cover the different types and some advantages and disadvantages.

Resistive

Simply put, resistive touch screen panels are glass panels with two striped electrode plastic sheets and a center separation sheet with a grid of holes allowing the two out sheets to make contact through the holes when the panel is touched.

This is the least robust out of all the panels, as wearing eventually makes it unreliable. The quality of the display can also be affected as the plastic surface develops scratches over time. One advantage is that it will work with gloves.

Capacitive

There are four common types of capacitive touch screen technologies. Here is an outline of each one. All capacitive technologies are quite robust and will offer a good long-lasting product.

Surface Capacitance

Capacitance is formed from a finger that touches an uncoated surface with the other side of the glass panel that has a conductive layer.

Good finger contact is required for best results. These types of panels must be properly calibrated and can be sensitive to improper grounding, background noise, and temperature fluctuations.

Projected Capacitance

PCAP capacitive panels with an etched single conductive layer form a grid pattern of electrodes that processes touch using a more sophisticated firmware program to decode the touches.

Moisture or dirt particles can interfere with the operation, so it is not always the best choice for some applications.

Mutual Capacitance

A grid is laid out with a voltage that is applied to the rows or columns to detect a conductive element such as your finger or conductive stylus.

The detection works by picking up a change in the conductive field in the grid.

This kind of panel is good for multi-touch purposes, where it can simultaneously detect two or more contact points.

Self Capacitance

Self-capacitance panels are laid out very similarly to mutual capacitance panels. But the X and Y parts of the grid can operate independently.

The capacitive load is measured on each column or row by using a current meter or an RC oscillator to detect a change in frequency.

This kind of panel is very sensitive to touch and is great for multitouch applications like tablets and smartphones.

Infrared

An array of sending and receiving infrared LEDs is placed along the inside of the frame or bezel of a monitor to detect a disruption between them.

However, this is not a very reliable technology and is highly sensitive to dirt blocking the path of the infrared light causing false positive touches.

Optical imaging

With optical imaging touch screen panels, image sensors are placed in the corners at the edges of the screen, and a touch blocks the infrared backlight’s light in the sensor’s field of view.

These types of touch screens are becoming more popular for larger displays.

In conclusion, to touch screens, there are more technologies available on the market, and the list is growing.

Curved Displays

an example of a curved computer monitor

There are pros and cons to curved displays. In my opinion, you need to try one out to see if it’s something for you or not.

These curved monitors can offer a slightly more immersive experience when it comes to gaming but can be a bit more expensive compared to traditional flat panels.

Power consumption

Power consumption has been reduced considerably since CRT displays have fallen away.

Now, a common desktop monitor consumes between 60 and 250 watts of power. In standby mode, roughly between 1 and 6 watts.

Conclusion

And there you have it. You know what a monitor is, and more than that, the different types.

I hope you enjoyed the information and knowing more about them.