The term VDU is a more seasoned British term, which stands for visual display unit and uses to describe any device to show text and pictures. For case, examples of VDU are a projector and a flat-panel display. Although the term VDU usually depicts the CRT (Cathode Ray Tube) screen, a presently age-old standard that has been replaced by LED screens (flat-panel display). VDU functions to display pictures that are generated by any electronic devices like computer system.

The term VDU is often referred to use synonymously with "monitor," but it can also be used to describe the display as a digital projector. Generally, it is a device that may be integrated with the other components or may be peripheral devices. For instance, an all-in-one design is used by Apple iMac, in which computers and screens are integrated into a single unit.

Early VDUs had a 13" screen size or less and typically were primarily cathode ray tube display. During the 1990s, VDU display became more popular with 15," and 17" screen sizes and 20" screen size displays also began to produce by some manufacturers. During the early 2000s, flat-panel displays started to replace the CRT displays and became more popular; Even CRT displays became hard to find. In modern times, 20" to 30" of screen size is most common to come with computers. Also, the new technology LCD, plasma, and LED come with a large screen and much more cost-effective as compared to before technology.

Types of Visual Display Units

There are two types of screen technologies liquid crystals, and organic light-emitting diodes are most common for visual displays in the market. The cathode ray tube, an earlier technology, has almost disappeared due to the invention of a flat-panel display. However, the use of plasma monitors may see in some applications.

1. Liquid Crystal Displays: Liquid crystals are fluid materials that are made of liquid crystals, which act like a cluster of tiny shades that convey or block light. A backlight (bright light source) is located on the backside of the screen, which sparkles with the help of LCD and creates thousands of tiny dots of red, blue, and green that generate a color picture. You will never be unable to see the backlight directly as it is situated inside the display; it is only filtered with the help of an LCD panel.

2. Cathode Ray Tube: Sometime recently, in the 1990s, cathode-ray tube technology was used by nearly all computer displays, video screens, and television sets. A CRT is a thick vacuum tube containing a flattened screen on one end with a phosphor covering on the interior. For producing a glow within the vacuum, a beam of electrons from a hot metal filament screen strikes the phosphors at the end opposite side of the screen. For checking over and down the screen, an electronic controlling component bends the beam that scans the screen at the downside, which led to an arrangement of visible images on the screen. Although CRTs offer high-quality images, LCD and other unused innovations have driven the cathode-ray tube's obsolescence because they are more secure and much lighter in size.

3. LCD with Fluorescent Backlight: A fluorescent lamp, which produces a bright white light, is used by some LCD displays. It is cheaper, thin, and lightweight. The small amounts of mercury vapor are contained by fluorescents on the downside. In office settings and household, mercury does not create a serious problem.

4. LCD with LED Backlight: The LED backlight utilizes light-emitting diodes rather than a fluorescent lamp, which (LED backlight) is a newer technology for LCD displays. Although the LED does not use mercury, it produces white light.

5. Plasma Screens: Plasma screens produce a high-resolution image as they contain tiny gas capsules in the form of a grid, which shines much like a neon sign. The three-pixel colors (red, green, and blue) are combined by plasma display screens in order to form the whole range of colors, which is a much richer color as compared to CRT or LCD shows. However, due to battery life concerns, LCDs are more energy-efficient while comparing with plasma screens. Also, nearly all laptop computers do not use plasma technology, and they use the LCD screen. With most plasma screens, image quality helps justify the greater energy consumption as currently, they come in the 40-inch to the 60-inch size range. Although very large widescreens commonly use plasma shows, there are various plasmas that can be used as computer shows.

6. Organic Light-Emitting Diode: The OLED screen does not require a backlight, and they produce their own light; however, it is superficially similar to LCD technology. Due to this advantage, as compared to LCD equivalent, OLED displays can be much thinner in size. Also, OLEDs help to enhance battery life in mobile devices as a backlight consumes significant amounts of energy. Additionally, the working lifetime of OLEDs is currently not good as compared to LCDs, but their image quality is very good.

History of VDU

Initially visual display unit (VDU) was essentially cathode ray tube (CRT) shows. They were very large in size as of 13 inches or less. The size of 15" and 17" shows got to be standard in the mid-1990s, and 20" screen size displays also began to produce by some manufacturers. During the early 2000s, flat-panel shows started to replace the CRT displays and became more popular. Nowadays, the estimated size of 20" to 30" of screen size is most common to come with computers. After the development of LED, LCD, and plasma innovation, comparing to sometime recently, the construction of expansive screens is much more taken a toll.

Advantages of VDU

There are numerous benefits of visual display unit, which are as follows:

  • The price of VDU is not much high.
  • It produces a high-quality resolution.
  • Another benefit of VDU is animation capability.
  • It also contains a virtually boundless range of variable color capability.
  • The modern VDU's take less space as they are thinner.

Disadvantages of VDU

The visual display unit also has some limitation as well as advantages, which are discussed below:

  • Sometimes they require a specific number of graphics to display video and game on the screen.
  • They may impact character estimates as they may include restricting screen, and even it limits viable seeing distance.
  • The screen is sensitive that may lead to getting damage to the screen at the time of cleaning it.