Types of visual display units
Simply known as a monitor, a visual display unit or a visual display terminal (VDT) is an output device that receives video signals from a computer and projects moving images. It is widely used in computing, security, and entertainment, among other sectors. Different types of visual display units include;
- Cathode Ray Tube (CRT) Monitor: The technology involved in the production of VDTs is the same as that of television, and it has been around for decades. A cathode-ray tube monitor is a bulky, heavy screen that uses a vacuum tube to display images. The CRT can be used as a computer monitor. However, as technology advances, these monitors are being replaced by flat-panel displays because they are heavy, bulky, and consume more power. CRT monitors are available in various sizes, measured diagonally in inches. The most common sizes are 17 inches and 21 inches.
- Flat Panel Display: This is a thin, lightweight computer monitor that does not use cathode rays. It is made up of two large sheets of glass, which are liquid crystal display (LCD) and plasma display panels. The liquid crystal display panel consists of tiny cells that contain liquid crystals that can be polarized to allow or block light to pass through. They are available in various sizes, including 15, 17, and 19 inches. The LCD monitor is thinner and lighter than the CRT monitor, making it ideal for wall mounting. Additionally, it consumes less power. On the other hand, a plasma display panel is made up of cells of gas between two panels, which produce ultraviolet light when the cells receive an electric charge. The ultraviolet light excites the phosphors, causing them to glow and produce images.
- Organic Light Emitting Diode (OLED): An OLED visual display unit is a flat light-emitting technology that has a light source and light-emitting layer between the two electrodes. The organic layer contains a carbon-based compound that emits light when the current flows from the cathode to the anode. The material used in the production of an OLED is not only more flexible, but it also requires no backlight, making it thinner and lighter. The images produced are brighter and sharper, with a higher contrast, and the viewing angles are better.
- Medical Grade Display: A medical grade visual display unit is used in healthcare for various purposes. It is used in imaging modalities, which include X-ray, MRI, ultrasound, and endoscopy. These diagnostic imaging modalities have to be viewed on a display unit with high brightness and contrast to provide accurate results. Additionally, the visual display unit is used in surgical suites, where it is linked to cameras and equipment to monitor the patient and procedure. It is important for the display unit to provide accurate color reproduction to differentiate between tissues.
- Automotive Display: An automotive visual display unit is a visual display unit that is installed in cars to provide information and entertainment to the driver and passengers. Currently, there are two types of automotive display units: the instrument cluster and the central display. The instrument cluster is a digital replacement of the traditional analog dials that display information like speed and fuel levels. On the other hand, the central display unit is mounted on the dashboard to display audio and navigation information. It also acts as a control center for functions like climate control and seat heating.
Functions and features
Visual display units have several features that distinguish them, and these features are essential to their functioning and performance in various applications. Some of the most important features include the following:
- Resolution: One of the most important features of any display monitor is its resolution. This refers to the number of pixels that can be displayed on the screen. The higher the resolution, the better and sharper the image will be. VDUs come in several resolutions, ranging from standard definition to high definition and ultra-high definition.
- Contrast ratio: The contrast ratio is the difference between the brightest white and the darkest black that can be displayed on the screen. VDUs with a high contrast ratio will show more detail in the dark areas of the picture and bring the image to life.
- Brightness: Brightness is an essential factor to consider when selecting a monitor. It is measured in candelas per square meter (cd/m2) or nits. The standard brightness for indoor VDUs is 300 nits, while outdoor monitors should have a brightness of at least 700 nits.
- Refresh rate: The refresh rate of a monitor is the number of times per second the screen is refreshed. A higher refresh rate will provide a smoother viewing experience, especially when watching videos or playing games. Most standard monitors have a refresh rate of 60 Hz, while some newer models have a refresh rate of 144 Hz or even 240 Hz.
- Response time: Response time is the amount of time it takes for a pixel to change from one color to another. A lower response time will reduce motion blur and ghosting, providing a better gaming and viewing experience.
- Aspect ratio: The aspect ratio of a monitor is the ratio of its width to its height. The most common aspect ratios are 4:3, 16:9, and 16:10. Standard monitors have a 4:3 aspect ratio, while widescreen monitors have a 16:9 or 16:10 aspect ratio.
- Viewing angle: The viewing angle of a monitor is the maximum angle from which the screen can be viewed without any loss of image quality or color distortion. Most modern VDUs have a viewing angle of 178 degrees, which means the image can be seen from almost any angle.
- Display technology: There are several display technologies available, including liquid crystal display (LCD), light-emitting diode (LED), organic light-emitting diode (OLED), and quantum dot. LCD monitors use a liquid crystal to display images, while LED monitors use light-emitting diodes. OLED monitors have individual organic pixels that emit light, providing a higher contrast ratio and better color reproduction. Quantum dot monitors use quantum dots to produce more vivid colors. Each technology has its advantages and disadvantages, so it is essential to choose the one that best suits the needs of the application.
Applications of Visual Display Units
Visual display units can be employed in numerous applications, which include the following:
- Entertainment: One of the primary applications of visual display units is for entertainment. Televisions are used to watch movies, shows, and sports. Gaming monitors are also a popular form of visual display designed for gaming. They offer features like high refresh rates and adaptive sync for a smoother gaming experience.
- Education and Training: VDUs are extensively used in educational institutions for teaching purposes. Interactive whiteboards are a type of large VDU that allows teachers to display visual aids, videos, and presentations. Students can also interact with the content by touching the whiteboard. Additionally, VDUs are used in training programs for employees to visualize information and learn new skills.
- Control Centers: In control centers such as traffic control rooms, security monitoring stations, and power plants, multiple visual display units are used to monitor and manage various operations. These VDUs are usually arranged in a video wall configuration to display multiple sources simultaneously.
- Advertising and Digital Signage: In shopping malls, airports, and other public spaces, visual display units are used for advertising purposes. These displays can be used to display ads, announcements, or other information. They can be in the form of digital signage, which is a dedicated display for this purpose.
- Medical Imaging: VDUs are essential in medical environments for viewing medical images such as X-rays, MRIs, and CT scans. These displays need to be of high quality and resolution to accurately view and diagnose medical images. They are usually calibrated so that the colors are accurate.
- Gaming: Gamers use visual display units to play video games. Gaming monitors have features such as high refresh rates and low response times to provide a smooth and responsive gaming experience. They are also available in large screen sizes for an immersive experience.
- Home Office: With the rise of remote work, visual display units are used in home offices for tasks such as video conferencing, productivity, and content consumption. Many people use a computer monitor as their display for their work laptop or desktop.
- Industrial Applications: In industrial settings, like manufacturing plants, VDUs are used for process monitoring, control, and visualization. These displays help operators to monitor equipment, processes, and alarms.
- Simulation and Virtual Reality: VDUs are used in simulation systems and virtual reality setups to create immersive experiences. These displays need to have a high refresh rate and low latency to provide a smooth experience.
How to Choose Visual Display Units
When buying visual display units in bulk, consider the following factors to ensure the monitors meet the needs of various customers.
- Screen size and resolution
Screen size is an important factor when choosing a visual display unit. If people want to use it for watching movies or playing games, a larger screen would be better. However, when it comes to work, a smaller size is more appropriate as it is more space-saving, and it is good for the eyes. About the resolution, the higher, the clearer. Normally, 1920*1080 is enough for most uses. The sellers can choose the size according to the customer group's needs, and 1920*1080 is a very common resolution for them to choose.
When buying a visual display unit, it is important to know what kind of ports and cables it has. This is because different devices require different ports and cables to connect. For example, a laptop may need an HDMI cable to connect to the monitor, while a gaming console may require a VGA port. Therefore, before buying a monitor, it is essential to check its connectivity options to ensure that it can be easily connected to other devices.
- Refresh rate and response time
The refresh rate and response time of a visual display unit are important considerations when buying a monitor. The refresh rate refers to how many times per second the screen refreshes, while the response time is the time it takes for a pixel to change color. A higher refresh rate and lower response time result in smoother motion and reduced motion blur. For gaming and fast-paced content, a 144Hz refresh rate is recommended, while a 60Hz refresh rate is sufficient for general use. Likewise, a response time of 1ms is ideal for gaming, but 5ms is acceptable for other purposes. Understanding the significance of refresh rate and response time enables a buyer to make an informed decision when purchasing a monitor.
When choosing a visual display unit, the kind of panel technology should be taken into consideration, as the panel has a significant impact on image quality, color reproduction, and viewing angles. There are a few common types of panel technologies: TN (Twisted Nematic), IPS (In-Plane Switching), and VA (Vertical Alignment). TN panels are affordable but have narrower viewing angles and less accurate colors. On the other hand, IPS panels are more expensive but offer better color accuracy and wider viewing angles. VA panels provide high contrast ratios but are slower, resulting in motion blur. The panel technology is an important factor when choosing a monitor, as it affects image quality and viewing angles. IPS panels are usually preferred for their color accuracy and wide viewing angles, although they are more expensive than other types.
Q and A
Q: What are the different types of visual display units?
A: The types of visual display units may vary, such as multi-touch screens, digital signage, desktop monitors, interactive whiteboards, and video walls.
Q: What are the benefits of a visual display unit?
A: A visual display unit can improve productivity and efficiency. It can also improve communication, enhance learning, and engage customers and employees.
Q: What is a visual display system?
A: A visual display system is an information presentation system that gives form to data in a chart, graph, or other pictorial representation, which can be displayed on a VDU.
Q: What are the 4k and 8k visual display units?
A: 4k and 8k visual display units have a high resolution and are mainly used for professional purposes like video editing and gaming.
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