Display technologies have come a long way since the birth of the Cathode Ray Tube (CRT) that was invented by Noble-prize winning physicist and inventor, Karl Ferdinand Braun, in 1897. From a large, bulky display, TVs and monitors of the 21st century are now wide, flat and supports multi-touch gestures, a concept that Braun may have never thought possible.
Computer Displays: How Did We Get Here
Long before the CRT was invented, there were already devices that can translate simple binary patterns into text, such as the teletype machines that were used by the military for many years. But meeting the demands for creating imagery on a display is still lacking, and the first primitive graphics solutions that IBM introduced, the Cathode Ray Tube Output Recorder – model 740, was only able to draw lines one at a time. The use of digital-to-analog converters to make the cathode ray tube work and create lines will be later known as vector graphics.
• CRT Displays
CRTs were commonly used for video display terminal, which are monochromatic displays that are less sharp. Nevertheless, it was the display technology used in the earliest home computers. Color display capability was later achieved by Apple and became a standard feature in its pioneering computer, Apple II. CRTs use a wide range of display technology with different characteristics and screen shape. Shadow mask CRT was used for spherical curve or flat computer monitors, which can be used in bright rooms. It shares the same characteristics with the Monochrome CRT. The Aperture Grille CRT, on the other hand, is used on cylindrical curve or flat screens.
Continuous improvements led to the development of CRT monitors that could clearly display 1024 x 768 pixels. Because it is more affordable than newly developed display technology at that time, CRT remained dominant in the market of PC monitors, until LCD displays beat the CRT out of the competition.
• LCD Displays
Liquid-crystal display (LCD) was primarily used as a computer monitor for laptops throughout the 1990s. This is because it is lightweight, smaller in physical size, and consumes less power than a CRT monitor. It is more expensive, however. But consumers are willing to overlook the high price point in exchange for the convenience that laptops have to offer. During the 90s, laptops were offered in monochrome, passive color or active matrix color (TFT) displays, until the first two options were dropped from most manufacturing companies’ product lines.
Multiple technologies were used to implement LCDs, but the most dominant option is the thin-film transistor liquid crystal display (TFT-LCD). For the first time in a long time, TFT-LCDs outsold CRT displays in 2003. Not only has the price dropped, but also offers plenty of advantages over CRT. As previously mentioned, it consumes less power and is lightweight. More importantly, it takes up less space, and the TFT-LCD technology used is good on the eyes. With flickering reduced, eye strain is also reduced.
• OLED Displays
Organic light-emitting diode (OLED) displays, provide better viewing angles and higher contrast than LCD displays. It is also one of those display technologies that has amazing potentials and can lead to product categories that people can only imagine. It can be made as flexible and thin as paper, opening doors for a wide range of possibilities. As of this writing, however, OLED technology is still very expensive and consumes a lot of power when displaying documents with a bright or white background.
But because technology never sleeps, computer displays continue to improve and develop, integrating touch screen input and impressive pixel display, an example of which is Mac’s Retina 5K. If the display used on television is any indication, computer and laptop monitors will only become better than ever.
The performance of a computer monitor is measured by several different parameters, such as aspect ratio, luminance, refresh rate, contrast ratio, power consumption, viewing angle and display resolution. But, in terms of output, it is the resolution that is often used as basis when shopping or choosing the right monitor. From a modest Monochrome display adapter (MDA) with 1 color depth and 720 x 320 pixels, resolution has reached Ultra XGA (UXG) with over 4 million color depth and 1600 x 1200 pixels.
While there is no question of the quality of the output display, there are concerns on power consumption and processing workload. When the number of pixels double horizontally and vertically, the total number of pixels increase by a factor of 4. This means an increase in the processing workload by a factor of 4, requiring a higher processor speed, if the images are to be displayed at the same time. Higher resolution also tend to make flicker more noticeable. So before you decide to get a high-resolution monitor, consider all the pros and cons.
Different I/O Options for Monitors
Depending on how a computer display will be used, it can be an input or output device – for dual or extended display or an input for a projector or wide screen. Laptops and computers can have a Display Port, DVI, VGA or HDMI connectors, with each one requiring a specific type of connector.
Monitors that use touch-screen technology, on the other hand, can be used as input devices, depending on the software or applications installed.
Cost of Laptop Monitors
The cost of a laptop screen varies from one manufacturer to another, and based on its features, performance and size. High resolution displays are more expensive than those with lower resolutions. When it comes to monitors, you get what you pay for. The cost of an HP screen, for example, can range anywhere from $30 to $200, excluding the repair cost, if you’re buying one as a replacement. Acer displays, on the other hand, can set you back $20 to $200. Know though that even 10-inch LCDs can be expensive, depending on its features.
Display technologies certainly has changed. It has grown bigger and works better, and are showing no signs of ever slowing down in terms of development and improvements. Although evolution of computer monitors are more gradual today than it was 20 years ago, it still has plenty of room for amazing innovations.