From ECDL.web

A monitor or display (sometimes called a visual display unit) is an electronic visual display for computers. The monitor comprises the display device, circuitry, and an enclosure. The monitor connects to the computer by the graphics card.

The display device in modern monitors is typically a thin film transistor liquid crystal display (TFT-LCD) thin panel, while older monitors use a cathode ray tube about as deep as the screen size.

[edit] Screen size

The size of an approximately rectangular display is usually given as the distance between two opposite screen corners, that is, the diagonal of the rectangle. One problem with this method is that it does not take into account the display aspect ratio, so that for example a 16:9 21 in (53 cm) widescreen display is far less high, and has less area, than a 21 in (53 cm) 4:3 screen. The 4:3 screen has dimensions of 16.8 × 12.6 in (43 × 32 cm) and area 211 sq in (1,360 cm2), while the widescreen is 18.3 × 10.3 in (46 × 26 cm), 188 sq in (1,210 cm2). For many purposes the height of the display is the main parameter; a 16:9 display needs a diagonal 22% larger than a 4:3 display for the same height.

This method of measurement is inherited from the method used for the first generation of CRT television, when picture tubes with circular faces were in common use. Being circular, only their diameter was needed to describe their size. Since these circular tubes were used to display rectangular images, the diagonal measurement of the rectangle was equivalent to the diameter of the tube's face. This method continued even when cathode ray tubes were manufactured as rounded rectangles; it had the advantage of being a single number specifying the size, and was not confusing when the aspect ratio was universally 4:3.

[edit] Additional features

• Power saving: most modern monitors will switch to a power-saving mode if no video-input signal is received. This allows modern operating systems to turn off a monitor after a specified period of inactivity. This also extends the monitor's service life. Some monitors will also switch themselves off after a time period on standby.
• Integrated accessories: many monitors have other accessories (or connections for them) integrated - USB hub, camera, microphone, or set of speakers.

[edit] Comparison

[edit] CRT

Pros:

• High dynamic range (up to around 15,000:1), excellent color, wide gamut and low black level. The color range of CRTs is unmatched by any display type except OLED.
• Can display natively in almost any resolution and refresh rate.
• No input lag.
• Sub-millisecond response times.
• Near zero color, saturation, contrast or brightness distortion. Excellent viewing angle.
• Usually much cheaper than LCD or plasma screens.

Cons:

• Large size and weight, especially for bigger screens (a 20-inch unit weighs about 50 lb, or 23 kg).
• High power consumption.
• Generates a considerable amount of heat when running.
• Geometric distortion caused by variable beam travel distances.
• Can suffer screen burn-in.
• Produces noticeable flicker at low refresh rates.
• Normally only produced in 4:3 aspect ratio (though some widescreen ones, notably Sony's FW900, do exist).
• Hazardous to repair/service.
• Effective vertical resolution limited to 1024 scan lines.
• Color displays cannot be made in sizes smaller than 7 inches (5 inches for monochrome). Maximum size is around 24 inches (for computer monitors; televisions run up to 40 inches).

[edit] LCD

Pros:

• Very compact and light.
• Low power consumption.
• No geometric distortion.
• Little or no flicker depending on backlight technology.
• Not affected by screen burn-in.
• No high voltage or other hazards present during repair/service.
• More reliable than CRTs.
• Can be made in almost any size or shape.
• No theoretical resolution limit.

Cons:

• Limited viewing angle, causing color, saturation, contrast and brightness to vary, even within the intended viewing angle, by variations in posture.
• Bleeding and uneven backlighting in some monitors, causing brightness distortion, especially toward the edges.
• Slow response times, which cause smearing and ghosting artifacts. However, this is mainly a problem with passive-matrix displays. Current generation active-matrix LCDs have response times of 6-8 ms.
• Only one native resolution. Displaying resolutions either requires video scaling, lowering perceptual quality, or display at 1:1 pixel mapping, in which images will be physically too large or won't fill the whole screen.
• Fixed color depth, many cheaper LCDs are only able to display 262,000 colors.
• Input lag.
• Dead pixels may occur either during manufacturing or through use.
• In a constant on situation, thermalization may occur, which is when only part of the screen has overheated and therefore looks discolored compared to the rest of the screen.
• Not all LCD displays are designed to allow easy replacement of the backlight.

[edit] Plasma

Pros:

• High contrast ratios (10,000:1 or greater) excellent color, and low black level.
• Virtually no response time.
• Near zero color, saturation, contrast or brightness distortion. Excellent viewing angle.
• No geometric distortion.
• Softer and less blocky-looking picture than LCDs.
• Highly scalable, with less weight gain per increase in size.

Cons:

• Large pixel pitch, meaning either low resolution or a large screen. As such, color plasma displays are only produced in sizes over 32 inches.
• Image flicker due to being phosphor-based
• Heavy weight
• Glass screen can induce glare and reflections
• High operating temperature and power consumption
• Only has one native resolution. Displaying other resolutions requires video scaling, which degrades image quality at lower resolutions.
• Fixed color depth. Plasma cells can only be on or off, resulting in a more limited color range than LCDs or CRTs.
• Can suffer image burn-in. This was a severe problem on early plasma displays, but much less on newer ones.
• Dead pixels are possible during manufacturing.

[edit] Well-known manufacturers

• Acer
• AOC
• Apple Inc.
• Asus
• Belinea
• BenQ
• Dell
• Eizo
• Hewlett-Packard
• IBM
• Iiyama Corporation
• LG
• NEC
• Philips
• Samsung
• Sony
• Toshiba
• ViewSonic