Lunes, Marso 28, 2011
visual display
A monitor or display (sometimes called a visual display unit) is an electronic visual display forcomputers. The monitor comprises the display device, circuitry, and an enclosure. 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.Originally computer monitors were used for data processing and television receivers for entertainment; increasingly computers are being used both for data processing and entertainment and TVs implement some typical computer functionality. Displays exclusively for data use tend to have an aspect ratio of 4:3; those used also (or solely) for entertainment are usually 16:9 widescreen, Sometimes a compromise is used, e.g. 16:10[1].
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.
A problematic practice was the use of the size of a monitor's imaging element, rather than the size of its viewable image, when describing its size in publicity and advertising materials. On CRT displays a substantial portion of the CRT's screen is concealed behind the case's bezel or shroud in order to hide areas outside the monitor's "safe area" due to overscan. These practices were seen as deceptive, and widespread consumer objection and lawsuits eventually forced most manufacturers to instead measureviewable size[citation needed].
Performance measurements
Comparison
[edit]CRT
Pros:- High dynamic range (up to around 15,000:1),[2] 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.
- Allows the use of light guns/pens
Cons:Cons:- Large size and weight, especially for bigger screens (a 20-inch unit weighs about 50 lb (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
Phosphor burn-in
Phosphor burn-in is localized aging of the phosphor layer of a CRT screen where it has displayed a static image for long periods of time. This results in a faint permanent image on the screen, even when turned off. In severe cases, it can even be possible to read some of the text, though this only occurs where the displayed text remained the same for years.Screensavers were developed as a means to avoid burn-in, which was a widespread problem on IBM Personal Computer monochrome monitors in the 1980s. Monochrome displays are generally more vulnerable to burn-in because the phosphor is directly exposed to the electron beam while in colour displays, the shadow mask provides some protection. Although still found on newer computers, screen savers are not necessary on LCD monitors.Phosphor burn-in can be "fixed" by running a CRT with the brightness at 100% for several hours, but this merely hides the damage by burning all the phosphor evenly. CRT rebuilders can repair monochrome displays by cutting the front of the picture tube off, scraping out the damaged phosphor, replacing it, and resealing the tube. Colour displays can theoretically be repaired, but it is a difficult, expensive process and is normally only done on professional broadcasting monitors (which can cost up to $10,000).
GlareGlare is a problem caused by the relationship between lighting and screen or by using monitors in bright sunlight. Matte finish LCDs and flat screen CRTs are less prone to reflected glare than conventional curved CRTs or glossy LCDs, and aperture grille CRTs, which are curved on one axis only and are less prone to it than other CRTs curved on both axes.
Colour misregistration
With exceptions of correctly aligned video projectors and stacked LEDs, most display technologies, especially LCD, have an inherent misregistration of the color channels, that is, the centers of the red, green, and blue dots do not line up perfectly. Sub-pixel renderingdepends on this misalignment; technologies making use of this include the Apple II from 1976[3], and more recently Microsoft (ClearType, 1998) and XFree86 (X Rendering Extension).Analog monitors
Most modern computer displays can show the various colors of the RGB color space by changing red, green, and blue analog video signals in continuously variable intensities. These are almost exclusively progressive scan. Although televisions used an interlaced picture, this was too flickery for computer use. In the late 1980s and early 1990s, some VGA-compatible video cards in PCs used interlacing to achieve higher resolution, but the event of SVGA quickly put an end to them. While many early plasma and liquid crystal displays have exclusively analog connections, all signals in such monitors pass through a completely digital section prior to display.CRTs remained the standard for computer monitors through the 1990s. The first standalone LCD displays appeared in the early 2000s and over the next few years, they gradually displaced CRTs for most applications. First-generation LCD monitors were only produced in 4:3 aspect ratios, but current models are generally 16:9. The older 4:3 monitors have been largely relegated to point-of-service and some other applications where widescreen is not required.
Comparison
[edit]CRT
Pros:
- High dynamic range (up to around 15,000:1),[2] 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.
- Allows the use of light guns/pens
Cons:
Cons:
- Large size and weight, especially for bigger screens (a 20-inch unit weighs about 50 lb (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
Phosphor burn-in
Phosphor burn-in is localized aging of the phosphor layer of a CRT screen where it has displayed a static image for long periods of time. This results in a faint permanent image on the screen, even when turned off. In severe cases, it can even be possible to read some of the text, though this only occurs where the displayed text remained the same for years.
Screensavers were developed as a means to avoid burn-in, which was a widespread problem on IBM Personal Computer monochrome monitors in the 1980s. Monochrome displays are generally more vulnerable to burn-in because the phosphor is directly exposed to the electron beam while in colour displays, the shadow mask provides some protection. Although still found on newer computers, screen savers are not necessary on LCD monitors.
Phosphor burn-in can be "fixed" by running a CRT with the brightness at 100% for several hours, but this merely hides the damage by burning all the phosphor evenly. CRT rebuilders can repair monochrome displays by cutting the front of the picture tube off, scraping out the damaged phosphor, replacing it, and resealing the tube. Colour displays can theoretically be repaired, but it is a difficult, expensive process and is normally only done on professional broadcasting monitors (which can cost up to $10,000).
GlareGlare is a problem caused by the relationship between lighting and screen or by using monitors in bright sunlight. Matte finish LCDs and flat screen CRTs are less prone to reflected glare than conventional curved CRTs or glossy LCDs, and aperture grille CRTs, which are curved on one axis only and are less prone to it than other CRTs curved on both axes.
Colour misregistration
With exceptions of correctly aligned video projectors and stacked LEDs, most display technologies, especially LCD, have an inherent misregistration of the color channels, that is, the centers of the red, green, and blue dots do not line up perfectly. Sub-pixel renderingdepends on this misalignment; technologies making use of this include the Apple II from 1976[3], and more recently Microsoft (ClearType, 1998) and XFree86 (X Rendering Extension).
Analog monitors
Most modern computer displays can show the various colors of the RGB color space by changing red, green, and blue analog video signals in continuously variable intensities. These are almost exclusively progressive scan. Although televisions used an interlaced picture, this was too flickery for computer use. In the late 1980s and early 1990s, some VGA-compatible video cards in PCs used interlacing to achieve higher resolution, but the event of SVGA quickly put an end to them. While many early plasma and liquid crystal displays have exclusively analog connections, all signals in such monitors pass through a completely digital section prior to display.CRTs remained the standard for computer monitors through the 1990s. The first standalone LCD displays appeared in the early 2000s and over the next few years, they gradually displaced CRTs for most applications. First-generation LCD monitors were only produced in 4:3 aspect ratios, but current models are generally 16:9. The older 4:3 monitors have been largely relegated to point-of-service and some other applications where widescreen is not required.
Most modern computer displays can show the various colors of the RGB color space by changing red, green, and blue analog video signals in continuously variable intensities. These are almost exclusively progressive scan. Although televisions used an interlaced picture, this was too flickery for computer use. In the late 1980s and early 1990s, some VGA-compatible video cards in PCs used interlacing to achieve higher resolution, but the event of SVGA quickly put an end to them. While many early plasma and liquid crystal displays have exclusively analog connections, all signals in such monitors pass through a completely digital section prior to display.
CRTs remained the standard for computer monitors through the 1990s. The first standalone LCD displays appeared in the early 2000s and over the next few years, they gradually displaced CRTs for most applications. First-generation LCD monitors were only produced in 4:3 aspect ratios, but current models are generally 16:9. The older 4:3 monitors have been largely relegated to point-of-service and some other applications where widescreen is not required.
The graphics display resolution describes the width and height dimensions of a display, such as a computer monitor, in pixels. Certain combinations of width and height are standardized and typically given a name and an acronym that is descriptive of its dimensions. A higher display resolution means that displayed content appears sharper and smaller (depending on the physical size of the display).
Video graphics array
QQVGA (160×120)
Quarter-QVGA (QQVGA or qqVGA) denotes a resolution of 160×120 or 120×160 pixels, usually used in displays of handheld devices. The term Quarter-QVGA signifies a resolution of one fourth the number of pixels in a QVGA display (half the number of vertical and half the number of horizontal pixels) which itself has one fourth the number of pixels in a VGA display.
The acronym qqVGA may be used to distinguish quarter from quad, just like qVGA.[1]
[QVGA (240×160)
Half-QVGA denotes a display screen resolution of 240×160 or 160×240 pixels, as seen on the Game Boy Advance. This resolution is half ofQVGA, which is itself a quarter of VGA, which is 640×480 pixels.
WQVGA (432×240)
Wide QVGA or WQVGA is any display resolution having the same height in pixels as QVGA, but wider. This definition is consistent with other 'wide' versions of computer displays.
Since QVGA is 320 pixels wide and 240 pixels high (aspect ratio of 4:3), a WQVGA screen might be 384 pixels wide for 8:5 aspect ratio, 400 for 5:3 (such as the Nintendo 3DS screen), or 432 for 9:5. As with WVGA, exact ratios of N:9 are not practical because of the way VGA controllers internally deal with pixels. For instance, when using graphical combinatorial operations on pixels, VGA controllers will use 1 bit per pixel. Since bits cannot be accessed individually but by chunks of 16 or an even higher power of 2, this limits the horizontal resolution to a 16-pixel granularity, i.e., the horizontal resolution must be divisible by 16. In the case of 16:9 ratio, with 240 pixels high, the horizontal resolution should be 240 / 9 x 16 = 426.66 which is not a multiple of 16. The closest is 432, which is where the '432' comes from.
WQVGA has also been used to describe displays that are not 240 pixels high, for example Sixteenth HD1080 displays which are 270 or 272 pixels high or displays like 480×272. This may be due to QVGA having the nearest screen height.
WQVGA resolutions are commonly used in touch screen mobile phones, such as 240×400, 240×432, and 240×480. For example, the Sony Ericsson Aino and the Samsung Instinct both have WQVGA screen resolutions - 240x432. Other devices such as the Apple iPod nano also use a WQVGA screen, 240×376 pixels.
graphic and visual display
graphic display-the display of data in graphical form on a screen on the cathode ray tube.
example :
The monitor has an innovative LCD picture enhancing chip. This state-of-the-art technology provides not only astounding and Another futuristic feature is theFlatron f-Engine. This image-enhancing technology fine-tunes the contrast and brightness independently of each other to produce amazing images. This gives further variation in your setting adjustment. It is now possible to reproduce a broader and more accurate range of colors. Of course the setting will greatly depend on the comfort of your eyes and your aesthetic standard. This is perfect for demanding applications that require color accuracy such as photo and video editing.
The 1920 x 1200 resolution and wide 16:10 aspect ratio deliver a better view of the images produced by the monitor. Have an outstandingly lifelike collection of images and pictures which are closer to life than you have ever imagined. Watch movies or online streaming, professionally edit photographs or even play hardcore computer games. Whatever application and task you do, you’ll get stunning graphic display every single time. color, but also splendid contrast and brilliant over-all image quality.
The 1920 x 1200 resolution and wide 16:10 aspect ratio deliver a better view of the images produced by the monitor. Have an outstandingly lifelike collection of images and pictures which are closer to life than you have ever imagined. Watch movies or online streaming, professionally edit photographs or even play hardcore computer games. Whatever application and task you do, you’ll get stunning graphic display every single time. color, but also splendid contrast and brilliant over-all image quality.
Graphic Display Systems is the original manufacturer of affordable wire mesh display panels, print racks, tabletop displays and many accessories for Artists, Craftsman, Schools to display their work in a professional manner.
Graphic Display Systems has over 32 years of experience in providing artists and craftsman the most light weight, most durable, most used and easy to assemble display panel on the mark..
Mag-subscribe sa:
Mga Post (Atom)