Flat panel display
A flat panel display is a monitor having a small depth. Flat screens can be prepared by various technical principles. Spreads are currently LCD and OLED. Other technologies such as plasma, Mirasol and FED are used for special applications. Flat screens in particular LCD flat screens have due to their better image as well as its smaller size, mass, and energy consumption, the cathode ray tube (CRT 's - cathode ray tubes, cathode ray tube) close to completely out of the market.
- 4.1 advantages
- 4.2 disadvantages
Flat screens are characterized by:
- Diagonal ( see also: widescreen monitor)
- Resolution (as usual with Monitors 15 " 1024 × 768 in 17 " and 19 " 1280 × 1024 to 1600 × 1200 at 24 " 1920 × 1200)
- Response time ( usual: 2 to 25 ms for gray to gray)
- Contrast ( usual: 300:1 to 5000:1 )
- Brightness (usually 200 to 500 cd/m2 ) (also see image brightness)
- View angle ( e.g. 140 ° to 178 ° )
- Pixel density (the number of physical pixels per inch, is in direct proportion to the size of a single pixel )
An available at some screens pivot function is used to rotate the screen. The power consumption at 19 " LCDs is usually at about 50 watts, large TV ( about 90 cm LCDs or plasma displays 1 meter ) need around 300 watts.
There are several basic techniques that allow a small depth:
Plasma screens are another possibility to realize flat screens. Although they resemble externally LC displays, their functioning - ignition of noble gases for lighting up - another.
For large displays they provide for their luminosity an alternative dar. Due to the high power consumption and poor usability for small displays, they are no competition in the mobile sector. In addition, they lose about 3 years of operation clear of brightness. This is especially true for older devices. Newer plasma screens are much lower in energy consumption and have a life, which is identical to modern LC displays.
OLEDs (Organic Light Emitting Diode, Organic Light Emitting Diode ) are one of the emerging techniques which could replace LCDs. There are thin sheets of glass or plastic films using ink-jet technology ( pressure principle as an ink jet printer ) are printed with organic compounds ( polymeric compounds ) and then sealed. By suitable semiconductor devices OLEDs are stimulated to emit light. Extremely thin they can be used practically anywhere - for some years provided research time. The biggest problem of the OLEDs are the high sensitivity to oxygen and moisture, which decompose the polymeric material by chemical reactions.
- Liquid Crystal Display ( LCD, especially TFT display )
- Field emission display (FED )
- IFire technology (inorganic thick-film technology)
- Mirasol - screen with interferometric modulator -working
Native screen resolution
Flat panel know to the design - with some exceptions - generally a single screen resolution. Only in this representation is exact pixel sharp. This resolution is also called native screen resolution or as a native display resolution, this is specified by the manufacturer in the trade name. All other resolutions need to be adapted only to this native display resolution in front of a display on the flat screen by scaling. This process generally leads to an illustrated image blur at different resolutions.
Pros and Cons
- Through digital control via DVI, HDMI or DisplayPort lossless image can be transferred.
- Your image playback is sharper than that of a CRT especially in digital control to the native resolution a lot.
- Flat panel displays are more compact and easier due to the absence of glass tubes and can thus be much easier used in mobile devices.
- Due to their very small depth they can also be more easily placed in eye-friendly distance of about 1.5 × the screen diagonal.
- Flat panel type LCD have static images as they predominate in computer applications, a significantly lower energy consumption and a correspondingly low heat.
- They are not as strongly affected by a permanent same picture as CRT monitors (although nowadays are less sensitive than at that time, were introduced in the screensaver to prevent burn- in the phosphor screen ).
- In addition, the disposal is less problematic, with the backlight often contains environmentally hazardous mercury when using CCFLs.
- LCD TFT flat screens do not generate X-rays and are largely insensitive to electric and magnetic fields.
- Flat screens, in contrast to CRT monitors on a much lower reaction rate. This can lead to streaking during fast movements and screen changes. , Even by the overdrive technique used in modern LCDs can not be achieved, the level of CRT. This does not apply for OLEDs.
- You have a fixed resolution. Other resolutions that are not an integral multiple - eg. 800x600 native resolution 1600x1200 - the physical resolution are necessary to interpolate and thus appear blurred. Unlike CRT monitors so no lossless individual screen display by selecting any graphics card resolution is possible.
Depending on the technology of the flat screen is very various other disadvantages. In the presently most widely used technology of LCD screens that are in particular the following:
- You can reach lower contrast ratios than CRTs.
- They have inferior brightness values .
- You can not be a "real" black because the backlight is always on. Improved blacks have those LCD screens, which have image content-driven dynamic LED backlighting. OLEDs, however, may represent a "real" black.
- The picture quality is more or less dependent on the viewing angle, depending on the panel technology used.
In 2009, according to a study by the market research institute EITO and sold on the basis of market figures GfK in Germany about 8.3 million flat screen TVs, it alone over a million through the online trade. Focus of the sell-off was held on the electronics stores.
The term refers to flat screens flat mainly due to the depth of the housing and less on the fact that the screen surface is flat. Level screen surfaces are also some CRTs.